A novel biodegradable-polymer-coated drug-eluting stent (DES) was found to be as safe and effective as the contemporary polymer-based DES in patients with acute coronary syndromes (ACS) and chronic coronary syndromes (CCS) undergoing percutaneous coronary intervention (PCI), according to late-breaking trial results presented Sunday at the American Heart Association Scientific Sessions 2020 virtual conference.
Alexandra Lansky, MD, of the Yale School of Medicine, presented the results of the PIONEER III trial.
Current DES carry late failure rates that range between 2% and 3% per year. This is mostly secondary to delayed healing as a result of chronic inflammation associated with their polymer coatings. SINOMED, a technology company based in China, developed a novel stent that is made of cobalt chromium (CoCr), is as thin as some current polymer-based DES (80 microns) and has biodegradable coating that facilitates rapid drug delivery and polymer degradation.
In the PIONEER III trial, patients with acute or chronic coronary artery disease who had up to three de novo native lesions in up to two major vessels were randomized in a 2:1 fashion to undergo intervention with either the novel healing targeted Supreme DES (HT-DES, SINOMED) or contemporary polymer based DES (DP-DES, Xience [Abbott] or Promus [Boston Scientific]).
The primary endpoint was target lesion failure (TLF), a composite of cardiac death, target vessel (TV) myocardial infarction (MI) and ischemic-driven (ID) target lesion revascularization (TLR) at 12 months. Secondary safety endpoints included death, MI and Academic Research Consortium-defined stent thrombosis. An efficacy endpoint included device and lesion success, TLR and vessel revascularization.
A total of 1629 ACS or CCS patients were randomized at 74 sites in North America, Europe and Japan. The patients’ average age was 64±10 years, 25.4% were women, 30.4% had diabetes, 72.7% had hypertension, and 28.8% had prior PCI. The most common clinical presentation was stable angina (49.4%) followed by non-ST-elevation myocardial infarction ACS (20.9%), unstable angina (20.4%) and silent ischemia (9.3%). Most treated lesions were complex (American Heart Association/American College of Cardiology type B2 or C: 66.2%), with a mean of 1.2±0.5 treated lesions per patient with 1.3±0.6 stents (range: 0-5). Approximately half of the lesions were located in the left anterior descending artery (44.8%), 25.4% were in the left circumflex artery, and 29.7% were in the right coronary artery. Most cases (80.4%) were performed via radial access.
The primary endpoint occurred in 5.3% of the HT-DES group and 5.0% of the DP-DES group (hazard ratio [HR], 1.05; 95% confidence interval [CI], 0.67-1.66; p=0.82), meaning that the primary non-inferiority end point was met. The secondary end-point of ID-TLR was numerically higher in the HT-DES group than in the DP-DES group (2.3% vs. 1%, p=0.06), while the rates of TV-MI, CV-death and that of the composite secondary endpoints were not significantly different between the groups.
There was no significant difference between the groups for stent thrombosis. However, late stent thrombosis did show a numerical difference, with 0.1% in the HT-DES group and 0.4% in the DP-DES group (p=0.22). Finally, there were no significant differences in TLF at 1-year by subgroups.
Lansky concluded by saying that HT-DES was as safe and effective as DP-DES in patients undergoing PCI for ACS and CCS. Whether the findings of a numerically higher rate of CV death, TV-MI and late stent thrombosis favoring HT-DES translate into significant clinical benefits in the longer-term will be assessed at 5-years follow-up, she said.