DERIVATION AND VALIDATION OF THE CONTINUE-ONE-TWO-HOLD PROTOCOL FOR OPTIMIZING PERI-CARDIOVERSION RATE CONTROL MEDICATIONS

Abstract

Most patients with atrial fibrillation (AF) are prescribed rate control medications . There are no guidelines for adjustment of these medications prior to electrical cardioversion (DCCV). We sought to derive and validate a pre-procedural medication adjustment protocol that maintains peri-cardioversion rate control and avoids bradycardia, conversion pauses, need for pacing, and CPR after DCCV. Retrospectively derived and prospectively validated an algorithm in patients undergoing DCCV at our multidisciplinary AF clinic. Each patient taking an AV nodal blocker was given adjustment instructions based on their ECG heart rate two days before DCCV. Medication dosages were standardized based on dose equivalency tables (Table 1). The magnitude of dosage reduction was compared with peri-cardioversion heart rates, where rate control was considered adequate if the 30-minute pre-DCCV and five-minute post-DCCV heart rates were both within 50 to 100 bpm. In the derivation cohort, we assessed the effectiveness of all medication adjustment strategies and evaluated which strategy was effective for the highest proportion of patients from 2015 to 2017. This strategy was then prospectively evaluated as a protocol in the validation cohort for one year onwards. Patients with atrial flutter or pacemaker were excluded. A total of 71 patients were included in the derivation cohort (mean age 65.5 ± 10.3 years; 73% male). The strategy with the highest proportion of patients achieving adequate peri-cardioversion rate control was i) CONTINUE AV nodal blocker when two-day pre-DCCV heart rate ≥100 bpm, ii) reduce dose by ONE increment when 80 to 99 bpm, iii) reduce dose by TWO increments when 60 to 79 bpm, and iv) HOLD when <60 bpm. When this CONTINUE-ONE-TWO-HOLD protocol (Figure 1) was evaluated in the validation cohort of 48 consecutive patients (mean age 63.1 ± 10.1 years; 77% male), 37 (77%) patients achieved adequate peri-cardioversion rate control. Proportion of patients with post-procedural bradycardia was significantly reduced from 69% to 48% between cohorts (P=0.02). Of the 11 inadequate cases, four patients had pre-DCCV heart rates >100 bpm and 2 had post-DCCV heart rates <50 bpm, but these patients were already experiencing tachycardia and bradycardia respectively before medication adjustment. There were no conversion pauses ≥five seconds, need for pacing, or CPR post-procedure in patients following the CONTINUE-ONE-TWO-HOLD protocol in either cohort. The CONTINUE-ONE-TWO-HOLD protocol is a feasible and effective pre-procedural strategy of optimizing medications for peri-cardioversion rate control in patients with AF.View Large Image Figure ViewerDownload Hi-res image Download (PPT)