Subclinical left ventricular dysfunction in severe obesity and reverse cardiac remodeling after bariatric surgery

Aim: Obesity is associated with an increased cardiovascular risk. This study aimed to assess the role of echocardiography in the early detection of subclinical cardiac abnormalities in a cohort of obese patients with a preserved ejection fraction (EF) undergoing bariatric surgery. Methods and Results: Forty consecutive severely obese patients (body mass index≥35 kg/m2) referring to our center for bariatric surgery were enrolled in this prospective cohort study. Despite a baseline EF of 61% ± 3%, almost half patients (43%) had a systolic dysfunction (SD) defined as global longitudinal strain (GLS)>−18%, and most of them (60%) had left ventricular hypertrophy (LVH) or concentric remodeling (CR). At 10-months after surgery, body weight decreased from 120 ± 15 kg to 83 ± 12 kg, body mass index from 44 ± 5 kg/m² to 31 ± 5 kg/m² (both P < 0.001). Septal and left ventricular posterior wall thickness decreased respectively from 10 ± 1 mm to 9 ± 1 mm (P = 0.004) and from 10 ± 1 mm to 9 ± 1 mm (P = 0.007). All systolic parameters improved: EF from 61% ± 3% to 64% ± 3% (P = 0.002) and GLS from −17% ± 2% to −20% ± 1% (P < 0.001). Epicardial fat thickness reduction (from 4.7 ± 1 mm to 3.5 ± 0.7 mm, P < 0.001) correlated with the reduction of left atrial area (P < 0.001 R = 0.35) and volume (P = 0.02 R = 0.25). Following bariatric surgery, we observed a reduced prevalence of LVH/CR (before 60%, after 22%, P = 0.001) and a complete resolution of preclinical SD (before 43%, after 0%, P < 0.001). Moreover, a postoperative reduction of at least 30 kg correlated with regression of septal hypertrophy (P < 0.001).Conclusions: Obese patients candidate to bariatric surgery have an high prevalence of preclinical SD and LVH/CR, early detectable with echocardiography. Bariatric surgery is associated with reverse cardiac remodeling; it might also have a preventive effect on atrial fibrillation occurrence by reducing its substrate.