Optimal Strain Combinations for Prognostic Prediction in Pulmonary Arterial Hypertension.

BACKGROUND: Strain parameters are sensitive indicators of myocardial performance, but the optimal combination for prognostic prediction in pulmonary arterial hypertension remains unclear. METHODS: Patients diagnosed with pulmonary arterial hypertension between June 2013 and June 2024 were prospectively recruited. Strain parameters, including left ventricular global longitudinal strain, right ventricular GLS, right ventricular free-wall longitudinal strain, and right atrial phasic strain, were analyzed. Feature selection used elastic net Cox regression and stepwise Cox regression with the Akaike information criterion. Survival analyses were performed for all-cause mortality and a composite end point (mortality and heart failure rehospitalization). RESULTS: A total of 269 patients with pulmonary arterial hypertension (mean age, 42±15 years) were included. During a median follow-up of 39.3 months, 68 patients reached the primary end point, and 91 reached the secondary end point. The combination of left ventricular global longitudinal strain and right atrial reservoir strain had the strongest prognostic value. Both left ventricular global longitudinal strain (hazard ratio, 1.46, per 5% increase [95% CI, 1.07-2.00]; P=0.02) and right atrial reservoir strain (hazard ratio, 0.77, per 5% increase [95% CI, 0.62-0.95]; P=0.02) remained independent predictors of all-cause mortality. Their combination outperformed conventional cardiac magnetic resonance and clinical models, as evidenced by higher C-index values (all P≤0.05), and stratified patients into low-, intermediate-, and high-risk groups with distinct 1-year mortality rates (2.8%, 6.2%, 21.0%, respectively; P<0.001). Landmark analysis confirmed their long-term prognostic relevance. CONCLUSIONS: The combined assessment of left ventricular global longitudinal strain and right atrial reservoir strain yields the strongest prognostic utility among the strain parameters in pulmonary arterial hypertension, significantly improves risk stratification beyond several established cardiac magnetic resonance and clinical predictors, and holds promise as a practical tool for guiding management strategies.