Identification of intermediate-risk patients with acute symptomatic pulmonary embolism.

The identification of normotensive patients with acute pulmonary embolism (PE) at high risk of adverse PE-related clinical events (i.e. intermediate-risk group) is a major challenge. We combined individual patient data from six studies involving 2874 normotensive patients with PE. We developed a prognostic model for intermediate-risk PE based on the clinical presentation and the assessment of right ventricular dysfunction and myocardial injury. We used a composite of PE-related death, haemodynamic collapse or recurrent PE within 30 days of follow-up as the main outcome measure. The primary outcome occurred in 198 (6.9%) patients. Predictors of complications included systolic blood pressure 90-100 mmHg (adjusted odds ratio (aOR) 2.45, 95% CI 1.50-3.99), heart rate ≥ 110 beats per min (aOR 1.87, 95% CI 1.31-2.69), elevated cardiac troponin (aOR 2.49, 95% CI 1.71-3.69) and right ventricular dysfunction (aOR 2.28, 95% CI 1.58-3.29). We used these variables to construct a multidimensional seven-point risk index; the odds ratio for complications per one-point increase in the score was 1.55 (95% CI 1.43-1.68; p<0.001). The model identified three stages (I, II and III) with 30-day PE-related complication rates of 4.2%, 10.8% and 29.2%, respectively. In conclusion, a simple grading system may assist clinicians in identifying intermediate-risk PE.