Abstract 1896: Cardiac Resynchronization In Patients With Atrial Fibrillation: A Meta-analysis Of Prospective Cohort Studies
Background: Although close to one-third of patients with advanced heart failure exhibit atrial fibrillation (AF), there is a paucity of data regarding the impact of cardiac resynchronization therapy (CRT) in these patients. The objective of this study was to determine the impact of CRT in patients with AF compared to patients in sinus rhythm (SR).
Methods: This is a meta-analysis of prospective cohort studies comparing the effect of CRT in patients in normal SR versus chronic AF. Studies reported death, NYHA Class, ejection fraction, 6-minute walk test, and Minnesota score or its equivalent as outcomes. Of the 2487 potentially relevant reports identified, 5 studies following a total of 1164 patients were included. Data sources included: Ovid MEDLINE (1950 to May 2007), Ovid MEDLINE In-Process & Other Non-Indexed Citations, the Cochrane Central Register of Controlled Trials (Second Quarter, 2007), the Database of Abstracts of Reviews of Effects (Second Quarter, 2007), the ACP Journal Club (1991 to May/June 2007), and the Cumulative Index to Nursing & Allied Health Literature (CINAHL).
Results: Mortality was not significantly different for patients in AF versus SR (pooled-odds ratio [OR] 1.19, 95% confidence interval [CI]: 0.70 to 2.03). The NYHA class at end of study was similar for patients in AF and SR, though there was slightly greater improvement in NYHA class for patients in SR (0.06 additional improvement in NYHA class, 95% CI: 0.04 to 0.08). While both groups benefited from CRT in regards to quality of life measures, patients in SR showed greater improvements in 6-minute walk test (38 feet greater, 95% CI 34 to 42 feet) and Minnesota heart failure score (3.9 points less, 95% CI 3.4 to 4.5 points) when compared to patients in AF. Improvement in ejection fraction, however, revealed a small but statistically significant greater change for patients in AF (0.36% more than patients in SR, 95% CI 0.15 to 0.52%).
Conclusion: Patients in atrial fibrillation treated by CRT exhibit evidence of similar or improved ejection fraction as compared to sinus rhythm patients, but demonstrate lesser functional benefit, as measured by NYHA class, 6-minute walk test and Minnesota score. There was no significant difference in mortality between the two groups.