Antiarrhythmic drug therapy for atrial fibrillation: Are the guidelines guiding clinical practice?

The AFFIRM study showed no clear survival advantage for a rhythm versus rate control strategy in patients with atrial fibrillation (AF). However, rhythm control with antiarrhythmic drugs (AADs) is appropriate in a large number of patients with AF. The American College of Cardiology/ American Heart Association/European Society of Cardiology AF management guidelines include a safety-based algorithm for selection of AAD therapy. Class 1C agents are recommended as first-line therapy in patients without or with minimal structural heart disease. However, market research and clinical study data indicate a growing use of class III agents (mainly amiodarone) despite long-term safety and tolerability concerns, suggesting that clinical practice does not adhere to current guidelines.     

Is left atrial appendage occlusion useful for prevention of stroke or embolism in atrial fibrillation?

Since in atrial fibrillation more than 90% of the thrombi are located in the left atrial appendage, an "elimination" of the left atrial appendage, either by resection or occlusion, seems an attractive alternative to oral anticoagulation. Although frequently regarded as an useless appendage, data from animal and human investigations show that the left atrial appendage may play an important role in the maintenance and regulation of the cardiac function, especially in arterial hypertension, atrial fibrillation, coronary heart disease, valvular heart disease and heart failure. Elimination of the left atrial appendage may impede thirst in hypovolemia, deteriorate hemodynamic responses to volume or pressure overload, decrease cardiac output and promote heart failure. Instead of preventing stroke, the consequences of left atrial appendage elimination may create new risk factors for stroke and thus might induce more harm than benefit to patients with atrial fibrillation. As long as the physiologic and pathophysiologic role of the left atrial appendage is not fully understood, left atrial appendage elimination should not be an alternative to oral anticoagulation.     

Have sanctioned algorithms replaced empiric judgment in the selection process of antiarrhythmic drugs for the therapy for atrial fibrillation?

Treatment of atrial fibrillation (AF) includes rate control, anticoagulation, rhythm control, and therapy of any underlying structural heart disease and/or AF precipitant. Rhythm control, restoration of and maintenance of sinus rhythm (NSR), is required in patients who remain significantly symptomatic despite rate control. Rhythm control generally employs antiarrhythmic drugs (AAD). When the selection of AADs was limited, and included only class IA agents, the choice of drug to use was empiric, guided by anticipated tolerance and compliance. Now, with multiple classes of AADs available and with a better understanding of organ toxic and proarrhythmic risks, algorithms to guide drug selection have become both popularized and sanctioned. Notably, although such algorithms are now the standard of care and the norms to which practitioners should be held regarding the selection of an AAD for AF management, they have not removed empiricism and clinical judgment from the AAD selection process. Clinical decision making is still required to select from among any group of drug options as listed in the published algorithms, and to select the dosing regimen to use. Prior history, dosing frequency, desirability of à-blocking effect, electrolyte status, renal function, concomitant therapies, site of initiation, and anticipated patient compliance are also all nonalgorithmic issues in the decision process.     

Very long-term outcomes after a single catheter ablation procedure for the treatment of atrial fibrillation—the protective role of antiarrhythmic drug therapy

Background

Pulmonary vein isolation (PVI) is the cornerstone of AF ablation, but its long-term clinical outcomes, predictors of relapse, and optimal pharmacological treatment remain controversial.

Objective

The objectives of this paper were to (1) assess very long-term AF recurrence, (2) identify predictors of relapse, and (3) evaluate the impact of continued antiarrhythmic drug (AAD) treatment after ablation.

Methods

Multicenter observational registry including all consecutive patients with drug-resistant AF who underwent a first PVI between 2006 and 2008 (n?=?253 (age 55 years (IQR 48–63)), 80% males, 64% with paroxysmal AF. Endpoint was AF/AT/AFL relapse after a 3-month blanking period. Predictors and protective factors of AF relapse were assessed with multivariate Cox regression.

Results

A total of 144 patients (57%) relapsed over a median 5-year (IQR 2–9) follow-up—annual relapse rate of 10%/year. Female sex (aHR 1.526, 95% CI 1.037–2.246, P?=?0.032), non-paroxysmal AF (aHR 1.410, 95% CI 1.000–1.987, P?=?0.050), and LA volume/BSA (aHR 1.012, 95% CI 1.003–1.021, P?=?0.008) were identified as independent predictors of relapse. A total of 139 patients (55%) continued AAD (55% on amiodarone) after blanking period. One-year overall PVI success rate of patients under AAD was 86 vs 76% with no AAD (P?<?0.001)—annual relapse rates were 8%/year vs 14%/year (P?<?0.001), respectively. AAD was associated with a long-term reduction in AF relapse (aHR 0.673, 95% CI 0.509–0.904 P?=?0.004).

Conclusion

Half the patients remained free from AF 5 years after a single procedure. Female sex, non-paroxysmal AF, and LA volume/BSA independently predicted recurrence, whereas continuing AAD after the 3-month blanking period reduced relapse.

Condensed abstract

In a multicenter registry of AF patients undergoing a first PVI, 57% relapsed over a median 5-year follow-up. Female sex, non-paroxysmal AF and LA volume/BSA were identified as independent predictors of relapse. Maintaining AAD therapy after the blanking period was associated with a long-term reduction in AF relapse.