Review: Aspirin does not reduce CHD or cancer mortality but increases bleeding
A partir d'une revue de la littérature publiée jusqu'en juin 2011 (9 essais contrôlés ; 102 621 participants ; âge moyen pondéré : 57 ans ; 54 % de femmes), cette étude montre que l'aspirine ne réduit pas le risque de maladie coronarienne ou la mortalité par cancer mais augmente le risque de saignements
QUESTION What are the efficacy and safety of aspirin for primary prevention of vascular and nonvascular outcomes? REVIEW SCOPE Included studies compared aspirin for primary prevention with placebo in>/= 1000 participants without previous coronary heart disease (CHD) or stroke; had>/= 1 year of follow-up; measured CHD or cardiovascular disease (CVD) outcomes (CHD, stroke, cerebrovascular disease, heart failure, or peripheral arterial disease [PAD]) as primary endpoints; and reported bleeding events. Exclusion criteria were mixed primary and secondary prevention and pilot studies. Primary outcomes were total CHD and cancer mortality. Secondary outcomes were nonfatal myocardial infarction (MI), fatal MI, stroke, total CVD events, CVD mortality, and all-cause mortality. Composite safety outcome was nontrivial bleeding (fatal bleeding from any site, cerebrovascular or retinal bleeding, bleeding from hollow viscus, bleeding requiring hospitalization or transfusion, or study-defined major bleeding). REVIEW METHODS PubMed and Cochrane Library (both to Jun 2011) and reference lists were searched for randomized controlled trials (RCTs). Additional data on cancer and nonvascular outcomes were obtained from subsequent trial reports, a recent meta-analysis, and study authors. 9 RCTs (n = 102 621, weighted mean age 57 y, 54% women) met inclusion criteria. 5 RCTs met all 9 quality criteria, 2 did not include intention-to-treat analysis, and 2 did not blind care providers or patients. MAIN RESULTS The main results of the meta-analyses are in the Table. CONCLUSION Aspirin for primary prevention reduces nonfatal myocardial infarction but not total coronary heart disease or cancer mortality; risk for bleeding is increased.Aspirin vs placebo for primary prevention*OutcomesNumber of trials (n)Weighted event ratesAt a mean 6 yAspirinPlaceboRRR (95% CI)NNT (CI)daggerTotal CHD9 (102 621)1.9%2.2%14% (-1 to 26)NSNonfatal MI9 (102 621)1.3%1.7%20% (4 to 33)305 (184 to 1525)Stroke9 (102 621)1.4%1.5%6% (-6 to 16)NSTotal CVD events9 (102 621)3.9%4.3%10% (4 to 14)242 (161 to 607)Cancer mortality8 (98 126)1.5%1.6%7% (-3 to 16)NSAll-cause mortality9 (102 621)3.6%3.8%6% (0 to 12)NSRRI (CI)NNH (CI)daggerNontrivial bleeding9 (100 076)12%9.6%27% (12 to 43)39 (25 to 84)Total bleeding9 (100 076)50%37%35% (10 to 59)8 (5 to 27)CVD mortality9 (102 621)1.2%1.2%1% (-15 to 15)NSFatal MI9 (102 621)0.55%0.52%6% (-17 to 37)NS*CHD = coronary heart disease; CVD = cardiovascular disease; MI = myocardial infarction; NS = not significant; other abbreviations defined in Glossary. RRR, RRI, NNT, NNH, and CI calculated from control event rates and odds ratios in article using a random-effects model.daggerCalculated NNTs and NNHs differ quantitatively, but not in direction, from those reported in the article.