Clinical outcomes with the Biodegradable-polymer Dual-therapy COMBO stent in patients with coronary artery disease

In this thesis, we examined the clinical outcomes in patients treated with a new generation coronary stent – the biodegradable-polymer dual therapy COMBO stent. This stainless-steel stent includes an anti-restenotic layer with antiproliferative drug sirolimus which is eluted from a biodegradable polymer coated on the stent abluminally. In addition, a unique pro-healing circumferential layer of anti-CD34 antibodies attracts circulating endothelial progenitor cells which mature into healthy endothelium. We hypothesized that treatment with this coronary stent would allow for low rates of adverse cardiac outcomes during follow-up in several patient groups. By virtue of a pooled patient level analysis from two large COMBO stent registries (REMEDEE and MASCOT), we were able to explore for differences in outcomes among special high-risk populations from the COMBO collaboration. We found that treatment with COMBO stents was associated with similar 1-year target lesion failure (TLF) rates in men and women, young (≤ 75 years) and elderly (>75 years) patients, small vessel (<3mm) and large vessel (≥3mm) coronary disease. We observed regional differences between patients treated in Asia and Europe 1-year after COMBO stenting, which are likely to be a reflection of variances in patient profiles, and potentially diverse cultural and local governance issues. Chronic kidney disease (CKD) patients experienced worse outcomes than non-CKD patients after PCI with COMBO stents, highlighting the challenges in managing this subgroup despite the availability of novel technologies. Patients at increasing bleeding risk using the PARIS score demonstrated greater risk of ischemic and bleeding events at 1-year after COMBO stenting. We observed that treating physicians tended to stop aspirin and continue P2Y₁₂ inhibitor monotherapy in patients with greater bleeding risk. In propensity matched analyses, COMBO stents were not statistically different to biodegradable polymer Orsiro stents for 1-year TLF in all-comer patients. In long term follow-up, COMBO stents were associated with low risk of events to 5 years, with no very late stent thrombosis events beyond 3 years. These results demonstrate the safety and effectiveness of COMBO stents in real world patients, while data from large randomized trials are presently awaited.