Selvanayagam Joseph B, Porto Italo, Channon Keith, Petersen Steffen E, Francis Jane M, Neubauer Stefan, Banning Adrian P
University of Oxford Centre for Clinical Magnetic Resonance Research, Oxford, United Kingdom.
Circulation. 2005 Mar 1;111(8):1027-32. doi: 10.1161/01.CIR.0000156328.28485.AD. Epub 2005 Feb 21.
Although troponin elevation after percutaneous coronary intervention (PCI) is common, uncertainties remain about the mechanisms of its release and its relationship to the volume of myocardial tissue loss. Delayed-enhancement MRI of the heart has been shown to reliably quantify areas of irreversible myocardial injury. To investigate the quantitative relationship between irreversible injury and cardiac troponin release, we studied the incidence and extent of new irreversible injury in patients undergoing PCI and correlated it to postprocedural changes in cardiac troponin I.
Fifty patients undergoing PCI were studied with preprocedural and postprocedural (24 hours) delayed-enhancement MRI for assessment of new irreversible myocardial injury. Cardiac troponin I measurements were obtained before PCI and 24 hours after PCI. Of these 50 patients, 24 underwent a further third MRI scan at a median of 8 months after the procedure. Mean patient age was 64+/-12 years. After the procedure, 14 patients (28%) had evidence of new myocardial hyperenhancement, with a mean mass of 6.0+/-5.8 g, or 5.0+/-4.8% of total left ventricular mass. All of these patients had raised troponin I levels (range 1.0 to 9.4 mug/L). Thirty-four patients (68%) had no elevated troponin I and no evidence of new myocardial necrosis on MRI. There was a strong correlation between the rise in troponin I measurements at 24 hours and mean mass of new myocardial hyperenhancement, both early (r=0.84; P<0.001) and late (r=0.71; P<0.001) after PCI, although there was a trend for a reduction in the size of PCI-induced myocardial injury in the late follow-up scan (P=0.07).
In the setting of PCI, patients demonstrating postprocedural elevation in troponin I have evidence of new irreversible myocardial injury on delayed-enhancement MRI. The magnitude of this injury correlates directly with the extent of troponin elevation.
尽管经皮冠状动脉介入治疗（PCI）后肌钙蛋白升高很常见，但其释放机制及其与心肌组织损失量的关系仍存在不确定性。心脏延迟强化磁共振成像（MRI）已被证明可可靠地量化不可逆心肌损伤区域。为了研究不可逆损伤与心肌肌钙蛋白释放之间的定量关系，我们研究了接受PCI患者新的不可逆损伤的发生率和范围，并将其与术后心肌肌钙蛋白I的变化相关联。
对50例接受PCI的患者进行术前和术后（24小时）延迟强化MRI检查，以评估新的不可逆心肌损伤。在PCI术前和术后24小时测量心肌肌钙蛋白I。这50例患者中，24例在术后中位时间8个月时接受了第三次MRI扫描。患者平均年龄为64±12岁。术后，14例患者（28%）有新的心肌强化证据，平均质量为6.0±5.8 g，占左心室总质量的5.0±4.8%。所有这些患者的肌钙蛋白I水平均升高（范围为1.0至9.4μg/L）。34例患者（68%）肌钙蛋白I未升高，MRI上也没有新的心肌坏死证据。PCI术后24小时肌钙蛋白I测量值的升高与新的心肌强化平均质量之间存在很强的相关性，无论是在PCI术后早期（r = 0.84；P < 0.001）还是晚期（r = 0.71；P < 0.001），尽管在晚期随访扫描中PCI诱导的心肌损伤大小有减小趋势（P = 0.07）。
在PCI情况下，术后肌钙蛋白I升高的患者在延迟强化MRI上有新的不可逆心肌损伤证据。这种损伤的程度与肌钙蛋白升高的程度直接相关。
