Left ventricular late gadolinium enhancement – a marker of myocardial fibrosis – occurs commonly and may predict mortality in patients with atrial fibrillation, a prospective observational study has shown.
Of 664 consecutive patients with atrial fibrillation and no known prior myocardial infarction who were referred for radiofrequency ablation of the pulmonary veins between September 2006 and June 2011, 88 (13%) had unanticipated left ventricular late gadolinium enhancement (LV LGE) identified via cardiac magnetic resonance imaging, and 68 died over a median follow-up of 42 months. The mortality rate was 8.1% among those with LV LGE, compared with 2.3% among those without LV LGE, Dr. Thomas G. Neilan of Brigham and Women’s Hospital and Massachusetts General Hospital, Boston, and his colleagues reported online Aug. 28 in the Journal of the American College of Cardiology.
After adjustment for key variables, including sex, diabetes, and heart failure, the presence of LV LGE was significantly linked with mortality. Age and the extent of LGE were the strongest independent predictors of mortality (hazard ratios, 1.05 and 1.15, respectively), the investigators said (J. Am. Coll. Cardiol. 2013 Aug. 28 [doi.org/10.1016/j.jacc.2013.07.067 ]).
The presence of LV LGE provided strong prognostic information, they said, noting that each 1% increase in LGE was associated with a 15% increased risk of death.
The findings were similar when an additional 56 patients with a history of myocardial infarction were included in the analysis, they noted.
Patients in the study had an average age of 56 years. Most (73%) were men.
The pattern of LV LGE was ischemic in 59% and nonischemic in 41%; among those with no history of myocardial infarction, the pattern was ischemic in 50% and nonischemic in 50%.
The findings provide needed information about the presence, pattern, and prognostic significance of left ventricular myocardial fibrosis in patients with atrial fibrillation.
The presence of LV LGE provides "strong and complementary" prognostic information in patients with several conditions, such as congenital heart disease, myocardial infarction, and myocarditis to name a few, but limited data are available regarding the presence and prognostic significance of LV LGE in patients with atrial fibrillation, the investigators said.
The current findings highlight the frequency of LV LGE in this population and its strong association with mortality, and support "the robust and additive prognostic information" provided by cardiac magnetic resonance imaging in patients being referred for pulmonary vein isolation, they concluded, adding that the findings also may support further study in this high-risk cohort.