Prognostic Importance of Atrial Fibrillation and Anticoagulation in Alcoholic Versus Dilated Cardiomyopathy

Alcoholic cardiomyopathy: an update

Alcohol-induced cardiomyopathy (AC) is an acquired form of dilated cardiomyopathy (DCM) caused by prolonged and heavy alcohol intake in the absence of other causes. The amount of alcohol required to produce AC is generally considered as >80 g/day over 5 years, but there is still some controversy regarding this definition. This review on AC focuses on pathogenesis, which involves different mechanisms. Firstly, the direct toxic effect of ethanol promotes oxidative stress in the myocardium and activation of the renin-angiotensin system. Moreover, acetaldehyde, the best-studied metabolite of alcohol, can contribute to myocardial damage impairing actin-myosin interaction and producing mitochondrial dysfunction. Genetic factors are also involved in the pathogenesis of AC, with DCM-causing genetic variants in patients with AC, especially titin-truncating variants. These findings support a double-hit hypothesis in AC, combining genetics and environmental factors. The synergistic effect of alcohol with concomitant conditions such as hypertension or liver cirrhosis can be another contributing factor leading to AC. There are no specific cardiac signs and symptoms in AC as compared with other forms of DCM. However, natural history of AC differs from DCM and relies directly on alcohol withdrawal, as left ventricular ejection fraction recovery in abstainers is associated with an excellent prognosis. Thus, abstinence from alcohol is the most crucial step in treating AC, and specific therapies are available for this purpose. Otherwise, AC should be treated according to current guidelines of heart failure with reduced ejection fraction. Targeted therapies based on AC pathogenesis are currently being developed and could potentially improve AC treatment in the future.

Clinical Trajectories and Long-Term Outcomes of Alcoholic Versus Other Forms of Dilated Cardiomyopathy

BACKGROUND

Alcoholic cardiomyopathy (ACM) is a form of dilated cardiomyopathy (DCM) occurring secondary to long-standing heavy alcohol use and is associated with poor outcomes, but the cause-specific risks are insufficiently understood.

METHOD

Between 1997 and 2018, we identified all patients with a first diagnosis of ACM or DCM. The cumulative incidence of different causes of hospitalisation and mortality in the two groups was calculated using the Fine-Gray and Kaplan-Meier methods.

RESULTS

A Total of 1,237 patients with ACM (mean age 56.3±10.1 years, 89% men) and 17,211 individuals with DCM (mean age 63.6±13.8 years, 71% men) were identified. Diabetes (10% vs 15%), hypertension (22% vs 31%), and stroke (8% vs 10%) were less common in ACM than DCM, whereas obstructive lung disease (15% vs 12%) and liver disease (17% vs 2%) were more prevalent (p<0.05). Cumulative 5-year mortality was 49% in ACM vs 33% in DCM, p<0.0001, multivariable adjusted hazards ratio 2.11 (95% confidence interval 1.97-2.26). The distribution of causes of death was similar in ACM and DCM, with the predominance of cardiovascular causes in both groups (42% in ACM vs 44% in DCM). 5-year cumulative incidence of heart failure hospitalisations (48% vs 54%) and any somatic cause (59% vs 65%) were also similar in ACM vs DCM. At 1 year, the use of beta blockers (55% vs 80%) and implantable cardioverter defibrillators (3% vs 14%) were significantly less often used in ACM vs DCM.

CONCLUSIONS

Patients with ACM had similar cardiovascular risks and hospitalisation patterns as other forms of DCM, but lower use of guideline-directed cardiovascular therapies and greater mortality.