Department of Cardiology, Hospital Clínico Universitario de Valencia, Spain (V.M.G., J.C., J. Gonzalez, G.M., J.N., R.d.l.E., E.S., F.J.C., V.B.).
Instituto de Investigación Sanitaria del Hospital Clínico Universitario de Valencia (INCLIVA), Valencia, Spain (J. Gavara, C.R.-N., E.d.D., N.P., G.M., J.N., R.d.l.E., E.S., F.J.C., V.B.).
Circ Cardiovasc Imaging. 2020 Dec;13(12):e011491. doi: 10.1161/CIRCIMAGING.120.011491. Epub 2020 Dec 10.
Background Cardiac magnetic resonance (CMR) permits robust risk stratification of discharged ST-segment-elevation myocardial infarction patients, but its indiscriminate use in all cases is not feasible. We evaluated the utility of left ventricular ejection fraction (LVEF) by echocardiography for a selective use of CMR after ST-segment-elevation myocardial infarction. Methods Echocardiography and CMR were performed in 1119 patients discharged for ST-segment-elevation myocardial infarction included in a multicenter registry. The prognostic power of CMR beyond echocardiography-LVEF was assessed using adjusted C statistic, net reclassification improvement index, and integrated discrimination improvement index. Results During a 4.8-year median follow-up, 136 (12%) first major adverse cardiac events (MACE) occurred (47 cardiovascular deaths and 89 readmissions for acute heart failure). In the entire group, CMR-LVEF (but not echocardiography-LVEF) independently predicted MACE occurrence. The MACE rate significantly increased only in patients with CMR-LVEF<40% (≥50%: 7%, 40%-49%: 9%, <40%: 27%, <0.001). Most patients displayed echocardiography-LVEF≥50% (629, 56%), and they had a low MACE rate (57/629, 9%). In patients with echocardiography-LVEF<50% (n=490, 44%), the MACE rate was also low in those with CMR-LVEF≥40% (24/278, 9%) but significantly increased in patients with CMR-LVEF<40% (55/212, 26%; <0.001). Compared with echocardiography-LVEF, CMR-LVEF significantly improved MACE prediction in the group of patients with echocardiography-LVEF<50% (C statistic, 0.80 versus 0.72; net reclassification improvement index, 0.73; integrated discrimination improvement index, 0.10) but not in those with echocardiography-LVEF≥50% (C statistic 0.66 versus 0.66; net reclassification improvement index, 0.17; integrated discrimination improvement index, 0.01). Conclusions A straightforward strategy based on a selective use of CMR for risk prediction in ST-segment-elevation myocardial infarction patients with echocardiography-LVEF<50% can provide insights into patient care. The cost-effectiveness of this approach, as well as the direct implications in clinical management, should be further explored.
心脏磁共振（CMR）可对出院的 ST 段抬高型心肌梗死患者进行强有力的风险分层，但在所有情况下不加区分地使用是不可行的。我们评估了超声心动图左心室射血分数（LVEF）在 ST 段抬高型心肌梗死患者中选择性使用 CMR 的效用。
在一项多中心注册研究中，对 1119 例出院的 ST 段抬高型心肌梗死患者进行了超声心动图和 CMR 检查。使用校正的 C 统计量、净重新分类改善指数和综合判别改善指数评估 CMR 除超声心动图-LVEF 之外的预后能力。
在中位随访 4.8 年期间，136 例（12%）首次发生主要不良心脏事件（MACE）（47 例心血管死亡和 89 例急性心力衰竭再入院）。在整个组中，CMR-LVEF（而非超声心动图-LVEF）独立预测 MACE 发生。仅在 CMR-LVEF<40%的患者中，MACE 发生率显著增加（≥50%：7%，40%-49%：9%，<40%：27%，<0.001）。大多数患者的超声心动图-LVEF≥50%（629 例，56%），MACE 发生率较低（57/629，9%）。在超声心动图-LVEF<50%的患者中（n=490，44%），CMR-LVEF≥40%的患者 MACE 发生率也较低（27/278，9%），但 CMR-LVEF<40%的患者 MACE 发生率显著增加（55/212，26%；<0.001）。与超声心动图-LVEF 相比，CMR-LVEF 显著改善了超声心动图-LVEF<50%患者的 MACE 预测（C 统计量，0.80 与 0.72；净重新分类改善指数，0.73；综合判别改善指数，0.10），但在超声心动图-LVEF≥50%的患者中未改善（C 统计量 0.66 与 0.66；净重新分类改善指数，0.17；综合判别改善指数，0.01）。
基于超声心动图-LVEF<50%的 ST 段抬高型心肌梗死患者选择性使用 CMR 进行风险预测的简单策略，可以为患者护理提供参考。这种方法的成本效益，以及对临床管理的直接影响，应进一步探讨。
