Clinical Implication of the Right Ventricular/Left Ventricular Diameter Ratio in Patients with Pulmonary Thromboembolism

The role of the right to left ventricular (RV/LV) diameter ratio in predicating long-term outcomes in patients with pulmonary thromboembolisms (PTEs) treated with direct oral anticoagulants is unclear.We investigated the association between the RV/LV diameter ratio and clinical outcomes in PTE patients under rivaroxaban from the data of a multicenter, prospective, observational study (J'xactly Study) in Japanese patients with acute venous thromboembolisms (VTEs) including deep vein thromboses, PTEs, or both. Of a total of 1,039 patients with an acute VTE (from December 2016 to April 2018), 429 were diagnosed with PTEs, however, the population in this study consists of 216 patients in whom the RV/LV diameter ratio measured on the axial CT or transthoracic echocardiogram was available.The RV/LV diameter ratio increased significantly with the severity of the PTE classification (nonmassive 0.79 [0.67-0.93], submassive 1.10 [0.83-1.31], massive 1.13 [0.94-1.19], arrest or collapse 1.38 [0.66-2.38], P < 0.001). During a median follow-up of 624 (550-690) days, a sum of the composite adverse events including recurrent VTEs, acute coronary syndrome, ischemic strokes, death from any cause, or major bleeding events occurred in 26 patients (12.0%, 7.58 events per 100 patient-years). Multivariate analysis revealed that an RV/LV diameter ratio ≥ 1.0 had no association with the incidence of composite adverse events (HR 1.34, 95% confidence interval 0.59-2.91, P = 0.48).In summary, in Japanese PTE patients under rivaroxaban, the RV/LV diameter ratio measured on the CT or transthoracic echocardiogram was associated with the PTE severity, but not with the clinical outcomes.