Physicians' Academy for Cardiovascular Education

Bariatric surgery induced remission of hypertension in obese patients and diminishes medication

GATEWAY - Effects of Bariatric Surgery in Obese Patients with Hypertension

Presented at AHA 2017 Scientific Sessions in Anaheim, CA, USA by Carlos Schiavon (Heart Hospital, Sao Paulo, Brazil

Nov. 14, 2017 - news

Background

About 40% of American adults are obese, and 60-70% of hypertension in adults is attributable to adiposity. Observational and randomized trials (mainly focusing on T2DM) showed reduction or discontinuation of antihypertensive medication and overall reductions of CV events after bariatric surgery. RCTs in a population of hypertensive obese patients have not been performed yet. Bariatric surgery is a safe and effective method to treat obesity, and amelioration of hypertension is a potential beneficial effect of the procedure.

The GATEWAY aimed to evaluate whether bariatric surgery can provide a safe and effective auxiliary tool for blood pressure control in obese hypertensive patients. Reduction in antihypertensive medications can help in adherence to treatment. It was a single-center, open-label, randomized clinical trial to evaluate the efficacy of gastric bypass (Roux-en-Y) in reducing the prescription of antihypertensive drugs and its effect on hypertension and other CV risk factors. Patients with on average a BMI of about 37 kg/m2 (inclusion: BMI 30.0-39.9) were randomized (1:1) to either gastric bypass plus medical therapy, or to medical therapy alone (lifestyle intervention with visits to cardiologist, nutritionist and psychologist). At baseline, patients used a median of 3 antihypertensive drugs. The primary endpoint was reduction of at least 30% of antihypertensive drugs, maintaining BP <140/90 mmHg, at 12 months. Antihypertensive regimen was adapted to achieve the BP target of <140/90 mmHg.

Main results

Conclusion

The GATEWAY study shows that bariatric surgery represents an effective strategy in the treatment of obese patients with hypertension. These results are relevant in the context of minimizing non-adherence to therapy and its related consequences. Considering the improved metabolic and inflammatory profile, the observed effects have, in theory, the potential to reduce major CV events.

Discussion

Discussant Paul Poirier (Quebec Heart and Lung Institute, Quebec, Canada) said that the GATEWAY trial is one of the biggest bariatric surgery trials. He noted that those patients technically do not fulfill criteria for bariatric surgery, as the minimal BMI is normally 40, of 35 with comorbidities. In the trial, patients were quite young (43.8±9.2 years). Only 4 were lost to follow-up. The observed remission of hypertension was true both based on office and ABPM 24-hour blood pressure. Considering SPRINT-insights, he proposed that maybe we should go even lower in obese patients.

The literature of bariatric surgery speaks of a broad range of positive effects, but most of the data was obtained in the diabetes remission world. This is the first study showing hypertension as a primary outcome. It confirms that bariatric surgery can do good things. Possible mechanisms include an effect on insulin resistance (renal sodium reabsorption and increased sympathetic tone), or on the renin-angiotensin-aldosterone system, gut hormones (GLP-1 and peptide YY may play a role in the entero-renal axis) or inflammation (modulation of arterial stiffness).

The question remains what this means for more obese patients. It is currently unknown and the main challenge in BP measurement is that upper arms are frequently short, large and conical. Overall, Poirier concluded that this trial confirms the results of observational studies, with better control of residual confounding due to the randomized and standardized design.

Disclosures

- Our reporting is based on the information provided at the AHA 2017 congress -

The results were published simultaneously at Circulation