Wilber David J, Zareba Wojciech, Hall W Jackson, Brown Mary W, Lin Albert C, Andrews Mark L, Burke Martin, Moss Arthur J
Cardiovascular Institute, Loyola University Medical Center, Maywood, Ill 60153, USA.
Circulation. 2004 Mar 9;109(9):1082-4. doi: 10.1161/01.CIR.0000121328.12536.07. Epub 2004 Mar 1.
Prophylactic implantable defibrillators (ICDs) improve survival in patients with impaired ventricular function after myocardial infarction (MI), but it is uncertain whether mortality risk and survival benefit depend on the elapsed time from MI.
The Multicenter Automatic Defibrillator Implantation Trial II examined the impact of ICDs on survival in post-MI patients with ejection fractions < or =30%. In 1159 patients, mean time from most recent MI to enrollment was 81+/-78 months. Patients were randomized to an ICD (n=699) or conventional care (n=460) in a 3:2 ratio. Mortality rates (deaths per 100 person-years of follow-up) in both treatment groups were analyzed by time from MI divided into quartiles (<18, 18 to 59, 60 to 119, and > or =120 months). In conventional care patients, these rates increased as time from MI increased (7.8%, 8.4%, 11.6%, 14.0%; P=0.03). Mortality rates in ICD patients were consistently lower in each quartile and showed minimal increase over time (7.2%, 4.9%, 8.2%, 9.0%; P=0.19). Covariate-adjusted hazard ratios for risk of death associated with ICD therapy were 0.97 (95% CI, 0.51 to 1.81; P=0.92) for recent MI (<18 months) and 0.55 (95% CI, 0.39 to 0.78; P=0.001) for remote MI (> or =18 months).
Mortality risk in patients with ejection fractions < or =30% increases as a function of time from MI. The survival benefit associated with ICDs appears to be greater for remote MI and remains substantial for up to > or =15 years after MI.
预防性植入式心脏除颤器（ICD）可提高心肌梗死（MI）后心室功能受损患者的生存率，但死亡风险和生存获益是否取决于MI后的时间间隔尚不确定。
多中心自动除颤器植入试验II研究了ICD对MI后射血分数≤30%患者生存的影响。1159例患者中，距最近一次MI至入组的平均时间为81±78个月。患者按3:2比例随机分为ICD组（n = 699）或传统治疗组（n = 460）。根据MI后的时间分为四分位数（<18、18至59、60至119以及≥120个月），分析两个治疗组的死亡率（每100人年随访的死亡人数）。在传统治疗组患者中，这些死亡率随MI后时间的增加而升高（7.8%、8.4%、11.6%、14.0%；P = 0.03）。ICD组患者在每个四分位数中的死亡率始终较低，且随时间的增加增幅极小（7.2%、4.9%、8.2%、9.0%；P = 0.19）。与ICD治疗相关的死亡风险的协变量调整风险比，近期MI（<18个月）为0.97（95%CI，0.51至1.81；P = 0.92），远期MI（≥18个月）为0.55（95%CI，0.39至0.78；P = 0.001）。
射血分数≤30%患者的死亡风险随MI后时间的延长而增加。ICD带来的生存获益在远期MI中似乎更大，且在MI后长达≥15年时仍很显著。
