In reply

Abstract

Thank you for the opportunity to respond to the observations and comments submitted by Drs. Goyal and Gupta. The writers of this letter bring out a number of important questions regarding our recently published study, “A Prospective, Randomized Trial of an Emergency Department Observation Unit for Acute Onset Atrial Fibrillation.”1Decker W.W. Smars P.A. Vaidyanathan L. et al.A prospective, randomized trial of an emergency department observation unit for acute onset atrial fibrillation.Ann Emerg Med. 2008; 52: 322-328Abstract Full Text Full Text PDF PubMed Scopus (90) Google Scholar For clarity, we will address the concerns numerically.1Drs. Goyal and Gupta point out that we suggest the study is relevant to the importance of cost-effective management of a fibrillation. However, the length of stay and costs were not specified as primary or secondary outcomes.We are in agreement with the point of the authors. The primary endpoint was conversion to sinus rhythm versus rate control at the completion of the emergency department (ED) observation unit or hospital stay. Secondary endpoints were recurrence of atrial fibrillation and adverse events. As a surrogate to an economic analysis, utilization of health care resources as well as complications were monitored for a 6-month period. Due to the decreased length of stay during the initial ED observation unit arm which did not require a hospital bed, as well as no evidence of increased complication rates or increased outpatient health care utilization rates in the study group versus control, we are confident that the observation unit arm of the study represents a meaningful overall cost savings for the health care system. The amount of the savings will vary depending on health care systems and third-party payers involved with the individual patient with atrial fibrillation. Other studies from our institution that compared ED observation unit versus admission to the hospital and had a more in depth cost analysis showed a remarkable cost saving in favor of ED observation unit admission. This study was designed to overall follow a very similar practice pattern and thus cost savings.2Farkouh M.E. Smars P.A. Reeder G.S. et al.A clinical trial of a chest pain observation unit for patients with unstable angina Chest Pain Evaluation in the Emergency Room (CHEER) Investigators.N Eng J Med. 1998; 339: 1882-1888Crossref PubMed Scopus (461) Google Scholar2A notable difference between the two groups was the use of direct current cardioversion in the ED observation unit (51%) versus in the hospital (23%).The study was not designed nor powered to assess different methods for cardioversion of atrial fibrillation. Electrical cardioversion was chosen in the ED observation unit arm due to the high rate of success in previously published studies,3Page R.L. Kerber R.E. Russell J.K. et al.BiCard InvestigatorsBiphasic versus monophasic shock waveform for conversion of atrial fibrillation: the results of an international randomized, double-blind multicenter trial.J Am Coll Cardiol. 2002; 39: 1956-1963Abstract Full Text Full Text PDF PubMed Scopus (203) Google Scholar as well as the degree of familiarity and comfort with the use of deep sedation and electrical cardioversion in our ED.3Thromboembolism prophylaxis was provided to the inpatient group and not the ED observation unit group. Current Class American Heart Association IIa recommendations are referenced.4Fuster V. Ryden L.E. Cannom D.S. et al.ACC/AHH/ESC 2006 guidelines for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines and the European Society of Cardiology Committee for Practice Guidelines developed in collaboration with the European Hearth Rhythm Association and the he3art Rhythm Society.Circulation. 2006; 114: e257-e354Crossref PubMed Scopus (2006) Google ScholarWe would point out that the study was conceived prior to the current recommendations and an expert panel felt that the study protocol for the ED observation was within standard of care. We do recommend following the current American Heart Association recommendations for those choosing to implement an ED observation unit protocol, including the recommendation to anticoagulate based on the patient's risk of thromboembolism.4The American Heart Association guidelines recommend against anti-rhythmic therapy in patients with brief or minimally symptomatic episodes for recurrences or paroxysmal atrial fibrillation.In our study protocol the patients were observed for a period of 6 to 12 hours prior to decision on cardioversion if they converted spontaneously, electrical cardioversion was not necessary. The RACE5Van Gelder I.C. Hagens V.E. Bosker H.A. et al.A comparison of rate control and rhythm control in patients with recurrent persistent atrial fibrillation.N Eng J Med. 2002; 347: 1834-1840Crossref PubMed Scopus (1977) Google Scholar and AFFIRM6Wyse D.G. Waldo A.L. DiMarco J.P. et al.Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) InvestigatorsA comparison of rate control and rhythm control in patients with atrial fibrillation.N Engl J Med. 2002; 357: 1825-1833Google Scholar trials are cited as evidence of the need for rate over rhythm control. However, as Drs. Goyal and Gupta indicate, the trials were designed to assess chronic atrial fibrillation and not acute or less than 48 hours. Thus, this issue remains unresolved and the current practice at our center and much of the United States is to pursue initial attempts at rate control for new onset or for intermittent (but infrequent) paroxysmal atrial fibrillation.7Raghavan A.V. Decker W.W. Meloy T.D. Management of atrial fibrillation in the emergency department.Emerg Med Clin North Am. 2005; 23: 1127-1139Abstract Full Text Full Text PDF PubMed Scopus (26) Google Scholar5The similar outcomes at six months for the 2 groups may be due to starting anticoagulation at a later stage.The study was not designed to assess this. The impact of decision on anticoagulation were not included in the study design.6An ultimate strategy may be rate control in the ED with initiation of aspirin and Coumadin.While we are in agreement with this comment, we would suggest that before this can be decided, a prospective randomized trial is necessary to evaluate this treatment strategy. Thank you for the opportunity to respond to the observations and comments submitted by Drs. Goyal and Gupta. The writers of this letter bring out a number of important questions regarding our recently published study, “A Prospective, Randomized Trial of an Emergency Department Observation Unit for Acute Onset Atrial Fibrillation.”1Decker W.W. Smars P.A. Vaidyanathan L. et al.A prospective, randomized trial of an emergency department observation unit for acute onset atrial fibrillation.Ann Emerg Med. 2008; 52: 322-328Abstract Full Text Full Text PDF PubMed Scopus (90) Google Scholar For clarity, we will address the concerns numerically. 1Drs. Goyal and Gupta point out that we suggest the study is relevant to the importance of cost-effective management of a fibrillation. However, the length of stay and costs were not specified as primary or secondary outcomes.We are in agreement with the point of the authors. The primary endpoint was conversion to sinus rhythm versus rate control at the completion of the emergency department (ED) observation unit or hospital stay. Secondary endpoints were recurrence of atrial fibrillation and adverse events. As a surrogate to an economic analysis, utilization of health care resources as well as complications were monitored for a 6-month period. Due to the decreased length of stay during the initial ED observation unit arm which did not require a hospital bed, as well as no evidence of increased complication rates or increased outpatient health care utilization rates in the study group versus control, we are confident that the observation unit arm of the study represents a meaningful overall cost savings for the health care system. The amount of the savings will vary depending on health care systems and third-party payers involved with the individual patient with atrial fibrillation. Other studies from our institution that compared ED observation unit versus admission to the hospital and had a more in depth cost analysis showed a remarkable cost saving in favor of ED observation unit admission. This study was designed to overall follow a very similar practice pattern and thus cost savings.2Farkouh M.E. Smars P.A. Reeder G.S. et al.A clinical trial of a chest pain observation unit for patients with unstable angina Chest Pain Evaluation in the Emergency Room (CHEER) Investigators.N Eng J Med. 1998; 339: 1882-1888Crossref PubMed Scopus (461) Google Scholar2A notable difference between the two groups was the use of direct current cardioversion in the ED observation unit (51%) versus in the hospital (23%).The study was not designed nor powered to assess different methods for cardioversion of atrial fibrillation. Electrical cardioversion was chosen in the ED observation unit arm due to the high rate of success in previously published studies,3Page R.L. Kerber R.E. Russell J.K. et al.BiCard InvestigatorsBiphasic versus monophasic shock waveform for conversion of atrial fibrillation: the results of an international randomized, double-blind multicenter trial.J Am Coll Cardiol. 2002; 39: 1956-1963Abstract Full Text Full Text PDF PubMed Scopus (203) Google Scholar as well as the degree of familiarity and comfort with the use of deep sedation and electrical cardioversion in our ED.3Thromboembolism prophylaxis was provided to the inpatient group and not the ED observation unit group. Current Class American Heart Association IIa recommendations are referenced.4Fuster V. Ryden L.E. Cannom D.S. et al.ACC/AHH/ESC 2006 guidelines for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines and the European Society of Cardiology Committee for Practice Guidelines developed in collaboration with the European Hearth Rhythm Association and the he3art Rhythm Society.Circulation. 2006; 114: e257-e354Crossref PubMed Scopus (2006) Google ScholarWe would point out that the study was conceived prior to the current recommendations and an expert panel felt that the study protocol for the ED observation was within standard of care. We do recommend following the current American Heart Association recommendations for those choosing to implement an ED observation unit protocol, including the recommendation to anticoagulate based on the patient's risk of thromboembolism.4The American Heart Association guidelines recommend against anti-rhythmic therapy in patients with brief or minimally symptomatic episodes for recurrences or paroxysmal atrial fibrillation.In our study protocol the patients were observed for a period of 6 to 12 hours prior to decision on cardioversion if they converted spontaneously, electrical cardioversion was not necessary. The RACE5Van Gelder I.C. Hagens V.E. Bosker H.A. et al.A comparison of rate control and rhythm control in patients with recurrent persistent atrial fibrillation.N Eng J Med. 2002; 347: 1834-1840Crossref PubMed Scopus (1977) Google Scholar and AFFIRM6Wyse D.G. Waldo A.L. DiMarco J.P. et al.Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) InvestigatorsA comparison of rate control and rhythm control in patients with atrial fibrillation.N Engl J Med. 2002; 357: 1825-1833Google Scholar trials are cited as evidence of the need for rate over rhythm control. However, as Drs. Goyal and Gupta indicate, the trials were designed to assess chronic atrial fibrillation and not acute or less than 48 hours. Thus, this issue remains unresolved and the current practice at our center and much of the United States is to pursue initial attempts at rate control for new onset or for intermittent (but infrequent) paroxysmal atrial fibrillation.7Raghavan A.V. Decker W.W. Meloy T.D. Management of atrial fibrillation in the emergency department.Emerg Med Clin North Am. 2005; 23: 1127-1139Abstract Full Text Full Text PDF PubMed Scopus (26) Google Scholar5The similar outcomes at six months for the 2 groups may be due to starting anticoagulation at a later stage.The study was not designed to assess this. The impact of decision on anticoagulation were not included in the study design.6An ultimate strategy may be rate control in the ED with initiation of aspirin and Coumadin.While we are in agreement with this comment, we would suggest that before this can be decided, a prospective randomized trial is necessary to evaluate this treatment strategy. A Prospective, Randomized Trial of an Emergency Department Observation Unit for Acute Onset Atrial FibrillationAnnals of Emergency MedicineVol. 52Issue 4PreviewAn emergency department (ED) observation unit protocol for the management of acute onset atrial fibrillation is compared with routine hospital admission and management. Full-Text PDF In Response to “A Prospective, Randomized Trial of an Emergency Department Observation Unit for Acute Onset Atrial Fibrillation”Annals of Emergency MedicineVol. 53Issue 5PreviewThis interesting study compares emergency department (ED) observation unit treatment and inhospital treatment for patients presenting with <48h of atrial fibrillation.1 The authors suggest this study is relevant due to the importance of cost effective management of atrial fibrillation–the groups had similar outcomes except for length of stay, and the assumption is that costs are reduced by shorter stays. However, neither length of stay nor cost were specified as primary or secondary outcomes. The primary endpoint “conversion to sinus rhythm or rate control” is not specifically addressed; the assumption is that all patients were rate-controlled. Full-Text PDF