Head‐to‐head comparison of sirolimus‐eluting stent versus bare metal stent evaluation of the coronary endothelial dysfunction in the same patient presenting with multiple coronary artery lesions: The CREDENTIAL study

OBJECTIVES: To assess the endothelial dysfunction (ED) after bare metal stents (BMS) and sirolimus eluting stents (SES) implantation in the same patient, overcoming the confounding role of individual variables. BACKGROUND: SES reduce restenosis rate compared to BMS but causes more ED. ED is a potentially unsafe phenomenon, since it is the first step in the cascade of atherosclerosis. Studies showing more pronounced ED with drug eluting stents than BMS involved different series of patients, making the comparison difficult because endothelial function (EF) is responsive to many risk factors. METHODS: we designed a prospective comparison of 6 months post-deployment EF of SES versus BMS implanted in the same patient, but in different coronary segments. Forty-eight lesions were randomly assigned on a 1:1 allocation using block sizing of 4 according to a computer-generated sequence (SAS System, Version 9.1) basis to treatment with SES or BMS. The EF was evaluated by measuring vessel diameter variation in the stented segment, before and after selective intracoronary infusion of acetylcholine (iiAch). RESULTS: In eligible patients, the relative magnitudes of major vasoconstriction were 2.6, 2.9, 4.6, and 3.1 at 5 mm proximal and 5, 10 and 20 mm distal to the stent edge. Overall, a 3.5-fold major distal vasoconstriction after iiAch of SES vs. BMS was calculated. CONCLUSIONS: in the same patients, but treating different coronary segments, SES implantation induces a higher rate of vasoconstriction compared to BMS. The increased vasoconstriction after iiAch is an indicator of ED.