Bariatric Surgery Reduces Later Heart Failure Deaths

NASHVILLE, Tenn — Bariatric surgery may dramatically cut the risk for later death associated with heart failure, new research suggests.

The findings, from a large national US database sample of patients hospitalized for heart failure, were presented November 13 here at Obesity Week 2018 in a "Top Paper" session by Essa M. Aleassa, MD, a fellow at the Cleveland Clinic, Ohio.

"History of bariatric surgery has a significant protective effect on survival after acute exacerbation of heart failure," Aleassa said during his presentation.

In-hospital mortality during a heart failure-related hospitalization was cut nearly in half among those with prior bariatric surgery, and length of stay was also reduced.

"We can't tell with 100% certainty, but it implies that patients with a history of bariatric surgery have less severe heart failure, and that's why they spent less time in the hospital," Aleassa told Medscape Medical News in an interview.

Moreover, the protective effects in both heart failure survival and length of stay were seen even when subjects with prior bariatric surgery were matched with nonsurgical patients with the same body mass index (BMI), suggesting that the effect isn't simply because of lower body weight.

"We don't know...the mechanism, but at least we have a lead to follow," Aleassa said.

Indeed, session moderator Shanu Kothari, MD, director of bariatric surgery at Gundersen Health System, La Crosse, Wisconsin, told Medscape Medical News, "I think we're just scratching the surface of our understanding that there may be a unique metabolic benefit, that [with bariatric surgery] the heart benefits before the weight loss even occurs, much like there seems to be an incretin effect with diabetes. Maybe we're starting to see this with the heart."

HF Mortality, Length of Stay Both Lower Following Bariatric Surgery

Aleassa and colleagues used data from the National Inpatient Sample database (2007-2014), comprising 8 million hospital admissions and generally representing the US population. There were a total of 2810 patients admitted with heart failure (ICD-9 CM codes 428.X) who also had ICD-9 CM code V45.86, indicating prior bariatric surgery.

Each of those patients with prior bariatric surgery was propensity-matched with five other patients in two nonsurgical control groups: the first with BMI ≥ 35 kg/m²and the second matched by BMI at the time of heart failure. The propensity matching included demographic factors such as age, sex, race, and household income, hospital characteristics such as region and teaching status, and comorbidities including chronic pulmonary disease, renal failure, metastatic cancer, and the Elixhauser comorbidity index.

The total study sample included 33,720 (weighted) patients. All-cause inpatient mortality, the primary endpoint, was 0.96% for the group with prior bariatric surgery versus 1.86% for both control groups (odds ratio 0.52 for bariatric surgery compared with both controls; P = .0013 for the first control group and P = .0011 for the second).

Length of stay, the secondary endpoint, was significantly shorter in the prior bariatric surgery patients, at 4.79 days versus 5.75 days for control group one and 5.38 days for control group two (P < .001 for both).

Aleassa acknowledged several study limitations, including the fact that it was retrospective and there was no data on the type of bariatric surgery or the timing between bariatric surgery and heart failure diagnosis.

And an audience member pointed out that because this study was limited to patients who already had heart failure and prior bariatric surgery, it probably underestimates the benefits as it doesn't account for the preventative effect seen in other studies (Circulation. 2017;135:1577-1585).

In response to another audience member's question about whether the study findings support performing bariatric surgery on people once they develop heart failure, Aleassa said that they do practice this approach on selected patients at Cleveland Clinic.

Kothari commented, "We know patients with heart failure are at higher perioperative risk. I think these data lend support that even though we are front-loading the risk perioperatively, there may be some downstream potential benefits to the patients far beyond the traditional metrics that we look at in terms of reduction in comorbid conditions."

Overall, Kothari said, "When you talk about decreasing healthcare expenditures, stress on the healthcare system, when you start thinking more globally along those lines, that's where I find this type of data very intriguing and I think we need to do more studies to look at this kind of topic."

Aleassa has reported no relevant financial relationships.  Kothari is a consultant for Ethicon and Lexington Medical, and a speaker for Gore.

Obesity Week 2018. November 13, 2018; Nashville, TN. Abstract A-105.