Background: Elevated troponin levels are detected in high sensitive assays in up to half of the patients who experience acute ischemic stroke (AIS) or transient ischemic attack (TIA) [1]. Coronary artery disease (CAD) is common in patients with AIS or TIA, however, there is little information about the prevalence and predictors for an underlying obstructive CAD in these patients [2]. This study, therefore, aimed to identify predictors of obstructive CAD in patients with AIS or TIA having elevated troponin, thus, to improve the risk stratification and diagnostic work-up of these patients.

Methods: In this retrospective observational study, we analysed patients presenting with AIS or TIA and elevated serum high-sensitivity troponin I (hs-TnI) levels who underwent invasive coronary angiography (ICA).

Results: A total of 123 patients (mean age 71 ±12 years; 67% male) met the inclusion criteria. CAD was present in 98 (80%) patients, obstructive CAD was found in 51 (41%) patients. Obstructive CAD was indicated by at least one of the hallmarks of myocardial ischemia (35% vs. 65%; p=0.006): angina pectoris (15% vs. 31%; p=0.03) and regional wall motion abnormality (32% vs. 49%; p=0.07). Patients with a high number of clinical risk factors (≥ 3, odds ratio [OR] 3.9; p<0.01) were more likely to have an obstructive CAD. Of the 51 obstructive CAD patients, 46 (90%) had a CHA₂DS₂-VASc score ≥ 4 (61% vs. 90%; p<0.001). The AUC of the HEART score was highest at 0.68 (95% confidence interval [CI] 0.59-0.78). The following factors indicated exclusion of CAD (AUC 0.82): low cardiovascular risk (OR 0.4; p<0.001), no signs of myocardial ischemia (OR 0.1; p<0.01), the presence of alternate reasons for elevated hs-TnI (OR 3.3; p<0.05).

Conclusions: Patients with AIS or TIA and elevated hs-TnI presenting with a low cardiovascular risk, no signs of acute ischemia, and alternative reasons for myocardial damage are unlikely to have obstructive CAD. In addition to the established clinical signs of myocardial ischemia, risk scores such as the HEART score or the CHA₂DS₂-VASc score should be included in a risk stratification for obstructive CAD when making the decision to perform an ICA.

References: 1. Scheitz, J.F., et al., Prognostic relevance of cardiac troponin T levels and their dynamic changes measured with a high-sensitivity assay in acute ischaemic stroke: analyses from the TRELAS cohort. Int J Cardiol, 2014. 177(3): p. 886-93. 
2. Amarenco, P., et al., Prevalence of coronary atherosclerosis in patients with cerebral infarction. Stroke, 2011. 42(1): p. 22-9.