**4. Risk assessment based on clinical parameters and risk models**

The presence of co-morbidities increases the risk of adverse events, even with a small PE. Advanced age (more than 70 years old), congestive heart failure, cancer, or chronic lung disease were identified as independent predictors of 3-month mortality from PE (Goldhaber, 1999).

The clinical manifestations of acute PE are non-specific and often overlap with other cardiac and pulmonary conditions. Chest pain is one of the most frequent presentations of PE. Pleuritic chest pain, with or without dyspnea, is usually caused by pleural irritation due to distal emboli which may be associated with pulmonary infarction. Individuals may also present with retrosternal angina-like chest pain, reflecting right ventricular ischemia. Isolated dyspnea of a rapid onset is suspicious of a more central and hemodynamically significant PE. Occasionally, the onset of dyspnea is more insidious especially in patients with co-existing heart failure or pulmonary disease.

Cardiogenic shock occurs in less than 5% of acute PE, and these patients have a high risk of death. Conversely, patients with non-massive PE present with stable blood pressure and have a lower risk of death. In the International Cooperative Pulmonary Embolism Registry,

Risk Stratification of Patients with Acute Pulmonary Embolism 23

Age 1 point/year

**Risk category Points 30-day mortality risk** 

Class I < 65 0 % Class II 66 to 85 1.0 % Class III 86 to 105 3.1 % Class IV > 125 24.4 %

**5. Risk assessment based on presence of right ventricular dysfunction** 

The majority of patients with acute PE are stable at time of diagnosis, but this may not necessarily imply a benign course. Patients may appear stable initially because the development of RV failure and cardiogenic shock can be delayed as the vicious cycle of elevated pulmonary resistance, RV dilatation, and the RV hypokinesis unfolds. In stable patients with acute PE, the presence of RV dysfunction is associated with a high mortality

In addition, RV dysfunction in acute PE predicts recurrent thromboembolic events. During a mean follow-up of three years, patients with persistent RV dysfunction were more likely to have a recurrent PE, deep venous thrombosis or higher PE-related deaths compared with patients without RV dysfunction or had RV dysfunction that resolved at discharge (Grifoni

Echocardiography is non-invasive and able to provide very useful information promptly. However, it is not recommended as a routine imaging test to diagnose PE because an echocardiogram can appear normal in about 50% of the patients with suspected PE. Despite its limitations, a bedside echocardiogram in a hemodynamically unstable patient is an

Table 2. Pulmonary Embolism Severity index (Low risk = Class I and II)

rate (Sanchez et al., 2008).

**5.1 Echocardiography** 

et al., 2006).

Male gender 10 Cancer 30 Congestive heart failure 10 Chronic lung disease 10 Heart rate > 110/min 20 Systolic blood pressure < 100mmHg 30 Respiratory rate ≥ 30/min 20 Body temperature < 36° 20 Disorientation, lethargy, stupor or coma 60 Oxygen saturation < 90%(pulsoximetry) 20

**Variable Points** 

the death rate was about 58% in hemodynamically unstable patients and about 15% in patients who were hemodynamically stable (Goldhaber et al., 1999).

Despite the limited sensitivity and specificity of individual symptoms, and signs, clinical risk models consisting of a combination of clinical variables makes it possible to identify patients with suspected PE into risk categories. The Geneva prognostic index and the Pulmonary Embolism Prognostic Index (PESI) are two standardized prognostic scores that incorporated systolic blood pressure, amongst other clinical parameters, to predict risk of PE-related adverse outcomes. These scores have been well validated to identify low-risk, clinically stable patients for outpatient treatment.

The Geneva prognostic index is based mainly on findings from the past medical history and the clinical examination (Table 1). Risk stratification was performed using the score with a maximum of 8 points. Patients with a score of 2 or less are considered at low risk for PErelated adverse events. Of the 180 low risk patients identified, only 4 experienced an adverse outcome at 3 months (Wicki et al., 2000).

The PESI score uses 11 weighted clinical parameters commonly available on presentation (Table 2). Patients are stratified by their scores into five classes of increasing risk of death and adverse outcomes. Patients classified as low risk (score of 85 or less corresponding to PESI Class I or II) have a 30-day mortality of 1.0% (Aujesky et al., 2006).

Of the two, the PESI score appears to be more accurate at predicting low-risk patients. In a head-to-head comparison, the two models were retrospectively applied in a cohort of 599 patients with PE. The 30-day mortality in the Geneva low-risk patients was 5.6% compared to the PESI low-risk mortality rate of 0.9%. The PESI score classified fewer patients as lowrisk than the Geneva model (36% vs. 84%), but the area under the receiver operating curve was higher for the PESI (0.76 vs. 0.61) (Jiménez et al., 2007).

Unfortunately, the major limitation of the PESI is the difficulty to apply in a busy clinical environment. There are many variables to be considered, each with its own weight. To address this limitation, a simplified PESI has been developed with similar prognostic accuracy (Jiménez et al., 2010). However, prospective validation of the simplified PESI is lacking.


Table 1. Geneva Pulmonary Embolism Prognostic Index

the death rate was about 58% in hemodynamically unstable patients and about 15% in

Despite the limited sensitivity and specificity of individual symptoms, and signs, clinical risk models consisting of a combination of clinical variables makes it possible to identify patients with suspected PE into risk categories. The Geneva prognostic index and the Pulmonary Embolism Prognostic Index (PESI) are two standardized prognostic scores that incorporated systolic blood pressure, amongst other clinical parameters, to predict risk of PE-related adverse outcomes. These scores have been well validated to identify low-risk,

The Geneva prognostic index is based mainly on findings from the past medical history and the clinical examination (Table 1). Risk stratification was performed using the score with a maximum of 8 points. Patients with a score of 2 or less are considered at low risk for PErelated adverse events. Of the 180 low risk patients identified, only 4 experienced an adverse

The PESI score uses 11 weighted clinical parameters commonly available on presentation (Table 2). Patients are stratified by their scores into five classes of increasing risk of death and adverse outcomes. Patients classified as low risk (score of 85 or less corresponding to

Of the two, the PESI score appears to be more accurate at predicting low-risk patients. In a head-to-head comparison, the two models were retrospectively applied in a cohort of 599 patients with PE. The 30-day mortality in the Geneva low-risk patients was 5.6% compared to the PESI low-risk mortality rate of 0.9%. The PESI score classified fewer patients as lowrisk than the Geneva model (36% vs. 84%), but the area under the receiver operating curve

Unfortunately, the major limitation of the PESI is the difficulty to apply in a busy clinical environment. There are many variables to be considered, each with its own weight. To address this limitation, a simplified PESI has been developed with similar prognostic accuracy (Jiménez et al., 2010). However, prospective validation of the simplified PESI is

> Active cancer 2 Systolic blood pressure < 100mmHg 2

> at diagnosis <sup>1</sup>

History of venous thromboembolism 1 Congestive heart failure 1 Hypoxia (arterial PaO2 < 60mmHg) 1

**Geneva Risk Categories**  Low risk: 2 or fewer points; High risk: 3 or more points

Concomitant deep venous thrombosis

Table 1. Geneva Pulmonary Embolism Prognostic Index

**Risk Factor Geneva Risk Scale** 

**(Points)** 

patients who were hemodynamically stable (Goldhaber et al., 1999).

PESI Class I or II) have a 30-day mortality of 1.0% (Aujesky et al., 2006).

was higher for the PESI (0.76 vs. 0.61) (Jiménez et al., 2007).

clinically stable patients for outpatient treatment.

outcome at 3 months (Wicki et al., 2000).

lacking.



Table 2. Pulmonary Embolism Severity index (Low risk = Class I and II)
