My patient with atrial fibrillation (AF) with a CHA2DS2-VASc score ≥2 is not a candidate for anticoagulation due to excessive bleeding risk. Does high-dose aspirin provide an effective alternative for stroke prevention in this setting?

 The SPAF (Stroke Prevention in Atrial Fibrillation) trial1 found a 42% reduction in overall risk of stroke with daily aspirin (325 mg). However, critics note that no benefit was observed among patients > 75 y or those with severe stroke.

7 other studies on the topic failed to confirm reduction in the risk of stroke at a range of aspirin doses (25mg bid-1,300mg qd) 2. These studies reported that aspirin is associated with a 19% reduction in stroke incidence (similar to patients with vascular disease), with a 95% CI that crosses zero (-1% to 35%), raising doubts about its actual benefit in AF3. For secondary prevention, aspirin was associated with a 2.5% reduction in the annual risk of stroke. However, these results were influenced by the only trial with a favorable outcome, SPAF-14.

In short, even at higher doses, aspirin may not be the answer for stroke prevention in patients with AF.

 References

  1. Stroke Prevention in Atrial Fibrillation Study. Final results. Circulation 1991;84, 527–39.
  2. January CT, Wann LS, Alpert  JS, et al. 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society. Circulation  2014;130, e199–e267.
  3. European Heart Rhythm Association et al. Guidelines for the management of atrial fibrillation: the Task Force for the Management of Atrial Fibrillation of the European Society of Cardiology (ESC). Europace  2010; 12, 1360–420.
  4. Sabir IN, Matthews GDK,  Huang, CL-H. Antithrombotic therapy in atrial fibrillation: aspirin is rarely the right choice. Postgrad Med J 2013; 89, 346–51.

 

Contributed by Jacqueline Boehme, M.D., Medical Resident, Mass General Hospital

My patient with atrial fibrillation (AF) with a CHA2DS2-VASc score ≥2 is not a candidate for anticoagulation due to excessive bleeding risk. Does high-dose aspirin provide an effective alternative for stroke prevention in this setting?

Does electroconvulsive therapy (ECT) pose a risk of embolic stroke in patients with atrial fibrillation (AF)?

Acute embolic stroke in the setting of AF without anticoagulation after ECT has been reported in a single case report in the absence of conversion to normal sinus rhythm (1). Several cases of episodic or persistent conversion to normal sinus rhythm (NSR) in patients with AF undergoing ECT have also been reported (in the absence of embolic stroke), leading some to recommend anticoagulation therapy in such patients (2), though no firm data exist.

The mechanism by which ECT promotes cardioversion from AF to NSR is unclear as direct electrical influence of ECT on the heart is thought to be negligible (1). Arrhythmias such as atrial flutter and AF have also been reported after ECT (1). Curiously, ECT is associated with increased 5- hydroxytryptamine (5- HT2)-receptor densities of platelets in patients with depression which may enhance platelet reactivity and increase the risk of embolic stroke (3) even in the absence of cardioversion.

 

References

  1. Suzuki H, Takano T, Tominaga M, et al. Acute embolic stroke in a patient with atrial fibrillation after electroconvulsive therapy. J Cardiol Cases 2010; e12-e14.
  2. Petrides G, Fink M. Atrial fibrillation, anticoagulation, electroconvulsive therapy. Convulsive Therapy 1996;12:91-98.
  3. Stain-Malmgren R, Tham A, Ǻberg-Wistedt A. Increased platelet 5-HT2 receptor binding after electroconvulsive therapy in depression. J ECT 1998;14:15-24.
Does electroconvulsive therapy (ECT) pose a risk of embolic stroke in patients with atrial fibrillation (AF)?