Troponin Elevation After Percutaneous Coronary Intervention Directly Represents the Extent of Irreversible Myocardial Injury

Abstract

Background-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. Delayedenhancement 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. Methods and Results-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 64Ϯ12 years. After the procedure, 14 patients (28%) had evidence of new myocardial hyperenhancement, with a mean mass of 6.0Ϯ5.8 g, or 5.0Ϯ4.8% of total left ventricular mass. All of these patients had raised troponin I levels (range 1.0 to 9.4 g/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 (rϭ0.84; PϽ0.001) and late (rϭ0.71; PϽ0.001) after PCI, although there was a trend for a reduction in the size of PCI-induced myocardial injury in the late follow-up scan (Pϭ0.07). Conclusions-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.

Persistent decline in longitudinal and radial strain after coronary microembolization detected on velocity encoded phase contrast magnetic resonance imaging

“…Characterization of microinfarction in patients has previously been performed with cine and DE-MRI (1,3,26). This study provides additional characterization of coronary microembolization by adding strain measurements by PC-MRI for evaluation of discrete microinfarction and demonstrating a direct link between microembolization and LV dysfunction.…”

Risk Factors of Cardiac Troponin T Elevation in Patients with Stable Coronary Artery Disease After Elective Coronary Drug‐Eluting Stent Implantation

“…The relationship between postprocedural cardiac marker elevation and adverse long-term outcome was very intriguing. One possible explanation was that regional myocardial damages occurred or local scar formed in patients with elevated troponin T. 21 Myocardial injury could impair left ventricular function and predispose to arrhythmic events, which influenced the survival and clinical outcomes. Alternatively, postprocedural troponin T elevation per se could be a biomarker of severe coronary artery disease, vulnerable coronary plaques, 22 or complicated coronary procedure.…”

Management and Outcomes in Patients with a Diagnosis of Myocardial Infarction but with Normal Coronary Arteries Angiographically

“…In patients without significant coronary artery stenosis the use of late gadolinium enhancement (LGE) cardiac magnetic resonance imaging (CMRI) may be useful in establishing an accurate diagnosis. CMRI is non invasive and can identify small areas of myocardial damage that may be due to myocardial infarction or myocarditis [8][9][10]. In a study of 91 patients with cardiac chest pain, positive troponin and unobstructed coronaries on angiography, the role of LGE-CMRI was assessed.…”