Evolving Contemporary Management of Atrial Fibrillation in Hypertrophic Cardiomyopathy

Abstract

Atrial fibrillation (AF) is the most common sustained arrhythmia in hypertrophic cardiomyopathy (HCM) with clinical and subclinical episodes occurring in nearly one-half of patients. AF in HCM historically has been characterized as a decisive disease complication associated with substantial risk for thromboembolic stroke and increased morbidity and mortality. However, there have been many advances in treatment strategy resulting in improved outcomes for this patient group. For example, stroke risk in HCM has been greatly reduced by using systemic oral anticoagulation initiated after the first clinical (symptomatic) AF episode, usually with preference given to direct anticoagulants over warfarin. In contrast, stroke risk scoring systems (such as CHA 2 DS 2 -VASc score) are not informative in HCM given the substantial potential for stroke events in patients with low scores, and therefore should not be used for anticoagulation decisions in this disease. A novel risk score specifically designed for HCM (HCM-AF score) can reliably identify most patients with HCM at risk for future AF. Although a strategy focused on controlling ventricular rate is effective in asymptomatic (or minimally symptomatic) patients with AF, restoring and maintaining sinus rhythm is required for most patients with marked AF symptom burden and impaired quality of life. Several antiarrhythmic drugs such as sotalol, disopyramide, and amiodarone, can be effective in suppressing AF episodes; albeit safe, long-term efficacy is supported by only limited data. Catheter AF ablation has emerged as an important treatment option for some patients, although freedom from AF after a single ablation is relatively low (35% at 3 years), multiple ablations and the concomitant use of antiarrhythmic drugs can control AF with more than two-thirds of patients maintaining sinus rhythm at 5 years. Surgical AF ablation with biatrial Cox-Maze IV performed as an adjunctive procedure during myectomy can reduce symptomatic AF episodes (70% of patients free from AF at 5 years). For the vast majority of patients who have HCM with AF, the implementation of contemporary therapies has allowed for improved quality of life and low HCM-related mortality.

Aggressive treatment of atrial fibrillation in hypertrophic cardiomyopathy patients improve quality of life

“…Atrial fibrillation (AF) is the most commonly occurring tachyarrhythmia and often occurs in patients with structural heart disease. Thus, it is not surprising that AF occurs in about 25% of patients with HCM and is likely to occur due to changes in atrial histology including myocyte hypertrophy and disarray, interstitial fibrosis and left atrial dilatation secondary to left ventricular hypertrophy, outflow obstruction, and mitral regurgitation 1,2 . AF can lead to rapid rates, the loss of an atrial contribution to cardiac output and shortening of diastolic filling time that can lead to increased left ventricular filling pressures and significant hemodynamic symptoms and heart failure in HCM patients.…”