**3. Coronary Artery Bypass Grafting and psychological predictors**

#### **3.1 Depression and Post-Traumatic Stress Disorder**

A proposed psychological model for outcomes following Coronary Artery Bypass Grafting Surgery is proposed in Figure 1. Research has demonstrated that medical and demographic factors such as age, gender, diabetes, etc. cannot fully explain the outcomes following Coronary Artery Bypass Grafting surgery (Blumenthal et al., 2003; Saur et al., 2001). Several studies have been published investigating the association between Coronary Artery Disease and psychological functioning, primarily depression (Bankier et al., 2004; Oxland et al., 2006). It has been reported that up to 60% of patients with Coronary Artery Disease have comorbid depression which has a significant impact on the outcomes of Coronary Artery Disease (Blumenthal et al., 2003; Connerney et al., 2001; Krannich et al., 2007; Tully et al., 2008). Those with depression have higher rates of mortality as well as an overall risk of major cardiac events (Blumenthal et al., 2003; Carney et al., 1988; Connerney et al., 2001). Specifically, depressive symptoms also signicantly predict mortality 2 to 5 years after Coronary Artery Bypass Grafting surgery, independent of medical and operative factors (Blumenthal et al., 2003; Burg et al., 2003a; Burg et al., 2003b. Unlike depression, the impact of other psychological conditions, such as Post-traumatic Stress Disorder on outcomes after Coronary Artery Bypass Grafting surgery has received less attention in research.

The gap in the literature investigating the relationship between Post-traumatic Stress Disorder on outcomes after Coronary Artery Bypass Grafting surgery needs to be examined independently from depression for several reasons. Specifically, studies have demonstrated

Psychiatric Factors Which Impact Coronary Heart Disease and

**3.3 Anxiety as a moderator/mediator** 

receiving Coronary Artery Bypass Grafting surgery.

outcomes.

Influence Outcomes Post-Coronary Artery Bypass Grafting Surgery 67

Secondarily, the study was designed to assess whether geographic status would serve as a moderating variable that would subsequently affect the relationship between depression and Coronary Artery Bypass Grafting surgery outcomes. The colleagues hypothesized that those living in the rural areas would have increased depression and that depression and geographical status would contribute to outcomes following Coronary Artery Bypass Grafting surgery (mortality and length of hospital stay). The results of the study indicated that rural patients were more likely than urban patients to have a concurrent depression diagnosis. In addition, both depression and living in rural areas combined were associated with less favorable outcomes (i.e., increased length of hospital stay) following Coronary Artery Bypass Grafting surgery. Similarly, those living in rural areas and having a

Compared to depression and PTSD, there has been limited research on the influence of clinical anxiety in the relationship between psychological distress and outcomes following Coronary Artery Bypass Grafting surgery. The evidence that does exist suggests that anxiety in Coronary Artery Bypass Grafting patients contributes to post-surgery complications and elevated risk of sudden cardiac death (Rozanski et al., 1999; Stengrevics et al., 1996). In addition, it has been reported that up to 50% of patients undergoing Coronary Artery Bypass Grafting surgery have elevated anxiety scores (Januzzi et al., 2000; Rymaszewska et al; 2003; Krannich et al., 2007). Yet, there had been no previous evidence that those with anxiety would have better outcomes post-Coronary Artery Bypass Grafting surgery than those with depression and/or PTSD. In an effort to address this literature gap, Dao et al. (2011c) conducted a study investigating the relationship between anxiety and outcomes following Coronary Artery Bypass Grafting surgery. Results indicated that 27% of patients undergoing Coronary Artery Bypass Grafting surgery had a comorbid anxiety diagnosis, and patients who had non-routine discharge were more likely to have comorbid anxiety diagnoses compared to patients who had a routine discharge. Thus, for this study sample it was largely concluded that anxiety disorders are prevalent in patients who are undergoing a Coronary Artery Bypass Grafting surgery. Further, for this sample, anxiety was a significant independent predictor of both length of hospital stay and non-routine discharge for patients

It is expected that the number of octogenarians will increase from 6.9 million to 25 million by 2050 (Spencer, 1989). While there is a clear relationship between age and adverse Coronary Artery Bypass Grafting outcomes, the mechanism(s) underlying this relationship are not fully understood. There are two lines of evidence suggesting that psychosocial risk factors might mediate this relationship. Recent studies have suggested that Coronary Artery Bypass Grafting outcomes (e.g., mortality and patient disposition) cannot be fully explained by factors such as age, gender, and medical co-morbidities (Blumenthal et al., 2003). It has been reported that depression and anxiety can independently predict mortality and patient disposition following Coronary Artery Bypass Grafting surgery (Dao et al., 2010c). The second line of evidence has been shown in studies which have demonstrated the relationship between increased age with depression and anxiety disorders. The most common geriatric psychiatric disorders among the elderly are generalized anxiety disorder and depression (Beekmanet al., 1998). By simply looking at the relationship between age and Coronary Artery Bypass Grafting outcomes as linear, we may limit the understanding of potential critical mechanisms (i.e., mediators) influencing Coronary Artery Bypass Grafting

depression diagnosis had an elevated probability of in-hospital mortality.

that both depression and Post-traumatic Stress Disorder involve increased secretion of corticotropin-releasing factor. However, patients with Post-traumatic Stress Disorder have hypocortisolemia due to the increased secretion, whereas severe depression is associated with hypercortisolemia, showing that the pathophysiology of the 2 disorders might be different (Lyons et al., 2001). In addition, the psychiatric comorbidities of Post-traumatic Stress Disorder and depression may potentially affect cardiac prognosis adversely. Thus, by treating only depression and not the Post-traumatic Stress Disorder, cardiac outcomes may be adversely affected.

Dao et al (2010c) proposed a study examining the effect of clinical depression, PTSD, and comorbid depression and PTSD on outcomes following Coronary Artery Bypass Grafting surgery. It was hypothesized that depression, PTSD, and comorbid depression and PTSD would independently contribute to an increased risk for mortality following Coronary Artery Bypass Grafting surgery. In addition, it was hypothesized that comorbid depression and PTSD will have the greatest effect on mortality rates and outcomes in general. It was determined that, depression, posttraumatic stress disorder, and comorbid depression and posttraumatic stress disorder are prevalent in patients undergoing Coronary Artery Bypass Grafting surgery. In addition, depression, posttraumatic stress disorder, and comorbid depression and posttraumatic stress disorder increased the risk of mortality following Coronary Artery Bypass Grafting surgery.

#### **3.2 Geographic status**

Another topic that has received limited focus in literature to date is the impact geographic status may have on Coronary Artery Bypass Grafting outcomes. While death rates due to heart disease have decreased in recent decades (Cooper et al., 2000), vulnerable populations (e.g., individuals in rural areas) persist (Barnett et al., 2000; Pearson et al., 1998). In fact, recent reports indicate that Coronary Artery Disease is 1.3 times more prevalent in rural areas than in urban areas (McCrone et al., 2007). Another recent survey revealed that Coronary Artery Disease was the second health priority for those residing in rural areas (Gamm et al., 2002). Given that individuals who reside in rural areas are more likely to experience circumstances and situations that could compromise their physical and mental health (Healthcare Cost Utilization Project, 2001), it makes sense that health concerns such as Coronary Artery Disease are such a persistent issue. These circumstances include poverty, physical inactivity, and alcohol abuse and dependence (Miller et al., 1987). Furthermore, the lack of rural health services and difficulties of traveling long distances to larger hospitals, increase the possibility that these rural residents will not receive the best preventative, medical, and psychological care (Wallace et al., 2006). Overall, the clear association between geographic status and Coronary Artery Disease leads to questions regarding whether geographic status may actually be a predictor of adverse outcomes following Coronary Artery Bypass Grafting surgery. Since depression is associated with adverse Coronary Artery Bypass Grafting outcomes (discussed previously), depressive symptomatology must also be taken into account in these investigations. This is particularly important because those who reside in rural areas experience the stressors mentioned above (poverty, alcohol abuse, etc.) and are likely to endorse some symptoms of depression as a result of these (or similar) situations.

In an attempt to address some of the above questions, Dao and colleagues (2010b) proposed a study investigating the relationships between depression, geographical status, and outcomes following Coronary Artery Bypass Grafting surgery. The primary focus was to determine the relationship between Coronary Artery Bypass Grafting outcomes, depression, and geographical status while controlling for medical and sociodemographic factors. Secondarily, the study was designed to assess whether geographic status would serve as a moderating variable that would subsequently affect the relationship between depression and Coronary Artery Bypass Grafting surgery outcomes. The colleagues hypothesized that those living in the rural areas would have increased depression and that depression and geographical status would contribute to outcomes following Coronary Artery Bypass Grafting surgery (mortality and length of hospital stay). The results of the study indicated that rural patients were more likely than urban patients to have a concurrent depression diagnosis. In addition, both depression and living in rural areas combined were associated with less favorable outcomes (i.e., increased length of hospital stay) following Coronary Artery Bypass Grafting surgery. Similarly, those living in rural areas and having a depression diagnosis had an elevated probability of in-hospital mortality.

#### **3.3 Anxiety as a moderator/mediator**

66 Front Lines of Thoracic Surgery

that both depression and Post-traumatic Stress Disorder involve increased secretion of corticotropin-releasing factor. However, patients with Post-traumatic Stress Disorder have hypocortisolemia due to the increased secretion, whereas severe depression is associated with hypercortisolemia, showing that the pathophysiology of the 2 disorders might be different (Lyons et al., 2001). In addition, the psychiatric comorbidities of Post-traumatic Stress Disorder and depression may potentially affect cardiac prognosis adversely. Thus, by treating only depression and not the Post-traumatic Stress Disorder, cardiac outcomes may

Dao et al (2010c) proposed a study examining the effect of clinical depression, PTSD, and comorbid depression and PTSD on outcomes following Coronary Artery Bypass Grafting surgery. It was hypothesized that depression, PTSD, and comorbid depression and PTSD would independently contribute to an increased risk for mortality following Coronary Artery Bypass Grafting surgery. In addition, it was hypothesized that comorbid depression and PTSD will have the greatest effect on mortality rates and outcomes in general. It was determined that, depression, posttraumatic stress disorder, and comorbid depression and posttraumatic stress disorder are prevalent in patients undergoing Coronary Artery Bypass Grafting surgery. In addition, depression, posttraumatic stress disorder, and comorbid depression and posttraumatic stress disorder increased the risk of mortality following

Another topic that has received limited focus in literature to date is the impact geographic status may have on Coronary Artery Bypass Grafting outcomes. While death rates due to heart disease have decreased in recent decades (Cooper et al., 2000), vulnerable populations (e.g., individuals in rural areas) persist (Barnett et al., 2000; Pearson et al., 1998). In fact, recent reports indicate that Coronary Artery Disease is 1.3 times more prevalent in rural areas than in urban areas (McCrone et al., 2007). Another recent survey revealed that Coronary Artery Disease was the second health priority for those residing in rural areas (Gamm et al., 2002). Given that individuals who reside in rural areas are more likely to experience circumstances and situations that could compromise their physical and mental health (Healthcare Cost Utilization Project, 2001), it makes sense that health concerns such as Coronary Artery Disease are such a persistent issue. These circumstances include poverty, physical inactivity, and alcohol abuse and dependence (Miller et al., 1987). Furthermore, the lack of rural health services and difficulties of traveling long distances to larger hospitals, increase the possibility that these rural residents will not receive the best preventative, medical, and psychological care (Wallace et al., 2006). Overall, the clear association between geographic status and Coronary Artery Disease leads to questions regarding whether geographic status may actually be a predictor of adverse outcomes following Coronary Artery Bypass Grafting surgery. Since depression is associated with adverse Coronary Artery Bypass Grafting outcomes (discussed previously), depressive symptomatology must also be taken into account in these investigations. This is particularly important because those who reside in rural areas experience the stressors mentioned above (poverty, alcohol abuse, etc.) and are likely to

endorse some symptoms of depression as a result of these (or similar) situations.

In an attempt to address some of the above questions, Dao and colleagues (2010b) proposed a study investigating the relationships between depression, geographical status, and outcomes following Coronary Artery Bypass Grafting surgery. The primary focus was to determine the relationship between Coronary Artery Bypass Grafting outcomes, depression, and geographical status while controlling for medical and sociodemographic factors.

be adversely affected.

**3.2 Geographic status** 

Coronary Artery Bypass Grafting surgery.

Compared to depression and PTSD, there has been limited research on the influence of clinical anxiety in the relationship between psychological distress and outcomes following Coronary Artery Bypass Grafting surgery. The evidence that does exist suggests that anxiety in Coronary Artery Bypass Grafting patients contributes to post-surgery complications and elevated risk of sudden cardiac death (Rozanski et al., 1999; Stengrevics et al., 1996). In addition, it has been reported that up to 50% of patients undergoing Coronary Artery Bypass Grafting surgery have elevated anxiety scores (Januzzi et al., 2000; Rymaszewska et al; 2003; Krannich et al., 2007). Yet, there had been no previous evidence that those with anxiety would have better outcomes post-Coronary Artery Bypass Grafting surgery than those with depression and/or PTSD. In an effort to address this literature gap, Dao et al. (2011c) conducted a study investigating the relationship between anxiety and outcomes following Coronary Artery Bypass Grafting surgery. Results indicated that 27% of patients undergoing Coronary Artery Bypass Grafting surgery had a comorbid anxiety diagnosis, and patients who had non-routine discharge were more likely to have comorbid anxiety diagnoses compared to patients who had a routine discharge. Thus, for this study sample it was largely concluded that anxiety disorders are prevalent in patients who are undergoing a Coronary Artery Bypass Grafting surgery. Further, for this sample, anxiety was a significant independent predictor of both length of hospital stay and non-routine discharge for patients receiving Coronary Artery Bypass Grafting surgery.

It is expected that the number of octogenarians will increase from 6.9 million to 25 million by 2050 (Spencer, 1989). While there is a clear relationship between age and adverse Coronary Artery Bypass Grafting outcomes, the mechanism(s) underlying this relationship are not fully understood. There are two lines of evidence suggesting that psychosocial risk factors might mediate this relationship. Recent studies have suggested that Coronary Artery Bypass Grafting outcomes (e.g., mortality and patient disposition) cannot be fully explained by factors such as age, gender, and medical co-morbidities (Blumenthal et al., 2003). It has been reported that depression and anxiety can independently predict mortality and patient disposition following Coronary Artery Bypass Grafting surgery (Dao et al., 2010c). The second line of evidence has been shown in studies which have demonstrated the relationship between increased age with depression and anxiety disorders. The most common geriatric psychiatric disorders among the elderly are generalized anxiety disorder and depression (Beekmanet al., 1998). By simply looking at the relationship between age and Coronary Artery Bypass Grafting outcomes as linear, we may limit the understanding of potential critical mechanisms (i.e., mediators) influencing Coronary Artery Bypass Grafting outcomes.

Psychiatric Factors Which Impact Coronary Heart Disease and

outcomes following Coronary Artery Bypass Grafting surgery.

techniques to maximize his/her Heart Rate Variability (Lehrer et al., 2000).

Tan and colleagues (2010) reported that veterans with Post-Traumatic Stress Disorder exhibited significantly lower Heart Rate Variability compared to those without Post-Traumatic Stress Disorder. It was also discovered that those individuals receiving Heart Rate Variability biofeedback along with treatment as usual (TAU) had a significant reduction in Post-Traumatic Stress Disorder symptoms when compared to those receiving TAU alone (Tan et al.,

**4.1 Treatment using Heart Rate Variability** 

**Bypass Grafting surgery** 

Influence Outcomes Post-Coronary Artery Bypass Grafting Surgery 69

Over the past several years, the relationship between emotional states and outcomes in cardiac patients has been the subject of increased scrutiny by researchers and clinicians (Doering et al., 2005). In particular, post-traumatic stress symptoms have been reported in up to 15 percent of Coronary Artery Bypass Grafting patients (Doerfler et al., 1994; Stoll et al., 2000). Similar to Coronary Artery Bypass Grafting patients with depression, higher levels of post-traumatic stress symptoms are related to increased mortality (Oxlad & Wade, 2006), lower health-related quality of life (Rothenhausler et al., 2010), and increased length of post-operative hospital stay (Oxlad et al., 2006). While several treatments for Post-Traumatic Stress Disorder have been proven to be effective, one of the primary drawbacks of these interventions is that they can be very lengthy and take weeks or months for treatment. Specifically, long term treatments are unrealistic and unfeasible given the sudden onset of Coronary Artery Bypass Grafting surgeries (Doerfler et al., 1994). Since there is evidence that patients suffering from Post-Traumatic Stress Disorder have an increased likelihood of mortality following Coronary Artery Bypass Grafting surgery (Dao et al., 2010a), in combination with length of treatment necessary for effective Post-Traumatic Stress Disorder care, there is a necessary need for an effective, short term treatment for improving

As mentioned earlier, Heart Rate Variability is a measure which examines the interplay between the parasympathetic and sympathetic influences on heart rate and represents the psychophysiological mechanism of emotion regulation (Appelhans & Luecken, 2006). In addition, increased Heart Rate Variability has been correlated with the increased capability of regulating stress, arousal, and attention (Bornstein et al., 2002). Recent research has demonstrated that the emotion regulation characteristics of patients with Post-Traumatic Stress Disorder have been associated with low Heart Rate Variability (Tan et al., 2010). Also, the physiological profile of a Coronary Artery Bypass Grafting patients with Post-Traumatic Stress Disorder may be complicated given purported research that low Heart Rate Variability is related to cardiovascular disease (van der Kolk, 2006). As previously discussed, it has been reported that patients with Coronary Artery Disease and a diagnosis of Post-Traumatic Stress Disorder have lower Heart Rate Variability than those patients with Coronary Artery Disease alone (Dao et al., 2010a; Krittayaphong et al., 1997; Stein et al., 2000). Since Post-Traumatic Stress Disorder and cardiovascular disease are associated with decreased Heart Rate Variability and Autonomic Nervous System dysregulation, Heart Rate Variability biofeedback training may reduce complications post-surgery. This has been supported by previous reports demonstrating that biofeedback training can increase Heart Rate Variability (Cohen et al., 2002; Tan et al., 2009). Other research has shown that Heart Rate Variability biofeedback training may be effective in reducing psychiatric symptoms associated with trauma (Karavidas et al., 2007; Zucker et al., 2009). Heart Rate Variability biofeedback training entails determining an individual's heart rate resonance frequency at baseline, calculating the optimal resonance frequency, and then providing specific breathing

**4. Treatments for comorbid psychological factors prior to Coronary Artery** 

Dao and colleagues (2011c) constructed a study to examine whether clinical levels of anxiety and depression act as a mediator between patient age and mortality and patient discharge status among octogenarian patients following Coronary Artery Bypass Grafting surgery. It was hypothesized that clinical anxiety and depression levels would mediate the relationship between increased age and Coronary Artery Bypass Grafting outcomes. This hypothesis was based on the established relationships between increased age and adverse Coronary Artery Bypass Grafting outcomes (Blumenthal et al., 2003), as well as the relationship between increased age and prevalence of anxiety and depression symptoms. Study results indicated that patients with an anxiety/depression diagnosis had a 6% higher postoperative mortality rate and had an 18% greater likelihood of having postoperative complications. In addition, it was found that an anxiety/depression diagnosis served as a partial mediator of the relationship between age and post-Coronary Artery Bypass Grafting outcomes for both postoperative mortality and discharge status.

Fig. 1. Proposed Model of Psychological Factors Predicting Outcomes following Coronary Artery Bypass Grafting Surgery Versus the Traditional Medical Model

#### **4. Treatments for comorbid psychological factors prior to Coronary Artery Bypass Grafting surgery**

#### **4.1 Treatment using Heart Rate Variability**

68 Front Lines of Thoracic Surgery

Dao and colleagues (2011c) constructed a study to examine whether clinical levels of anxiety and depression act as a mediator between patient age and mortality and patient discharge status among octogenarian patients following Coronary Artery Bypass Grafting surgery. It was hypothesized that clinical anxiety and depression levels would mediate the relationship between increased age and Coronary Artery Bypass Grafting outcomes. This hypothesis was based on the established relationships between increased age and adverse Coronary Artery Bypass Grafting outcomes (Blumenthal et al., 2003), as well as the relationship between increased age and prevalence of anxiety and depression symptoms. Study results indicated that patients with an anxiety/depression diagnosis had a 6% higher postoperative mortality rate and had an 18% greater likelihood of having postoperative complications. In addition, it was found that an anxiety/depression diagnosis served as a partial mediator of the relationship between age and post-Coronary Artery Bypass Grafting outcomes for both

Fig. 1. Proposed Model of Psychological Factors Predicting Outcomes following Coronary

Artery Bypass Grafting Surgery Versus the Traditional Medical Model

postoperative mortality and discharge status.

Over the past several years, the relationship between emotional states and outcomes in cardiac patients has been the subject of increased scrutiny by researchers and clinicians (Doering et al., 2005). In particular, post-traumatic stress symptoms have been reported in up to 15 percent of Coronary Artery Bypass Grafting patients (Doerfler et al., 1994; Stoll et al., 2000). Similar to Coronary Artery Bypass Grafting patients with depression, higher levels of post-traumatic stress symptoms are related to increased mortality (Oxlad & Wade, 2006), lower health-related quality of life (Rothenhausler et al., 2010), and increased length of post-operative hospital stay (Oxlad et al., 2006). While several treatments for Post-Traumatic Stress Disorder have been proven to be effective, one of the primary drawbacks of these interventions is that they can be very lengthy and take weeks or months for treatment. Specifically, long term treatments are unrealistic and unfeasible given the sudden onset of Coronary Artery Bypass Grafting surgeries (Doerfler et al., 1994). Since there is evidence that patients suffering from Post-Traumatic Stress Disorder have an increased likelihood of mortality following Coronary Artery Bypass Grafting surgery (Dao et al., 2010a), in combination with length of treatment necessary for effective Post-Traumatic Stress Disorder care, there is a necessary need for an effective, short term treatment for improving outcomes following Coronary Artery Bypass Grafting surgery.

As mentioned earlier, Heart Rate Variability is a measure which examines the interplay between the parasympathetic and sympathetic influences on heart rate and represents the psychophysiological mechanism of emotion regulation (Appelhans & Luecken, 2006). In addition, increased Heart Rate Variability has been correlated with the increased capability of regulating stress, arousal, and attention (Bornstein et al., 2002). Recent research has demonstrated that the emotion regulation characteristics of patients with Post-Traumatic Stress Disorder have been associated with low Heart Rate Variability (Tan et al., 2010). Also, the physiological profile of a Coronary Artery Bypass Grafting patients with Post-Traumatic Stress Disorder may be complicated given purported research that low Heart Rate Variability is related to cardiovascular disease (van der Kolk, 2006). As previously discussed, it has been reported that patients with Coronary Artery Disease and a diagnosis of Post-Traumatic Stress Disorder have lower Heart Rate Variability than those patients with Coronary Artery Disease alone (Dao et al., 2010a; Krittayaphong et al., 1997; Stein et al., 2000). Since Post-Traumatic Stress Disorder and cardiovascular disease are associated with decreased Heart Rate Variability and Autonomic Nervous System dysregulation, Heart Rate Variability biofeedback training may reduce complications post-surgery. This has been supported by previous reports demonstrating that biofeedback training can increase Heart Rate Variability (Cohen et al., 2002; Tan et al., 2009). Other research has shown that Heart Rate Variability biofeedback training may be effective in reducing psychiatric symptoms associated with trauma (Karavidas et al., 2007; Zucker et al., 2009). Heart Rate Variability biofeedback training entails determining an individual's heart rate resonance frequency at baseline, calculating the optimal resonance frequency, and then providing specific breathing techniques to maximize his/her Heart Rate Variability (Lehrer et al., 2000).

Tan and colleagues (2010) reported that veterans with Post-Traumatic Stress Disorder exhibited significantly lower Heart Rate Variability compared to those without Post-Traumatic Stress Disorder. It was also discovered that those individuals receiving Heart Rate Variability biofeedback along with treatment as usual (TAU) had a significant reduction in Post-Traumatic Stress Disorder symptoms when compared to those receiving TAU alone (Tan et al.,

Psychiatric Factors Which Impact Coronary Heart Disease and

behavioral variables?

Coronary Artery Bypass Grafting surgery.

**Sample Characteristics** 

underwent CABG surgery

underwent CABG surgery

underwent onpump CABG surgery or offpump surgery

**Size** 

Choi 2009 49,357 Pts who

Chu 2008 1,164 Pts who

Chu 2009 63,047 Pts who

Bypass Grafting Surgery

**Author Year Sample** 

Influence Outcomes Post-Coronary Artery Bypass Grafting Surgery 71

psychological risk factors such as depression and anxiety in predicting adverse Coronary Artery Bypass Grafting outcomes. Second, the relations were more pronounced for certain groups of patients (e.g., rural versus non-rural and females versus males), which could help explain why females often seem to derive less functional benefit from Coronary Artery Bypass Grafting surgery than men. Third, while the treatment of presurgical and postsurgical depression and anxiety have not been extensively studied to date, the results thus far are somewhat promising. The aforementioned studies, however, do not fully explain the nature of psychological risk factors and outcomes following Coronary Artery Bypass Grafting surgery. In other words, are psychological risk factors such as depression and anxiety causal factors, directly related to adverse outcomes following Coronary Artery Bypass Grafting surgery? Or, are psychological risk factors risk markers, indirectly related to outcomes following Coronary Artery Bypass Grafting surgery through

As pointed out by Rumsfeld and Ho (2005), the relations between psychological factors and adverse Coronary Artery Bypass Grafting outcomes may be mediated by behavioral mechanisms that are well documented in the literature to be associated with psychological symptoms. For instance, symptoms such as low energy or fatigue, loss of interest in activities, diminished ability to concentrate or indecisiveness, and psychomotor retardation are common in individuals diagnosed with depression. Thus, it is not surprising that these individuals are significantly less likely to adhere to prescribedmedications, follow lifestyle recommendations (e.g., exercising), practice self-management (e.g., monitor weight), and even follow up or

Overall, no studies to date have concurrently examined the physiological mechanisms (elevated plasma norepinephrine levels, cortisol, heart rate variability) and behavioral mechanisms (not following through with medication suggestions, lack of exercise, etc.) to determine which mechanisms (if any) are more responsible for adverse outcomes following

> **Primary Outcome**

Compare outcomes of CABG surgery in VA versus non-VA hospitals

Compare outcomes of those with concurrent PVD with those that did not

Compare outcomes of onpump CABG surgery versus off-pump surgery

Table 1. Review of Research Reporting Predictors of Outcomes Following Coronary Artery

**Result** 

non-VA hospitals

hospital costs

Pts who underwent CABG surgery at VA hospitals had significantly lower mortality rate than those at

PVD was a predictor of poor long-

Off-pump did not produce lower mortality or stroke rates when compared to on-pump. Off-pump was associated with longer hospital stays and higher

term survival among pts undergoing CABG surgery

receive recommended cardiac testing compared to those with no depression.

2010). Thus, evidence exists in support of the use of biofeedback as a potential, beneficial treatment for Post-Traumatic Stress Disorder. However, it remains unclear as to whether this treatment would be beneficial in reducing Post-Traumatic Stress Disorder symptoms in patients with Coronary Artery Disease or if it might improve outcomes post-Coronary Artery Bypass Grafting surgery. Incorporating Heart Rate Variability biofeedback training may result in Autonomic Nervous System regulation and subsequently improve outcomes post-surgery by reducing Post-Traumatic Stress Disorder symptoms.

Dao et al (2011b) proposed a study examining the efficacy of a Heart Rate Variability biofeedback treatment in 65 patients with Post-Traumatic Stress Disorder symptoms prior to Coronary Artery Bypass Grafting surgery. This study was designed to assess the impact of the Heart Rate Variability biofeedback intervention on Post-Traumatic Stress Disorder symptoms and in-hospital length of stay. It was hypothesized that symptoms associated with Post-Traumatic Stress Disorder would decrease following Heart Rate Variability biofeedback training and that their length of inpatient hospital duration would decrease following their Coronary Artery Bypass Grafting surgeries. The results from the study suggested that Heart Rate Variability biofeedback treatment can cause improvement in Post-Traumatic Stress Disorder symptoms in patients undergoing Coronary Artery Bypass Grafting surgery. It was also suggested that this treatment pre-surgery might improve patient quality of life and decrease the length of hospital stay.

#### **4.2 Treatment using brief Cognitive Behavioral Therapy**

While there have been some studies investigating the benefits of treating depression or anxiety in Coronary Artery Bypass Grafting patients postoperatively (Freedlandet al., 2009a; Freedlandet al., 2009b; Lie et al., 2007; Rollman et al., 2009), there has been little published investigating the impact of cognitive–behavioral approaches in treating depression or anxiety on Coronary Artery Bypass Grafting patients prior to surgery. Specifically, the SADHART (Sertraline Anti-Depressant Heart Attack Trial) study found a trend toward reduced cardiovascular mortality and morbidity when utilizing selective serotonin reuptake inhibitors. However, this trial had too small of a sample size and a too brief treatment duration to draw useful conclusions (Levin et al., 2005). Another study, the ENRICoronary Artery Disease (Enhancing Recovery in Coronary Heart Disease) trial found that cognitive behavioral therapy (CBT) after myocardial infarction had an effect on depression (Berkmanet al., 2003), but did not affect cardiac events such as nonfatal infarction, death from any cause, and cardiac death. To further address questions stemming from the previous trials, Dao et al (2011a) proposed a study to examine the feasibility of a brief, tailored Cognitive Behavioral Therapy intervention entitled "Managing Anxiety and Depression using Education and Skills" (MADES), for treating patients with Coronary Artery Disease and symptoms of depression or anxiety prior to Coronary Artery Bypass Grafting surgery. The specific focus of this study was to assess the impact of this brief intervention on depression/anxiety symptoms and inhospital length of stay. This study demonstrated that brief, tailored Cognitive Behavioral Therapy was not only feasible, but was successful in improving depressive/anxiety symptoms and quality of life while simultaneously reducing in-hospital length of stay.

#### **5. Conclusion**

#### **5.1 What we still don't know**

The studies reviewed in this chapter are important for several reasons (for a brief synopsis of each article, please refer to Table 1). First, these studies highlight the importance of

2010). Thus, evidence exists in support of the use of biofeedback as a potential, beneficial treatment for Post-Traumatic Stress Disorder. However, it remains unclear as to whether this treatment would be beneficial in reducing Post-Traumatic Stress Disorder symptoms in patients with Coronary Artery Disease or if it might improve outcomes post-Coronary Artery Bypass Grafting surgery. Incorporating Heart Rate Variability biofeedback training may result in Autonomic Nervous System regulation and subsequently improve outcomes post-surgery

Dao et al (2011b) proposed a study examining the efficacy of a Heart Rate Variability biofeedback treatment in 65 patients with Post-Traumatic Stress Disorder symptoms prior to Coronary Artery Bypass Grafting surgery. This study was designed to assess the impact of the Heart Rate Variability biofeedback intervention on Post-Traumatic Stress Disorder symptoms and in-hospital length of stay. It was hypothesized that symptoms associated with Post-Traumatic Stress Disorder would decrease following Heart Rate Variability biofeedback training and that their length of inpatient hospital duration would decrease following their Coronary Artery Bypass Grafting surgeries. The results from the study suggested that Heart Rate Variability biofeedback treatment can cause improvement in Post-Traumatic Stress Disorder symptoms in patients undergoing Coronary Artery Bypass Grafting surgery. It was also suggested that this treatment pre-surgery might improve

While there have been some studies investigating the benefits of treating depression or anxiety in Coronary Artery Bypass Grafting patients postoperatively (Freedlandet al., 2009a; Freedlandet al., 2009b; Lie et al., 2007; Rollman et al., 2009), there has been little published investigating the impact of cognitive–behavioral approaches in treating depression or anxiety on Coronary Artery Bypass Grafting patients prior to surgery. Specifically, the SADHART (Sertraline Anti-Depressant Heart Attack Trial) study found a trend toward reduced cardiovascular mortality and morbidity when utilizing selective serotonin reuptake inhibitors. However, this trial had too small of a sample size and a too brief treatment duration to draw useful conclusions (Levin et al., 2005). Another study, the ENRICoronary Artery Disease (Enhancing Recovery in Coronary Heart Disease) trial found that cognitive behavioral therapy (CBT) after myocardial infarction had an effect on depression (Berkmanet al., 2003), but did not affect cardiac events such as nonfatal infarction, death from any cause, and cardiac death. To further address questions stemming from the previous trials, Dao et al (2011a) proposed a study to examine the feasibility of a brief, tailored Cognitive Behavioral Therapy intervention entitled "Managing Anxiety and Depression using Education and Skills" (MADES), for treating patients with Coronary Artery Disease and symptoms of depression or anxiety prior to Coronary Artery Bypass Grafting surgery. The specific focus of this study was to assess the impact of this brief intervention on depression/anxiety symptoms and inhospital length of stay. This study demonstrated that brief, tailored Cognitive Behavioral Therapy was not only feasible, but was successful in improving depressive/anxiety symptoms and quality of life while simultaneously reducing in-hospital length of stay.

The studies reviewed in this chapter are important for several reasons (for a brief synopsis of each article, please refer to Table 1). First, these studies highlight the importance of

by reducing Post-Traumatic Stress Disorder symptoms.

patient quality of life and decrease the length of hospital stay.

**4.2 Treatment using brief Cognitive Behavioral Therapy** 

**5. Conclusion** 

**5.1 What we still don't know** 

psychological risk factors such as depression and anxiety in predicting adverse Coronary Artery Bypass Grafting outcomes. Second, the relations were more pronounced for certain groups of patients (e.g., rural versus non-rural and females versus males), which could help explain why females often seem to derive less functional benefit from Coronary Artery Bypass Grafting surgery than men. Third, while the treatment of presurgical and postsurgical depression and anxiety have not been extensively studied to date, the results thus far are somewhat promising. The aforementioned studies, however, do not fully explain the nature of psychological risk factors and outcomes following Coronary Artery Bypass Grafting surgery. In other words, are psychological risk factors such as depression and anxiety causal factors, directly related to adverse outcomes following Coronary Artery Bypass Grafting surgery? Or, are psychological risk factors risk markers, indirectly related to outcomes following Coronary Artery Bypass Grafting surgery through behavioral variables?

As pointed out by Rumsfeld and Ho (2005), the relations between psychological factors and adverse Coronary Artery Bypass Grafting outcomes may be mediated by behavioral mechanisms that are well documented in the literature to be associated with psychological symptoms. For instance, symptoms such as low energy or fatigue, loss of interest in activities, diminished ability to concentrate or indecisiveness, and psychomotor retardation are common in individuals diagnosed with depression. Thus, it is not surprising that these individuals are significantly less likely to adhere to prescribedmedications, follow lifestyle recommendations (e.g., exercising), practice self-management (e.g., monitor weight), and even follow up or receive recommended cardiac testing compared to those with no depression.

Overall, no studies to date have concurrently examined the physiological mechanisms (elevated plasma norepinephrine levels, cortisol, heart rate variability) and behavioral mechanisms (not following through with medication suggestions, lack of exercise, etc.) to determine which mechanisms (if any) are more responsible for adverse outcomes following Coronary Artery Bypass Grafting surgery.


Table 1. Review of Research Reporting Predictors of Outcomes Following Coronary Artery Bypass Grafting Surgery

Psychiatric Factors Which Impact Coronary Heart Disease and

**Sample Characteristics**

> 80 years of age that underwent CABG surgery

underwent CABG surgery

> 80 years of age that underwent CABG surgery

**Author Year Sample** 

**Size** 

Gopaldas 2009 5,731 Pts who were

Gopaldas 2010 614,177 Pts who

Mahoney 2011 51,266 Pts who were

Bypass Grafting Surgery (continuation)

2000;35:731–8.

1983, 140:1623-1625.

2000;10(6):370-379.

2008;14:369.

1998; 13:717-726.

surgery. J Card Surg 1995;10:620–5.

**6. References** 

Influence Outcomes Post-Coronary Artery Bypass Grafting Surgery 73

To examine outcomes and predictors of discharge status in pts> 80 years of age

Compare outcomes pre-work reform versus post-work

Investigate whether anxiety/depression mediates the relationship between age and outcomes following CABG surgery

reform

Table 1. Review of Research Reporting Predictors of Outcomes Following Coronary Artery

Alexander KP, Anstrom KJ, Muhlbaier LH, et al. Outcomes of cardiac surgery in patients 80

Appelhans BM, Luecken LJ: Heart rate variability as an index of regulated emotional

Bankier B, Januzzi JL, Littman AB: The high prevalence of psychiatric disorders in stable outpatients with coronary heart disease. Psychosom Med 2004, 66:645-650. Barnes RF, Veith RC, Borson S, Verhey J, Raskind MA, Halter JB: High levels of plasma

Barnett E, Halverson JA, Elmes GA, et al. Metropolitan and non-metropolitan trends in

Baslaim G, Bashore J, Alhoroub K. Impact of obesity on early outcomes after cardiac

Beekman A, Breemer M, Deeg D, et al. Anxiety disorder in later life: a report from the

Benetti FJ, Ballester C, Sani G, Doonstra P, Grandjean J. Video assisted coronary bypass

responding. Review of General Psychology 2006, 10:229-240.

years: results from the National Cardiovascular Network. J Am CollCardiol

catecholamines in dexamethasone-resistant depressed patients. Am J Psychiat

coronary heart disease mortality within Appalachia, 1980–1997. Ann Epidemiol.

surgery: Experience in a Saudi Arabian center. Ann ThoracCardiovascSurg

longitudinal aging study Amsterdam. International Journal of Geriatric Psychiatry.

**Primary Outcome Result** 

27% were referred to home health care, 45% were transferred to another facility, 21% had normal

While those older than 80 years of age have acceptable mortality risk, these pts require further specialized care at discharge

Work-hour reform did not affect

Work-hour reform was associated with increased morbidity

Anxiety/depression diagnosis actsas a mediator through which age influences mortality and patient discharge status

discharge

mortality rates


Table 1. Review of Research Reporting Predictors of Outcomes Following Coronary Artery Bypass Grafting Surgery (continuation)


Table 1. Review of Research Reporting Predictors of Outcomes Following Coronary Artery Bypass Grafting Surgery (continuation)
