No significant differences on cardiovascular outcomes were seen in a trial that compared ARBs to CCBs in patients with glucose tolerance and hypertension.
NEW ORLEANS — April 4, 2011 – Two antihypertensive drugs competing for first-line status will have to share the spotlight, as both performed similarly in a study that researchers reported on here today in a late-breaking news conference at the American College of Cardiology’s (ACC) 60th Annual Scientific Session and ACC.i2 Summit.
“In the first randomized trial to compare the effects an angiotensin II receptor blocker (ARB) to a calcium channel blocker (CCB) on cardiovascular outcomes in patients with glucose tolerance and hypertension, we found no significant differences,” reported Toyoaki Morohara, MD, PhD, professor, Department of Cardiology, Nagoya University Graduate School of Medicine, in Nagoya, Japan. “Our study showed no differences in the efficacies between ARB and CCB in terms of preventing major CVD events, although the ARB was superior to the CCB regarding the prevention of heart failure.”
The study enrolled 1,150 hypertensive patients with either type 2 diabetes or impaired glucose tolerance at 46 facilities between October 2004 and July 2010 to receive either ARB (valsartan, n = 575) or CCB (amlodipine, n = 575) as first-line treatment.
Patients were followed for an average of 3.2 years and underwent follow-ups every month for the first three months, and every one to three months subsequently. In all patients, blood pressure and blood glycated hemoglobin levels were tested.
Primary CVD endpoints included acute heart attack, stroke, coronary revascularation, hospital admission due to CHF, and sudden cardiac death.
The primary outcome occurred in 54 patients (9.4%) who were taking valsartan and 56 patients (9.7 %) who were taking amlodipine (HR, 0.97 95% CI 0.66 P = 0.85), an insignificant difference.
When the team compared each component of the primary outcome, individually, they also found no significant difference in four of the five events. “Only hospital admission for CHF showed a signifantant difference, with 3 patients in the valsartan group and 15 patents (2.6%) in the amlodipine group experiencing this outcome [HR 0.20.95% CI 0.06-.69 P = 0.01].
“No significant differences were found in all-cause mortality or in adverse events,” said Dr. Murohara.“Blood pressure was reduced to 131/73mmHg in the valsartan group and 132/74 mmHg in the amlodipine group at 54 months, and both groups showed a steady decrease in HbA1c to 6.7%. These results highlight the safety and efficacy of ARBs, especially in preventing heart failure in diabetic hypertensive patients.”