Calcium channel blockers in hypertension: reappraisal after new trials and major meta-analyses.
This review evaluates the current position of calcium channel blockers (CCB) in antihypertensive treatment in the light of three major comparative studies and two extensive meta-analyses. The latter both show that CCB are equivalent to conventional (initial beta-blocker or diuretic therapy) when total and cardiovascular mortality are the end points. Divergent points between the meta-analyses include stroke and myocardial infarction (MI). One meta-analysis compared CCB with conventional therapy, to find a small 13% reduction in stroke and a small, nonsignificant 12% increase in MI. The other meta-analysis found a 26% increase in MI when CCB were compared with all other therapies including the angiotensin converting enzyme (ACE) inhibitors. This increase was most robust (P < .001) when comparing CCB with ACE inhibitors, consonant with proposed protective effects of ACE inhibitors on cardiovascular risk. At present, only the comparison of CCB with conventional therapy, and not that with ACE inhibitors, rests on secure comparative data. When cost is compelling, conventional therapy is less expensive. For the individual patient, issues of quality of life (for example, impotence with diuretics and beta-blockers) might be decisive. Nonetheless, beta-blockers are preferred in postinfarct patients or in those with heart failure or unstable angina (a contraindication to dihydropyridines in the absence of beta-blockade). In others, the benefits of only a borderline stroke reduction with CCB versus an equally borderline increase in MI should be evaluated for each individual patient, taking into account the age group and the patient's preferences. In conclusion, overall CCB are neither better nor worse than conventional therapy, allowing for possible small differences in stroke and MI. The ACE inhibitors may protect better, although data are incomplete.
Opie
L H
LH
Cape Heart Centre, University of Cape Town, South Africa. opie@capeheart.uct.ac.za
D000319:Adrenergic beta-Antagonists / Q000009:adverse effects / Q000627:therapeutic use; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000009:adverse effects / Q000627:therapeutic use; D002121:Calcium Channel Blockers / Q000009:adverse effects / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D004232:Diuretics / Q000009:adverse effects / Q000627:therapeutic use; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000401:mortality; D015201:Meta-Analysis as Topic; D009203:Myocardial Infarction / Q000139:chemically induced; D020521:Stroke / Q000517:prevention & control
D000319:Adrenergic beta-Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D002121:Calcium Channel Blockers; D004232:Diuretics