Abstract
BackgroundClass 1C antiarrhythmic drugs (AADs) are effective first‐line agents for atrial fibrillation (AF) treatment. However, these agents commonly are avoided in patients with known coronary artery disease (CAD), due to known increased risk in the postmyocardial infarction population. Whether 1C AADs are safe in patients with CAD but without clinical ischemia or infarct is unknown. Reduced coronary flow capacity (CFC) on positron emission tomography (PET) reliably identifies myocardial regions supplied by vessels with CAD causing flow limitation.ObjectiveTo assess whether treatment with 1C AADs increases mortality in patients without known CAD but with CFC indicating significantly reduced coronary blood flow.MethodsIn this pilot study, we compared patients with AF and left ventricular ejection fraction ≥50% who were treated with 1C AADs to age‐matched AF patients without 1C AAD treatment. No patient had clinically evident CAD (ie, reversible perfusion defect, known ≥70% epicardial lesion, percutaneous coronary intervention, coronary artery bypass grafting, or myocardial infarction). All patients had PET‐based quantification of stress myocardial blood flow and CFC. Death was assessed by clinical follow‐up and social security death index search.ResultsA total of 78 patients with 1C AAD exposure were matched to 78 controls. Over a mean follow‐up of 2.0 years, the groups had similar survival (P = .54). Among patients with CFC indicating the presence of occult CAD (ie, reduced CFC involving ≥50% of myocardium), 1C‐treated patients had survival similar to (P = .44) those not treated with 1C agents.ConclusionsIn a limited population of AF patients with preserved left ventricle function and PET‐CFC indicating occult CAD, treatment with 1C AADs appears not to increase mortality. A larger study would be required to confidently assess the safety of these drugs in this context.
Highlights
Atrial fibrillation (AF) is the most common abnormal heart rhythm in the United States, with a prevalence of approximately 6.1 million people.[1]
A relative perfusion abnormality indicating overt coronary artery disease (CAD) was defined as a contiguous defect in greater than 10% of the left ventricle (LV) myocardium with activity less than 60% of maximum at rest, or a contiguous defect in greater than 5% of LV myocardium with activity less than 60% of maximum at stress
One patient had started taking the 1C drug before undergoing positron emission tomography (PET) stress (2 weeks prior). These patients were compared to the age‐matched control group of 78 patients with atrial fibrillation (AF) with no 1C antiarrhythmic drug (AAD) exposure
Summary
Atrial fibrillation (AF) is the most common abnormal heart rhythm in the United States, with a prevalence of approximately 6.1 million people.[1]. Due to an extension of the CAST results, which were reported three decades ago, many clinicians still commonly avoid AF treatment with 1C agents in patients with any known coronary artery disease (CAD), due to perceived increased risk.[5]. Whether the existence of CAD but without infarction or clinically evident ischemia truly increases the risk of 1C AAD use is unknown. Class 1C antiarrhythmic drugs (AADs) are effective first‐line agents for atrial fibrillation (AF) treatment. These agents commonly are avoided in patients with known coronary artery disease (CAD), due to known increased risk in the postmyocardial infarction population. Objective: To assess whether treatment with 1C AADs increases mortality in patients without known CAD but with CFC indicating significantly reduced coronary blood flow. A larger study would be required to confidently assess the safety of these drugs in this context
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
