Post-Stroke Pneumonia Prevention by Angiotensin-Converting Enzyme Inhibitors: Results of a Meta-analysis of Five Studies in Asians

Abstract

Angiotensin-converting enzyme inhibitors (ACEIs) are reported to reduce the incidence of aspiration pneumonia in hypertensive patients. In this study, a metaanalysis was conducted to obtain statistically more reliable estimates of outcome. The MEDLINE and JMEDICINE databases were searched and the following study selection criteria were applied: (1) comparative controlled studies identified with the following keywords: drug therapy, ACEI, hypertension, swallowing function, dysphagia, stroke, and pneumonia; (2) a minimum follow-up period of 6 months; and (3) a minimum number of patients of more than 100. Patients with hypertension and a history of stroke or transient ischemic attack (TIA) in five controlled studies that reported the incidence of pneumonia were included in the analysis. A total of 8,693 post-stroke patients were given ACEIs with another antihypertensive agent or placebo as a control. In all studies, ACEIs, particularly imidapril, exhibited preventive effects equating to a relative risk that ranged from 0.32 to 0.81 compared with controls. In the combined studies the overall relative risk of ACEI-treated patients versus controls was 0.61 (95% confidence intervals [CI] 0.51-0.75; P < 0.001). Among Asian patients, the relative risk was 0.42 (95% CI 0.32-0.56; P < 0.001). Among Japanese patients, an even greater preventive effect was found for ACEIs versus other antihypertensives (relative risk: 0.38 [95% CI 0.27-0.54; P < 0.001]). ACEIs appear to be more effective than other antihypertensive agents or placebo in reducing pneumonia risk in post-stroke patients, especially in Asian populations.