Prevalence and Predictors of Cardiogenic Shock in Intermediate-Risk Pulmonary Embolism: Insights From the FLASH Registry

Background: Patients with acute pulmonary embolism (PE) and hypotension (high-risk PE) have high mortality. Cardiogenic shock can also occur in nonhypotensive or normotensive patients (intermediate-risk PE) but is less well characterized.

Objectives: The authors sought to evaluate the prevalence and predictors of normotensive shock in intermediate-risk PE.

Methods: Intermediate-risk PE patients in the FLASH (FlowTriever All-Comer Registry for Patient Safety and Hemodynamics) registry undergoing mechanical thrombectomy with the FlowTriever System (Inari Medical) were included. The prevalence of normotensive shock (systolic blood pressure ≥90 mm Hg but cardiac index ≤2.2 L/min/m²) was assessed. A composite shock score consisting of markers of right ventricular function and ischemia (elevated troponin, elevated B-type natriuretic peptide, moderately/severely reduced right ventricular function), central thrombus burden (saddle PE), potential additional embolization (concomitant deep vein thrombosis), and cardiovascular compensation (tachycardia) was prespecified and assessed for its ability to identify normotensive shock patients.

Results: Over one-third of intermediate-risk PE patients in FLASH (131/384, 34.1%) were in normotensive shock. The normotensive shock prevalence was 0% in patients with a composite shock score of 0 and 58.3% in those with a score of 6 (highest score). A score of 6 was a significant predictor of normotensive shock (odds ratio: 5.84; 95% CI: 2.00-17.04). Patients showed significant on-table improvements in hemodynamics post-thrombectomy, including normalization of the cardiac index in 30.5% of normotensive shock patients. Right ventricular size, function, dyspnea, and quality of life significantly improved at the 30-day follow-up.

Conclusions: Although hemodynamically stable, over one-third of intermediate-risk FLASH patients were in normotensive shock with a depressed cardiac index. A composite shock score effectively further risk stratified these patients. Mechanical thrombectomy improved hemodynamics and functional outcomes at the 30-day follow-up.