Background: Habitual moderate alcohol consumption is associated with a lower risk of acute myocardial infarction (MI), whereas heavy (binge) drinking is associated with higher cardiovascular risk. However, less is known about the immediate effects of alcohol consumption on the risk of acute MI and whether any association differs by beverage type or usual drinking patterns.
Methods: We conducted a case-crossover analysis of 3869 participants from the Determinants of Myocardial Infarction Onset Study who were interviewed during hospitalization for acute MI in one of the 64 medical centers across the United States in 1989–1996. We compared the observed number of times that each participant consumed wine, beer, or liquor in the hour preceding MI symptom onset with the expected frequency based on each participant’s control information, defined as the number of times the participant consumed alcohol in the past year.
Results: Among 3869 participants, 211 9 (55%) reported alcohol consumption in the past year, including 76 within 1 hour before acute MI onset. The incidence rate of acute MI onset was elevated 1.72 - fold (95% confidence interval [CI] = 1.37–2.16) within 1 hour after alcohol consumption. The association was stronger for liquor than for beer or wine. The higher rate was not apparent for daily drinkers. For the 24 hours after consumption, there was a 14% lower rate (relative risk = 0.86 [95% CI = 0.79–0.95]) of MI compared with periods with no alcohol consumption.
Conclusions: Alcohol consumption is associated with an acutely higher risk of MI in the subsequent hour among people who do not typically drink alcohol daily.
Comments by Professor R Curtis Ellison The authors’ summary statement is “These results suggest that there is a transiently higher risk of MI onset in the hour after alcohol consumption among people who do not drink alcohol every day, and the elevated risk is higher for liquor than beer or wine.” A case-crossover design is an accepted method for estimating short-term effects (using risk of an event at a particular time after an exposure versus at a similar time when there was not the exposure). It thus uses an individual as his/her own control, and avoids having to adjust for age, sex, risk factors, etc. For total alcohol, there was a significant increase in risk (RR=1.72) in the hour after drinking alcohol. The increase in risk during the first hour was not seen for the 24% of their drinkers who stated that they normally consumed alcohol daily (RR=0.95). For those not drinking daily, the short-term RR was 3.29. In beverage-specific analysis a significant increase in risk of MI was seen only for liquor, but not for beer or wine. The risk returned to baseline by 3 hours after drinking, and the risk during the total 24 hours after drinking was reduced (RR=0.86) for beer and wine drinkers. (The authors state that they cannot explain why the risk was lower over the 24 hours, but state in the discussion: “Alcohol consumption may have hastened the onset of acute MI for people who would have had an MI in a few hours even in the absence of alcohol intake. Therefore, the susceptible pool would be depleted in the 2–24 hours after the hypothesized hazard of 1 hour after alcohol consumption; this may at least partially explain our finding that alcohol intake is associated with lower MI risk within 24 hours. However, it seems likely that briefly advancing the timing of MI onset would have led to a null association by 24 hours rather than resulting in estimates indicative of a protective association. “
The increase in MI risk was greater among subjects who stated that their usual consumption was 2-3 or more than 3 (versus 1-2) per occasion, but specific amounts in the hour related to MI were not known. The risk of MI in the hour after drinking was greater among smokers and those with a previous history of CAD.
In this large study of 3,886 subjects with MI, the authors calculated that approximately 1.5% of the cases were associated with recent alcohol consumption, “suggesting that the acute effects of alcohol consumption on acute MI risk do not have a large public health impact)”. A similar association as that reported in this paper for alcohol has been seen for physical activity, where regular activity blunts an acutely higher risk of MI associated with episodes of strenuous physical activity. The study may help us understand the short-term protective effects of alcohol consumption (especially on coagulation, fibrinolysis, endothelial function.
Source: An increase in the risk of myocardial infarction in the hour following alcohol consumption. Mostofsky E, van der Bom JG, Mukamal KJ, Maclure M, Tofler GH, Muller JE, Mittleman MA. Risk of Myocardial Infarction Immediately After Alcohol Consumption. Epidemiology 2015;26:143-150.