The Evaluation of Right Ventricular Synchrony by Two-Dimensional Speckle Tracking Echocardiography in Connective Tissue Disease-Associated Pulmonary Arterial Hypertension.

Objectives: Numerous studies have demonstrated impaired right ventricular (RV) synchronicity in pulmonary arterial hypertension (PAH). However, few studies have focused on connective tissue disease (CTD)-associated PAH. This study evaluates RV dyssynchrony and its prognostic value in CTD-associated PAH.

Methods: One hundred thirteen CTD patients and 32 healthy controls were consecutively recruited. The patients were further divided into two groups: the CTD-nonPAH group (sPAP ˂ 36 mmHg, n = 60) and the CTD-PAH group (sPAP ≥ 36 mm Hg, n = 53). RV dyssynchrony was evaluated by determining the standard deviation of the heart rate-corrected intervals from QRS onset to peak strain for the four segments (RV-SD4) using 2D speckle-tracking echocardiography (2D-STE). All patients were followed up, and the primary endpoint was clinical worsening.

Results: Compared to the health control, the CTD patients exhibited obviously prolonged RV-SD4 (13.3 ± 6.8 ms vs. 41.2 ± 36.5 ms, p < 0.001). Among 113 CTD patients, the CTD-PAH patients had longer RV-SD4 than the CTD-nonPAH patients (20.8 ± 9.9 ms vs. 64.3 ± 41.6 ms, p < 0.001). RV-SD4 was moderately positively correlated with RV longitudinal strain (r = 0.632, p < 0.001), sPAP (r = 0.644, p < 0.001), and were negatively correlated with TAPSE (r = -0.547, p < 0.001), and FAC (r = -0.611, p < 0.001). In the follow-up, 23 patients experienced clinical worsening. The ROC analysis suggested that RV-SD4 level >60.6 ms predicted clinical worsening with 91.3% sensitivity and 66.7% specificity (AUC = 0.891, p < 0.001). Multivariate Cox analysis showed that TAPSE (HR = 0.739; 95% CI 0.623-0.878; p = 0.001) and RV-SD4 (HR = 6.148; 95% CI 1.718-22.000; p = 0.005) were independent predictive parameters of clinical worsening.

Conclusion: CTD patients exhibit impaired RV synchronicity, which is linked to RV function and pulmonary artery pressure. RV dyssynchrony could predict clinical worsening in CTD-PAH.