Nitrates for stable angina: a systematic review and meta-analysis of randomized clinical trials.
OBJECTIVE
To assess the effect (harms and benefits) of nitrates for stable angina.


METHODS
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE. Randomized controlled trials with both parallel and crossover design were included. The following outcome measures were evaluated: number of angina attacks weekly and nitroglycerin consumption, quality of life, total exercise duration, time to onset of angina and time to 1 mm ST depression.


RESULTS
Fifty-one trials with 3595 patients meeting inclusion criteria were analyzed. Both intermittent and continuous regimens of nitrates lengthened exercise duration significantly by 31 and 53 s respectively. The number of angina attacks was significantly reduced by 2.89 episodes weekly for continuous administration and 1.5 episodes weekly for intermittent administration. With intermittent administration, increased dose provided with 21 s more length of exercise duration. With continuous administration, exercise duration was pronged more in low-dose group. Quality of life was not improved by continuous application of GTN patches and was similar between continuous and intermittent groups. In addition, 51.6% patients receiving nitrates complained with headache.


CONCLUSIONS
Long-term administration of nitrates was beneficial for angina prophylaxis and improved exercise performance but might be ineffective for improving quality of life. With continuous regimen, low-dose nitrates were more effective than high-dose ones for improving exercise performance. By contrast, with intermittent regimen, high-dose nitrates were more effective. In addition, intermittent administration could bring zero-hour effect.
Wei
Jiafu
J
Department of Cardiovascular Medicine, West China Hospital, Sichuan University, China.
Wu
Taixiang
T
Yang
Qing
Q
Chen
Mao
M
Ni
Juan
J
Huang
Dejia
D
D000787:Angina Pectoris / Q000188:drug therapy* / Q000503:physiopathology; D005080:Exercise Test / Q000187:drug effects / Q000379:methods; D006261:Headache / Q000139:chemically induced; D006801:Humans; D009566:Nitrates / Q000009:adverse effects / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic / Q000379:methods*
D009566:Nitrates