Right ventricular dysfunction and pulmonary hypertension following sub-massive pulmonary embolism

Persistent right ventricular dysfunction (RVD) and pulmonary hypertension (PHT) are important outcomes following sub-massive pulmonary embolism (PE). The aims were to determine the rates and factors associated with RVD and/or PHT on echocardiography (ECHO) and the rate of 30-day and 1-year all-cause mortality following sub-massive PE. Patients who received thrombolysis and non-thrombolysis were also compared.

Consecutive patients with sub-massive PE over a five year period with at least 1-year follow-up were retrospectively identified. Regression analysis was performed to identify predictors of outcomes.

Eighty-seven patients met inclusion criteria. Sixty-one (70%) had admission ECHOs with a follow-up ECHO in 42 (48.3%) at a mean of 7.6 months (SD 5.2). Fifty-one had RVD (58.6%) and 35 (40.2%) had PHT on admission. The rates of persistent RVD and raised right ventricular systolic pressure in this study population were 12% and 17%, respectively. Thrombolysis was associated with a trend towards improvement of PHT (53.3% PHT on admission to 0% PHT on follow-up in the thrombolysis group, P = 0.29). The rate of 30-day and 1-year all-cause mortality were 12.6% and 21.8%, respectively. Thirty-day all-cause mortality was independently predicted by the presence of right heart strain on computed tomography pulmonary angiography [OR 3.7 (P = 0.045)], echocardiographic evidence of RVD [OR 3.9 (P = 0.041)] and age.

The majority of patients with RVD and PHT at the time of sub-massive PE improve on follow-up; however, there is a subset who remain abnormal. Future studies are needed to identify modifiable risk factors for these complications.