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Robinson MR, Epstein AE, Callans DJ. Secondary prevention in heart failure. Heart Fail Clin 2011; 7:185-94, vii-viii. [PMID: 21439497 DOI: 10.1016/j.hfc.2010.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Although most recent investigations into sudden cardiac death prevention in heart failure patients have been focused on primary prevention, secondary indications for defibrillators and medical therapy remain vitally important in this complex patient group. Antiarrhythmic therapy is currently used primarily as adjuvant therapy to implantable defibrillators. Secondary prophylaxis defibrillator trials have shown clear benefit in preventing recurrent sudden cardiac death, despite concern over inappropriate shocks and the potential detrimental effects of appropriate shocks. Device programming for secondary prophylaxis can help ameliorate these issues. This article discusses these issues as well as the continued underuse of defibrillators in specific populations.
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Affiliation(s)
- Melissa R Robinson
- Electrophysiology Section, Division of Cardiovascular Medicine, Hospital of the University of Pennsylvania, 9 Founders Pavilion, 3400 Spruce Street, Philadelphia, PA 19104, USA
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Hohnloser SH. Implantable devices versus antiarrhythmic drug therapy in recurrent ventricular tachycardia and ventricular fibrillation. Am J Cardiol 1999; 84:56R-62R. [PMID: 10568661 DOI: 10.1016/s0002-9149(99)00702-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The implantable cardioverter defibrillator (ICD) protects patients from sudden cardiac death due to ventricular tachyarrhythmias. The capability of an improved overall survival of high-risk patients in comparison to the best pharmacologic therapy has been evaluated over the last few years in prospective randomized trials. In patients with a history of resuscitated ventricular fibrillation (VF) or unstable ventricular tachycardia (VT), the ICD was superior to therapy with amiodarone in 3 large trials involving 2,024 patients. At 2-year follow-up, ICD therapy was associated with a relative reduction in the risk of death of 20% to 30%. With respect to primary prevention of arrhythmogenic death, data are less convincing. The Multicenter Automatic Implantable Defibrillator (MADIT) study proved superiority of ICD therapy over medical treatment in coronary patients with depressed left ventricular function, nonsustained VT, and inducible but not suppressible sustained VT/VF. The second trial, the Coronary Artery Bypass Graft (CABG)-Patch trial, failed to show a similar superiority in 900 patients with an ejection fraction of < or = 35% and an abnormal signal-averaged electrocardiograph undergoing coronary artery bypass grafting. Thus, the role of device therapy for primary prevention of sudden death has not been established. Future prospective studies are needed to clarify this issue.
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Affiliation(s)
- S H Hohnloser
- J.W. Goethe University, Department of Internal Medicine, Frankfurt, Germany
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Affiliation(s)
- E Gilbert-Barness
- Department of Pathology, University of South Florida, Tampa General Hospital, P.O. Box 1289, Tampa, FL 33601-1289, USA
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Affiliation(s)
- J R Zaidan
- Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA 30021, USA
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Naccarelli GV, Wolbrette DL, Dell'Orfano JT, Patel HM, Luck JC. A decade of clinical trial developments in postmyocardial infarction, congestive heart failure, and sustained ventricular tachyarrhythmia patients: from CAST to AVID and beyond. Cardiac Arrhythmic Suppression Trial. Antiarrhythmic Versus Implantable Defibrillators. J Cardiovasc Electrophysiol 1998; 9:864-91. [PMID: 9727666 DOI: 10.1111/j.1540-8167.1998.tb00127.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Multiple trials using antiarrhythmic drugs, pharmacologic therapy, and implantable cardioverter defibrillators have been performed in an attempt to improve survival in patients: (1) postmyocardial infarction; (2) with congestive heart failure, with and without nonsustained ventricular tachycardia; and (3) with sustained ventricular tachycardia and those who have survived an out-of-hospital cardiac arrest. This article reviews some of the key findings and limitations of completed and ongoing trials. We also make recommendations for the current treatment of such patients based on the results of these trials.
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Affiliation(s)
- G V Naccarelli
- Section of Cardiology and Cardiovascular Center, Penn State University College of Medicine, Hershey, USA
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Haverkamp W, Eckardt L, Borggrefe M, Breithardt G. Drugs versus devices in controlling ventricular tachycardia, ventricular fibrillation, and recurrent cardiac arrest. Am J Cardiol 1997; 80:67G-73G. [PMID: 9354413 DOI: 10.1016/s0002-9149(97)00715-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Patients with symptomatic ventricular tachycardia, ventricular fibrillation, or aborted sudden cardiac death remain at high risk for arrhythmia recurrence. In recent years, strategies to treat these patients have changed. Concerns about the proarrhythmia risk and uncertain efficacy of class I agents have resulted in a shift in interest to non-class I antiarrhythmic drugs such as sotalol and amiodarone. Both drugs have class III antiarrhythmic properties (i.e., both lengthen repolarization and refractoriness); however, each also has its own additional electrophysiologic effects. Prospectively designed, randomized studies have shown that both sotalol and amiodarone have more potent antiarrhythmic actions than class I agents. However, even as the advantages of sotalol and amiodarone have been recognized, enthusiasm for nonpharmacologic modes of treatment, particularly the implantable cardioverter-defibrillator (ICD), has also markedly increased. The ICD has been shown to decrease dramatically the incidence of sudden death, which may lead to the reduction of total mortality. Whether patients with life-threatening ventricular tachyarrhythmias should be treated first with antiarrhythmic agents or with an ICD is an important question. The results of recent studies suggest that treatment with an ICD is more effective than electrophysiologically guided treatment with class I agents. However, results of prospectively designed randomized studies comparing the efficacy of the ICD with that of sotalol and amiodarone must become available before definitive recommendations can be made concerning the use of the ICD as first-line therapy in patients with ventricular tachycardia/ventricular fibrillation or aborted sudden cardiac death. In addition, there may be a significant role for the use of antiarrhythmic drugs in conjunction with ICDs.
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Affiliation(s)
- W Haverkamp
- Department of Cardiology and Angiology and Institute for Arteriosclerosis Research, WestfâlischeWilhelms-University, Münster, Germany
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Singh BN. Amiodarone: the expanding antiarrhythmic role and how to follow a patient on chronic therapy. Clin Cardiol 1997; 20:608-18. [PMID: 9220176 PMCID: PMC6656071 DOI: 10.1002/clc.4960200706] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/1996] [Accepted: 12/04/1996] [Indexed: 02/04/2023] Open
Abstract
Amiodarone was introduced as an antiarrhythmic compound in the early 1970s and was approved in the U.S. for the treatment of refractory ventricular arrhythmias in late 1984. Since that time the drug has become the most widely studied antiarrhythmic compound with expanding potential indications, including maintaining stability of sinus rhythm, secondary prevention in the survivors of myocardial infarction, and prolongation of survival in certain subsets of patients with congestive heart failure. Intravenous amiodarone was introduced in the U.S. in 1995 for the control of recurrent destabilizing ventricular tachycardia or ventricular fibrillation resistant to conventional therapy. The level of comfort in its use has risen considerably in the recent past. This has stemmed from the reasonably decisive evidence that class I agents increase mortality in patients with structural heart disease. In contrast, amiodarone either reduces mortality or its effect is neutral; this is consistent with its low to negligible proarrhythmic actions. The drug does not aggravate heart failure and it may even increase left ventricular ejection fraction and improve exercise capacity. Above all, it is becoming increasingly evident from wider experience and from controlled clinical trials that the side-effect profile of the drug is not as compelling an issue as it appeared to be when first used in much higher doses. Therefore, the overall objective of amiodarone therapy is to use the lowest dose that produces a defined therapeutic end point without causing serious side effects. Careful clinical surveillance in conjunction with monitoring of certain laboratory parameters and indices of efficacy at regular intervals permits the drug to be used effectively in a large number of patients who fail to respond to, or are intolerant of other antiarrhythmic compounds. Many experienced clinicians have begun to consider the use of amiodarone as first-line therapy in certain disorders of rhythm, especially in patients with severely compromised ventricular function.
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Affiliation(s)
- B N Singh
- Section of Cardiology, VAMC of West Los Angeles, CA 90073, USA
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Affiliation(s)
- P Spirito
- Servizio di Cardiologia, Ospedale Sant'Andrea, La Spezia, Italy
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Nielsen JC, Mortensen PT, Pedersen AK. Long-term follow-up of patients treated with implantable cardioverter defibrillators in a Danish centre. Accurrence ICD therpay and patient survivors. SCAND CARDIOVASC J 1997; 31:151-6. [PMID: 9264163 DOI: 10.3109/14017439709058085] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The aim of the this prospective follow-up study was to evaluate long-term survival and implantable cardioverter-defibrillator (ICD) therapy for ventricular tachyarrhythmias in patients treated with an ICD in a Danish centre. A total of 140 consecutive patients (112 men), of which 70.7% had coronary artery disease, received an ICD at Skejby University Hospital between March 1989 and October 1996. Mean age was 55.6 +/- 14.6 years (range 14-78 years). After implantation, 136 of the patients were followed for a median (range) of 17.7 (0.4-74.1) months. Survival, mode of death and incidence of appropriate ICD therapy and therapy due to potential life-threatening ventricular tachyarrhythmia were the main outcome measures. Kaplan-Meier plots representing total survival, cardiac death, sudden cardiac death and first episode of ICD therapy are presented. After 1, 2, 3 and 4 years, respectively, the cumulative incidences of death were 9, 18, 20 and 24%, of cardiac death 4, 11, 14 and 18%, and of sudden cardiac death 2, 3, 6 and 6%. The cumulative incidences of appropriate therapy after 1, 2, 3 and 4 years were 47, 56, 66 and 80%, respectively. The cumulative incidences of cardiac death after the first episode of appropriate therapy were 9, 11, 15 and 20% after 1, 2, 3 and 4 years, respectively. The occurrence of ICD therapy and patient survival in the present study population treated with ICD at a Danish centre was comparable to results published previously from other larger centres. The rate of sudden cardiac death was low and most of our patients received appropriate ICD therapy during follow-up, indicating correct patient selection and probable benefit of the ICD device.
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Affiliation(s)
- J C Nielsen
- Department of Cardiology, Skejby University Hospital, Aarhus, Denmark
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Singh BN. Amiodarone and Homogeneity of Ventricular Repolarization and Refractoriness. J Cardiovasc Pharmacol Ther 1996; 1:265-270. [PMID: 10684426 DOI: 10.1177/107424849600100401] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- BN Singh
- Division of Cardiology, UCLA School of Medicine, Los Angeles, California, USA
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Abstract
Antiarrhythmic drug therapy is in a state of continuous flux. In the last decade or so, numerous experimental and clinical studies have revealed that drugs that act by delaying conduction, while markedly suppressing ventricular arrhythmias, have the proclivity to increase mortality in subsets of patients with significant cardiac disease. The adverse impact on mortality was confirmed by placebo-controlled randomized trials as well as meta-analysis of smaller randomized clinical trials. The latter indicated that beta blockers exert a beneficial effect on mortality. Benefit from drugs that lengthen repolarization, especially drugs that have the additional property of blocking sympathetic excitation, was also seen in relatively small numbers of patients. Sotalol and amiodarone fell into this category of antiarrhythmic drugs. There were 2 major consequences that stemmed from the results of these trials. First, the endpoint of clinical trials shifted to total mortality from surrogates such as defined degree of suppression of ventricular arrhythmias. Second, concern regarding increases in mortality produced by class I drugs engendered a shift in favor of drugs that prolong repolarization. Such a shift was bolstered by the growing body of data that established the efficacy of sotalol and amiodarone as potent agents for the control of life-threatening ventricular arrhythmias. They were both found to be superior to class I agents. The perception that the critical factor that mediates their efficacy is the homogeneous prolongation of repolarization has led to the synthesis and characterization of so-called pure class III agents, which include d-sotalol and other lKr blockers such as dofetilide, sematilide, E-4031, and almokalant, among numerous others. The increase in mortality produced by d-sotalol in patients with myocardial infarction and lowered ejection fraction and in patients with and without heart failure has led researchers to question how to design future antiarrhythmic molecules. In the search for an ideal antifibrillatory agent, should emphasis be placed on simple molecules such as pure class III agents or on those with more complex profiles, such as sotalol and amiodarone, which exhibit antiadrenergic actions and the ability to prolong cardiac repolarization? The available data are in favor of the latter approach.
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Affiliation(s)
- B N Singh
- Division of Cardiology, Veterans Affairs Medical Center, Los Angeles, California 90073, USA
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Abstract
Amiodarone, a complex compound with variegated electropharmacologic and pharmacokinetic properties and an equally complex side-effect profile, continues to have a critical role in the control of ventricular and supraventricular tachyarrhythmias as the use of class I agents has declined. Such is also the case with sotalol. Unlike other so-called class III agents, amiodarone non-competitively blocks sympathetic stimulation, and its effects on repolarization are not associated with reverse use dependency. Rarely does it produce torsades de pointes despite its propensity to induce significant bradycardia and marked prolongation of the QT interval. During long-term therapy with the drug, there is no impairment of ventricular function; in fact, there are significant increases in the left ventricular ejection fraction during protracted amiodarone therapy in patients with heart failure. Long-term amiodarone administration consistently demonstrates marked efficacy in a wide spectrum of arrhythmias. The major limitation of amiodarone during long-term therapy is its unusual side-effect profile, although the increasing trend for low-dose drug therapy has demonstrated a major decline in the overall incidence of serious adverse reactions. Amiodarone is effective in controlling symptomatic ventricular tachycardia and fibrillation (VT/VF) in > 60-70% of patients when conventional agents (especially class I) are ineffective or not well tolerated. The efficacy of amiodarone compared with that of an implantable cardioverter-defibrillator in patients with VT/VF and in survivors of cardiac arrest remains uncertain when total mortality is used as the primary endpoint of comparison. Amiodarone suppresses ventricular ectopy and markedly suppresses nonsustained VT. It prevents inducible VT/VF in a small number of patients, but slows VT rate in a larger number. The role of the drug in prolonging survival in the postmyocardial infarction patient is unclear, although preliminary data from blinded studies suggest that the drug decreases arrhythmia-related mortality. Similarly, in heart failure, amiodarone has the potential to reduce total mortality but appears to be selectively effective in nonischemic rather than in ischemic cardiomyopathy. Intravenous amiodarone was recently introduced in the United States for the control of recurrent destabilizing VT or VF resistant to conventional therapy. There is also evolving data indicating that the drug might be the most potent agent in maintaining sinus rhythm in patients with atrial fibrillation or flutter converted chemically or electrically to sinus rhythm. However, blinded controlled comparative studies involving sotalol, quinidine, or pure class III drugs have not been carried out. The available data nevertheless suggest that, barring its side-effect profile, amiodarone is a desirable prototype of a broad-spectrum antifibrillatory and antiarrhythmic compound.
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Affiliation(s)
- B N Singh
- Division of Cardiology, University of California, Los Angeles, School of Medicine, USA
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Saksena S, Breithardt G, Dorian P, Greene HL, Madan N, Block M. Nonpharmacological therapy for malignant ventricular arrhythmias: implantable defibrillator trials. Prog Cardiovasc Dis 1996; 38:429-44. [PMID: 8638024 DOI: 10.1016/s0033-0620(96)80007-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Implantable cardioverter-defibrillators (ICDs) are an important nonpharmacological option in the treatment of malignant ventricular arrhythmias. Technological advances in current devices permit nonthoracotomy implantation with transvenous lead systems using biphasic shocks. Decreasing device size has resulted in pectoral implantation. Battery longevity is still short in comparison with that of pacemakers. Lead failure rates as well as pacing thresholds are significantly higher than those for cardiac pacing lead systems. Other complications of ICD systems include infection, perforation, and thrombosis. The long-term performance of nonthoracotomy lead systems for ICD devices has now been extensively studied. Sudden death recurrence rates for these systems are less than 2% in 3 years and less than 5% at 5 years. Clinical trials with both monophasic and biphasic systems show a high degree of prevention of sudden death. Comparison of ICD outcome with that of drug therapy in three large retrospective studies and two small prospective randomized trials favors improved survival and sudden death prevention with device therapy. However, these studies need corroboration from large prospective trials. Two large prospective trials, CIDS and the AVID study, are now in progress to address this issue.
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Affiliation(s)
- S Saksena
- Division of Cardiology, Eastern Heart Institute, Passaic, NJ, USA
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Josephson M, Nisam S. Prospective trials of implantable cardioverter defibrillators versus drugs: are they addressing the right question? Am J Cardiol 1996; 77:859-63. [PMID: 8623740 DOI: 10.1016/s0002-9149(97)89182-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Singh BN. Rise and Fall of Guided Antiarrhythmic Therapy for Ventricular Tachycardia and Fibrillation. J Cardiovasc Pharmacol Ther 1996; 1:89-94. [PMID: 10684404 DOI: 10.1177/107424849600100201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- BN Singh
- Veterans Affairs Medical Center of West Los Angeles, Los Angeles, California, USA
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Ferguson TB, Ferguson CL, Crites K, Crimmins-Reda P. The additional hospital costs generated in the management of complications of pacemaker and defibrillator implantations. J Thorac Cardiovasc Surg 1996; 111:742-51;discussion 751-2. [PMID: 8614134 DOI: 10.1016/s0022-5223(96)70334-3] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The rapid approach of capitated reimbursement mandates that providers examine their practice patterns associated with all surgical procedures. Documentation of (1) the complications associated with these procedures and (2) the additional hospital costs associated with the management of these complications is critical for comprehensive fiscal accountability. This study analyzed (1) the feasibility of obtaining accurate hospital cost data specific for complications and (2) the outcome in terms of fully loaded hospital costs generated in the management of the most common surgical complications associated with pacemaker and nonthoracotomy implantable defibrillator therapies. Between July 1989 and September 1994, a total of 1031 pacemaker and 105 implantable defibrillator procedures were performed by a cardiac surgeon in a tertiary-level teaching hospital setting. The additional fully loaded hospital costs were determined by (1) correlating clinical data from the complete medical record with complete hospital charge data for the admission(s) related to the complication, (2) carving out complication-related charges based on the clinical data, (3) converting complication-related charges to fully loaded costs based on conversion factors in effect at the time of service, and (4) correlating cost with hospital net reimbursement and payor source. The feasibility study determined that accurate and reliable cost data specific to complications can be obtained, although the process was cumbersome and difficult. The outcomes study determined that mean fully loaded complication costs were $4345 +/- $1540 for pacemaker lead revision and $4879 +/- $3167 for implantable defibrillator lead dislodgement, $24,459 +/- $14,585 for pacemaker infection, and $13,736 +/- $12,505 for defibrillator generator system malfunction. The one infected defibrillator cost $57,213 to treat. Costs exceeded reimbursement for almost all Medicare patients with complications in this study, suggesting that similar shortfalls would occur under a capitation scheme. This information is critical to a complete understanding of the financial impact of interventional procedures in a capitated reimbursement environment.
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Affiliation(s)
- T B Ferguson
- Department of Surgery, Washington University School of Medicine, St. Louis, MO, USA
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Singh BN. Antiarrhythmic Therapy of Ventricular Arrhythmias: The Contemporary Dilemma. J Cardiovasc Pharmacol Ther 1996; 1:3-8. [PMID: 10684393 DOI: 10.1177/107424849600100102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- BN Singh
- Department of Cardiology, Veterans Affairs Medical Center of West Los Angeles, Los Angeles, California, USA
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Abstract
The evidence that antiarrhythmic compounds that act by slowing conduction velocity increase mortality in patients with cardiac disease is now compelling. Emphasis is now shifting to agents that act by lengthening repolarization and have additional antiadrenergic properties. There is preliminary evidence that pure Class III agents devoid of antisympathetic activity may also increase rather than decrease mortality in certain patients. Thus, in recent years, sotalol and amiodarone have emerged as the preferred agents for the control of most ventricular arrhythmias occurring in the setting of significant heart disease. Sotalol has not been widely studied in postinfarct patients; one trial indicated that the drug did reduce total mortality but the difference did not reach statistical significance. A number of studies with amiodarone in the postmyocardial infarction patients have revealed benefit, but these were from nonblinded studies. Two blinded, placebo-controlled studies are currently ongoing. A potential new indication of amiodarone is in patients with arrhythmias in heart failure in whom amiodarone markedly increased left ventricular ejection fraction, with a pronounced suppressant effect on premature ventricular complexes and nonsustained ventricular tachycardia and a trend for a decrease in mortality in patients with nonischemic cardiomyopathy. The most promising indication of amiodarone in low doses is in the maintenance of sinus rhythm in patients with atrial flutter and fibrillation. For the present, amiodarone appears to be the best prototype of a desirable complex antiarrhythmic compound, if its variegated side effect profile can be favorably modified from knowledge of structure-activity relationships.
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Affiliation(s)
- B N Singh
- Division of Cardiology, Veterans Affairs Medical Center, Los Angeles, CA 90073, USA
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