Tom Deering, MD, on Pharmacological Therapies for AFib

Atrial fibrillation (AF) can be managed with or without pharmacological therapy. At the Interpro AFib Forum 2019, Dr Tom Deering spoke about the pharmacological options available for this patient population. Cardiology Consultant caught up with Dr Deering with a few of our burning questions.

Tom Deering, MD, is chief of the Arrhythmia Center, chairman of the Clinical Centers for Excellence, and chief quality officer for Piedmont Heart Institute in Atlanta, Georgia.

CARDIOLOGY CONSULTANT: What pharmacological therapies are currently available for rate and rhythm control? Are any of them contraindicated in certain populations?

Tom Deering: Pharmacological rate control of atrial fibrillation is typically achieved with the use of ß-blockers, non-dihydropyridine calcium channel blockers, and digoxin preparations with ß-blockers serving as the mainstay of therapy. Calcium channel blockers are sometimes used, but caution should be exercised in patients with left ventricular systolic dysfunction. Caution must also be exercised when using digoxin since the parasympathomimetic mechanism of action can be reversed during periods of high adrenergic tone. Amiodarone is used infrequently for rate control. While effective, its side effect profile limits use to acute care patients in whom there are no other options and to chronic patients only as agent of last resort, as is noted in the European Society of Cardiology guidelines.

Certain cautions should be considered when using antiarrhythmic drugs to prevent important drug-related side effects and limit mortality risk. Based on the CAST study, class 1C drugs should be avoided in patients with heart failure and coronary ischemia. Similarly, cautionary steps (eg, in-patient initiation, adjustment or discontinuation based on criteria-defined QT prolongation, avoidance of drugs with potential deleterious interactions) must be exercised when using class 3 drugs because of the risk for torsades de pointes. While amiodarone is the most effective antiarrhythmic drug, because of its high side effect profile, careful analysis of the risk-benefit ratio should be considered before utilization.

For clinicians deciding between a rate or rhythm control approach, the decision-making process pivots upon assessment of the potential benefits and risks associated with each option. While the AFFIRM and RACE trials showed no benefit between the 2 approaches, it is important for clinicians to understand that the patients in both studies typically were older with relatively minimal symptoms. There was also a moderately high cross-over rate and a reasonable prevalence of sinus rhythm in both treatment arms (63% in AFFIRM and 39% in RACE), making it difficult to recommend whether trying to maintain sinus rhythm or aiming to achieve adequate rate control is the best approach. While the mortality rate for patients in AFFIRM taking antiarrhythmic drugs was higher than those not taking those drugs, the mortality rate for patients maintaining sinus rhythm was lower, suggesting that the maintenance of sinus rhythm might have beneficial survival benefits if a safe way of doing such can be pursued.

CARDIO CON: Can you talk about a challenging patient who failed therapy? What did you do for that patient?

TD: Because there is no perfect therapy, even the best care, delivered by dedicated, concerned, and discerning clinicians in concert with committed clinician team members sometimes falls short. Every patient has his/her own intrinsic goals related to his/her underlying situation. Therefore, working with patients as partners in an effective shared decision-making manner is important. In my experience, the most challenging situations manifest when noncompliance, on the part of the patient, or pursuit of therapies, which do not align a patient’s intrinsic values and wishes, by clinicians create untoward outcomes.

CARDIO CON: What role do wearable devices play in managing or controlling rate and rhythm? Does this method reduce clinic visits for patients?

TD: The use of wearable devices to augment arrhythmia outcomes has immense potential. At present, this field is in its infancy. Innovators, entrepreneurs, societies, regulators, and payers need to coordinate efforts to determine how these evolving game-changing technologies can be best used to improve patient outcomes. While existing devices are reasonably accurate, the false-positive rate, particularly among patients with a low arrhythmia risk, is unacceptably high. While this situation might actually increase office visits today, continuing technological enhancements have a distinct potential to reduce clinic visits and more importantly to positively revolutionize how we deliver arrhythmia care to our patients.

CARDIO CON: What is the biggest challenge in managing patients with rate and rhythm control issues?

TD: The main goal of treatment is usually to improve patient quality of life by limiting symptoms related to AF and minimizing complications deriving from AF. Employing medications with minimal or no side effects and, when necessary, performing procedures with a low and acceptable complication rate to maximize outcomes are key. Accordingly, an important challenge is getting physicians to limit their use of medications to patients in whom the benefit outweighs the risk. For example, the high side effect profile associated with amiodarone should minimize its use in younger patients. Similarly, for patients early in the disease process with infrequent and well-tolerated AF episodes, avoiding chronic drug treatment and/or using a pill in the pocket method as necessary should both be strongly considered.

CARDIO CON: What is an Arrhythmia Center of Excellence, and why is it important in today’s world?

TD: The ‘Arrhythmia Center of Excellence’ concept is an evolving consideration, focusing on advancing broad-based individual and population-based arrhythmia patient care processes to achieve consistently better and excellent clinical outcomes. Typically, a center of excellence establishes a multidisciplinary team with a variety of backgrounds and diverse areas of expertise, who work in a coordinated and integrated fashion, establish quality goals, launch programs to manage clinical issues in ways that achieve those quality goals, reduce unnecessary variation, and establish metrics to accomplish all of the above to which they hold themselves individually and collectively accountable.