Berisso Massimo Zoni, Delfino Luigi, Viani Stefano
Divisione di Cardiologia E.O. Ospedali Galliera Via Volta, 8 16128 Genova.
Ital Heart J Suppl. 2002 Jan;3(1):36-44.
Heart failure is one of the most important public health problems in western countries because of its frequent association with cardiac death and with rehospitalization. Patients with heart failure generally die of sudden arrhythmic death (SD) and progressive pump failure with a SD incidence inversely related to the severity of the underlying heart disease. SD occurs approximately in one half of the patients in New York Heart Association (NYHA) functional classes II-II/III and in one third of those in NYHA classes III/IV-IV, respectively. In the last decade, numerous studies have shown that the automatic implantable cardioverter-defibrillator (ICD) significantly reduces the incidence of SD in those patients who are identified as being at risk. Unfortunately, little is known on whether the ICD actually prolongs the survival of the subgroup of patients with most severe heart failure. The main reasons for such a paucity of information are the small number of available studies, the unavailability of randomized and controlled investigations and the difficulty in comparing the results of such studies owing to the lack of homogeneity. In patients with severe heart failure, both the perioperative mortality and morbidity related to transvenous ICD implantation are similar to those of patient subgroups with moderate or slight heart failure. The defibrillation threshold at implantation and the frequency of intractable ventricular arrhythmias during follow-up (2% of all ICD implantations) are slightly higher than in the patient subgroup with moderate or no heart failure. In the patient subgroup with severe heart failure or with a very poor left ventricular function, ICD implantation is unable to prolong the 1- and 2-year survival despite a clear reduction in the incidence of SD. On the other hand, in the patient subgroup with moderate left ventricular dysfunction, ICD implantation prolongs survival and reduces the incidence of SD. No information is available regarding the primary prevention of SD in patients with heart failure.
心力衰竭是西方国家最重要的公共卫生问题之一，因为它常常与心源性死亡及再次住院相关。心力衰竭患者通常死于心律失常性猝死（SD）和进行性泵衰竭，SD的发生率与潜在心脏病的严重程度呈负相关。在纽约心脏协会（NYHA）心功能II-II/III级的患者中，约有一半发生SD，而在NYHA III/IV-IV级的患者中，这一比例分别为三分之一。在过去十年中，大量研究表明，自动植入式心律转复除颤器（ICD）可显著降低被确定为有风险的患者的SD发生率。不幸的是，关于ICD是否真的能延长最严重心力衰竭患者亚组的生存期，人们知之甚少。信息如此匮乏的主要原因是可用研究数量少、缺乏随机对照研究，以及由于缺乏同质性而难以比较这些研究的结果。在严重心力衰竭患者中，与经静脉植入ICD相关的围手术期死亡率和发病率与中度或轻度心力衰竭患者亚组相似。植入时的除颤阈值和随访期间顽固性室性心律失常的发生率（占所有ICD植入的2%）略高于中度或无心衰的患者亚组。在严重心力衰竭或左心室功能极差的患者亚组中，尽管SD发生率明显降低，但ICD植入并不能延长1年和2年生存率。另一方面，在左心室功能中度不全的患者亚组中，ICD植入可延长生存期并降低SD发生率。关于心力衰竭患者SD的一级预防尚无相关信息。
