Incomplete functional reverse remodelling of the left ventricle one year after bariatric surgery. Insights from the prospective FatWest study

Abstract

Abstract Background Patients with severe obesity are predisposed to development of left ventricular (LV) hypertrophy with subsequent increased myocardial oxygen demand and impaired myocardial function. Bariatric surgery leads to rapid weight loss and improves cardiovascular risk profile. Purpose To assess whether LV systolic function, wall mechanics, and cardiac power improve 1 year after bariatric surgery. Methods 91 severely obese patients (43±10 years, 70% women, body mass index [BMI] 41.7±4.9 kg/m2, 55% with hypertension, 17% with diabetes mellitus) underwent echocardiography before, 6 and 14 months after Roux-en-Y gastric bypass surgery in the prospective FatWest (Bariatric Surgery on the West Coast of Norway) study. We assessed LV systolic function by biplane ejection fraction (EF), LV wall mechanics by midwall shortening (MWS) and global longitudinal strain (GLS), and cardiac power normalized for LV mass by 0.222 x cardiac output x mean blood pressure (BP)/LV mass. Results Surgery induced a significant reduction in BMI, heart rate, systolic BP, and LV mass (Figure 1). Prevalence of LV hypertrophy fell from 34 to 20% 14 months after surgery (p<0.001), while that of concentric geometry remained stable: 8 vs 10% (p=0.36). GLS improved by 28%, however LV EF and MWS did not change (Figure 2). LV power at rest decreased postoperatively, reflecting the lower BP and heart rate, but was unaltered when normalized for LV mass (Figure 2). In backward stepwise multivariate regression analyses, 1 year improvement in GLS was predicted by the systolic BP reduction (p<0.05) (R2 0.73, p<0.001), while low 1-year MWS was independently associated with female gender, concentric geometry and higher myocardial oxygen demand (all p<0.01) (Nagelkerke R2 0.44, p<0.001), and lower 1-year LV power-mass with female gender and LV hypertrophy (p<0.01) (R2 0.24, p<0.001). Conclusion In severely obese patients, LV longitudinal function normalizes 1 year after bariatric surgery, mainly due to the BP reduction. LV midwall mechanics and power do not improve, especially in women and patients with persistent LV geometric abnormalities. Funding Acknowledgement Type of funding sources: None. Figure 1Figure 2