Background Percutaneous Coronary Intervention (PCI) with metal stents can result in long-term impairment of microvascular function. Bioresorbable Vascular Scaffolds (BVS) may not have the same impact on the coronary microcirculatory network.

Aims Our study sought to investigate the effect of elective BVS implantation (with the Absorb stent) on coronary microvascular resistance in patients with stable coronary disease.

Methods 28 patients scheduled for elective PCI with BVS had invasive pressure wire assessment before and after scaffold implantation. 5 mls of normal saline were injected into the coronary artery and the mean transit time was recorded using a dual pressure sensor and thermistor-tipped wire, both at rest and during adenosine hyperaemia. Aortic and distal coronary pressures were also recorded at rest and hyperaemia. Using these measures, the Fractional Flow Reserve (FFR), Index of Microcirculatory Resistance (IMR) and Coronary Flow Reserve (CFR) were calculated.

Results Complete pressure wire data was obtained in 25 patients. Pre and post BVS implantation, the FFR changed from 0.75±0.12 to 0.92±0.04 (p<0.001), the IMR changed from 32±20 to 24±13 (p=0.084) and the CFR changed from 2.3±1.1 to 3.1±1.8 (p=0.048).

Conclusion Following elective implantation of BVS, we did not observe a significant immediate increase in microcirculatory resistance. This suggests that the Abbott ABSORB stent does not adversely affect coronary microvasculature acutely. Follow up data is required to determine whether BVS has long term effect on the coronary microvasculature.