The Journal of Emergency Medicine, Vol. 49, No. 2, pp. 175–182, 2015 Copyright Ó 2015 Elsevier Inc. Printed in the USA. All rights reserved 0736-4679/$ - see front matter http://dx.doi.org/10.1016/j.jemermed.2015.01.014 Pharmacology in Emergency Medicine DILTIAZEM VS. METOPROLOL IN THE MANAGEMENT OF ATRIAL FIBRILLATION OR FLUTTER WITH RAPID VENTRICULAR RATE IN THE EMERGENCY DEPARTMENT Christian Fromm, MD, FAAEM, FACEP,* Salvador J. Suau, MD, FACEP,* Victor Cohen, PHARMD,*† Antonios Likourezos, MA, MPH,* Samantha Jellinek-Cohen, PHARMD,* Jonathan Rose, MD, FACEP,* and John Marshall, MD, FACEP* *Department of Emergency Medicine, Maimonides Medical Center, Brooklyn, New York and †Arnold & Marie College of Pharmacy and Allied Health Sciences, Brooklyn, New York Reprint Address: Christian Fromm, MD, FAAEM, FACEP, Department of Emergency Medicine, Maimonides Medical Center, 4802 Tenth Avenue, Brooklyn, NY 12219 , Abstract—Background: Diltiazem (calcium channel heart rate (HR) of <100 beats per minute (bpm) (p <0.005). blocker) and metoprolol (beta-blocker) are both commonly By 30 min, 95.8% of the diltiazem group and 46.4% of the me- used to treat atrial fibrillation/flutter (AFF) in the emergency toprolol group reached the target HR < 100 bpm (p < 0.0001). department (ED). However, there is considerable regional Mean decrease in HR for the diltiazem group was more rapid variability in emergency physician practice patterns and and substantial than that of the metoprolol group. From a debate among physicians as to which agent is more effective. safety perspective, there was no difference between the To date, only one small prospective, randomized trial has groups with respect to hypotension (systolic blood compared the effectiveness of diltiazem and metoprolol for pressure < 90 mm Hg) and bradycardia (HR < 60 bpm). rate control of AFF in the ED and concluded no difference Conclusions: Diltiazem was more effective in achieving rate in effectiveness between the two agents. Objective: Our aim controlinEDpatientswithAFFanddidsowithnoincreased was to compare the effectiveness of diltiazem with metoprolol incidence of adverse effects. Ó 2015 Elsevier Inc. for rate control of AFF in the ED. Methods: A convenience sample of adult patients presenting with rapid atrial fibrilla- , Keywords—diltiazem; metoprolol; atrial fibrillation; tion or flutter was randomly assigned to receive either diltia- atrial flutter; rate control zem or metoprolol. The study team monitored each subject’s systolic and diastolic blood pressures and heart rates for 30 min. Results: In the first 5 min, 50.0% of the diltiazem INTRODUCTION group and 10.7% of the metoprolol group reached the target Acute atrial fibrillation is the most common sustained, clinically significant dysrhythmia encountered in the Presented at the Society for Academic Emergency Medicine, emergency department (ED), and the most common Boston, MA, June 2011 and New York ACEP Scientific Assem- dysrhythmia treated by emergency physicians. Atrial bly, Bolton Landing, NY, July 2014. fibrillation accounts for approximately 1% of all ED Samantha Jellinek-Cohen’s current affiliations are St. John’s visits, and nearly 65% of patients presenting to the ED University, College of Pharmacy and Allied Health Professions, Jamaica, NY and Emergency Medicine, Beth Israel Medical with atrial fibrillation are admitted to the hospital (1,2). Center-Petrie Division, New York, New York. In addition, the aging general population has increased Jonathan Rose’s current affiliation is Emergency Medicine, the number of visits to the ED of patients with atrial Brookdale Medical Center, Brooklyn, NY. fibrillation by 66% in the last 20 years (3,4). RECEIVED: 29 August 2014; FINAL SUBMISSION RECEIVED: 7 January 2015; ACCEPTED: 11 January 2015 175 Downloaded for Anonymous User (n/a) at Washington University in Saint Louis Bernard Becker Medical Library from ClinicalKey.com by Elsevier on August 31, 2020. For personal use only. No other uses without permission. Copyright ©2020. Elsevier Inc. All rights reserved. 176 C. Fromm et al. Atrial flutter is less common than atrial fibrillation, but study is registered with clinicaltrials.gov, ID#: its management in the ED is very similar, and the majority NCT01914926. The study was done and is reported ac- of patients with atrial flutter also have atrial fibrillation. cording to the CONSORT (Consolidated Standards of Symptomatic relief and ventricular rate control are gener- Reporting Trials) Group (11). ally the primary therapeutic objectives in the ED manage- ment of acute atrial fibrillation and flutter (AFF). Study Setting and Selection of Participants Conversion to sinus rhythm in the ED is considerably less important, and may be undesirable before initiation This study was set in the adult ED at an urban teaching of anticoagulation. The majority of patients with AFF hospital with an annual ED census of >120,000 patients. and rapid ventricular rate do not require immediate elec- A convenience sample of adult patients aged 18 years or trical cardioversion, which is generally reserved for pa- older presenting with atrial fibrillation or atrial flutter tients with significant hemodynamic compromise, were evaluated for enrollment. Eligible patients had a although recent data advocate its use earlier in therapy 12-lead electrocardiogram (ECG) showing atrial fibrilla- (5). However, if a sustained rapid rate is allowed to persist tion or atrial flutter with a ventricular rate of $120 beats for hours, tachycardia-induced left ventricular dysfunc- per minute (bpm) and a systolic blood pressure (SBP) of tion can result. The need for swift, appropriate action $90 mm Hg. by the emergency physician is highlighted by the fact Patients were excluded if they had any of the that up to 18% of patients with AFF develop potentially following: SBP < 90 mm Hg, ventricular rate $ 220 life-threatening complications, such as congestive heart bpm, QRS > 0.100 s, second- or third-degree atrioventric- failure, hypotension, ventricular ectopy, respiratory fail- ular (AV) block, temperature > 38.0C, acute ST eleva- ure, angina, and myocardial infarction (6,7). tion myocardial infarction, known history of New York Both beta-blocking agents and calcium channel Heart Association Class IV heart failure or active blockers are commonly used to treat AFF in the ED. wheezing with a history of bronchial asthma or chronic Metoprolol is the most commonly used beta-blocker; and obstructive pulmonary disease (COPD). In addition, diltiazem is the most frequently used calcium channel patients were excluded if there was prehospital adminis- antagonist (8). Diltiazem was released by the United States tration of diltiazem or any other AV nodal blockading Food and Drug Administration for treatment of AFF in agent, a history of cocaine or methamphetamine use in 1992. Schreck et al. were the first to demonstrate both the 24 hours before arrival, a history of allergic reaction the efficacy of diltiazem in the ED management of AFF to diltiazem or metoprolol, a history of sick sinus or with rapid rate and its clear superiority over the previously pre-excitation syndrome, a history of anemia with hemo- most commonly used pharmacologic agent, digoxin (9). globin < 11.0 g/dL, pregnancy, or breastfeeding. To date, only one prospective, randomized trial has compared the effectiveness of a calcium channel blocker Interventions (diltiazem) with a beta-blocker (metoprolol) for rate con- trol of AFF in the ED (10). Despite the relatively small After a patient was identified as fulfilling inclusion and sample size (n = 20 in each group), the authors concluded exclusion criteria and informed consent and HIPAA that both pharmacologic agents were similarly effective. authorization were obtained, data were collected prospec- In order to test this finding, we conducted a prospective tively. These data included demographics, medical comparison of metoprolol and diltiazem for the manage- history, vital signs, and ECG findings. All patients were ment of patients presenting to the ED with AFF with rapid immediately evaluated by the treating physician utilizing ventricular rate. Advanced Cardiovascular Life Support (ACLS) proto- cols. At the discretion of the treating physician, intrave- nous adenosine was administered in order to facilitate MATERIALS AND METHODS identification of the underlying supraventricular tachy- Study Design dysrhythmia. All patients were attached to a monitor that displays cardiac rhythm, heart rate (HR), blood We conducted a prospective, randomized, double-blind pressure, and oxygen saturation. study to compare the effectiveness of intravenous meto- Upon enrollment, patients were randomly assigned, in prolol with that of diltiazem in achieving rate control in a 1:1 ratio, to receive diltiazem administered parenterally adult ED patients with rapid AFF. Approval of the study at a dose of 0.25 mg/kg (to a maximum dose of 30 mg) or was obtained from our hospital’s Institutional Review metoprolol administered at a dose of 0.15 mg/kg (to a Board. All enrolled patients provided written informed maximum dose of 10 mg). Randomization was performed consent and Health Insurance Portability and Account- through the use of a computer-generated randomization ability Act (HIPAA) authorization documentation. The by one of the investigators (AL) and was given to the Downloaded for Anonymous User (n/a) at Washington University in Saint Louis Bernard Becker Medical Library from ClinicalKey.com by Elsevier on August 31, 2020. For personal use only. No other uses without permission.