Cappato R
Second Department of Internal Medicine, St. Georg Hospital, Hamburg, Germany.
Am J Cardiol. 1999 Mar 11;83(5B):68D-73D. doi: 10.1016/s0002-9149(98)01006-6.
Although indisputably effective in the prevention of sudden death, use of implantable cardioverter defibrillator (ICD) therapy may not necessarily affect all-cause mortality, as most patients at risk also present with severely depressed left ventricular dysfunction. Correction of the sudden death risk in these patients creates a new clinical condition in need of a careful assessment. Should all-cause mortality be affected by the expected reduction in sudden death rate associated with ICD therapy, issues of critical importance, such as the time extent of life prolongation and the associated quality of life, still remain to established. To investigate the potential benefit of ICD therapy compared with antiarrhythmic drug treatment, 4 prospective studies--the Dutch trial, the Antiarrhythmics Versus Implantable Defibrillators (AVID) study, the Cardiac Arrest Study Hamburg (CASH), and the Canadian Implantable Defibrillator Study (CIDS)--have been conducted in which patients with documented sustained ventricular arrhythmia were randomized to 1 of these 2 treatment strategies. The enrollment criteria differed in these 4 studies: (1) in the Dutch trial, they included cardiac arrest secondary to a ventricular arrhythmia, old (> 4 weeks) myocardial infarction, and inducible ventricular arrhythmia; (2) in AVID and CIDS, ventricular fibrillation or poorly tolerated ventricular tachycardia; and (3) in CASH, cardiac arrest secondary to a ventricular arrhythmia regardless of the underlying disease. With regard to the antiarrhythmic drugs, the Dutch trial tested class I and III agents, whereas AVID and CIDS compared ICD therapy with class III agents (mostly amiodarone). In CASH, 3 drug subgroups were investigated: propafenone, amiodarone, and metoprolol. All trials used all-cause mortality as the primary endpoint. Data from these trials provide support for ICD as a therapy superior to antiarrhythmic drugs in prolonging survival in patients meeting the entry criteria. This review briefly summarizes the methods, results, limitations, and clinical implications of these 4 studies.
尽管植入式心脏复律除颤器（ICD）疗法在预防猝死方面的有效性无可争议，但它不一定会影响全因死亡率，因为大多数有风险的患者还存在严重的左心室功能不全。纠正这些患者的猝死风险会产生一种需要仔细评估的新临床状况。如果全因死亡率受到与ICD疗法相关的预期猝死率降低的影响，那么诸如生命延长的时间范围和相关生活质量等至关重要的问题仍有待确定。为了研究ICD疗法与抗心律失常药物治疗相比的潜在益处，已经进行了4项前瞻性研究——荷兰试验、抗心律失常药物与植入式除颤器（AVID）研究、汉堡心脏骤停研究（CASH）以及加拿大植入式除颤器研究（CIDS）——在这些研究中，患有持续性室性心律失常的患者被随机分配到这两种治疗策略中的一种。这4项研究的入选标准有所不同：（1）在荷兰试验中，入选标准包括室性心律失常继发的心脏骤停、陈旧性（>4周）心肌梗死以及可诱发的室性心律失常；（2）在AVID和CIDS中，入选标准为心室颤动或耐受性差的室性心动过速；（3）在CASH中，入选标准为室性心律失常继发的心脏骤停，无论潜在疾病如何。关于抗心律失常药物，荷兰试验测试了I类和III类药物，而AVID和CIDS将ICD疗法与III类药物（主要是胺碘酮）进行了比较。在CASH中，研究了3个药物亚组：普罗帕酮、胺碘酮和美托洛尔。所有试验均将全因死亡率作为主要终点。这些试验的数据支持ICD作为一种在延长符合入选标准患者生存期方面优于抗心律失常药物的疗法。本综述简要总结了这4项研究的方法、结果、局限性及临床意义。
