Evaluating Hemodynamic Indices as Predictors of 30-day Mortality in Intermediate-risk Pulmonary Embolism

Abstract Rationale: Certain hemodynamic indices, such as the modified shock index, among others, have been proposed as potential predictors of in-hospital mortality in patients with pulmonary embolism (PE). This study aimed to assess whether these indices can predict 30-day mortality in stable patients with intermediate-risk PE. Methods: This retrospective cohort study included adult patients diagnosed with intermediate-risk PE. Hemodynamic indices calculated included the Shock Index (SI), Modified Shock Index (MSI), Respiratory Adjusted Shock Index (RASI), Age-adjusted Shock Index (ASI), and Oximetry Adjusted Shock Index (OASI), alongside other risk scores, including the Bova score and National Early Warning Score (NEWS). The primary outcome was 30-day mortality, with survivors and non-survivors compared based on demographics, clinical characteristics, treatments, and score performance. Multivariable analysis and AUROCs were used to evaluate the predictive value of each score. Results: Of 235 patients, 214 survived and 21 died within 30 days. The median age was 64 years for survivors and 69 for non-survivors (p=0.285). Non-survivors had higher rates of active malignancy (28.6% vs. 11.2%, p=0.035), active smoking (23.8% vs. 7.9%, p=0.033), and elevated BNP levels (median 401 vs. 158 pg/mL, p=0.002). Key clinical differences included lower heart rate (median 87 vs. 99 bpm, p=0.008) and systolic blood pressure (median 117 vs. 132 mmHg, p=0.026) among non-survivors. In terms of treatment, systemic thrombolytics were more frequently used among non-survivors (19.0% vs. 4.2%, p=0.020). No significant associations with 30-day mortality were observed for SI (adjusted OR=0.326, p=0.433, AUROC=0.599), MSI (adjusted OR=0.354, p=0.364, AUROC=0.605), RASI (adjusted OR=1.364, p=0.504, AUROC=0.592), ASI, or OASI. Bova and NEWS scores similarly failed to predict 30-day mortality, with AUROCs of 0.616 and 0.583, respectively. Conclusions: Hemodynamic indices, including SI, MSI, and RASI, did not reliably predict 30-day mortality in stable, intermediate-high risk PE patients. These findings suggest limited utility of these indices for short-term mortality risk stratification in this population, highlighting the need for further research to identify more accurate predictive tools.