Drug-eluting stents are associated with delayed vascular healing. Anatomical and functional healing of coronary arteries after balloon angioplasty with stenting was investigated in patients presenting with acute coronary syndrome. Bioactive stents, sirolimus-, zotarolimus-, and everolimus-eluting stents were compared in two ran-omized trials with optical coherence tomography and coronary flow reserve measurement at 2- or 3-month follow-up after stenting. Coronary flow reserve measurements were obtained by invasive thermodilution and transthoracic echocardiography. Variability of optical coherence tomography data was assessed between observers and sampling intervals. 

Uncovered stent struts and impaired coronary flow reserve values were detected in all stent groups, and a link between anatomical and functional healing was discovered. Bioactive stents showed earlier and more comprehensive neointimal coverage, which happened at the expense of luminal narrowing. Strut malapposition occurred frequently despite post-dilatation. 

Measurement of coronary flow reserve by transthoracic echocardiography was feasible after stenting in the left anterior descending artery of non-diabetic patients, and agreement with the invasive method was good. The results confirm that noninvasive measurement of coronary flow reserve by echocardiography can be considered for follow-up after stenting. 

The sampling interval of optical coherence tomography cross-sections had a significant effect on the observed percentage of uncovered and malapposed struts. The shorter sampling interval of 0.6 mm can be used to reduce variability and overestimation of strut level data.