Potymorphism modulates symptomatic response to antiarrhythmic drug therapy in patients with lone atrial fibrillation

BACKGROUND The angiotensin-converting enzyme (ACE) deletion allele, ACE D, is associated with increased ACE activity and adverse outcomes in cardiovascular disease. Although activation of the renin-angiotensin-aldosterone system (RAAS) now appears to play a rote in the pathophysiology of atrial fibrillation (AF), it remains to be determined if ACE genotype impacts response to conventional AAD therapy in patients with AF. OBJECTIVES The purpose of this study was to investigate whether response to antiarrhythmic drug (AAD) therapy in patients with AF is modulated by the ACE I/D polymorphism. METHODS We studied 213 patients (147 men, 66 women; ages 52 +/- 15 years) prospectively enrolled in the Vanderbilt AF Registry. AAD therapy outcome was defined prospectively as response if there was a >= 75% reduction in symptomatic AF burden or nonresponse if AF burden was unchanged, necessitating a change in drugs or therapy. RESULTS Lone AF (age <65 years, no identifiable cause) was present in 72 (34%) patients, whereas hypertension was the most common underlying disease in the remaining 141 (41%). AF was paroxysmal in 170 (80%) and persistent in 43 (20%). The frequencies of the DD, ID, and II genotypes were in Hardy-Weinberg equilibrium. Lone AF and DD/ID genotypes were highly significant predictors of failure of drug therapy (P < .005). In patients with lone AF, failure of drug response was 5%, 41%, and 47% in patients with 11, ID, and DD genotypes, respectively, (P < .005, Il vs. ID/DD). CONCLUSIONS These results provide further evidence for a rote of RAAS activation in the pathophysiology of AF and point to a potential role for stratification of therapeutic approaches by ACE genotype.