Background: An increase in the plasma levels of catecholamines and other neurohormones after
acute myocardial infarction (AMI) leads to coronary vasoconstriction and may cause the
undersizing of stents during primary percutaneous coronary intervention (PCI) in STsegment elevation myocardial infarction (STEMI). We aimed to compare the reference
vessel diameter of the infarct-related artery during and after primary PCI in patients with
AMI.
Methods: This prospective interventional study was performed on 43 consecutive patients with
STEMI (TIMI flow grade III), who were candidated for primary PCI. The main proximal
diameter of the coronary artery (reference vessel diameter) was assessed at baseline and also
3 days to 3 months after 2nd angiography. The study end point was to compare the reference
vessel diameter within and after primary PCI.
Results: Comparison between the mean diameter of the involved coronaries after PCI and the mean
diameter during the procedure showed a significant increase in the real size of the right
coronary artery (RCA) and a slight decrease in the size of the left circumflex artery (LCx).
However, the mean sizes of the left anterior descending coronary artery remained
insignificant. The decrease in the LCx diameter and inversely the increase in the RCA
diameter remained significant in the study population even after adjusting cardiovascular
risk factors as potential confounders.
Conclusions: The changes in the diameter of the reference coronary arteries, namely an increase in
the RCA diameter and a decrease in the LCx diameter, are expected following primary PCI
in patients with STEMI.