Prevalence and Prognostic Significance of Left Ventricular Dysfunction in Patients Presenting Acutely with Atrial Fibrillation

Abstract

The prevalence and prognostic importance of CM occurring as a consequence of AF is poorly defined. This study investigated the incidence of CM in patients with AF, its clinical features and long-term outcomes. We demonstrated that CM is common in patients presenting acutely with newly diagnosed rapid AF, and carries a worse long-term prognosis. Systolic dysfunction was reversible in an important proportion of patients, suggesting a greater prevalence of rate-related CM in AF than has previously been postulated. This underscores the importance of appropriate rhythm management strategies and repeat imaging studies. Background Atrial fibrillation (AF) may precipitate LV dysfunction, potentially leading to cardiomyopathy (CM). The prevalence and prognostic importance of CM occurring as a consequence of AF is poorly defined. We investigated the incidence of CM in patients with AF, its clinical features and long-term outcomes. Methods We reviewed 292 consecutive patients (average age 72 ± 13yrs) presenting acutely with AF and tachycardia over a 3 year period from June 2004. Clinical details were obtained from medical records. CM was defined as ejection fraction (EF) ≤ 50% on index admission. Results Echo was performed 93% of patients at index admission, and 69 (24%) had CM (average EF% = 37 ± 11), 60 of which were newly diagnosed. Patients with CM had significantly higher presenting heart rate (141 ± 19 vs. 132 ± 23 bpm), larger end-diastolic (5.7 vs. 5.2 cm) and end-systolic (4.5 vs. 3.2 cm) dimensions, and larger left atrial size (4.6 vs. 4.3 cm) ( P < 0.05 for all). They were also statistically more likely ( P < 0.05) to be male, present with breathlessness, have a history of coronary disease, and be treated with digoxin and warfarin. Follow-up echo between 6 and 12 months was performed in 46% of patients with new CM, and average EF rose to 53 ± 12%. At an average follow-up of 2.5 years, there was a significant increase in mortality in CM patients (16% vs. 9.5%, P < 0.05). Conclusion CM is common in patients presenting acutely with newly diagnosed rapid AF, and carries a worse long-term prognosis. Systolic dysfunction was reversible in an important proportion of patients, suggesting a greater prevalence of rate-related CM in AF than has previously been postulated. This underscores the importance of appropriate rhythm management strategies and repeat imaging studies.