Hypothesis: We examined the hypothesis that a specific myocardial injury marker, namely high sensitive cardiac troponin-I (HsTn-I), is elevated in patients with slow coronary flow (SCF) pattern.

Aim: To examine the above hypothesis by studying a group of patients who had undergone coronary angiography for the detection of their chest pain aetiology with SCF pattern despite an angiographically normal coronary arteriogram.

Methods: We evaluated and performed coronary angiography (CAG) of 97 patients with chest discomfort. The indication forCAG was at least Canada class 3 angina and/or proven myocardial ischaemia according to noninvasive diagnostic tests. We further divided patients into three subgroups according to CAG images and compared HsTn-I plasma levels in 39 patients with SCF pattern, 28 patients with coronary artery disease (CAD), and 30 patients with normal coronary arteries. We researched the association between qualitative HsTn-I positivity and demographic features including cardiovascular risk factors, inflammation markers and TIMI frame count for each of the epicardial coronary arteries.

Results: TIMI frame count for each epicardial coronary artery was significantly higher in patients with SCF pattern than in patients with CAD and normal coronary arteries (p < 0.001). HsTn-I positivity was not statistically different between patients with SCF pattern and normal coronary arteries (p = 512), but it was significantly higher in the CAD group than the other two group of patients (p < 0.001).

Conclusions: In patients with SCF, HsTn-I may be detectable, but it is not elevated as in patients with normal coronary arteries.