China Rural Intervention Still Reaping BP Control Wins at 3 Years

A simple stepped-care approach to lowering hypertension carried out by village doctors in rural China continues to show impressive results at 3 years of follow-up, with evidence of an impact on clinical events, researchers from the China Rural Hypertension Control Project (CRHCP) said at the American Heart Association 2022 Scientific Sessions.

Presenting the results, lead study author Jiang He, MD, PhD (Tulane University School of Public Health & Tropical Medicine, New Orleans, LA), said individuals enrolled in the BP-lowering intervention had a 31% drop in the primary composite outcome of MI, stroke, heart failure, or CVD death at 3 years compared with those who received a usual-care strategy.

In China, where awareness, treatment, and control of hypertension have become a major public health challenge, Jiang suggested that the CRHCP is offering hope that intensive blood pressure-lowering to a systolic BP of less than 130 mm Hg and diastolic BP of less than 80 mm Hg can make a big impact across the general population who have hypertension.

“The effect of blood pressure reduction on cardiovascular disease was consistent between older and middle-aged individuals and between those at high risk for cardiovascular disease and not at high risk for cardiovascular disease,” he noted. Jiang added that the study shows that treating all adults with hypertension to a low BP target “is both feasible and beneficial for cardiovascular disease risk reduction.”

By 36 months, the intervention group saw a decline in systolic pressure from a mean of 157 mm Hg at baseline to 126.1 mm Hg, while the usual-care group saw a much more modest decline from a mean of 155.4 mm Hg to 146.7 mm Hg. Similarly, diastolic pressure in the intervention group decreased from a mean of 87.9 mm Hg at baseline to 73.1 mm Hg, while the usual-care group saw a decrease from 87.2 mm Hg to 82.3 mm Hg. When Jiang presented the 18-month data last year at this meeting, the average BP was 131/73 mm Hg in the intervention group and 144/80 mm Hg in the control group.

Getting Results in Rural Care

The premise of the CRHCP was to test whether blood-pressure control could be improved through an intervention delivered by nonphysician village doctors. These community health workers have some medical training and are certified by local authorities in rural areas of China to deliver basic primary and public healthcare.

The study took place among residents of 326 villages across three Chinese provinces. Jiang and colleagues recruited 33,995 patients aged 40 or older (mean age 63 years; 61% women) with uncontrolled hypertension and enrolled them in the China New Rural Cooperative Medical Scheme, which covers basic healthcare services for 99% of rural residents. The intervention group consisted of 17,407 adults, while the usual-care group totaled 16,588 individuals. Nearly one-third of participants in each group had a self-reported history of CVD.

The study’s stepped-care protocol for hypertension treatment was adapted from the US guidelines, and targeted a BP goal of < 130/80 mm Hg, which is lower than the goal recommended in Chinese guidelines (< 140/90 mm Hg). The village doctors were supervised by primary care physicians and hypertension specialists from nearby hospitals. Their training included performing standardized BP measurement, delivering antihypertensive medications according to the protocol, and counseling patients on lifestyle modification and medication adherence. At baseline, 61% in the intervention group and 54% in the usual-care group were on antihypertensive agents, with a mean duration of hypertension of 7 years.

The primary composite outcome occurred at a rate of 1.98% per year in the intervention group and 2.85% per year in the usual-care group (HR 0.69; 95% CI 0.63-0.76). Among the individual components of the primary endpoint, there were 33% fewer strokes in the intervention vs usual-care group (P < 0.0001), 39% fewer cases of HF (P = 0.005), 24% fewer CVD deaths (P = 0.0004), and 15% fewer all-cause deaths (P = 0.009). Separation in rates of the cumulative incidence of CVD and all-cause mortality between the intervention and usual-care groups became clear by 12 months, Jiang said, and continued out to 36 months.

The results of the primary endpoint were consistent across subgroups, including age, sex, education, antihypertensive medication use at baseline, and baseline CVD risk.

Discussant Dorairaj Prabhakaran, MD (Public Health Foundation of India, Gurgaon), noted that utilizing community health workers in this way is a fairly new concept, adding “this is the largest implementation trial of task shifting with hard outcomes using a robust design like a cluster randomized trial.” According to Prabhakaran, the absolute risk reduction in the primary endpoint between the intervention and usual-care groups of nearly 1% is “huge.” Furthermore, he said the study raises important questions about how to adapt the trial design to low- and middle-income countries with high burdens of hypertension.

For starters, Prabhakaran said the study must be replicated using process outcomes and frameworks not unique to China, with evaluation of the cost and cost-effectiveness of implementing such a program. It is not clear if the Chinese experience can be scaled and made sustainable as part of the healthcare systems of other countries, he said. Other major questions are whether patients and physicians will accept the intervention style and whether the intervention itself can be personalized to the needs of communities where it will be implemented.

“How do we account for multimorbidity, because they diseases do not occur alone,” he added. “There are more questions than answers.”