Evaluation of microcirculatory protection in percutaneous revascularisation: A stent implantation technique and device comparison

Abstract Background Coronary microvascular dysfunction (CMD) after percutaneous coronary intervention (PCI) is prognostically important and may also be a cause of persistent angina. The stent balloon inflation technique or material properties may influence the degree of CMD post‐PCI. Methods Thirty‐six patients with stable angina attending for elective PCI were randomized to either slow drug eluting stent (DES) implantation technique (DES slow group): +2 atm. every 5 s., maintained for a further 30 s or a standard stent implantation technique (DES std group): rapid inflation and deflation. PressureWire X with thermodilution at rest and hyperemia and optical coherence tomography (OCT) were performed pre‐ and post‐PCI. Combined primary endpoints were changes in index of microvascular resistance (delta IMR) and coronary flow reserve (delta CFR) following PCI. The secondary endpoints included differences in cardiac troponin I (delta cTnI) at 6 h post‐PCI, Seattle angina questionnaire (SAQ) at 1, 3, 6, and 12 months and OCT measures of stent results immediately post‐PCI and at 3 months. Results Both groups were well matched, with similar baseline characteristics and OCT‐defined plaque characteristics. Delta IMR was significantly better in the DES slow PCI arm with a median difference of −4.14 (95% CI ‐10.49, −0.39, p = 0.04 ). Delta CFR was also numerically higher with a median difference of 0.47 (95% CI −0.52, 1.31, p = 0.46). This did not translate to improved delta median cTnI (1.5 (34.8) vs. 0 (27.5) ng/L, p = 0.75) or median SAQ score at 3 months, (85 (20) vs. 95 (17.5), p = 0.47). Conclusion Slow stent implantation is associated with less CMD after elective PCI in patients with stable angina.