Noninvasive Cardiovascular Imaging Section, Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St, Boston, MA 02115, USA.
Circulation. 2013 Aug 6;128(6):605-14. doi: 10.1161/CIRCULATIONAHA.113.001430. Epub 2013 Jun 26.
A recent large-scale clinical trial found that an initial invasive strategy does not improve cardiac outcomes beyond optimized medical therapy in patients with stable coronary artery disease. Novel methods to stratify at-risk patients may refine therapeutic decisions to improve outcomes.
In a cohort of 815 consecutive patients referred for evaluation of myocardial ischemia, we determined the net reclassification improvement of the risk of cardiac death or nonfatal myocardial infarction (major adverse cardiac events) incremental to clinical risk models, using guideline-based low (<1%), moderate (1% to 3%), and high (>3%) annual risk categories. In the whole cohort, inducible ischemia demonstrated a strong association with major adverse cardiac events (hazard ratio=14.66; P<0.0001) with low negative event rates of major adverse cardiac events and cardiac death (0.6% and 0.4%, respectively). This prognostic robustness was maintained in patients with previous coronary artery disease (hazard ratio=8.17; P<0.0001; 1.3% and 0.6%, respectively). Adding inducible ischemia to the multivariable clinical risk model (adjusted for age and previous coronary artery disease) improved discrimination of major adverse cardiac events (C statistic, 0.81-0.86; P=0.04; adjusted hazard ratio=7.37; P<0.0001) and reclassified 91.5% of patients at moderate pretest risk (65.7% to low risk; 25.8% to high risk) with corresponding changes in the observed event rates (0.3%/y and 4.9%/y for low and high risk posttest, respectively). Categorical net reclassification index was 0.229 (95% confidence interval, 0.063-0.391). Continuous net reclassification improvement was 1.11 (95% confidence interval, 0.81-1.39).
Stress cardiac magnetic resonance imaging effectively reclassifies patient risk beyond standard clinical variables, specifically in patients at moderate to high pretest clinical risk and in patients with previous coronary artery disease.
http://www.clinicaltrials.gov. Unique identifier: NCT01821924.
最近一项大规模临床试验发现，在稳定性冠心病患者中，初始有创策略并不能改善优化药物治疗之外的心脏结局。新的分层高危患者的方法可能会改进治疗决策以改善结局。
在 815 例连续就诊的心肌缺血评估患者队列中，我们确定了基于指南的低（<1%）、中（1%-3%）和高（>3%）年风险类别，风险比增量到临床风险模型的心脏死亡或非致死性心肌梗死（主要不良心脏事件）的风险净重新分类改善。在整个队列中，可诱导缺血与主要不良心脏事件有很强的关联（危险比=14.66；P<0.0001），主要不良心脏事件和心脏死亡的阴性事件率均较低（分别为 0.6%和 0.4%）。这种预后稳健性在有既往冠状动脉疾病的患者中得以维持（危险比=8.17；P<0.0001；分别为 1.3%和 0.6%）。将可诱导缺血加入多变量临床风险模型（调整年龄和既往冠状动脉疾病）可提高主要不良心脏事件的区分度（C 统计量，0.81-0.86；P=0.04；调整危险比=7.37；P<0.0001），并重新分类 91.5%的中度术前风险患者（65.7%为低风险；25.8%为高风险），相应的观察到的事件发生率也发生变化（低风险和高风险的术后分别为 0.3%/年和 4.9%/年）。分类净重新分类指数为 0.229（95%置信区间，0.063-0.391）。连续净重新分类改善为 1.11（95%置信区间，0.81-1.39）。
应激心脏磁共振成像能有效重新分类患者的风险，超出标准临床变量，特别是在中度至高度术前临床风险患者和有既往冠状动脉疾病的患者中。
