Background—The Danish Study to Assess the Efficacy of Implantable Cardioverter Defibrillators (ICD) in Patients with Non-ischemic Systolic Heart Failure on Mortality (DANISH) did not demonstrate an overall effect on all-cause mortality with ICD implantation. However, the pre-specified subgroup analysis suggested a possible age-dependent association between the ICD and mortality with survival benefit seen only in the youngest patients. The nature of this relationship between age and outcome of a primary prevention ICD in patients with non-ischemic systolic heart failure warrants further investigation.Methods—All 1116 patients from the DANISH study were included in this pre-specified subgroup analysis. We assessed the relationship between the ICD and mortality by age, and an optimal age cut-off was estimated non-parametrically using selection impact curves. Modes of death were divided into sudden cardiac death (SCD) and non-sudden death and compared between patients younger and older than this age cut-off, respectively, with the use of Chi2-analysis.Results—Median age of the study population was 63 years (range 21 - 84 years). There was a linearly decreasing relationship between the ICD and mortality with age, HR 1.03 (95% CI 1.003 - 1.06), p=0.03. An optimal age cut-off for ICD implantation was present at ≤70 years. There was an association between reduced all-cause mortality and the ICD in patients ≤70 years, HR 0.70 (0.51 - 0.96), p=0.03, but not in patients >70 years, HR 1.05 (0.68 - 1.62), p=0.84. For patients ≤70 years, SCD rate was 1.8 (1.3 - 2.5) and non-sudden death rate was 2.7 (2.1 - 3.5) events/100 patient years, whereas for patients older than 70 years SCD rate was 1.6 (0.8 - 3.2) and non-sudden death rate was 5.4 (3.7 - 7.8) events/100 patient years. This difference in modes of death between the two age groups was statistically significant (p=0.01).Conclusions—In patients with systolic heart failure not caused by ischemic heart disease, the association between the ICD and survival decreased linearly with increasing age. In this study population, an age cut-off for ICD implantation at ≤70 years yielded the highest survival for the population as a whole.

背景—丹麦评估可植入式心脏复律除颤器（ICD）对非缺血性收缩期心力衰竭患者死亡率（DANISH）疗效的研究并未显示出对ICD植入对全因死亡率的总体影响。但是，预先指定的亚组分析表明，ICD和死亡率之间可能存在年龄相关的关联，只有在最年轻的患者中才能看到生存获益。对于非缺血性收缩期心力衰竭患者，年龄与一级预防ICD结局之间这种关系的性质值得进一步研究。方法—来自DANISH研究的所有1116名患者均包括在此预先指定的亚组分析中。我们按年龄评估了ICD与死亡率之间的关系，并使用选择影响曲线非参数地估计了最佳年龄界限。死亡模式分为心源性猝死（SCD）和非猝死，并使用Chi2分析法比较年龄在该年龄临界值以下的患者。结果—研究人群的中位年龄为63岁（范围21-84岁）。ICD与死亡率之间的线性关系呈线性下降，HR 1.03（95％CI 1.003-1.06），p = 0.03。ICD植入的最佳年龄临界值是≤70岁。≤70岁的患者，HR 0.70（0.51-0.96），p = 0.03与降低的全因死亡率和ICD之间存在相关性，而> 70岁的患者，HR 1.05（0.68-1.62），p = 0.84与ICD之间没有关联。 。≤70岁的患者的SCD发生率是1.8（1.3-2.5），非突然死亡的发生率是2.7（2.1-3.5）事件/ 100患者年，而70岁以上的患者的SCD发生率是1.6（0.8-3.2）非突发性死亡率为5.4（3.7-7.8）事件/ 100患者年。两个年龄组之间死亡方式的差异具有统计学意义（p = 0.01）。结论—对于不是由缺血性心脏病引起的收缩性心力衰竭患者，ICD与存活率之间的相关性随年龄的增长而线性下降。在该研究人群中，ICD植入≤70岁的年龄截止值为整个人群带来了最高的存活率。