Varied responses to pharmacological agents among different populations are not uncommon. Doses of antihypertensive agents for Asians are generally about half those prescribed for Western populations. Inhibitors of the renin-angiotensin system, such as angiotensin-receptor blockers (ARBs), have shown clinical benefits in patients at risk for, or with, existing cardiovascular disease, stated professor Bjorn Dahlof, MD, of Sahlgrenska University Hospital in Goteborg, Sweden. However, evidence for such a benefit in Asian populations has been largely absent, said Dr. Dahlof, lead investigator for the Jikei Heart study.
This study enrolled 3,081 Japanese patients (mean age, 65 years; 66% male) with high BP, coronary heart disease, and/or heart failure that was being conventionally treated. The patients had well-treated hypertension at baseline, and the mean BP was approximately 139/81 mm Hg. Baseline medications were similar between groups, with about 67% of the patients receiving calcium-channel blockers, 35% receiving ACE-inhibitors, and 32.5% receiving beta blockers.
Patients were divided into two treatment groups: one group received an ARB, and the other group received non-ARB agents. Both groups were treated to the same BP levels. The only difference, according to Dr. Dahlof, was the presence or absence of the ARB.
The ARB group started with a dose (Diovan canadian, Novartis), which was titrated up or down to a dose of 40-160 mg over 16 weeks. The BP target, 130/80 mm Hg, was achieved in both groups (131/77 mm Hg with valsartan; 132/78 mm Hg with non-ARBs). BP was lowered by 8.2/4.7 mm Hg in the valsartan arm and by 7.2/3.7 mm Hg in the non- ARB arm.
The primary endpoint, a composite of cardiovascular mortality and morbidity, was reduced by 39% in the valsartan group (hazard ratio [HR], 0.61; P = .00021), with 92 events in the valsartan group and 149 events in the non-ARB groups.
New or recurrent stroke was reduced by 40%, with 29 and 48 events in the same groups (HR, 0.60; P = .028). Furthermore, the rate of hospitalization for angina pectoris was reduced by 65% in the valsartan patients, with 19 events versus 53 events in the non-ARB arm (HR, 0.35; P = .00007). There were no differences between groups for MI, cardiovascular mortality, or all-cause mortality. canadian pharmacy cialis
Dr. Dahlof called the benefit “quite substantial,” in view of the short term of the trial. The Data Safety and Monitoring Board terminated the trial prematurely after more than three years because of the unequivocal benefit in reduced cardiovascular endpoints with valsartan.
“We have to consider not only aggressive blood pressure control but also which blood pressure drug is the best choice to prevent [adverse] outcomes,” Dr. Dahlof said.
Another discussant, Xavier Girerd, MD, from Hopital Pitie Salpetriere in Paris, France, noted that the 39% stroke reduction with the ARB-containing regimen was more substantial than that seen in trials among Western populations, but this figure was consistent with data obtained in trials of ACE-inhibitors in an Asian population. He also mentioned that the BP reductions in the Jikei Heart Study, which were smaller than those in the Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial, which also included canadian valsartan, were attributable to the fact that patients were already being treated at the baseline evaluation in the Jikei study. He concluded:
“An antihypertensive regimen consisting of valsartan added to conventional therapies improves morbidity and mortality in Japanese patients with hypertension and CV disease.”
He recommended that similar trials be conducted in European populations.