Aims: To evaluate the incidence of cardiovascular events in the long-term clinical course of patients with a first episode of symptomatic, objectively confirmed pulmonary embolism.
Methods and results: Three hundred and sixty patients with a first episode of pulmonary embolism were included in a prospective study: 209 with idiopathic pulmonary embolism and 151 with pulmonary embolism associated with transient risk factors. The study outcomes were cardiovascular events (recurrent venous thrombo-embolism, acute myocardial infarction, stroke, sudden otherwise unexplained death), cardiovascular death, and death due to any cause. The median follow-up was 38 months. Sixty-four patients had at least one cardiovascular event (5.5% patient-year). Recurrent venous thrombo-embolism occurred in 45 patients (3.9% patient-year), acute myocardial infarction in 12 patients (1.0% patient-year), stroke in six patients (0.5% patient-year), and sudden otherwise unexplained death in four patients (0.3% patient-year). A cardiovascular event occurred in 47 patients with idiopathic pulmonary embolism (7.5% patient-year) and in 17 patients with pulmonary embolism associated with transient risk factors (3.1% patient-year) (RR 2.0; 95% CI 1.20-3.34; P=0.006). Twenty patients with idiopathic pulmonary embolism (3.2% patient-year) and two patients with pulmonary embolism associated with transient risk factors (0.4% patient-year) presented an arterial cardiovascular event (RR 7.2; 95% CI 1.71-30.45; P=0.001). Thirty-three patients died (9.2%). Cardiovascular mortality and cancer mortality accounted for 42.4 and 21.2% of overall mortality, respectively. Idiopathic pulmonary embolism was an independent predictor of cardiovascular events after adjusting for age.
Conclusions: Cardiovascular events are more common in patients with idiopathic pulmonary embolism than in patients with pulmonary embolism associated with transient risk factors. Cardiovascular events are the major cause of death in patients with idiopathic pulmonary embolism.