Antihypertensive efficacy and safe use of once-daily sustained-release diltiazem in the elderly: a comparison with captopril. The Dilcacomp Study Group

A network meta-analysis comparative the efficacy of angiotensin-converting enzyme inhibitors and calcium channel blockers in hypertension

BACKGROUND

Currently, most studies primarily focus on directly comparing the efficacy and safety of angiotensin-converting enzyme inhibitors (ACEIs) and calcium channel blockers (CCBs), the two major classes of antihypertensive drugs. Moreover, the majority of studies are based on randomized controlled trials and traditional meta-analyses, with few exploring the efficacy and safety comparisons among various members of ACEIs and CCBs.

METHODS

ACEIs and CCB were searched for in randomized controlled trials in CNKI, Wanfang, VIP, China Biology Medicine Disc (Si-noMed), PubMed, EMbase, and Cochrane Library databases. The search can be conducted till November 2022. Stata software (version 16.0) and R 4.1.3 was used for statistical analysis and graphics plotting, applying mvmeta, gemtc, and its packages. Meta-regression analysis was used to explore the inconsistencies of the studies.

RESULTS

In 73 trials involving 33 different drugs, a total of 9176 hypertensive patients were included in the analysis, with 4623 in the intervention group and 4553 in the control group. The results of the analysis showed that, according to the SUCRA ranking, felodipine (MD = -12.34, 95% CI: -17.8 to -6.82) was the drug most likely to be the best intervention for systolic blood pressure, while nitrendipine (MD = -8.01, 95% CI: -11.71 to -4.18) was the drug most likely to be the best intervention for diastolic blood pressure. Regarding adverse drug reactions, nifedipine (OR = 0.32, 95% CI: 0.14-0.74) was the drug most likely to be the safest.

CONCLUSION

The research findings indicate that nifedipine is the optimal intervention for reducing systolic blood pressure in hypertensive patients, nitrendipine is the optimal intervention for reducing diastolic blood pressure in hypertensive patients, and felodipine is the optimal intervention for safety.

Heart rate-lowering and -regulating effects of once-daily sustained-release diltiazem

BACKGROUND

Epidemiologic evidence suggests that an elevated heart rate (HR) is an adverse and independent prognostic factor in arterial hypertension and other cardiovascular diseases. Although diltiazem is characterized as an HR-lowering calcium antagonist, no studies have quantified the magnitude of HR changes in patients with angina or hypertension.

HYPOTHESIS

The study was undertaken to explore the magnitude of proportional HR reduction at varying levels of resting HR with the sustained-release formulation of diltiazem (SR diltiazem) at the usual clinical doses of 200 or 300 mg once daily.

METHODS

This meta-analysis was conducted on six comparative double-blind studies including 771 patients with angina or hypertension in which SR diltiazem 200-300 mg once daily was compared either with placebo or with other agents known not to influence HR (angiotensin-converting enzyme inhibitors, diuretics). Sustained-release diltiazem decreases elevated baseline HR, with an increasing effect at higher initial rates.

RESULTS

Multiple comparisons by baseline HR category showed a significant difference between both groups for baseline HR of 74-84 beats/min and > or = 85 beats/min (p = 0.001). Sustained-release diltiazem had no significant HR-decreasing effect on baseline HR < or =74 beats/min but appears to have a genuine regulating effect on HR: it reduces tachycardia without inducing excessive bradycardia. These findings are in contrast to those with dihydropyridine calcium antagonists, which tend to increase HR and have been associated with an adverse outcome in acute cardiovascular conditions. At the same time, there is evidence to suggest that HR-lowering calcium-channel blockers decrease cardiovascular event rates following myocardial infarction.

CONCLUSION

When calcium antagonists are indicated for use in patients with angina or hypertension, an HR-lowering agent, that is, diltiazem rather than dihydropyridine, should be recommended.