The effect of transdermal nitroglycerin on exercise tolerance in relation to patch application time—a meta-analysis

摘要

Disagreeing results have been reported in the many studies on continuous treatment with nitroglycerin patches. The effects on exercise tolerance are partly studied at the end of a 24-hour application period, and partly examined only a few hours after patch renewal. The present meta-analysis estimates the overall efficacy of nitroglycerin patches in trials with and without concomitant antianginal therapy, and investigates if the treatment effect depends on the patch application time. A computed search (MEDLINE) identified 110 publications, of which 17 trials on nitrate patch monotherapy and six trials on combined therapy satisfied the inclusion criteria. Data on ‘exercise duration’ and ‘ST-segment depression’ were converted to a standardized treatment effect size d, and pooled to an overall treatment effect size d+. In tests 2–5 hours after patch renewal, moderate but significant effects of nitrate monotherapy were observed; d+ was 1.20 with regard to ‘ST-segment depression’ and 0.39 with regard to ‘exercise duration’ (both p<0.0001). In contrast, 24 hours after patch application, the values for d+ were 0.09 (not significant) and 0.36 (p<0.01), respectively. When adding the results from the six trials on combined therapy, d+ with regard to ‘exercise duration’ was reduced to 0.28 (p<0.0001) 2–5 hours after renewal and to 0.17 (p=0.04) after 24 hours. Thus, the efficacy of continuous nitroglycerin patch treatment is moderate but evident during exercise tests 2–5 hours after patch renewal; however, it is reduced after 24 h