Any Hypertension Drug Combo Can Work in Underserved Groups

Three combination therapies for hypertension are equally effective in reducing blood pressure, according to a new global study conducted in India, where this significant health burden affects nearly 300 million people.

Control rates in the country are “abysmal”; just 10%-20% of people with hypertension have their condition under control, Dorairaj Prabhakaran, MD, a cardiologist and executive director of the Centre for Chronic Disease Control in New Delhi, reported at the American Heart Association (AHA) Scientific Sessions in Chicago.

Current international hypertension guidelines suggest that various medications to lower blood pressure be combined, but most of those guidelines are based on studies done in Western populations. There is no existing research on which ones work best in people of South Asian descent, despite them accounting for around one quarter of the world’s population. To address this, Prabhakaran and his colleagues created the TOPSPIN trial.

The study was conducted in India, but the results will be significant to the large South Asian population in the United States. “More than 5 million South Asian people live in the US, so these findings have huge relevance for them,” said Prabhakaran.

The TOPSPIN Trial

In TOPSPIN, almost 2000 adults were randomly assigned to one of three treatment groups. Each group was prescribed a single pill, taken daily, that contained two of the following three medications: perindopril, a renin-angiotensin enzyme inhibitor; amlodipine, a calcium-channel blocker; and indapamide, a diuretic. The primary outcome was 24-hour ambulatory systolic blood pressure at 6 months.

All three combinations lowered blood pressure equally. The absolute reduction in blood pressure for participants in all three groups was approximately 30/14 mm Hg when measured in a physician’s office and 14/8 mm Hg when measured using 24-hour ambulatory blood pressure monitors.

About 70% of participants achieved a blood pressure below 140/90 mm Hg. More than 40% achieved the stricter blood pressure target of 130/80 mm Hg or lower.

All three combinations had a good safety profile; less than 3% of study participants ended treatment because of adverse effects related to the medications. About 17% of participants did not complete the trial, which is not unusual for this kind of study, Prabhakaran said. Measuring ambulatory blood pressure can be uncomfortable, especially in a hot country such as India, and some participants did not want to do it repeatedly.

The message from this trial is that physicians can use any combination of these medications to treat hypertension in patients and can choose whichever is most appropriate based on availability and cost, Prabhakaran explained.

“This has the potential to have huge implications in terms of hypertension management,” he added.

The large reduction in blood pressure seen with all combinations indicates that TOPSPIN is “a great trial,” introducing “combination therapy in a population that needs better blood pressure control,” said Shawna Nesbitt, MD, a cardiologist at UT Southwestern Medical Center in Dallas, who was not involved in the study.

Whereas rates of hypertension have increased by 41% in Europe and North American over the past 30 years, they have shot up by 144% in South Asia and Southeast Asia during the same period, Nesbitt pointed out. But lowering blood pressure by just 5 mm Hg can result in big improvements in outcomes for patients who experience cardiovascular disease, stroke, or heart attack.

“This is an opportunity to greatly improve the clinical environment,” she said.