Allen Jason E, Knight Stacey, McCubrey Raymond O, Bair Tami, Muhlestein Joseph Brent, Goldberger Jeffrey J, Anderson Jeffrey L
Intermountain Healthcare, Heart Institute, Murray, UT; University of Utah, Division of Internal Medicine, Salt Lake City, UT.
Intermountain Healthcare, Heart Institute, Murray, UT; University of Utah, Division of Internal Medicine, Salt Lake City, UT.
Am Heart J. 2017 Feb;184:26-36. doi: 10.1016/j.ahj.2016.10.012. Epub 2016 Oct 22.
Although β-blockers increase survival in acute coronary syndrome (ACS) patients, the doses used in trials were higher than doses used in practice, and recent data do not support an advantage of higher doses. We hypothesized that rates of major adverse cardiac events (MACE), all-cause death, myocardial infarction, and stroke are equivalent for patients on low-dose and high-dose β-blocker.
Patients admitted to Intermountain Healthcare with ACS and diagnosed with ≥70% coronary stenosis between 1994 and 2013 were studied (N = 7,834). We classified low dose as ≤25% and high dose as ≥50% of an equivalent daily dose of 200 mg of metoprolol. Multivariate analyses were used to test association between low-dose versus high-dose β-blocker dosage and MACE at 0-6 months and 6-24 months.
A total of 5,287 ACS subjects were discharged on β-blockers (87% low dose, 12% high dose, and 1% intermediate dose). The 6-month MACE outcomes rates for the β-blocker dosage (low versus high) were not equivalent (P = .18) (hazard ratio [HR] = 0.76; 95% CI, 0.52-1.10). However, subjects on low-dose β-blocker therapy did have a significantly decreased risk of myocardial infarction for 0-6 months (HR = 0.53; 95% CI, 0.33-0.86). The rates of MACE events during the 6-24 months after presentation with ACS were equivalent for the 2 doses (P = .009; HR = 1.03 [95% CI, 0.70-1.50]).
In ACS patients, rates of MACE for high-dose and low-dose β-blocker doses are similar. These findings question the importance of achieving a high dose of β-blocker in ACS patients and highlight the need for further investigation of this clinical question.
尽管β受体阻滞剂可提高急性冠状动脉综合征（ACS）患者的生存率，但试验中使用的剂量高于实际应用剂量，且近期数据并不支持高剂量具有优势。我们推测，低剂量和高剂量β受体阻滞剂治疗的患者发生主要不良心脏事件（MACE）、全因死亡、心肌梗死和中风的发生率相当。
对1994年至2013年间因ACS入住山间医疗保健机构且诊断为冠状动脉狭窄≥70%的患者进行研究（N = 7834）。我们将低剂量定义为相当于每日200 mg美托洛尔剂量的≤25%，高剂量定义为≥50%。采用多变量分析来检验低剂量与高剂量β受体阻滞剂剂量在0至6个月和6至24个月时与MACE之间的关联。
共有5287例ACS患者出院时使用β受体阻滞剂（87%为低剂量，12%为高剂量，1%为中等剂量）。β受体阻滞剂剂量（低剂量与高剂量）的6个月MACE结局发生率并不相当（P = 0.18）（风险比[HR] = 0.76；95%置信区间，0.52 - 1.10）。然而，接受低剂量β受体阻滞剂治疗的患者在0至6个月时心肌梗死风险显著降低（HR = 0.53；95%置信区间，0.33 - 0.86）。ACS发病后6至24个月期间，两种剂量的MACE事件发生率相当（P = 0.009；HR = 1.03[95%置信区间，0.70 - 1.50]）。
在ACS患者中，高剂量和低剂量β受体阻滞剂的MACE发生率相似。这些发现质疑了在ACS患者中达到高剂量β受体阻滞剂的重要性，并强调了对这一临床问题进行进一步研究的必要性。
