Stents (Bare-metal, Drug-eluting)
A Non-randomized, Clinical Registry of the DynamX Novolimus Eluting Coronary Bioadaptor System in the Treatment of Patients with De Novo Native Coronary Artery Lesions - “DynamX Hong Kong Registry”
Bryan Ping-Yen Yan1, Li Wah Tam2, Sunny C F Tsang3, Wai Kin Chi4
Chinese University of Hong Kong, Hong Kong, China1, Kwong Wah Hospital, Hong Kong, China2, Queen Elizabeth Hospital, Hong Kong, China3, Prince of Wales Hospital, Hong Kong, China4
Drug Eluting Stents (DES) are the mainstay of coronary artery disease treatment. Although DES design iterations have reduced major adverse cardiac events (MACE) in the first year after PCI, beyond 1-year, a persistent 2 – 3 % annualized event rate without plateau is observed. The DynamX™ Novolimus-Eluting Coronary Bioadaptor System is a 71 µm, cobalt-chromium platform with a novel “uncaging” mechanism of circumferential rings which maintains the axial links between the rings following uncaging. Conventional metallic DES “cage” the coronary artery inhibit positive adaptive remodeling, vasomotion, and cause geometric distortion. These factors likely contribute to the persistent annual MACE rate after percutaneous coronary intervention (PCI). The DynamX Bioadaptor combines acute performance of contemporary DES and unique benefits of arterial “uncaging” beyond 6 months, allowing positive adaptive remodeling and restoring vessel compliance and normal geometry.
In this first-ever Asia Pacific study evaluating the DynamX Novolimus-eluting Bioadaptor, 50 patients were enrolled at three centers in Hong Kong, China. The Bioadaptor was available in diameters of 2.25 - 3.5 mm and lengths of 14 - 38 mm. Key inclusion criteria were: Subject age between 18 and 80 years; indication for percutaneous intervention in native coronary vessels; and subjects presenting with stable coronary artery disease and acute coronary syndromes (non-ST-segment myocardial infarction (MI)). Key exclusion criteria were: lesions located in the left main or in venous or arterial bypass grafts; in-stent re-stenosis or chronic total occlusion; and bifurcation lesions requiring a planned 2 or more stent technique. Subjects presenting with ST-segment MI and acute MI with Killip Class III and IV were also exclusions. Multiple endpoints were assessed and included: acute device and procedure success; a device-oriented composite endpoint defined as: cardiac death, target-vessel myocardial infarction (MI) and clinically-indicated target lesion revascularization (TLR); and stent thrombosis. Clinical follow-up was to be assessed at 1, 6 and 12 months. Dual anti-platelet therapy (DAPT) was to be given per current AHA/ACC Guidelines and per hospital standards. Lesions were to be successfully pre-dilated prior to implantation of the DynamX Bioadaptor.
This is the first clinical study evaluating the DynamX Novolimus Eluting Bioadaptor System performed in the Asia Pacific territories. A summary of subject demographics, baseline lesion characteristics and clinical results through 30 days will be presented. In a previous mechanistic study, the DynamX Bioadaptor enrolled 50 subjects at six European centers. At two years, a low target lesion failure (TLF) rate of 4.3 % was observed, including two non-device related cardiac deaths; there were no target lesion revascularizations or probable / definite device thrombosis observed. A low in-device late lumen loss of 0.12 ± 0.18 mm was observed at 9 - 12 months by qualitative coronary angiography (QCA). Intravascular Ultrasound (IVUS) imaging results showed the mean lumen area maintained with 0% change from post-procedure to follow-up (7.39 ± 1.20 mm2 to 7.36 ± 1.31 mm2, p=0.594); an increase in mean vessel area by 3% (14.11 ± 2.99 mm2 to14.54 ± 3.12mm2, p=0.02); and an increase in mean bioadaptor area of 5% (7.39 ± 1.20 mm2 to 7.74 ± 1.46 mm2, p=0.0005). The optical coherence tomography (OCT) imaging showed thin, uniform neointimal coverage of 140 µm along the entire length of the Bioadaptor struts. Stationary OCT in a patient subset demonstrated restoration of cyclic pulsatility with an approximate lumen area variance of 11% between systole and diastole. The results confirmed the unique benefit afforded by the uncaging of the DynamX Bioadaptor. DynamX offers excellent acute performance similar to that of DES with the additional benefits of restoring the natural ability of the vessel for positive adaptive remodeling and pulsatility from the uncaging of the expansion segments. The clinical results of this study may be summarized in comparison to the DynamX Mechanistic Study.
In summary, in this first-ever, Asia-Pacific study evaluating the DynamX Bioadaptor, a summary of acute safety and performance will be presented. The results may be compared to a previous study which demonstrated the unique benefit afforded by the uncaging of the DynamX Bioadaptor that is distinct from contemporary metallic DES. The DynamX Bioadaptor offers not only an equivalent acute performance profile to that of DES, but it allows for positive adaptive vessel remodeling and more normal movement from the uncaging of the expansion segments.