Cardiac remodeling after substantial weight loss: a prospective cardiac magnetic resonance study after bariatric surgery

Background: Obesity is a risk factor for left ventricular (LV) hypertrophy and excess cardiovascular disease and mortality. Substantial weight loss is associated with a decrease in cardiovascular mortality. Using volumetric cardiovascular magnetic resonance (CMR) imaging, we studied changes in cardiac anatomy and systolic function in women undergoing substantial weight loss in a university hospital. Methods: A total of 17 women (body mass index [BMI] 44.1 ± 4.2 kg/m²; age 44 ± 11 yr) scheduled for bariatric surgery underwent volumetric CMR imaging before and 3 and 17 months after surgery. Results: The body weight declined by 37.2 ± 10.5 kg (32%) with a decrease in BMI to 29.9 ± 4.7 kg/m² (32%, P < .004) during 17 months of observation. The LV mass decreased from 120 ± 23 g to 82 ± 11 g (32%, P < .004), with a linear relationship between the decrease in BMI and decrease in LV mass (P = .008) for the duration of the observation period. After adjustment for systolic and/or diastolic blood pressure, the relationship remained significant (P < .001). The right ventricular (RV) mass declined from 31.7 ± 6.7 g preoperatively to 26.6 ± 4.5 g at 3 months (16%, P < .001) but without additional changes at 17 months. No change was found in the LV or RV end-diastolic volume or ejection fraction. Conclusion: In morbidly obese women, substantial weight loss was associated with a reduction of LV and RV mass. The decrease in LV mass was linearly related to the reduction in BMI, independent of changes in blood pressure, and might partially explain the reduction in cardiovascular mortality associated with substantial weight loss. The BMI was a predictor of LV mass in this population.