[In-hospital mortality and early preinfarction angina: a meta-analysis of published studies].

INTRODUCTION AND OBJECTIVES The occurrence of preinfarction angina (PA) reduces the extent of myocardial necrosis, increases the volume of viable myocardium, and improves left ventricular function. However, there is no agreement about the effect of PA on mortality. The objective of this study was to determine whether PA is associated with in-hospital mortality. METHOD A meta-analysis (fixed effects model) of all published reports evaluating in-hospital mortality in patients with acute myocardial infarction according to the presence or absence of PA was performed. PA was defined as the occurrence of angina in the 24 hours before onset of the infarction. We searched the Medline and Embase databases in June 2004 using <> as search terms. Six studies involving a total of 3497 patients were finally identified. RESULTS Only one study reported that PA had a statistically significant beneficial effect on in-hospital mortality. However, combining the data showed that the presence of PA was associated with a significant decrease in the probability of in-hospital death (odds ratio=0.61; 95% CI: 0.48-0.78; P<.0001. We did not detect any significant heterogeneity between the studies (chi2=5.92; P=.31). CONCLUSIONS The occurrence of preinfarction angina in the 24 hours before the onset of myocardial infarction was associated with a significant reduction in in-hospital mortality of 39%.