Right Ventricular Global Longitudinal Strain and 30-Day Mortality in Intermediate-Risk Pulmonary Embolism: An External Validation Study

Background: Intermediate-risk pulmonary embolism (PE) carries substantial short-term mortality. Our group previously demonstrated that right ventricular global longitudinal strain (RVGLS) predicted 30-day mortality in a single-center cohort using data collected before contemporary guideline updates, identifying a cutoff value of 17.7%. However, its prognostic value in contemporary external cohorts remains uncertain. We aimed to externally validate the association between RVGLS and 30-day mortality in an independent cohort. Methods: We performed a retrospective cohort study of 119 patients with intermediate-risk PE treated between 2019 and 2022 at an independent institution. The primary outcome was all-cause 30-day mortality. Clinical and echocardiographic parameters were compared between survivors and non-survivors. Receiver operating characteristic and Kaplan–Meier analyses were used to assess prognostic performance. Results: The mean age was 66.1 years, and 48.7% were female. Six patients (5.0%) died within 30 days. RV strain analysis was feasible in 110 patients (92.4%). Non-survivors had lower RVGLS (17.3% vs. 19.6%, p = 0.013). In univariable analysis, RVGLS was associated with mortality (odds ratio 0.567, p = 0.033). RVGLS demonstrated discriminatory performance for 30-day mortality, with an area under the curve of 0.802. Using the previously established cutoff of 17.7%, patients with reduced RVGLS had higher 30-day mortality (Log-rank p = 0.042). Conclusions: In this external cohort, RVGLS ≤ 17.7% was associated with increased 30-day mortality, supporting the prognostic value of the previously established threshold beyond the original derivation cohort.