Relation of cardiac troponin I and microvascular obstruction following ST-elevation myocardial infarction

Abstract

Background: Presence of microvascular obstruction (MVO) following primary percutaneous coronary intervention (pPCI) for ST-elevation myocardial infarction (STEMI) confers higher risk of left-ventricular remodelling and dysfunction. Measurement of cardiac troponin I (cTnI) after STEMI reflects the extent of myocardial destruction. We aimed to explore whether cTnI values were associated with presence of MVO independently of infarct size in STEMI patients receiving pPCI.

Methods: 175 patients with STEMI were included. cTnI was sampled at 24 and 48 h. MVO and infarct size was determined by delayed enhancement with cardiac magnetic resonance at five to seven days post index event.

Results: The presence of MVO following STEMI was associated with larger infarct size and higher values of cTnI at 24 and 48 h. For any given infarct size or cTnI value, there was a greater risk of MVO development in non-anterior infarctions. cTnI was strongly associated with MVO in both anterior and non-anterior infarctions (P < 0.01) after adjustment for covariates (including infarct size); and was reasonably effective in predicting MVO in individual patients (area-under-the-curve ≥0.81).

Conclusion: Presence of MVO is reflected in levels of cTnI sampled at an early time-point following STEMI and this association persists after adjustment for infarct size.

Acknowledgement

The authors thank the physician investigators who contributed to patient enrolment at each participating center. The authors would also like to thank Jens Bremerich, MD (University Hospital Basel, Switzerland) for reading cardiac magnetic resonance images.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.