GATEWAY at 3 Years: Bariatric Surgery Continues to Reduce Need for Antihypertensive Drugs

In obese patients with hypertension, gastric bypass surgery is a durable and more-efficacious method for reducing the number of medications needed to control blood pressure than standard therapy, according to 3-year results of the GATEWAY trial.

The study is the latest effort to examine the long-term potential for bariatric surgery to minimize polypharmacy and reduce CV risk. In overweight patients with diabetes, the STAMPEDE trial showed that in addition to reducing medication requirements, gastric bypass led to remission of diabetes in some patients.

“STAMPEDE really put bariatric surgery, now sometimes called metabolic surgery, on the map as a treatment for diabetes in people with obesity,” said Deepak Bhatt, MD (Brigham and Women’s Hospital, Boston, MA), who was an investigator on both GATEWAY and STAMPEDE. “What GATEWAY has done, I think, is entirely analogous to what we did in STAMPEDE, but now for high blood pressure as the endpoint as opposed to diabetes.”

To TCTMD, Bhatt said long-term follow-up of the GATEWAY cohorts out to 5 years will be important to show, as STAMPEDE showed, a sustainable impact of the surgery. The 3-year GATEWAY results were published last week in Annals of Internal Medicine.

Less Polypharmacy, but Not Superior BP Control

Led by Carlos A. Schiavon, MD, PhD (Hospital do Coracão, São Paulo, Brazil), GATEWAY randomized 100 obese patients with hypertension to medical therapy alone or Roux-en-Y gastric bypass plus medical therapy. All patients had a body max index between 30.0 and 39.9 kg/m² and were prescribed moderate doses of two or more antihypertensive drugs, including beta-blockers, ACE inhibitors, calcium-channel blockers, and diuretics.

Total weight loss was 27.8% with bariatric surgery and -0.1% with medical therapy. Around one-quarter of patients in the medical-therapy group gained more than 5% of their baseline weight. The surgery patients “demonstrated greater improvements in the other non-BP metabolic parameters,” the researchers note.

The primary outcome was the number of patients who achieved a greater than 30% reduction in the number of antihypertensive medications while maintaining BP levels below 140/90 mm Hg.

Here is a procedure that will, in general, make patients feel better in terms of both physical and mental health, that reduces multiple cardiovascular factors, and that reduces medication burden. Deepak Bhatt

At 3 years, 73% of bariatric surgery patients achieved the primary endpoint versus 11% of those in the medical-therapy arm (P < 0.001). Overall, the surgery group was taking an average of one drug to control hypertension at 3 years versus three drugs in the medical-therapy group (P < 0.001).

However, in terms of maintaining BP levels below 140/90 mm Hg, there was no significant difference between surgery and medical therapy. Similarly, the percentage of patients with non-dipping BP (characterized by < 10% reduction while asleep versus awake) was not different between groups.

Drilling Down on Who’s Likely to Benefit

In an accompanying editorial, Christina C. Wee, MD (Beth Israel Deaconess Medical Center, Boston, MA), the journal’s deputy editor, notes that the inability to show superior BP control compared with medication alone suggests that patients with milder obesity, as well as isolated and well-controlled hypertension, should not be routinely referred for bariatric surgery.

“Nonetheless, surgery may have a role for patients with milder obesity and resistant hypertension or those for whom reduction in polypharmacy is an overriding priority,” she writes.

In their paper, Schiavon and colleagues point out that 35% of patients in the gastric-bypass group achieved hypertension remission, as did one patient in the medical-therapy group. That patient also underwent gastric bypass, but outside the trial.

Schiavon and colleagues acknowledge that despite the promising results and the safety observed following surgery, choosing this intervention for patients must be weighed against surgical risks and costs.

According to Bhatt, referral for gastric bypass should be a last resort after other reasonable and proven options for losing weight and reducing BP, including serious attempts at exercise and diet. But for certain patients, he added, the benefits are too great to ignore.

“Here is a procedure that will, in general, make patients feel better in terms of both physical and mental health, that reduces multiple cardiovascular factors, and that reduces medication burden. So, in line with shared decision-making, it's an option to at least discuss in patients that have obesity,” Bhatt said. “It's another trick up our sleeve, and we probably ought to consider it in more patients and sooner.”