Invasive hemodynamic assessment of patients with submassive pulmonary embolism

To investigate the invasive hemodynamics in patients with intermediate-risk pulmonary embolism (PE) and the change that occurs with catheter-directed thrombolysis (CDT).

Intermediate-risk PE is associated with right ventricular strain and worse outcomes yet the invasive hemodynamics have not been well described.

Ninety-two consecutive patients with intermediate-risk PE referred for CDT at two tertiary medical centers with Pulmonary Embolism Response Teams were included in this prospective cohort study. Hemodynamics at baseline and after CDT therapy was measured. Patients with cardiac index (CI) ≤1.8 L min^-1 m^-2 were compared to those without shock (CI > 1.8). Linear regression analysis was performed to study the relationship between clinical variables and low CI.

Thirty-seven out of 92 (40%) had a CI less than 1.8 L min^-1 m^-2 . When comparing the low CI to the normal CI groups, most demographics, vital signs, biomarkers, and PE severity index (PESI) scores were similar. The low CI group had more females and slightly lower systolic blood pressures although still in the normal range (122 vs. 132 mmHg, p = .026). Treatment with CDT was associated with significant improvement in CI, heart rate, and pulmonary artery pressures in both groups. Linear regression analysis did not reveal a strong correlation between CI and noninvasive metrics such as heart rate, blood pressure, or PESI score.

Forty percent of patients with submassive PE had a depressed CI and treatment with CDT lead to hemodynamic improvements. Invasive hemodynamics may help better identify higher risk patients and guide therapy.