OSCAR: Olmesartan improves outcomes in patients with diabetes
American College of Cardiology 60th Annual Scientific Sessions
NEW ORLEANS — Combination therapy with olmesartan and a calcium antagonist was associated with similar rates of CV events and mortality when compared with a high-dose angiotensin II receptor antagonist alone in patients with CVD. However, dual therapy appeared inferior to AII receptor antagonist monotherapy in patients with diabetes, according to results of the OSCAR study.
High-dose AII receptor antagonists are more effective than low-dose AII receptor antagonists for the prevention of CVD in patients with diabetic nephropathy or heart failure; however, the question of whether combination therapy with an ARB plus a calcium antagonist is superior to AII receptor antagonist monotherapy remains unanswered.
Hisao Ogawa, MD, PhD, professor in the department of CV medicine at Kumamoto University in Japan, and colleagues aimed to address this question by initiating the Olmesartan and Calcium Antagonists Randomized (OSCAR) study.
“The OSCAR Study is the first single trial in the world to examine the effect of high-dose AII receptor antagonist and AII receptor antagonist plus calcium antagonist in high-risk elderly patients,” Ogawa said during a press conference here.
Between June 2005 and May 2007, Ogawa and colleagues recruited 1,164 high-risk patients aged 65 to 84 years from 134 institutions in Japan. To qualify for inclusion, patients had to have uncontrolled blood pressure despite receiving treatment with the AII receptor antagonist olmesartan (Benicar, Daiichi Sankyo) and CVD or type 2 diabetes. The study’s primary endpoint was a composite of CV events, including cerebrovascular disease, coronary artery disease, HF, other atherosclerotic diseases, diabetic microvascular diseases and renal dysfunction, as well as all-cause mortality.
Patients were randomly assigned to receive daily high-dose olmesartan (40 mg) or a calcium antagonist plus olmesartan (20 mg). At 36 months, adequate blood pressure control was observed in both treatment groups. However, compared with monotherapy, combination therapy induced considerably greater decreases in BP, according to the researchers. Mean systolic BP was a mean 2.4 mm Hg lower and mean diastolic BP 1.7 mm Hg lower.
The researchers noted no significant differences between the two treatment arms in the number of primary endpoints. Fifty-eight events occurred in the monotherapy group vs. 48 in the combination group (HR=1.31; 95% CI, 0.89-1.92).
Results of a subgroup analysis, however, revealed a statistically significant difference between treatment groups in patients with pre-existing CVD. Patients assigned to combination therapy experienced considerably fewer CV events and death compared with those assigned monotherapy (24 vs. 51; HR=1.63; 95% CI, 1.06-2.52).
In addition, a second subgroup analysis indicated a higher rate of the primary outcome between treatment arms in patients with diabetes only, with 14 events occurring in the combination group and seven occurring in the AII receptor antagonist monotherapy group (HR=0.52, 95% CI, 0.21-1.28). The researchers also noted a significant treatment-by-subgroup interaction for the primary endpoints between patients with CVD and patients with diabetes only.
These results suggest that the relative effect of the two therapies is dependent on the presence of CVD or diabetes, according to the researchers. – by Melissa Foster
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NAGOYA HEART: ARB, calcium antagonist equally effective in patients with diabetes, hypertension
American College of Cardiology 60th Annual Scientific Sessions
NEW ORLEANS — Valsartan, an angiotensin II receptor blocker, and amlodipine, a calcium antagonist, comparably reduced adverse CV events in hypertensive patients with diabetes or glucose intolerance, according to data presented here.
“Many hypertension treatment guidelines recommend angiotensin-converting enzyme (ACE) inhibitors or angiotensin-receptor blockers (ARBs) as first-line treatment for hypertensive patients with diabetes, especially for prevention of major CV events,” Toyoaki Murohara, MD, PhD, lead researcher of the NAGOYA HEART Study, said during a press conference. “But some clinical trials show that calcium antagonists are almost equally effective in reducing the risk of CV disease as compared to ARBs.”
The NAGOYA HEART Study is the first randomized trial comparing the efficacy of an ARB with a calcium antagonist, according to Murohara. For the trial, Murohara and colleagues recruited 1,150 hypertensive patients with diabetes or glucose intolerance at 46 facilities in Japan. Between October 2004 and July 2010, the researchers randomly assigned patients to receive valsartan (Diovan, Novartis) or amlodipine (Norvasc, Pfizer) as first-line treatment. The study’s primary outcome measure was a composite of CV events, including acute myocardial infarction, stroke, coronary revascularization, hospital admission resulting from congestive heart failure (CHF) and sudden cardiac death. Blood pressure and HbA1c levels were also monitored.
Follow-up lasted a median of 3.2 years, with analysis occurring every month for the first 3 months and then every 1 to 3 months thereafter. Results revealed that 54 patients (9.4%) assigned to valsartan and 56 (9.7%) assigned to amlodipine experienced the primary outcome (HR=0.97; 95% CI, 0.66-1.4), suggesting no significant differences between treatment groups. Analysis of individual components of the primary outcome, however, indicated that the incidence of hospital admission for CHF was higher in the amlodipine group, with the event occurring in three patients (0.5%) in the valsartan arm vs. 15 patients (2.6%) in the amlodipine arm (HR=0.2; 95% CI, 0.06-0.69).
BP and HbA1c levels also appeared similar between the groups, the researchers said. At 54 months, BP decreased to 131/73 mm Hg in the valsartan group and 132/74 mm Hg in the amlodipine group. HbA1c levels were lowered to 6.7% in both groups.
“Our present paper shows that ARB is superior to a calcium antagonist in HF, and clinical trends already show ACE inhibitors slow [the development of] some of the complications of diabetes,” Murohara said. “Our study results support the current guidelines recommending ARB and ACE inhibitors for first-line treatment in diabetic patients with hypertension.”
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Specialized clinic improved outcome in patients with AF
American College of Cardiology 60th Annual Scientific Sessions
NEW ORLEANS – Rates of CV-related mortality and hospitalization were improved in patients with atrial fibrillation treated in a specialized clinic that adheres to AF guidelines when compared with usual care, according to new data.
“In order to improve outcomes in our patients, we developed a AF clinic which was characterized by substation of care by specialized nurses and they also delegated a software program … which stays with you and warns you in case you’ve made the wrong decision and it also suggests the most appropriate therapy,” said Robert G. Tieleman, MD, PhD, study investigator and cardiologist at the Martini Hospital, Groningen, the Netherlands, in a press conference. “We believed that doing this approach would improve outcome in these patients.”
Tieleman and fellow researchers tested this theory by analyzing the outcomes of patients (n=712) who were newly diagnosed with AF referred to the specialized AF clinic (n=356) or usual care (n=356). Baseline data revealed similar rates of CV conditions including hypertension, stroke, coronary artery disease and HF between the AF clinic and usual care arms. The primary endpoint was a composite of CV mortality, life-threatening effects of drugs, and hospitalization due to HF, stroke, acute MI, systemic embolism, bleeding and arrhythmic events.
After a mean 22-month follow-up, the primary endpoint was reported in 14.3% of the AF clinic arm vs. 20.8% of the usual care arm (HR=0.65; 95% CI, 0.45-0.93). Lower rates were also found in the AF clinic arm regarding deaths (1.1% vs. 3.9%; HR=0.28, 95% CI 0.09-0.85) and hospitalizations (13.5% vs. 19.1%; HR=0.66; 95% CI 0.46-0.96).
In his concluding remarks, Tieleman said that this study is at least the first step towards treating more patients with this approach, “but we also have to improve cost-effectiveness,” he said. “But I think these are very promising data.” – by Brian Ellis