PHILADELPHIA – Obese people living in the United Kingdom who underwent bariatric surgery had a two-thirds lower rate of major cerebrovascular events than that of a matched group of obese residents who did not undergo bariatric surgery, in a retrospective study of 8,424 people followed for a mean of just over 11 years.
Although the cut in cerebrovascular events that linked with bariatric surgery shown by the analysis was mostly driven by a reduced rate of transient ischemic attacks, a potentially unreliable diagnosis, the results showed consistent reductions in the rates of acute ischemic strokes as well as in acute, nontraumatic intracranial hemorrhages, two other components of the combined primary endpoint, Maddalena Ardissino, MBBS, said at the American Heart Association scientific sessions.
This finding of an apparent benefit from bariatric surgery in obese patients in a large U.K. database confirms other findings from a “fast-growing” evidence base showing benefits from bariatric surgery for reducing other types of cardiovascular disease events, said Dr. Ardissino, a researcher at Imperial College, London. However, the impact of bariatric surgery specifically on cerebrovascular events had not received much attention in published studies, she noted.
Her study used data collected by the Clinical Practice Research, which has primary and secondary care health records for about 42 million U.K. residents. The researchers focused on more than 251,000 obese U.K. adults (body mass index of 30 kg/m2 or greater) without a history of a cerebrovascular event who had at least 1 year of follow-up, a data file that included 4,212 adults who had undergone bariatric surgery. Their analysis matched these surgical patients with an equal number of obese adults who did not have surgery, pairing the cases and controls based on age, sex, and BMI. The resulting matched cohorts each averaged 50 years old, with a mean BMI of 40.5 kg/m2.
During just over 11 years of average follow-up, the incidence of acute ischemic stroke, acute intracranial hemorrhage, subarachnoid hemorrhage, or transient ischemic attack was about 1.3% in those without bariatric surgery and about 0.4% in those who had surgery, an absolute risk reduction of 0.9 linked with surgery and a relative risk reduction of 65% that was statistically significant, Dr. Ardissino reported. All-cause mortality was about 70% lower in the group that underwent bariatric surgery compared with those who did not have surgery, a finding that confirmed prior reports. She cautioned that the analysis was limited by a relatively low number of total events, and by the small number of criteria used for cohort matching that might have left unadjusted certain potential confounders such as the level of engagement people had with their medical care.
SOURCE: Ardissino M. AHA 2019, Abstract .