Hemodynamic Super-Response to Mechanical Thrombectomy in Patients With Intermediate-Risk Pulmonary Embolism.

Background: Among patients with intermediate-risk pulmonary embolism undergoing mechanical thrombectomy, the mean change in cardiac index (CI) is modest. We sought to identify variables associated with a hemodynamic super-response or a CI increase of ≥25% postthrombectomy.

Methods: This was a single-center retrospective study including patients with intermediate-risk pulmonary embolism undergoing mechanical thrombectomy with pulmonary artery catheter-derived hemodynamic indices obtained preprocedure and postprocedure.

Results: Overall, 105 intermediate-risk patients had complete hemodynamic profiles, with 41 patients (39%) classified as super-responders. Super-responders had a lower baseline CI (1.9±0.7 versus 2.3±0.6 L/min per m²). The mean change in CI postthrombectomy was 0.8±0.4 L/min per m² among super-responders versus 0.1±0.4 L/min per m² among non-super-responders. Several established indices of poor right ventricular function were associated with a significant increase in the CI in a univariable model. An left ventricular outflow tract velocity-time integral ≤15 cm, tricuspid annular plane systolic excursion/pulmonary artery systolic pressure ≤0.34 mm/mm Hg, and substantial inferior vena cava contrast reflux were associated with a hemodynamic super-response with an odds ratio of 16.19 (95% CI, 1.97-133.24,), 6.5 (95% CI, 2.13-19.83), and 2.53 (95% CI, 1.09-5.88), respectively. In a multivariable model, a preprocedure CI ≤2.2 L/min per m² was associated with a hemodynamic super-response (odds ratio, 3.76 [95% CI, 1.09-13.0]).

Conclusions: Patients with intermediate-risk pulmonary embolism with the more severe hemodynamic derangements had the greatest improvement in CI post thrombectomy. This group can be identified with commonly available noninvasive indices of right ventricular dysfunction.