Optimizing sPESI with heart rate threshold adjustments for risk stratification in acute pulmonary embolism: A...

The simplified Pulmonary Embolism Severity Index (sPESI) is a validated tool for risk stratification in acute pulmonary embolism (PE). It incorporates heart rate (HR) ⩾ 110 beats per minute (bpm) as a prognostic factor; however, recent evidence suggests that lower HR thresholds may also be clinically relevant. This study evaluated the prognostic performance of sPESI-based models using varying HR cut-offs and assessed the incremental value of adding right ventricular dysfunction (RVD).

We conducted a retrospective cohort study of 696 outpatients with objectively confirmed PE between 2014 and 2019 in a Canadian health region. sPESI models were recalculated using HR thresholds of ⩾ 80, ⩾ 90, ⩾ 100, and ⩾ 110 bpm. The addition of imaging-confirmed RVD was also examined. Outcomes included 30- and 90-day all-cause mortality. Model performance was assessed using logistic regression, area under the curve (AUC), Youden's Index and net reclassification index (NRI).

Lowering the HR threshold improved event detection and reclassification. HR ⩾ 100 bpm provided the most balanced performance for 30-day mortality (AUC 74.7%, Youden Index 0.414), and HR ⩾ 90 bpm offered greater sensitivity. Adding RVD modestly improved model discrimination, with sPESI + RVD at HR ⩾ 80 bpm achieving the highest sensitivity (92.9%) and negative predictive value (> 99%) for 30-day mortality. The strongest association with mortality was observed for sPESI alone HR ⩾ 100 bpm (OR 2.06; 95% CI: 1.47-2.92). Findings remained consistent in a hospitalized-only sensitivity analysis.

Modifying HR thresholds within the sPESI model, particularly at ⩾ 100 bpm, and incorporating RVD meaningfully improves short-term mortality prediction in acute PE. These refinements may enhance clinical decision-making, especially in selecting patients for safe outpatient management.