Background: Recent studies have implied that platelet reactivity as well as certain lesion morphology may be linked to myocardial
injury during percutaneous coronary intervention (PCI). However, to date the abovementioned features have not been
investigated simultaneously in one population.

Aim: To determine if and how high on-treatment platelet reactivity, different lesion morphology, and plaque components are
associated with increased risk of periprocedural myocardial injury in patients referred for elective coronary stenting.

Methods: Sixty patients pretreated with aspirin and clopidogrel and undergoing elective PCI with stent(s) implantation were
included. On-treatment platelet reactivity was measured with VerifyNow Aspirin and P2Y12 assays (Accumetrics, USA) before
PCI. Grey-scale intravascular ultrasound (IVUS) and virtual histology were performed before stent(s) implantation (Volcano,
USA). Two levels of myocardial injury were considered: any elevation of troponin I (periprocedural myocardial damage, PMD)
and/or > 3 times the upper normal limit (periprocedural myocardial infarction, PMI).

Results: By receiver-operating characteristics analysis, the following factors, ranked from strongest to weakest, were able to
distinguish between patients with and without PMD: remodelling index (RI), fibrous tissue, fibro-fatty tissue volume (FFT),
plaque and media cross-sectional area, and external elastic membrane cross-sectional area (EEM CSA). Only platelet count
and RI could differentiate patients with and without PMI. PMD as well as PMI could not be predicted either by VerifyNow
Aspirin or P2Y12 assay. Likewise, there was no association between necrotic core volume and PMD or PMI. In logistic regression
analysis, after adjusting for possible clinical and procedural confounding factors, only EEM CSA > 14.6 mm2 (OR 23.7,
95% CI 1.9–302, p = 0.015), RI > 1.044 (OR 12.3, 95% CI 1.2–121.9, p = 0.032) and FFT > 11.2 mm3 (OR 13.6, 95% CI
1.1–160.9, p = 0.038) were independent predictors of PMD. Only RI > 1.044 was identified as an independent predictor
of PMI (OR 7.5, 95% CI 1.92–29.6, p = 0.004).

Conclusions: Greater total vessel area, positive remodelling at the lesion site, and high volume of FFT in the coronary plaque
are independently associated with increased risk of myocardial injury. Only positive RI was an independent predictor of PMI.
Simple lesion morphology, rather than more complex VH-IVUS analysis or platelet reactivity, seems to predict myocardial
injury after elective PCI.