Picano E, Sicari R, Landi P, Cortigiani L, Bigi R, Coletta C, Galati A, Heyman J, Mattioli R, Previtali M, Mathias W, Dodi C, Minardi G, Lowenstein J, Seveso G, Pingitore A, Salustri A, Raciti M
From the CNR Institute of Clinical Physiology, Pisa, Italy.
Circulation. 1998 Sep 15;98(11):1078-84. doi: 10.1161/01.cir.98.11.1078.
Residual viable myocardium identified by dobutamine stress after myocardial infarction may act as an unstable substrate for further events such as subsequent angina and reinfarction. However, in patients with severe global left ventricular dysfunction, viability might be protective rather than detrimental. The aim of this study was to assess the impact on survival of echocardiographically detected viability in medically treated patients with global left ventricular dysfunction evaluated after acute uncomplicated myocardial infarction.
The data bank of the large-scale, prospective, multicenter, observational Echo Dobutamine International Cooperative (EDIC) study was interrogated to select 314 medically treated patients (271 men; age, 58+/-9 years) who underwent low-dose (</=10 microg x kg-1 x min-1) dobutamine for the detection of myocardial viability and high-dose dobutamine for the detection of myocardial ischemia (</=40 microg x kg-1 x min-1 with atropine </=1 mg) performed 12+/-6 days after an acute uncomplicated myocardial infarction and showing a moderate to severe resting left ventricular dysfunction (wall motion score index [WMSI] >1.6). Patients were followed up for 9+/-7 months. Low-dose dobutamine stress echocardiography identified myocardial viability in 130 patients (52%). Dobutamine-atropine stress echocardiography was positive for ischemia in 148 patients (47%) and negative in 166 patients (53%). During the follow-up, there were 12 cardiac deaths (3.8% of the total population). With the use of Cox proportional hazards model, delta low-dose WMSI (the variation between rest WMSI and low-dose WMSI) was shown to exert a protective effect by reducing cardiac death by 0.8 for each decrease in WMSI at low-dose dobutamine (coefficient, -0.2; hazard ratio, 0.8; P<0.03); WMSI at peak stress was the best predictor of cardiac death in this set of patients (hazard ratio, 14.9; P<0.0018).
In medically treated patients with severe global left ventricular dysfunction early after acute uncomplicated myocardial infarction, the presence of myocardial viability identified as inotropic reserve after low-dose dobutamine is associated with a higher probability of survival. The higher the number of segments showing improvement of function, the better the impact is of myocardial viability on survival. The presence of inducible ischemia in this set of patients is the best predictor of cardiac death.
心肌梗死后通过多巴酚丁胺负荷试验确定的存活心肌可能是后续心绞痛和再梗死等进一步事件的不稳定底物。然而，在严重的全心左心室功能不全患者中，存活心肌可能具有保护作用而非有害作用。本研究的目的是评估在急性非复杂性心肌梗死后接受药物治疗的全心左心室功能不全患者中，超声心动图检测到的存活心肌对生存的影响。
对大规模、前瞻性、多中心、观察性的回声多巴酚丁胺国际合作（EDIC）研究的数据库进行查询，以选择314例接受药物治疗的患者（271例男性；年龄58±9岁），这些患者在急性非复杂性心肌梗死后12±6天接受低剂量（≤10μg·kg-1·min-1）多巴酚丁胺检测心肌存活情况，并接受高剂量多巴酚丁胺（≤40μg·kg-1·min-1且阿托品≤1mg）检测心肌缺血情况，且静息时左心室功能中度至重度不全（室壁运动评分指数[WMSI]＞1.6）。对患者进行了9±7个月的随访。低剂量多巴酚丁胺负荷超声心动图在130例患者（52%）中发现心肌存活。多巴酚丁胺-阿托品负荷超声心动图在148例患者（47%）中缺血阳性，在166例患者（53%）中缺血阴性。在随访期间，有12例心源性死亡（占总人群的3.8%）。使用Cox比例风险模型显示，低剂量WMSI变化值（静息WMSI与低剂量WMSI之间的差值）每降低一个单位，可使心源性死亡风险降低0.8，从而发挥保护作用（系数，-0.2；风险比，0.8；P＜0.03）；峰值负荷时的WMSI是这组患者心源性死亡的最佳预测指标（风险比，14.9；P＜0.0018）。
在急性非复杂性心肌梗死后早期接受药物治疗的严重全心左心室功能不全患者中，低剂量多巴酚丁胺后确定为变力储备的心肌存活与较高的生存概率相关。功能改善节段的数量越多，心肌存活对生存的影响越好。这组患者中诱发性缺血的存在是心源性死亡的最佳预测指标。
