Background: Habitual coffee consumption is protective against coronary heart disease in women; however, it is not clear whether such cardioprotection is conferred on those who have already experienced an acute myocardial infarction (AMI). Our aim was to investigate whether coffee consumption affected mortality after AMI.
Materials and methods: We carried out a dose-response meta-analysis of prospective studies that examined the relationship between coffee intake and mortality after an AMI. Using a defined-search strategy, electronic databases (MEDLINE and Embase) were searched for papers published between 1946 and 2015. Two eligible studies investigating post-AMI mortality risk against coffee consumption were identified and assessed using set criteria. Combined, these studies recruited a total of 3271 patients and 604 died. The hazard ratios for the following experimental groups were defined: light coffee drinkers (1-2 cups/day) versus noncoffee drinkers, heavy coffee drinkers (>2 cups/day) versus noncoffee drinkers and heavy coffee drinkers versus light coffee drinkers.
Results: A statistically significant inverse correlation was observed between coffee drinking and mortality; all three groups showed a significant reduction in risk ratio. Light coffee drinkers versus noncoffee drinkers were associated with a risk ratio of 0.79 [95% confidence interval (CI): 0.66-0.94, P=0.008]; heavy coffee drinkers versus noncoffee drinkers were associated with a risk ratio of 0.54 (95% CI: 0.45-0.65, P<0.00001); and heavy coffee drinkers versus light coffee drinkers were associated with a risk ratio of 0.69 (95% CI: 0.58-0.83, P<0.0001).
Conclusion: Drinking coffee habitually following AMI was associated with a reduced risk of mortality.