Abstract
Background: Atrial flutter (Afltr) and atrial fibrillation (Afib) are the two cardiac arrhythmias most frequently encountered in medical practice. Unlike Afib for which epidemiologic data paved the way for clinical trials that subsequently revolutionized its treatment, little is known about the course of the estimated 200,000 new cases diagnosed with Afltr in the U.S. every year. The purpose of this investigation was to determine whether Afltr is an independent predictor of death.
Methods: Using the Marshfield Epidemiologic Study Area, a database that captures nearly all medical care and deaths among its 58,820 residents, we identified all patients newly diagnosed with Afltr in the region from July 1, 1991, through June 30, 1995. Incident cases were age and gender matched with controls and all were followed prospectively. To minimize the potential contribution of associated comorbidities, the analysis was limited to incident Afltr cases without Afib and adjusted for 11 pre-existing risk factors selected a priori; age, gender, stroke, myocardial infarction, heart failure, hypertension, rheumatic heart disease, hyperlipidemia, chronic pulmonary disease, diabetes mellitus and thyroid abnormality. Multivariate Cox models were fitted to obtain hazard ratios and 95% confidence intervals.
Results: A total of 1356 person-years of follow-up were completed in 76 patients and 76 controls. There were 54 deaths (71%) among Afltr group and 37 deaths (49%) among controls (P=0.0079). After adjustment, the risk of death among incident cases with Afltr was 1.5 times that of controls (Hazard Ratio=1.56; 95% Confidence Interval: 1.01–2.41, P=0.04).
Conclusions:
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Our data suggest that Afltr is an independent predictor of death.
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Since Afltr can now be easily and safely cured in the outpatient setting in virtually all patients, if our findings can be reproduced in other populations, consideration should be given to conducting prospective randomized trials to determine whether eliminating Afltr can improve survival in these individuals.
- Received September 11, 2008.
