Prognostic value of right ventricular–pulmonary artery coupling in patients with muscular dystrophies

Muscular dystrophies can affect the heart and the respiratory system. Right ventricular‒pulmonary artery (RV‒PA) coupling may reflect right ventricular adaptation to respiratory status. Since RV function is very sensitive to afterload, evaluating RV function coupled with pulmonary circulation is more relevant for assessing clinical issues in patients. The aim of this study was to assess the prognostic value of the tricuspid annular plane systolic excursion/systolic pulmonary artery pressure (TAPSE/sPAP), an index of RV–PA coupling, in patients with Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD) and sarcoglycanopathies. The study included retrospectively, from 2015 to 2023, patients with DMD, BMD and sarcoglycanopathies, who were followed in Pitié-Salpêtrière Hospital and Raymond-Poincaré Hospital (France) and who benefited from echocardiography that included a measurement of TAPSE/sPAP. The primary goal was to assess the prognostic value of the TAPSE/sPAP in terms of predicting cardiac events. The study included 113 patients (median age 28 years): DMD (n = 60, 53%), BMD (n = 33, 29%) and sarcoglycanopathies (n = 20, 18%). Home mechanical ventilation was present in 51 patients (46%), and 69% of the patients were wheelchair bound. Left ventricular systolic dysfunction (LVEF < 50%) was present in 37% of the patients. The median sPAP was 22 mmHg [19–27], whereas the median TAPSE was 16 mm [13–18]. Using a Cox model, we found that the TAPSE/sPAP*10 was significantly associated with cardiac events; the higher the TAPSE/sPAP, the better was the outcome (HR 0.33, 95% CI [0.16–0.69], p 0.003). According to the Youden criterion, the cutoff TAPSE/sPAP*10 was 5.3 mm/mmHg. RV–PA coupling, defined by the TAPSE/sPAP, may be a prognostic biomarker in patients with muscular dystrophies.