Prognostic significance of subpulmonary left ventricular size and function in patients with a systemic right ventricle.

AIM: To assess the additional prognostic significance of echocardiographic parameters of subpulmonary left ventricular (LV) size and function in patients with a systemic right ventricle (SRV).

METHODS AND RESULTS: All adults with a SRV who underwent transthoracic echocardiography in 2010-2018 at a large tertiary center were identified. Biventricular size and function were assessed at the most recent exam. The study endpoint was all-cause mortality or heart/heart-lung transplantation.We included 180 patients, 100(55.6%) male, mean age 42.4±12.3 years, of whom 103(57.2%) had undergone Mustard/Senning operations and 77(42.8%) had congenitally corrected transposition of great arteries.Over 4.9[3.8-5.7] years, 28(15.6%) patients died and 4(2.2%) underwent heart or heart-lung transplantation. Univariable predictors of the study endpoint included age, NYHA functional class III or IV, history of atrial arrhythmias, presence of pacemaker or cardioverter-defibrillator, high BNP, and echocardiographic markers of SRV and subpulmonary LV size and function. On multivariable Cox analysis of echocardiographic variables, indexed LV end-systolic diameter (ESDi; HR 2.77 [95%CI 1.35-5.68], p=0.01), LV fractional area change (FAC; HR 0.7 [95%CI 0.57-0.85], p=0.002), SRV basal diameter (HR 1.66 [95%CI 1.21-2.29], p=0.005), and SRV FAC (HR 0.65 [95%CI 0.49-0.87], p=0.008) remained predictive of mortality or transplantation. On ROC analysis, subpulmonary LV parameters performed better than SRV markers in predicting adverse events.

CONCLUSIONS: SRV basal diameter, SRV FAC, LV ESDi, and LV FAC are significantly and independently associated with mortality and transplantation in adults with a SRV. Accurate echocardiographic assessment of both SRV and subpulmonary LV is therefore essential to inform risk stratification and management.