**Psychiatric Factors Which Impact Coronary Heart Disease and Influence Outcomes Post-Coronary Artery Bypass Grafting Surgery**

James J. Mahoney, III1,2,3, Emily A. Voelkel1, Jenny A. Bannister1, Raja R. Gopaldas4 and Tam K. Dao1,2 *1University of Houston, Department of Educational Psychology, 2Baylor College of Medicine, 3Michael E. DeBakey Veteran Affairs Medical Center, 4University of Missouri – Columbia School of Medicine, United States* 

## **1. Introduction**

60 Front Lines of Thoracic Surgery

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#### **1.1 Coronary Artery Bypass Grafting defined**

It has been reported that over 13 million individuals in the United States have been diagnosed with Coronary Artery Disease (Morrow & Gersh, 2008), and it is the leading cause of death in the United States with more than 650,000 deaths in 2005 (Centers for Disease Control and Prevention, 2009). One of the most effective and common methods of treating Coronary Artery Disease is Coronary Artery Bypass Grafting surgery (Niles et al., 2001). Typically, those patients with severe narrowing of the left main coronary artery and/or those with disease in at least 3 coronary arteries are candidates for Coronary Artery Bypass Grafting Surgery.

#### **1.2 Comorbidity with Coronary Artery Disease**

There is also a high comorbidity between Peripheral Vascular Disease and Coronary Artery Disease (Brandt et al., 2004; Eagle et al., 1994; Hertzer et al., 1984). While several studies have reported short-term adverse outcomes in Coronary Artery Bypass Grafting patients that also have Peripheral Vascular Disease (Gersh et al., 1989; Grover et al., 1990; Higgins et al., 1992; Kunadian et al., 2007; Magovern et al., 1996; O'Connor et al., 1992; Rosenthal et al., 2003; Sutton-Tyrrell et al., 1998) the long-term outcomes have not been thoroughly investigated. To address this gap in the literature, Chu et al. (2008) conducted a study investigating the long-term impact of Coronary Artery Bypass Grafting surgery in patients who concurrently had Peripheral Vascular Disease. After comparing 370 Peripheral Vascular Disease and 794 non-Peripheral Vascular Disease patients, Chu and colleagues determined there were no significant group differences in 30 day mortality or major cardiac adverse events; however, patients with Peripheral Vascular Disease had a significantly worse 9 year survival rate (i.e., almost twice the risk of mortality) when compared to those without Peripheral Vascular Disease. While the short-term outcomes of this study are contradictory to previous studies, the long-term outcomes suggest that those with Peripheral Vascular Disease have poorer outcomes over time when compared to those without Peripheral Vascular Disease.

Psychiatric Factors Which Impact Coronary Heart Disease and

patients undergoing Coronary Artery Bypass Grafting surgery.

**2.2 Coronary Artery Bypass Grafting and age** 

Influence Outcomes Post-Coronary Artery Bypass Grafting Surgery 63

2007). Others have found that morbid obesity independently predicts perioperative complications as well as operative mortality (Prabhakar et al., 2002). One study by Syrakas and colleagues (2007) even found that normal weight patients had a higher 30-day mortality rate than their obese peers post-surgery. In fact, overall, research seems to suggest that morbid obesity does not increase short-term mortality risk for Coronary Artery Bypass Grafting patients (Baslaim et al., 2008; Shirad et al., 2009; Syrakas et al., 2007). Since research regarding the association between obesity and cardiac surgery has included mostly shortterm outcomes, Del Prete and associates (2010) investigated the independent effect of obesity on long-term survival in patients (472 obese and 691 non-obese) who had Coronary Artery Bypass Grafting surgery. Results revealed obese and non-obese patients had similar intraoperative characteristics (e.g., cardiopulmonary bypass time, aortic cross-clamp time, and number of vein and IMA grafts) and post-operative outcomes. Of particular interest was that the rates of mortality and major adverse cardiac events after 30 days were not significantly different between the two groups. Most interestingly, the researchers determined that obese Coronary Artery Bypass Grafting patients demonstrated long-term survival (9 years follow-up) similar to non-obese Coronary Artery Bypass Grafting patients. While these findings are counterintuitive, these results combined with results of studies examining short-term outcomes seem to indicate that obesity is not a significant risk for

Due to improvements in medical care, the average life expectancy has increased significantly in recent years. Subsequently, there has been an increase in the number of geriatric patients with cardiac disease that need surgical intervention such as Coronary Artery Bypass Grafting surgery. In addition, this population also tends to have multiple comorbidities which may cause complications; however, Coronary Artery Bypass Grafting procedures in octogenarian patients (those over the age of 80), have demonstrated improved morbidity and mortality outcomes (Alexander et al., 2000; Kolh et al., 2001; Shigemitsu et al., 2001). However, while most of these Coronary Artery Bypass Grafting surgeries are technically successful, they may cause significant physiological adverse events, potentially deconditioning them substantially. Unfortunately, there has not been a wealth of literature investigating these physiological outcomes which may affect the health and well-being of these patients. As a result, Gopaldas et al. (2010) conducted a study investigating the

Gopaldas identified 5,731 patients over age 80 who underwent Coronary Artery Bypass Grafting surgery. It was discovered that the surgical mortality rate was 7%, and 21% of patients had a routine hospital discharge. Those that did not have a routine discharge had home health care (27%) or were transferred to another care facility (45%). In addition, several predictors of surgical mortality and nonroutine discharge were found: older age, females, a higher comorbidity index, and referral from the emergency room were all found to be independent predictors of these unfavorable outcomes. Thus, it is clear that while mortality rate in octogenarians is low, there are several circumstances that need to be

Women are particularly affected by heart disease, and coronary heart disease has consistently been reported as the leading cause of morbidity and mortality of women in most developed countries (Center for Disease Control and Prevention, 2010; Lloyd-Jones et

disposition of octogerians following Coronary Artery Bypass Grafting surgery.

considered to ensure more favorable outcomes following discharge.

**2.3 Coronary Artery Bypass Grafting and gender** 

#### **1.3 Variations of Coronary Artery Bypass Grafting Surgery**

Typically Coronary Artery Bypass Grafting surgery is performed via Cardiopulmonary Bypass; however, there are several drawbacks associated with Cardiopulmonary Bypass which may lead to complications following or during surgery (Edmunds et al., 2003). As a result of these complications, a technique utilizing an Off-Pump Coronary Artery Bypass procedure was developed. The Off-Pump Coronary Artery Bypass technique has recently gained popularity and can also be performed without involving Cardiopulmonary Bypass (Benetti et al., 1995; Buffolo et al., 1996; Calafiore et al., 1996; Dewey et al., 2001; Guler et al., 2001; Guru et al., 2007;Magee et al., 2001; Puskas et al., 1998; Trehan et al., 2001). While Off-Pump Coronary Artery Bypass has gained notoriety, some surgeons have opted out of using the technique due to suspicions that Off-Pump Coronary Artery Bypass may compromise patient outcomes. To help clarify these suspicions, researchers have turned their focus to investigating the effectiveness of Off-Pump Coronary Artery Bypass for treating patients with Coronary Artery Disease. The results of such studies have often been counter indicative. Some studies suggest that Off-Pump Coronary Artery Bypass has similar outcomes to conventional Coronary Artery Bypass Grafting surgery with respect to length of hospital stay, morbidity, and neurological deficiencies (Halkos et al., 2008; Puskas et al., 1998; Puskas et al., 2001) as well as comparable graft patency and hospitalization costs (Puskas et al., 2004). Conversely, other studies have reported less favorable Off-Pump Coronary Artery Bypass patient outcomes (e.g., lower graft patency rates and less complete revascularization) when compared to Coronary Artery Bypass Grafting patient outcomes (Khan et al., 2004). Still several other studies report no difference in early mortality, morbidity and hospitalization costs between the two procedures (Bull et al., 2001; Cheng et al., 2005; Cheng et al., 2002; Marasco et al., 2008; Takagi et al., 2007). Clearly, the studies to date comparing the Off-Pump Coronary Artery Bypass and Coronary Artery Bypass Grafting procedures present an unclear picture of potential differential outcomes for patients. In order to further investigate the difference between these two methods, Chu and colleagues (2009a) conducted a study using a nationwide database of over 63,000 Coronary Artery Bypass Grafting and Off-Pump Coronary Artery Bypass patients. The results revealed that the Off-Pump Coronary Artery Bypass and Coronary Artery Bypass Grafting procedures had similar in-hospital mortality, post-operative stroke incidences, and routine discharge rates. However, Off-Pump Coronary Artery Bypass patients had comparatively longer hospital stays and higher hospital costs than Coronary Artery Bypass Grafting patients.
