Dynamic Change of Coronary Artery Curvature

Coronary artery disease (CAD) is the most common type of heart disease and the leading cause of death worldwide. Percutaneous coronary intervention and coronary artery bypass graft are the guideline suggested treatment. Drug-eluting stents (DES) is the guideline suggested treatment options. Percutaneous coronary intervention with DES provides not just acute luminal gains, but also good long-term patency and clinical outcomes. However, in-stent neoatherosclerosis, very late stent thrombosis, and endothelial dysfunction remained important long-term issues. In addition, metallic stent encages the vessel segment, limits its remodeling and vasomotor function. The original vessel geometry, curvature, tortuosity, and wall shear stress, which are associated with plaque formation are also changed permanently by stent implantation. Although bioresorbable scaffolds attempted to address these issues by providing structural support to the vessel early on, followed by resorption, randomized trials showed that, prior to their resorption, they were less safe and effective than contemporary DES. Since that, the novel DES, DynamX Bioadaptor, is designed to improve these limitations.

The novel DES, DynamX Bioadaptor, is designed to restore normal pulsatility and adaptive remodeling in blood vessels after stent implantation. It is a cobalt-chromium stent with a biodegradable polymer coating that releases novolimus. Segments of the stent are held together by the polymer coating, which is designed to be fully absorbed in 6 months. After degradation of polymer, the stent struts unlink and uncage the stented segment. Pilot study demonstrated vessel uncaging and restoration of cyclic pulsatility 12 months after DynamX Bioadaptor implantation. Adaptive remodeling 12 months after DynamX Bioadaptor implantation will restore flexibility and natural geometry of the stented vessel segment. Thus, the dynamic beat-to-beat (cardiac cycle) changes of curvature and tortuosity will be more pronounced in the DynamX Bioadaptor group compared with that in the permanent metallic Elixir DESyne DES group. The DynamX Bioadaptor can potentially restore the vessel geometry and improve outcomes. The present randomized control study is designed to investigate the differences of dynamic coronary artery geometry changes after DynamX Bioadaptor and permanent metallic DES implantation, using coronary computed tomography angiography (CCTA) as an evaluation tool.

Inclusion criteria

• Patient is ≥ 20 years old.
• Written informed consent can be obtained.
• The enrolled coronary vessel only has one target coronary lesion required stenting.
• The target coronary lesion is 50 to 100% stenosis and stenting is required.
• Coronary artery de novo lesion requiring implantation of a single drug eluting stent with length ≥ 32 mm.
• Patients are able to tolerate dual antiplatelets for at least six months.

Exclusion criteria

• Patient is unwilling to join this study.
• Patients have end-stage renal disease under dialysis, chronic kidney disease (serum creatine > 1.5 mg/dL), symptomatic heart failure, active cancer, high bleeding risk, ST elevation myocardial infarction or hemodynamic unstable non-ST elevation myocardial infarction.
• Coronary lesion with following features: heavily calcification, ostial lesion, lesions requiring post-stenting side branch dilatation and lesions required more than one stent to treat.
• The left ventricular ejection fraction is ≤ 40%.
• No scheduled operation within six months after the coronary stenting is allowed unless continuous dual antiplatelet use is acceptable.
• Patients are unsuitable or unable to receive CCTA.
• Pregnant women or women with breast feeding or suitable pregnant women without contraception during the study period.
• Patient is currently participating another interventional trial.