Right ventricle-pulmonary artery coupling and adverse events after cardiac surgery

Abstract Background Right ventricular–pulmonary artery coupling (RV-PA coupling) refers to the relationship between RV contractility and RV afterload. RV-PA uncoupling occurs when RV contractility cannot increase to match RV afterload, resulting in RV dysfunction and right heart failure. Purpose Our study aimed to evaluate the prognostic value of RV-PA coupling in patients with coronary artery disease (CAD) and severe valvular disease undergoing cardiac surgery. Methods Study population included 55 patients of whom 20 with CAD undergoing coronary artery bypass grafting (CABG), 4 mitral valve replacement (MVR), 6 aortic valve replacement (AVR) and 25 combined surgery. Echo-Doppler assessment was realized according to EACVI recommendations, preoperatively and on postoperative day 4-7. A comprehensive assessment of RV systolic function was performed (Fig.1). TAPSE, RVs', RV global longitudinal strain (RV GS) and RV free wall global longitudinal strain (RV FWLS) were evaluated. TAPSE/PAPs ratio and RVFWLS/PAPs ratio were calculated to assess non-invasively RV-PA coupling. Study population was then divided into two subgroups according to presence or absence of in-hospital adverse events such as new onset of arrhythmias, acute or worsening HF, acute coronary syndrome and in-hospital death; baseline echocardiographic parameters of the two subgroups were retrospectively compared. Continuous normally distributed variables were compared by using the Student t-test. A probability value < 0.05 was considered statistically significant. Analyses were performed with SPSS. Results The comparison of post-operative versus baseline echocardiographic parameters showed statistically significant decrease of left ventricle ejection fraction (LVEF: 54.42±7.20 vs 56.80±7.88, p-value:0.005), LV global longitudinal strain (GLS) (12.79±3.02 vs 17.12±4.35, p-value:0.006) and right ventricular systolic function evaluated by TAPSE (14.67±3.16 vs 21.16±3.53, p-value