A strategy including insertable cardiac monitors (ICM) to guide rhythm control with antiarrhythmic drugs and assessment of atrial fibrillation burden may allow safe discontinuation of oral anticoagulation in atrial fibrillation patients at high risk of bleeding.
Following presentation at the European Society of Cardiology Congress (ESC; 28 August-2 September, London, UK) by Bharat K Kantharia (Cardiovascular and Heart Rhythm Consultants, New York, USA) senior author of the study, it was reported ahead-of-print in Europace.
“Long-term oral anticoagulation in patients with atrial fibrillation who are at risk of bleeding may not be safe. In real-world clinical practice settings, many such patients request and insist on withdrawal of oral anticoagulation and even become non-compliant to treatment.” Therefore, the authors sought to investigate whether a strategy of ICM-guided assessment of atrial fibrillation burden and optimisation of antiarrhythmic drugs to maintain normal sinus rhythm may allow safe withdrawal and obviate long-term use of oral anticoagulation in high-risk patients.
Daniel Mascarenhas (Coventry Cardiology Associates, Easton Hospital, Easton, USA) and others reported that this is the “first clinical study to suggest that an alternative strategy of no anticoagulation in carefully selected patients may work for those at risk for oral anticoagulation or who prefer not to use oral anticoagulants.”
In this longitudinal case-observation study, Mascarenhas implanted ICMs (using two models: Reveal XT and Reveal LINQ from Medtronic) in 70 patients (average age 73.3±11.7 years) with paroxysmal or persistent atrial fibrillation at high risk for stroke (CHADS2 ≥ 2, CHA2DS2-VASc score ≥ 2) and high risk for bleeding (HAS-BLED score ≥ 3), from December 2010 to February 2014, after restoration of normal sinus rhythm.
At index presentation, patients were placed on a novel non-vitamin K oral anticoagulant (NOAC)-dabigatran, rivaroxaban or apixaban-or warfarin and after three weeks on oral anticoagulation, they were started on antiarrhythmic drugs by week four (amiodarone for older patients and flecainide, propafenone, and sotalol for younger patients). After restoring sinus rhythm by cardioversion, ICMs were implanted.
Based on the atrial fibrillation burden data, which was quantified as the percentage of time spent in atrial fibrillation over the follow-up period (23.5±10.5 months), patients were divided into three groups: Group A included normal sinus rhythm patients / low atrial fibrillation burden (N=43), Group B included moderate sinus rhythm / variable atrial fibrillation burden (N=20) and Group C included high atrial fibrillation burden, even beyond 50% (N=7).
Mascarenhas et al highlight that “discontinuation of oral anticoagulation was permitted up on patients’ request and insistence conditionally if the patient maintained normal sinus rhythm and atrial fibrillation burden <1% for at least three consecutive months.” Patients were followed regularly for outcomes including stroke, transient ischaemic attack, bleeding and death that were directly associated with ICM-guided treatment alteration.
The three groups had similar CHADS2, CHA2DS2-VASc and HAS-BLED scores, found the researchers. Oral anticoagulation was discontinued, without adverse events, in 53 (76%) patients (Group A=41 and Group B=12) who maintained normal sinus rhythm and low atrial fibrillation burden.
Mascarenhas et al also reported that severe bleeding occurred in four of 17 (24%) patients who remained on oral anticoagulation. They also said that there were not ICM insertion-related complications including infection or malfunction and no strokes or transient ischaemic attacks occurred during the study follow-up.
The authors highlight that continuous rhythm monitoring with ICM played two critical roles: It allowed titration of antiarrhythmic drugs to achieve normal sinus rhythm or very low atrial fibrillation burden and it objectively identified those patients eligible for oral anticoagulation discontinuation by confirming normal sinus rhythm / low atrial fibrillation burden and conversely, identified those patients ineligible for discontinuation or oral anticoagulation by confirming high atrial fibrillation burden.
The researchers conclude: “Our data from a real-world community practice setting show that in patients with atrial fibrillation and ICM-guided rhythm-control strategy can be successfully applied to allow those at high risk of bleeding the option to safely discontinue anticoagulation.”
They also said that this study represents “a first step in a personalised medicine approach to anticoagulation management.” The results are “highly encouraging” and “form the basis for larger, adequate powered, randomised clinical trials.”