Right Ventricular Strain and Outflow Tract Velocity Time Integral Are Associated with Mortality in Critically Ill Patients with Pulmonary Embolism

Rationale: High-risk pulmonary embolism (PE) is often fatal because of right ventricular heart failure. However, right ventricular echocardiographic parameters that are associated with adverse outcomes in PE are incompletely characterized. Objective: Our objective was to evaluate if right ventricular global longitudinal strain (RVGLS) and right ventricular outflow tract velocity time integral (RVOT VTI) might be associated with mortality in PE. Methods: This is an observational study with prospective inclusion from June 1999 to December 2023. Only patients with PE requiring ICU admission were included. The study assessed mortality in the ICU and at 6 months of follow-up, as well as the development of heart failure. The independent variables included clinical and echocardiographic characteristics. Measurements and Main Results: A total of 463 patients with PE with a mean age of 62.3 ± 21.6 years were included in this study. The ICU and 6-month mortality were 18.4% and 20.7%, respectively. A total of 386 patients were treated with thrombolysis. Multivariable analysis showed that the variables associated with ICU mortality were pulmonary embolism severity index (odds ratio [OR], 1.241; 95% confidence interval [CI] [1.037-1.587]; P < 0.001), RVGLS (OR, 0.421; 95% CI [0.202-0.774]; P < 0.001), left atrial reservoir (OR, 0.357; 95% CI [0.141-0.756]; P < 0.001), right atrial pump (εa) (OR, 0.632; 95% CI [0.282-0.887]), RVOT VTI (OR, 0.678; 95% CI [0.321-0.881]; P < 0.001), and left ventricular outflow tract VTI (OR, 0.782; 95% CI [0.413-0.912]; P < 0.001). Multivariable analysis found that the development of heart failure assessed at 6 months was associated with RVGLS (OR, 0.538; 95% CI [0.182-0.785]; P = 0.001), left atrial strain (εa) (OR, 0.313; 95% CI [0.21-0.721]; P < 0.001), pulmonary flow acceleration time in RVOT (OR, 0.693; 95% CI [0.328-0.839]; P < 0.001), estimated pulmonary artery wedge pressure (OR, 1.437; 95% CI [1.131-2.274]; P < 0.001), and intracavitary thrombus (OR, 1.223; 95% CI [1.117-1.973]; P < 0.001). The variables that were associated with 6-month mortality in the multivariable analysis were pulmonary embolism severity index (OR, 1.029; 95% CI [1.012-1.377]; P < 0.001), RVGLS (OR, 0.657; 95% CI [0.438-0.871]; P < 0.001), RVOT VTI (OR, 0.324; 95% CI [0.102-0.541]; P < 0.001), right atrial pump (εa) (OR, 0.352; 95% CI [0.193-0.721]; P < 0.001), and left ventricular outflow tract VTI (OR, 0.814; 95% CI [0.281-0.948]; P < 0.001), with all P values <0.001. Conclusions: Among patients with PE in the ICU, right ventricular strain and RVOT VTI were associated with mortality in the ICU and at 6-month follow-up. Furthermore, right ventricular strain was independently associated with future heart failure. These data emphasize the clinical relevance of right ventricular parameters in prognosticating high-risk PE.