Metabolic surgery yields reduced CV events in obesity, type 2 diabetes
PARIS — Metabolic surgery for patients with obesity and type 2 diabetes was linked to lower incidence of major adverse CV events compared with nonsurgical methods of metabolic management, according to a late-breaking research presentation at the European Society of Cardiology Congress.
In a retrospective matched cohort study, 30.8% of individuals with obesity and type 2 diabetes who underwent metabolic surgery experienced all-cause mortality, coronary artery events, cerebrovascular events, HF, nephropathy and atrial fibrillation at a median of 3.9 years compared with 47.7% of those in a nonsurgical propensity-matched control group (HR = 0.61; 95% CI, 0.55-0.69), Ali Aminian, MD, associate professor of surgery at Cleveland Clinic Lerner College of Medicine, said during the presentation.
The surgical group also had a lower rate of the composite of all-cause death, MI or ischemic stroke (17% vs. 27.6%; HR = 0.62; 95% CI, 0.52-0.72), according to the researchers.
“Before this study, we knew that metabolic and bariatric procedures significantly decrease body weight and improve type 2 diabetes. But this large matched-cohort study showed that surgical procedures are associated with a striking 39% reduction in adverse CV events and mortality,” Aminian told Healio. “Specifically, metabolic surgery was associated with a 41% reduction in death, a 62% reduction in heart failure, a 31% reduction in coronary artery events, 33% reduction in cerebrovascular events, a 60% reduction in nephropathy and a 22% reduction in AF in 8 years. In another words, by operating on 13 patients, 1 life could be saved.”
The 8-year cumulative incidence rate of all-cause mortality was 10% in the surgical group and 17.8% in the nonsurgical group (absolute risk difference, 7.8%; 95% CI, 5.1-10.2; adjusted HR = 0.59; 95% CI, 0.48-0.72), Aminian and colleagues found.
HF was also lower in the surgical group (HR = 0.38; 95% CI, 0.3-0.49), as was CAD (HR = 0.69; 95% CI, 0.54-87), cerebrovascular disease (HR = 0.67; 95% CI, 0.48-0.94), nephropathy (HR = 0.4; 95% CI, 0.31-0.52) and AF (HR = 0.78; 95% CI, 0.64-0.97).
“By improving the cardiovascular risk factors, by reduction in coronary artery disease, reduction in AF and decrease in the workload of the heart, those would be possible reasons for seeing this remarkable result in heart failure incidence,” Aminian said during the presentation.
The surgical group consisted of 2,287 patients with diabetes who underwent metabolic surgery at Cleveland Clinic between 1998 and 2017 (66% women; median age, 53 years; BMI, 45.1 kg/m2; glycated hemoglobin level 7.1%). The nonsurgical group consisted of 11,435 propensity-matched patients who received the usual care at Cleveland Clinic during the same period (64% women; median age, 55 years; BMI, 42.6 kg/m2; glycated hemoglobin level 7.1%).
“We are in the planning stage of a large multicenter randomized clinical trial to confirm these findings in the setting of a clinical trial,” Aminian told Healio. “A randomized clinical trial would be essential. Comparison of metabolic surgical procedures with new diabetes medications that have better CV effects (eg, SGLT2 inhibitors) would be required. Head-to-head comparison of different surgical procedures in terms of CV benefits would be important. Furthermore, the mechanism of action of metabolic surgical procedures needs to be examined and clarified in future studies.”
“The results of this study should be interpreted with caution, reflecting the observational design and, as reported by Aminian et al, imprecise matching of the study groups,” Edward H. Livingston, MD, deputy editor of JAMA and professor of surgery at the University of California, Los Angeles, wrote in a related editorial in JAMA. “The control group was slightly older (52.5 years versus 54.8 years), had higher diastolic blood pressures and had much more missing data. Patients who underwent bariatric surgery had higher body mass index and systolic blood pressure and more hypertension and dyslipidemia. Despite careful propensity matching, these sorts of imbalances always persist in observational studies, highlighting the limitations of interpreting comparisons made between groups in such studies.” – by Scott Buzby
Aminian A, et al. Late-Breaking Science in Prevention 1. Presented at: European Society of Cardiology Congress; Aug. 31 to Sept. 4, 2019; Paris.
Disclosures: The study was funded in part by an unrestricted grant from Medtronic. Aminian reports he received research grants from Medtronic. Livingston reports no relevant financial disclosures.