Electrocardiographic subclinical myocardial injury and alcohol consumption: a cross-sectional analysis of data from the Third National Health and Nutrition Examination Survey

Background: Cardiac Infarction/Injury Score (CIIS), an electrocardiographic based scoring system, is a surrogate marker of subclinical myocardial injury (SC-MI) and has shown excellent prognostic value in predicting future cardiovascular mortality. As an association of mild to moderate alcohol consumption with cardiovascular disease (CVD) is conflicting, using an electrocardiographic based scoring system such as CIIS is a simple and cost-effective way to investigate this controversial relationship. Methods: This analysis included 6090 participants (58.42±13.12 years, 54.2% women) free of CVD from the Third National Health and Nutrition Examination Survey (NHANES III). We used multivariable linear regression analysis to examine the cross-sectional association between each alcohol category (non-drinker (reference), 1-6 drinks/week, 7-13 drinks/week, ≥14 drinks/week, and CIIS. SC-MI was defined as CIIS ≥10 units. Results: The prevalence of SC-MI was high among heavy drinkers (≥14 drinks/week) and was lower in participants who were moderate drinkers (7-13 drinks/week). There was a statistically significant and inverse association between moderate alcohol consumption and CIIS (β (95% CI): -0.64 (-1.27, -0.007), P = 0.04) using multivariable linear regression analysis. This inverse association between moderate alcohol consumption and CIIS was more striking among whites compared to non-whites (β (95% CI): -1.06 (-1.93, -0.19) vs. 0.05 (-0.91, 1.00) respectively; interaction p-value = 0.08). Also, the association was stronger among women and older participants, however interaction p-value did not reach statistical significance. Conclusion: There is an inverse association between moderate alcohol consumption and CIIS in participants without manifestations of CVD. As lower CIIS has been associated with low risk of poor outcomes including CVD mortality, these findings further support the existing evidence of the potential benefits of moderate alcohol consumption on cardiovascular health