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

Area of Science:

• Cardiology
• Pharmacology

Background:

• Continuous nitroglycerin patch therapy is used for angina, but study results vary.
• Previous research has not consistently evaluated efficacy based on patch application timing.

Purpose of the Study:

• To meta-analyze the efficacy of nitroglycerin patches for angina.
• To assess if treatment effects differ based on patch application time (2-5 hours vs. 24 hours).
• To evaluate efficacy in monotherapy and combined antianginal therapy trials.

Main Methods:

• A systematic literature search of MEDLINE identified relevant trials.
• Included 17 monotherapy and 6 combined therapy trials.
• Standardized treatment effect sizes (d) for exercise duration and ST-segment depression were calculated and pooled.

Main Results:

• Nitrate monotherapy showed significant effects 2-5 hours post-renewal (d+ for ST depression=1.20, exercise duration=0.39).
• After 24 hours, monotherapy effects were less significant (d+ for ST depression=0.09, exercise duration=0.36).
• Combined therapy reduced exercise duration benefits (d+ 0.28 at 2-5 hours, 0.17 at 24 hours).

Conclusions:

• Nitroglycerin patches offer moderate, evident efficacy 2-5 hours after application.
• Efficacy is reduced at 24 hours post-application.
• Concomitant antianginal therapy may moderate the benefits of nitroglycerin patches.