Clinical Significance of Right Heart Thrombus With and Without an Associated Pulmonary Embolism.

Background: Right heart thrombus is a rare but serious form of venous thromboembolic disease that may be associated with pulmonary embolism. The prognosis of patients with right heart thrombus presenting without a concomitant pulmonary embolism remains ill-defined.

Methods: We conducted a multi-center observational cohort study to compare patients presenting with right heart thrombus with and without a concurrent pulmonary embolism. The primary endpoint was 90-day all-cause mortality. Multivariable regression was utilized to assess primary and secondary outcomes.

Results: Of 231 patients with right heart thrombus, 104 (45.0%) had a pulmonary embolism at admission. The median age of the cohort was 59.4 years (interquartile range 44.9-71.3). Pulmonary embolism in the setting of a right heart thrombus was associated with an increased adjusted hazard of 90-day mortality (hazard ratio 3.68; 95% confidence interval [CI], 1.51-8.97). Additionally, these patients had a higher adjusted risk of in-hospital mortality (odds ratio [OR] 2.55; 95% CI, 1.15-5.94) and admission to the intensive care unit (OR 2.45; 95% CI, 1.23-4.94). Thrombus mobility (OR 2.99; 95% CI, 1.35-6.78) and larger thrombus sizes (OR 1.04; 95% CI, 1.00-1.07) were associated with development of concurrent pulmonary embolism.

Conclusions: Patients with right heart thrombus and pulmonary embolism had a more severe clinical presentation, required more advanced therapies, and had reduced survival compared with those without a concomitant pulmonary embolism. Important variables associated with development of concomitant pulmonary embolism include thrombus mobility and size. Right heart thrombus in the setting of acute pulmonary embolism represents a unique clinical entity that is associated with worse prognosis compared with right heart thrombus only.