Background: The impact of central localization of pulmonary embolism (PE) on clinical outcomes is uncertain.

Objectives: To compare clinical presentation, risk factors, and outcomes between patients with central pulmonary embolism (cPE) and non-cPE.

Methods: We retrospectively analyzed 597 patients with acute PE from the prospective SWITCO65+ cohort between September 2009 and December, 2013. cPE was defined as an embolus in the pulmonary trunk or the left or right pulmonary artery. We compared baseline clinical characteristics and outcomes at 3 months (recurrent venous thromboembolism [VTE], overall/PE-related mortality, PE-related quality of life) and over the entire follow-up (recurrent VTE, overall/PE-related mortality) between patients with cPE vs non-cPE. We examined the association between PE localization and recurrent VTE and overall mortality, adjusting for multiple confounders including thrombolysis, periods of anticoagulation, and competing risk of non-VTE-related death if appropriate.

Results: Overall, 217 (36.3%) patients had cPE. Symptoms/signs of respiratory distress, right ventricular dysfunction, and myocardial injury were more prevalent in those with cPE. VTE recurrence, overall/PE-related mortality, and PE-related quality of life at 3 months did not vary by PE localization. After a median follow-up of 29.6 months, patients with cPE had a higher risk of fatal PE (5.5% vs 2.1%; P = .033). After adjustment, cPE was associated with recurrent VTE (subhazard ratio, 2.22; 95% CI, 1.25-3.91) but not with overall mortality (hazard ratio, 0.74; 95% CI, 0.45-1.21) during follow-up.

Conclusion: cPE was associated with a 2.2-fold increased risk of recurrent VTE compared to non-cPE. Whether an extended anticoagulation duration could reduce the recurrence risk following cPE should be further examined.