Efficacy of Oral Anticoagulation in Stroke Prevention among Sinus-Rhythm Patients Who Lack Left Atrial Mechanical Contraction after Cryoablation

Abstract

The customary recommendation is that oral anticoagulation be withdrawn a few months after cryoablation for atrial fibrillation, independently of left atrial mechanical contraction in patients in sinus rhythm. Recently, a 5-fold increase in stroke has been described in sinus-rhythm patients who lack atrial mechanical contraction. One aim of this study was to evaluate the efficacy of oral anticoagulation in preventing postoperative stroke in such patients. This prospective study divided 154 sinus-rhythm patients into 2 groups, depending on the presence (108 patients) or absence (46 patients) of left atrial mechanical contraction at 6 months after surgery, and monitored them annually for 5 years. Those without left atrial contraction were maintained on acenocumarol. The primary endpoint was the occurrence of ischemic stroke. The median follow-up period was 29 ± 16 months; 4 patients (2.5%), all belonging to the group with preserved atrial contraction, had ischemic stroke; the group of patients without left atrial contraction had no episodes of stroke during follow-up. Logistic binary regression analyses showed no evidence of factors independently predictive of stroke. Among anticoagulated patients in sinus rhythm without left atrial contraction, we found the incidence of stroke to be zero. In a small, nonrandomized group such as this, we cannot discount the element of chance, yet we suggest that maintaining anticoagulation might lower the incidence of stroke in this population.

Cox maze IV versus left atrial reduction for atrial contraction restoration

“…The decision to discontinue anticoagulant should not be weighed solely on rhythm conversion, but should also take atrial contractility, clinical predictors, and the bleeding risk into consideration. 7,14,20 There were several limitations to our study. As it was a retrospective study, it had an inherent selection bias.…”

“…Limited studies have reported no increased risk of thromboembolic stroke with anticoagulant discontinuation 6 months after a Cox maze in such patients. 14,20 However, there was not enough power to recommend anticoagulant discontinuation due to the nonrandomized, retrospective, observational nature of the studies. The decision to discontinue anticoagulant should not be weighed solely on rhythm conversion, but should also take atrial contractility, clinical predictors, and the bleeding risk into consideration.…”

Amaze: a double-blind, multicentre randomised controlled trial to investigate the clinical effectiveness and cost-effectiveness of adding an ablation device-based maze procedure as an adjunct to routine cardiac surgery for patients with pre-existing atrial fibrillation

“…Some have reported the return of haemodynamically meaningful function, but others have suggested that the maze procedure is unlikely to achieve functional recovery, despite restoring SR. 69 In patients without atrial contraction, anticoagulant drugs significantly reduce stroke rate, but the incidence of major bleeding is increased. 72,73 Furthermore, patients with chronic AF have evidence of persistent left atrial dysfunction, even after restoration of SR by radiofrequency ablation. This suggests that global and regional atrial dysfunction may be attributable to a combination of injury from the ablation process and pre-existing disease.…”

Left atrial mechanical contraction in discontinuation of anticoagulants after surgical ablation of atrial fibrillation: A response letter

“…1 We have read the input with great interest as well as Dr. Martínez-Comendador's publication on left atrial mechanical contraction (LAMC) in the management of anticoagulation therapy post ablation. 2 In our study, anticoagulation therapy was discontinued if (a) sinus rhythm was documented by electrocardiogram, (b) atrial fibrillation was absent on 5-day Holter monitoring, (c) CHADS 2 score less than or equal to 2, and (d) no other indications for anticoagulation therapy were present. The rationale for not including LAMC in our study criteria was simply that LAMC was not established in the context of anticoagulation treatment in the early 2000s, when our first patients were operated.…”