First Study to Document the Pathology and Characteristics That Affect all Atrial Branches in New-Onset Atrial Fibrillation

FOR IMMEDIATE RELEASE
Contact: Kennesha Baldwin
Heart Rhythm Society
(202) 464-3476
kbaldwin@HRSonline.org

WASHINGTON, July 13, 2011 — Results from a case control study show that coronary artery disease affecting the atrial branches is an independent predictor for new-onset atrial fibrillation (AF) after acute myocardial infarction (MI), or heart attack. The study, published in the July edition of HeartRhythm, the official journal of the Heart Rhythm Society, evaluated the characteristics associated with the development of new-onset AF in a cohort of consecutive patients with acute MI. The study also considered the impact of the potential role of factors such as age, presences of left ventricular (LV) dysfunction, and left atrial (LA) enlargement and found that atrial branch disease was an independent risk of developing AF after MI. View the full study.

The study consisted of 2,460 consecutive patients with acute MI presented to a single university hospital between 2004 and 2009. Of the 2,460 patients who were admitted with MI during the study period, 149 (6 percent) developed AF within the first week. In total, 42 cases were identified as subjects who developed new-onset AF during the first week post-MI. The control group consisted of 42 MI patients without AF who were matched to cases for age, sex and left ventricle (LV) ejection fraction from the same cohort of patients and had undergone both coronary angiography and echocardiography.

Results showed that patients with new-onset AF had a higher proportion of inferior MI, more than 85 percent. In multivariate analysis, right coronary atrial branch disease (66.7 percent) and left circumflex atrial branch disease (59.5 percent) were predictors of new-onset AF during the first week post-MI, after adjustments. In addition, right coronary artery disease was a characteristic of more than 71 percent of new-onset AF patients. Overall, observation from the case control study reveals coronary artery disease affecting the atrial branches is a predictor for the development of AF early after MI.

"With the angiographic data and echocardiographic findings, our results provide novel insight into the mechanisms underlying the development of AF in patients after they experience a heart attack," stated senior author Prashanthan Sanders, MBBS, Ph.D., at the Royal Adelaide Hospital in Australia. "The findings shed new light on how coronary disease affects the atrial branches after the trauma of a heart attack regardless of measurable effects such as a patient's gender or age."

Previous studies have shown inconsistent and conflicting data regarding associations in MI and new-onset AF. The study determined coronary artery disease affecting the atrial branches to be a predictor of new-onset AF independent of measurable effects of age, gender, LV ejection fraction and several other factors.

For more information about this study, please visit www.heartrhythmjournal.com.

About HeartRhythm JournalAs the official journal of the Heart Rhythm Society, HeartRhythm publishes both basic and clinical subject matter of scientific excellence devoted to the EP of the heart and blood vessels, as well as therapy. The journal is the only EP publication serving the entire electrophysiology community from basic to clinical academic researchers, private practitioners, technicians, industry and trainees. HeartRhythm Journal has an impact factor of 4.559 (as of 2010) and ranks 11th out of 78 cardiovascular medicine journals worldwide by the Institute for Scientific Information, remaining the number one specialty journal in cardiology. It is also the official publication of the Cardiac Electrophysiology Society.