Aims: Troponin measurement is used in the assessment and risk stratification of patients presenting acutely with chest pain when the main cause of elevation is coronary artery disease. However, some patients have no coronary obstruction on angiography, leading to diagnostic uncertainty. We evaluated the incremental diagnostic value of cardiovascular magnetic resonance (CMR) in these patients. Methods and results: one hundred consecutive patients (mean age50 years,70% male)with a troponin-positive episode of chest pain and unobstructed coronary arteries were recruited within 3 months of initial presentation. All patients underwent CMR with cine imaging,T2-weighted imaging for detection of inflammation, and late gadolinium enhancement imaging for detection of infarct and fibrosis. An identifiable basis for troponin elevation was established in80%of patients. The commonest underlying cause was cardiomyopathy (37%) myocarditis (13%), followed by myocardial infarction (12%) and In the38%of patients where no clear diagnosis was identified by CMR, significant myocardial infarct and fibrosis was excluded. Conclusion: CMR is a valuable adjunct to conventional investigations in a diagnostically challenging and important group of patients with troponin-positive chest pain and unobstructed coronary arteries.
