Higher alcohol intake in young adults related to long-term adverse cardiac remodeling
Association Between Alcohol Intake and Cardiac RemodelingLiterature - Rodrigues P, Santos-Ribeiro S, Teodoro T et al. - JACC 2018; published online ahead of print, DOI: 10.1016/j.jacc.2018.07.050
Introduction and methods
Alcohol abuse is a known risk factor for alcoholic cardiomyopathy. Alcohol intake is shown to be associated with subtle echocardiographic changes in cardiac morphology and systolic/diastolic function, mostly in cross-sectional or short follow-up studies in middle-aged and older individuals [1,2]. However, the long-term effect of alcohol consumption in young adults on cardiac remodeling remains unknown and information about the impact of other patient characteristics or the pattern of alcohol consumption regarding the threshold level of being injurious seems to be controversial. Therefore, this study aimed to assess the potential cardiotoxic role of alcohol in cardiac structure and function in the long-term in young adults into middle age, with a focus on specific types of alcoholic beverages.
The Coronary Artery Risk Development in Young Adults (CARDIA) cohort study recruited 5,115 individuals aged 18-30 years who have been followed for >30 years and have undergone a series of questionnaires and examinations on alcohol consumption, with year 5 as baseline period (because it was the first year ECG evaluations were performed). Individuals with known heart disease or a left ventricular ejection fraction (LVEF) <55% at baseline, or with insufficient information about the echocardiographic outcomes or alcohol habits were excluded, leaving a study sample of 2,368 participants.
Self-reported data on past drinking habits and the number of drinks of wine, beer and liquor typically consumed per week were obtained from a questionnaire filled in at years 5, 15 and 25. Alcohol intake was categorized by calculated average alcohol consumption per week: no alcohol consumption, average consumption (>0 and <4 drinks), ≥4 and <7 drinks, ≥7 and <14 drinks, and ≥14 drinks per week. Cumulative alcohol intake during 20 years of follow-up was calculated, based on reported alcohol intake and total time interval.
The primary endpoint was LVEF and secondary endpoints were body surface area (BSA)-indexed left ventricular end-diastolic volume (LVEDV), BSA-indexed left ventricular (LV) mass and left atrial (LA) diameter. These endpoints were assessed by transthoracic echocardiography.
- The majority of subjects did not consume alcohol (n=619) or drank <4 (n=934) standard drinks per week. The average daily ethanol intake was 10 mL, and only 8.0% (n=192) of the subjects were “at risk” drinkers with >14 drinks per week. The estimated mean cumulative alcohol intake was 82 ± 130 L over 20 years (mean of 13 drink-years).
LVEF, LVEDV, LV mass and LA diameter
- Increasing alcohol intake resulted in a progressive and statistically significant non-linear increase in BSA-indexed LVEDV, which remained statistically significant after adjustment (53.1 ± 10.7 ml/m2 in non-drinkers vs. 58.8 ± 14.8 ml/m2 if >14 drinks/week; P=0.037).
- A significant and linear association was observed between alcohol intake and BSA-indexed LV mass (LV mass of 81.2 ± 20.9 g/m2 in nondrinkers vs. 92.4 ± 19.6 g/m2 if >14 drinks/week; P=0.014), which remained after adjustment.
Effect modification of sex and race
- There was no significant difference between women and men or white and black participants regarding the relationship between cumulative alcohol consumption and echocardiographic parameters.
- After multivariable adjustment, a non-linear association between alcohol and LA diameter was observed in women (P=0.018) and an independent non-linear association between LA diameter and alcohol in black participants (P=0.007).
- Variation in LVEDV in men (P=0.029), and LA diameter in women (P=0.007) and in African American participants (P=0.028) showed an independent linear association with average cumulative alcohol consumption.
Type of beverage and binge drinking
- Drinking wine or liquor was associated with smaller BSA-indexed LVEDV (P=0.001 for both), after adjustment for cumulative alcohol intake and covariates related to the type of predominant beverage taken.
- Drinking predominantly wine was also associated with higher LVEF (P=0.007), lower BSA-indexed LV mass (P=0.001) and lower LA diameter (P=0.019) as compared to beer or liquor.
- Binge-drinking was associated with echocardiographic parameters of cardiac remodeling, however, after adjustment for covariates, binge-drinking was only associated with higher LA diameter (P=0.050).
Greater alcohol intake in young adults had an independent adverse association with ventricular structure after 20 years of follow-up, which was not significantly modified by sex or race. Alcohol intake was also associated with LA diameter in women and among African American young adults, but it was not associated with LVEF in young adults with mild-to-moderate alcohol consumption. Binge-drinking had a non-significantly deleterious effect on cardiac remodeling and predominantly drinking wine was associated with less cardiac remodeling.
In their editorial comment , Fauchier et al. note that the results of Rodrigues et al. reinforce the opinion that mild alcohol consumption is not associated with a major CV risk in healthy subjects and these data suggest that drinking predominantly wine may be associated with less deleterious effects in cardiac structure. However, they also mention the main limitations of the current study, which are: the lack of information on genetic factors that may play a role in alcoholic cardiomyopathy, analysis on intraindividual association of alcohol intake and echocardiographic measures at each point for years 5, 15 and 25 since drinking habits can vary over 20 years, but also a variation analysis on binge-drinking since alcohol abstinence is associated with improved prognosis in patients with alcoholic cardiomyopathy. The authors conclude: ‘There are still considerable knowledge gaps about how alcohol in combination with other factors may affect incidence of alcoholic cardiomyopathy and prognosis in HF patients. Both observational real-life analyses and interventional trials are still needed to improve the clinical management in these patients’.