Clinical Significance and Prognosis of Right Heart Thrombi Associated With Acute Pulmonary Thromboembolism - Results of a Multicenter Registry of Thrombolysis in Japan

Background: Thrombolytic therapy is standard treatment in acute pulmonary thromboembolism (PTE) with hemodynamic instability. Although right heart thrombi (RHT) appear to increase mortality in acute PTE, large-scale studies of acute PTE with RHT are scarce.

Methods and results: Patient data (from August 2005 to May 2014) obtained from post-marketing surveillance of thrombolytic therapy using a tissue-type plasminogen activator were analyzed retrospectively. Of the 2,698 confirmed cases of acute PTE who underwent echocardiographic assessment, 166 (6.2%) were diagnosed with RHT. PTE patients with RHT, compared with those without RHT, had higher rates of mortality (20.2% vs. 10.4%, P<0.001), hemodynamic instability (53.0% vs. 37.7%, P<0.001), and PTE recurrence (6.6% vs. 2.3%, P=0.003). When considering PTE-related hemodynamic severity (cardiopulmonary arrest/collapse, massive, submassive, and non-massive), mortality was significantly higher in patients with RHT in the massive (19.8% vs. 7.7%, P=0.002) and submassive (8.0% vs. 2.8%, P=0.018) groups, whereas no significant differences was found between those with and without RHT in the cardiopulmonary arrest/collapse (51.7% vs. 52.1%, P=0.960) and non-massive (1.6% vs. 0%, P=0.596) groups.

Conclusions: PTE patients with RHT had higher mortality, severity, and PTE recurrence rates. RHT was particularly associated with worse outcomes in patients with massive or submassive PTE.