IJCS | Volume 32, Nº5, September/October 2019

532 Mourilhe-Rocha and Salvino Obesity and heart failure Int J Cardiovasc Sci. 2019;32(5):527-535 Review Article A retrospective study 17 has assessed 12 patients with morbid obesity and HFrEF (ejection fraction = 22 ± 7%) submitted to bariatric surgery and has compared them with a control group of 10 patients not submitted to surgery, who received diet and physical exercise orientation. In one year, the first group showed a lower incidence of rehospitalization and an improvement in functional capacity and ejection fraction as compared to the control group. One patient underwent successful transplantation, and another entered the transplant list, showing the importance of considering that procedure for patients with morbid obesity and HF. 17 However, a recent retrospective analysis 41 of 22,487 patients submitted to bariatric surgery has tried to identify the major risk factors for 1-year mortality, evidencing that, despite the low absolute risk of mortality, an increase in the relative risk was associated with open surgery, DM, male sex and HF. 41 Other authors have associated the last two risk factors with increased mortality. 42,43 Bariatric surgery in patients with advanced HF In obese patients with advanced HF, BMI increase has been strongly associated with a lower probability of receiving heart transplantation, once added to the transplant waiting list. In addition, a BMI ≥ 35 kg/m 2 is related to a worse prognosis after heart transplantation, which is considered a significant obstacle to placement in the transplant list. 8,34 The International Society of Heart and Lung Transplantation listing criteria 44 recommend a weight loss that achieves a BMI ≤ 35 kg/m 2 before placement in the heart transplantation list. 1,44 In obese patients with ventricular systolic dysfunction, surgical weight loss results in reverse ventricular remodeling. Thus, bariatric surgery is a strategy for weight reduction to be considered, as a bridge to heart transplantation or a path to clinical recovery. 17,26,34,45-47 A study 45 has reported that two patients with morbid obesity and severely reduced LV function, in addition to NYHA class IV symptoms, despite optimized medical treatment, one of them being dobutamine-dependent, were referred for bariatric surgery. Heart transplantation was initially contraindicated due to severe obesity. In the 2-year postoperative follow-up, both showed LV ejection fraction improvement, were symptomless and required no transplantation. 26,45 Another study 34 has assessed seven obese patients with LV ejection fraction ≤ 25%, who had undergone laparoscopic bariatric surgery to become eligible for heart transplantation, because a BMI ≥ 35 kg/m 2 is considered a relative contraindication for that procedure. Later, two patients lost sufficient weight to undergo heart transplantation, two other lost sufficient weight to meet the listing criteria, and three improved their LV ejection fraction and symptoms, so transplant listing was no longer indicated. The individuals not submitted to transplantation had a median LV ejection fraction in the follow-up of 30% (mean of 39%). 1,34 Traditionally LV assist devices (LVAD) are used as a bridge to transplant or “destination therapy” in individuals with advanced HF, despite maximum pharmacological therapy. 26 Currently, data on the impact of obesity on the efficacy of those devices are limited. 8 There is evidence that the LVAD implantation is safe, 26 although a BMI increase has been associatedwith a higher chance of infection and thrombosis. However, the studies are scarce and have no power to determine the impact of BMI on mortality in those individuals. 8 A recent analysis 8 of the United Network for Organ Sharing database with 3,856 patients who had received a continuous-flow LVAD between 2004 and 2014 has shown that the risk of death or exclusion from the heart transplant waiting list did no significantly differ in patients with different BMI. However, complications, such as thrombosis and infection of the device, were significantly more frequently observed in patients with increased BMI (risk rate of 1.48 for patients with BMI > 35 kg/m 2 ). In addition, there was an increased risk of mortality after heart transplantation for obese patients as compared to that for patients with normal BMI. 8 In 2013, the concurrent use of bariatric surgery and LVAD in a morbidly obese patient as a bridge to successful heart transplantation was reported for the first time. 48 The concurrent use of that device and bariatric surgery allowed the patient to lose weight and subsequently qualify for placement in the heart transplant waiting list. 48 In 2015 a review 49 was published with six morbidly obese patients with advanced systolic HF, three of whom had a LVAD in place at the time of laparoscopic sleeve gastrectomy. Within 12 months of surgery, all patients had lost weight to become heart transplant eligible, considering their BMI. After subgroup analysis, the patients with LVAD, as compared to those without mechanical circulatory support, had a slightly longer