Bariatric surgery may improve subclinical heart function

Undergoing bariatric surgery to treat obesity may also improve subclinical heart function, according to a small study presented at the EuroEcho 2019 conference.

“Bariatric surgery was conceived for weight loss; our study indicates it may also reverse subclinical heart dysfunction. Since this abnormality predicts adverse cardiovascular events and mortality, its reversal could translate into improved prognosis,” said study author Dr Marie-Eve Piché from the Quebec Heart and Lung Institute, Quebec, Canada.

Study participants were severely obese individuals (BMI >35 kg/m²; mean age 42 years, 82 percent female, mean BMI 48 kg/m²) with preserved left ventricular ejection fraction (LVEF; 50 percent). Of these, 38 underwent bariatric surgery (mean BMI 48 kg/m²) and 19 were managed conservatively (mean BMI 47 kg/m²), while 18 non-obese individuals were age- and sex-matched controls.

Six months following bariatric surgery, the percentage total weight loss in the surgery group was 26.3 percent compared with the group that was managed conservatively where there was no change in body weight. [EuroEcho 2019, abstract P924]

Compared with patients managed conservatively, undergoing bariatric surgery was tied to a significant reduction in hypertension (30 percent vs 61 percent; p=0.0005), dyslipidaemia (5 percent vs 42 percent; p=0.0001), and type 2 diabetes (T2D; 13 percent vs 40 percent; p=0.002).

Prior to surgery, 22 patients in the surgery group (58 percent) had evidence of subclinical myocardial dysfunction, as determined by an abnormal left ventricular global longitudinal strain (LV GLS). Six months post-surgery, these abnormal levels normalized in 82 percent of patients (p=0.0001). Conversely, the LV GLS worsened in  53 percent of patients (n=10) who were managed conservatively (p=0.002).

Additionally, prior to surgery, patients in the surgery group had greater subclinical myocardial dysfunction compared with the control group (LV GLS, -17.3 percent vs -19.6 percent; p=0.003). Six months following bariatric surgery, subclinical myocardial function was similar between the two groups (LV GLS, -19.2 percent vs -19.6 percent).

“A great proportion of severely obese individuals with preserved LVEF have subclinical myocardial dysfunction,” said the authors. “Early (6 months) after bariatric surgery, it normalizes in more than 80 percent of patients and is comparable to normal weight controls,” Piché said.

The effect of bariatric surgery on GLS may have been associated with the remission of T2D, said Piché. “[R]emission of T2D [6 months] after bariatric surgery was associated with improvement in subclinical heart function [GLS, -17.5 percent vs -18.6 percent]. Conversely, obese individuals with T2D who [were managed conservatively] showed a worsening in their subclinical myocardial function during follow-up [-18.0 percent vs -17.4 percent],” she said.

Longitudinal studies are necessary to establish if the impact of bariatric surgery on all these outcomes leads to reductions in cardiovascular disease incidence, she noted.