Bariatric surgery is associated with lower risk of acute cardiovascular events in patients with obesity and hypertrophic cardiomyopathy
Authors: Miyashita S , Zhao Y , Hasegawa K , Maurer M , Fifer M , Reilly M , Takayama H , Shimada Y J 
Published: October 2021

Abstract

Background
Prior studies have suggested causal relationships between obesity and acute cardiovascular events (e.g., acute coronary syndrome, hypertensive crisis, and heart failure exacerbation). It has been known that the risk of cardiovascular events is reduced by bariatric surgery, the most effective method for substantial and sustained weight loss. However, little is known about whether bariatric surgery lowers the risk of acute cardiovascular events in the hypertrophic cardiomyopathy (HCM) population.

Purpose
To test the hypothesis that patients with obesity and HCM who underwent bariatric surgery have lower risk of developing acute cardiovascular events than those who did not.

Methods
In this population-based study of adults with obesity and HCM, the bariatric surgery group consisted of patients who underwent bariatric surgery from January 2004 to December 2014, whereas the control group included those who received non-bariatric elective intra-abdominal surgery during the same period. The outcome was an acute cardiovascular event – defined as emergency department (ED) visit or unplanned hospitalization for cardiovascular disease – during a 1-year post-surgery period. We used the SPARCS database, a population-based ED and inpatient database that captures all the ED visits and hospitalizations in New York State. We constructed logistic regression models with generalized estimating equations to compare the risk of the outcome events during sequential 6-month periods. We conducted multivariable analysis, adjusting for age, sex, number of ED visits and hospitalizations for cardiovascular disease within 2 years before the index surgery, and the Elixhauser comorbidity measures. We also performed additional analyses with propensity score (PS)-matching at 2:1 ratio and inverse probability treatment weighting (IPTW) using these variables.

Results
The analytic cohort consisted of 207 adults with obesity and HCM, including 147 patients who underwent bariatric surgery and 60 who had non-bariatric elective intra-abdominal surgery. In the 7–12 months post-surgery period, the risk of acute cardiovascular event was significantly lower in the bariatric surgery group (adjusted OR 0.23; 95% CI, 0.068–0.71; P=0.01; Figure) compared to the control group. In the PS-matched cohort (n=82 vs. 47), there were no significant differences in the baseline characteristics (P&gt;0.50 for all comparisons). Similar to the main analysis, the PS-matched analysis demonstrated lower risk of the outcome event in the bariatric surgery group in the 7–12 months post-surgery period (OR 0.26; 95% CI, 0.083–0.73; P=0.01). The IPTW analysis also replicated the findings (OR 0.33; 95% CI, 0.16–0.71; P=0.004 during the 7–12 months post-surgery period).

Conclusion
In this population-based study of 207 adults with obesity and HCM, bariatric surgery was associated with a lower risk of acute cardiovascular events in the 7–12 months post-surgery period in real-world settings.

Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Institute of Health (USA) and American Heart Association