Cobalt-chromium-based titanium-nitride-oxide (TiNO)-coated stents were non-inferior to platinum-chromium-based biodegradable-polymer everolimus-eluting stents (EES) at 12 months and superior at 18 months with regard to major adverse cardiovascular events (MACE) in patients with acute coronary syndromes (ACS), according to study results released Monday.
For patients with ACS, stainless steel TiNO-coated stents have demonstrated an acceptable safety profile. Cobalt-chromium stents offer more radial strength, allowing for thinner stent struts than those of stainless steel stents. Cobalt-chromium-based TiNO-coated stents present a potential benefit in prothrombotic ACS patients but have not been compared directly to cobalt-chromium based EES
Pim A.L. Tonino, MD, PhD, of Catharina Hospital, Netherlands, and co-investigators reported the results from the multicenter (12 clinical sites across five European countries) randomized Comparison of Titanium-Nitride-Oxide-Coated Bio-Active-Stent to the Drug (Everolimus)-Eluting Stent in Acute Coronary Syndrome (TIDES-ACS) trial in a paper published in the July 27 issue of JACC: Cardiovascular Interventions
The trial randomized 1,491 ACS patients in a 2-to-1 ratio to receive either a TiNO-coated stent (n=989) or an EES (n=502). ACS was defined as ST-segment-elevation myocardial infarction (STEMI), non-ST-segment elevation MI (NSTEMI), or unstable angina. The trial’s primary goal was to evaluate non-inferiority of TiNO-coated stents as compared to EES at 12 months with regard to MACE. The co-primary goal was to test superiority of TiNO-coated stents compared to EES at 18 months with regard to the composite of cardiac death, nonfatal myocardial infarction and major bleeding. Secondary endpoints included stent thrombosis and individual components of the primary composite outcomes.
Baseline clinical characteristics were similar between both groups. The patients’ mean age was 62.7 years, and 24.3% were women. STEMI patients were 45.8% of the study population, and 45.9% presented with NSTEMI. Radial access was used in 76.2% of patients, with the majority of patients having single vessel disease (63.8%). Patients in the TiNO-coated stent arm were less likely to have direct stenting than patients in the EES arm (22.8% vs. 28.9%, p=0.011). There were no other significant procedural or anatomical differences between the two groups.
When examining the primary endpoint of MACE at 12 months, there were no differences between the two groups, supporting non-inferiority of the TiNO-coated stents (6.3% vs. 7.0%; hazard ratio [HR], 0.93; 95% confidence interval [CI], 0.71-1.22; p=0.657 for superiority). Furthermore, there were no differences in MACE at 18 months between the two groups (7.2% vs. 8.8%; HR, 0.87; 95% CI, 0.68-1.11, p=0.304 for superiority). When examining the co-primary endpoint of cardiac death, nonfatal myocardial infarction or major bleeding, patients who received a TiNO-coated stent had lower events at 12 months (3.0% vs. 6.2%; HR, 0.65; 95% CI, 0.50-0.84; p=0.005 for superiority) and 18 months (3.7% vs. 7.8%; HR, 0.64; 95% CI, 0.51-0.80; p=0.001 for superiority). Target lesion revascularization did not differ between the two groups (HR, 1.41; 95% CI, 0.92-2.14). At 18 months, patients receiving TiNO-coated stents had less myocardial infarction (HR, 0.62; 95% CI, 0.47-0.82), cardiac death (HR, 0.49; 95% CI, 0.35-0.84) and a trend toward less major bleeding (HR, 0.73; 95% CI, 0.48-1.11).
Davide Capodanno, MD, PhD, and Marco Angelo Monte, MD, of the University of Catania, Italy, wrote an accompanying editorial to the study. They acknowledge the improvements in the evolution of coronary stents over time but, emphasized that the current generation of drug-eluting stents is not perfect, with room for improvement in treating challenging cohorts, such as patients with ACS or complex coronary anatomy and diabetics). The editorialists point out the low proportion of patients with multivessel disease (36.2%) and diabetics (13.6%) in the TIDES-ACS study.
Additionally, there exists performance and ascertainment bias in this open-label trial, as in many stent trials. They add that the study may not have been adequately powered to convincingly alter and advance current practice. It is also noteworthy that the 18-month co-primary endpoint was driven by cardiac death and myocardial infarction, both of which were underpowered components.
“In reality, this study teaches us that we must clear our minds of preconceptions and look at the results of new devices that are neither (bare metal stents) nor (drug-eluting stents) with respect, curiosity, and genuine expectations,” Capodanno and Monte conclude
This trial was funded by grants from Hexacath.
Tonino PAL, Pijls NHJ, Collet C, et al. Titanium-Nitride-Oxide–Coated Versus Everolimus-Eluting Stents in Acute Coronary Syndrome: The Randomized TIDES-ACS Trial. JACC Cardiovasc Interv 2020;13:1697-705. DOI: 10.1016/j.jcin.2020.04.021
Capodanno D, Monte MA. Stent Wars: Coated Stents Strike Back. JACC Cardiovasc Interv 2020;13:1706-8. DOI: 10.1016/j.jcin.2020.05.017