Right ventricular outflow tract fractional shortening: a novel diagnostic parameter for pulmonary hypertension

Pulmonary hypertension (PH) is a progressive vascular disease characterized by elevated pulmonary arterial pressure and resistance in the pulmonary vascular bed. It is associated with high morbidity and mortality. Although right heart catheterization (RHC) is the gold standard for diagnosis, noninvasive methods, such as echocardiography, are essential for early detection and management. This study aimed to elucidate the potential of right ventricular outflow tract fractional shortening (RVOT-FS) as a noninvasive diagnostic tool for PH. This single-center observational cohort study was conducted between November 2023 and May 2024. The study included 141 patients referred to the PH clinic (75 with confirmed PH and 66 controls). Echocardiographic measurements were performed using standard protocols, and RVOT-FS was calculated. Hemodynamic parameters were obtained via RHC. RVOT-FS was significantly lower in the PH group (35.71%, IQR: 27.15-43.33) than in the control group (54.50%, IQR: 45.21-69.17) (p < 0.001). RVOT-FS showed negative correlations with mean pulmonary artery pressure (mPAP) (r = - 0.664, p < 0.001), pulmonary vascular resistance (PVR) (r = - 0.526, p < 0.001), and other RHC and RV echocardiographic parameters. ROC analysis demonstrated that RVOT-FS is a reliable parameter for predicting PH, with an area under the curve (AUC) of 0.866. An RVOT-FS value of 44.05% had a sensitivity of 82.7% and specificity of 83.3% for diagnosing PH. This study revealed that RVOT-FS was significantly lower in the PH group than in the control group. The correlations also observed between RVOT-FS and mPAP, PVR, and other RHC and echocardiographic parameters imply its potential clinical utility.