Background: Despite advances in pharmacologic therapies and ablation techniques, elective cardioversions (CV) remain integral to the care of patients with atrial fibrillation (AF). These outpatient procedures require appropriate patient preparation to maintain patient safety and maximize success rates. These preparations include confirming adequate anticoagulation and pre-CV heart rhythm recording. Despite these preparations, unexpected cancellations of CV occur and lead to patient dissatisfaction and lost productivity. The objective of this study was to examine the frequency and cause of unexpected CV cancellations in a large volume center and to assess how novel technologies may improve efficiency in the future.
Methods: Patients with AF who presented for scheduled elective CV were screened consecutively for enrollment. All patients were contacted the day before CV to confirm adequate anticoagulation and to provide instructions regarding fasting and the use of medications the morning of the planned CV. Information regarding the patients’ anticoagulation strategies and history were recorded at the time of enrollment. INR levels were obtained using routine serum and point of care testing. Statistical analysis was performed to evaluate trends in cancelled CV, potential impacts on the EP lab and to assess the ability of mobile technology to improve the CV process.
Results: Two hundred patients were enrolled (Age 68 ± 12). Anticoagulation strategies varied in this group and included apixaban (N=90), warfarin (N=73), rivaroxaban (N=35) and dabigatran (N=2). Three patients required unplanned transesophageal echocardiogram. Thirty-two patients presented for CV but had their procedure cancelled due to a subtherapeutic INR (N=5), supratherapeutic INR (N=2), being in normal sinus rhythm (N=14), thrombus present on TEE (N=5) and intolerance of the TEE (N=2). CV was successful in 96% of patients (N=192). Point of care testing (POCT) and standard serum measurements were strongly correlated (r=0.961, p<0.001) although POCT INR testing results were, on average, 0.2 higher than standard serum measurements (95% CI [0.15-0.25]).
Conclusions: A shocking percentage of CV are cancelled unexpectedly highlighting an opportunity to improve efficiency and productivity in the EP lab. The cancellations appear to be driven by inadequate anticoagulation and patients unexpectedly arriving in normal sinus rhythm. Technology providing remote assessment of both of these clinical variables is already commercially available. This remote monitoring of heart rhythm and INR may provide opportunities to reduce cancellations, improve patient satisfaction and boost EP lab productivity.