Figure 1: Flow diagram of study selection. Calcium Channel Blockers versus Beta-Blockers for Acute Rate Control of Atrial Fibrillation with Rapid Ventricular Response: A Systematic Review Mark Silverberg, Jennifer L. Martindale, Ian S. deSouza, Richard Sinert Department of Emergency Medicine at SUNY Downstate/Kings County Hospital Center, New York, NY BACKGROUND RESULTS The preferred therapeutic approach to most patients with atrial fibrillation and rapid ventricular response in the acute setting is rate control. The risk of thromboembolism is especially relevant to those ED patients for whom the time of onset is unknown, equivocal, or greater than 48 hours prior to presentation. Current guidelines impartially recommend beta blockers and calcium channel blockers as agents for rate control. The available evidence comparing nodal agents treatment for stable, atrial fibrillation with rapid ventricular response is extremely limited. The relative risk of rate control by diltiazem versus metoprolol was 1.13 (95% CI 0.86-1.46). None of the patients converted to sinus rhythm by the end of the study period. Figure 1: Flow diagram of study selection. . None of the patients in either group had hypotension or bradycardia. Titles and Abstracts Screened PubMed (191) and EMBASE (883) After duplicates removed N=1,003 Cochrane library (0) Additional studies from references (0) A major methodologic issue in this study was lack of a pre-determined sample size. The quality of evidence, according to GRADE criteria is low ++. Most studies were excluded because they evaluated long term outcomes of rate control, compared rhythm control to rate control, or evaluated rate control in the post-operative patient. Excluded by relevance: 996 OBJECTIVE Table 2. GRADE Evidence Profile. GRADE Criteria Quality Assessment Study Limitations No serious limitations Inconsitency N/A Indirectness of Evidence Serious limitation (lack of external validity) Imprecision Serious limitation (small sample size) Publication Bias To perform a systematic review of the literature for evidence comparing the efficacy of calcium channel blockers with beta-blockers for acute rate control of atrial fibrillation with rapid ventricular response. Abstract only: 4 Full-Text Review: N=3 METHODS PubMed, EMBASE, and the Cochrane Registry for trials from 1965 through November 2013 were screened using MeSH terms “calcium channel blockers”, “adrenergic beta-antagonist,” “atrial fibrillation,” and “heart rate.” Studies with evidence that addressed the following clinical question in PICO format were included: Patients: Adults (>18 years) in the acute care setting with rapid ventricular response to atrial fibrillation Intervention: Intravenous calcium channel blocker Comparator: Intravenous beta-blocker Outcome: Reduction in ventricular rate or conversion to sinus rhythm Relative risk was calculated using Review Manager (RevMan V.5.15.1. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2011.) Methodological quality of included studies was evaluated based on CONSORT guidelines and GRADE criteria. Insufficient Data: 2 Abbreviation: GRADE, Grading of Recommendations Assessment, Development, and Evaluation. Selected Studies: N=1 LIMITATIONS The one prospective, randomized study that addresses this clinical question is based on A small, arbitrarily determined sample size of select emergency department patients, and flawed statistical analysis. A single prospective, double blind, randomized study of 40 patients met our inclusion criteria and provided sufficient data. Table 1: Results of the Reviewed Study, Demircan, et al.* Group n Success Rate (%) Recalculated with 95% CI Adverse Effects Diltiazem (0.25 mg/kg, maximum 25 mg) 20 16 (80%) 68.9-98.4% Metoprolol (0.15 mg/kg, maximum 20 mg) 18 (90%) 57.6-92.5% CONCLUSIONS Based on the limited available evidence, preference for beta-adrenergic antagonists or calcium-channel blockers may be at the discretion of the emergency medicine provider for acute rate control of stable atrial fibrillation with rapid ventricular response. High-quality, randomized controlled trials comparing both AV-nodal blockers are needed. Demerican C, Cikriklar HI, Engindeniz Z et al. Comparison of the effectiveness of intravenous diltiazem and metoprolol in the management of rapid ventricular rate in atrial fibrillation. Emerg Med J. 2005; 22(6):411-4.