Meeting Highlights


COLM Results: Hypertensive Patients Aged 75 Years and Over Have Better Clinical Outcomes and Fewer Adverse Events on Calcium Channel Blockers Than on Diuretics

Presented by Toshio Ogihara, Japan

Hypertensive patients aged ≥75 years have a lower risk of stroke when they take calcium channel blockers (CCBs) along with olmesartan than when they take diuretics with olmesartan, according to the results of the Combination of Olmesartan and CCB or Low Dose Diuretics in High Risk Elderly Hypertensive Patients Study [COLM; NCT00454662]. Furthermore, the incidence of serious adverse events and discontinuation from the trial due to drug-related serious adverse events were also lower in elderly hypertensive patients receiving CCBs. The findings of this study were presented by Toshio Ogihara, MD, PhD, Morinomiya University of Medical Sciences, Osaka, Japan.

COLM is the first study to compare the effects of CCBs with those of diuretics in preventing cardiovascular disease when used in conjunction with olmesartan [Ogihara T et al. Hypertens Res 2009]. It was a multicenter, randomized, open-label, blinded-endpoint trial, conducted at 707 centers in Japan. High-risk elderly hypertensive Japanese patients (n=5141) aged 65 to 84 years were randomized to either CCBs plus olmesartan (n=2568) or low-dose diuretics plus olmesartan (n=2573). Of those in the CCB group, 38.1% were on CCBs at the start of enrollment versus with 35.8% in the diuretic group. The target BP was <140/90 mmHg.

Patients were followed-up for a median of 3.3 years. In both groups, BP decreased similarly, from 158/87 mmHg at baseline to 132/73 mmHg at the study end. The primary composite endpoint of fatal and nonfatal cardiovascular events was similar between the CCB and diuretic groups during the study (4.5% vs 5.3%; HR, 0.83; 95% CI, 0.65 to 1.07; p=0.16). None of the components of this endpoint were significantly different between the 2 groups.

In the subgroup of patients aged ≥75 years, the risk of the primary composite endpoint was significantly lower in the CCB group (5.2%) versus the diuretic group (7.2%; HR, 0.70; p=0.04). The risk of stroke was also significantly lower in the CCB group (2.4% vs 3.8%; HR, 0.63; p=0.05). However, there was no significant difference in the risk of cardiac events between the CCB and diuretic groups (1.9% vs 2.2%; HR, 0.83; p=0.68).

Overall, and regardless of the age subgroup (<75 or ≥75 years), 25.3% of CCB versus 29.1% of diuretic group patients experienced an adverse event (p=0.002). 8.2% of patients in the CCB group experienced serious adverse events compared with 9.8% in the diuretic group (p=0.046). The rate of discontinuation due to drug-related serious adverse events was also significantly lower in the CCB group (0.2% vs 0.6%; p<0.026).

COLM findings show that while CCBs and diuretics were equally effective at controlling BP in elderly patients with hypertension when given in combination with olmesartan, CCBs were more effective in preventing stroke in patients aged ≥75 years and were associated with a decreased risk of adverse events in all patients.