Secondary Atrial Fibrillation and Outcomes | Journal Scan

Study Questions:

How do patients with atrial fibrillation (AF) related to a secondary cause fare as compared to those without AF?

Methods:

Among 1,409 participants (mean age, 74 years; 48% women) in the Framingham Heart Study with newly diagnosed AF, those with a secondary cause of AF were identified. Secondary causes included surgery (cardiothoracic or non-cardiothoracic), infection, acute myocardial infarction, alcohol intoxication, thyrotoxicosis, pericardial disease, and pulmonary disease. The incidences of AF recurrence, heart failure, stroke, and death were determined. Patients with permanent AF and those who died within 30 days of the original AF diagnosis were excluded.

Results:

AF was attributed to a secondary cause in 439 patients (31%). The secondary cause was cardiothoracic surgery in 131 (30%), infection in 102 (23%), non-cardiothoracic surgery in 87 (20%), myocardial infarction in 78 (18%), and other causes in the remaining. The median follow-up was 5.4 years. The risk of recurrent AF at long-term follow-up was lower in patients with a secondary cause (62%) versus those without (71%). However, the risk of stroke and death was similar in patients with and without a secondary cause.

Conclusions:

AF recurs in most patients after the initial episode during long-term follow-up. Although patients with a secondary cause are less likely to experience recurrent AF, almost two-thirds of the patients develop AF during follow-up. The risk of stroke and death is similar among patients with and without a secondary cause of AF.

Perspective:

Evidence of atrial structural remodeling—thought to be important in arrhythmia maintenance—is evident in patients with AF even in the absence of advanced age and other comorbidities (i.e., idiopathic AF). The results of this study imply that patients with AF due to a secondary or reversible cause also harbor these changes since the majority develop AF during long-term follow-up. Antiarrhythmic and anticoagulant therapies are typically discontinued after the precipitant has resolved. However, the study further suggests that risk of AF recurrence and stroke may be ongoing even after the secondary cause has been addressed. Randomized studies are needed to determine how to manage these patients especially with respect to anticoagulation.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Heart Failure and Cardiomyopathies, Prevention, Anticoagulation Management and Atrial Fibrillation, Atrial Fibrillation/Supraventricular Arrhythmias, Acute Heart Failure

Keywords: Atrial Fibrillation, Anticoagulants, Comorbidity, Heart Failure, Incidence, Mortality, Myocardial Infarction, Risk Factors, Secondary Prevention, Stroke, Thoracic Surgery, Thyrotoxicosis


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