Biodegradable Coronary Stents Better Than Durable Stents in Registry Study

By Marilynn Larkin

January 17, 2020

NEW YORK (Reuters Health) - Patients with acute myocardial infarction (MI) who underwent percutaneous coronary intervention (PCI) had better outcomes with biodegradable polymer drug-eluting stents (BP-DES) than with second-generation durable polymer drug-eluting stents (DP-DES), a South Korean registry study found.

That was particularly true for outcomes beyond one year, said Dr. Jeong Cheon Choe of Pusan National University Hospital in Busan. "Thus, the use of BP-DES, rather than second-generation DP-DES, could reduce future adverse clinical events in (these) patients," he told Reuters Health by email.

That said, he added, "the clinical outcomes after BP-DES implantation in different real-world practices were insufficiently reported. Therefore, further studies regarding BP-DES are needed."

Dr. Choe and colleagues studied data from more than 13,000 patients (median age about 64; about 76% men) with acute MI who underwent PCI. BP-DES were implanted in 21.7% and second-generation DP-DES in 73%.

As reported in JACC Cardiovascular Interventions, major adverse cardiovascular events (MACE) occurred in 14.3% of patients during a median 723-day follow-up. As Dr. Choe suggested, MACE were less frequent with BP-DES compared to DP-DES implantation: entire cohort hazard ratio, 0.845; propensity score (PS)-matched HR, 0.669.

Specifically, HRs (entire cohort; PS-matched) were lower with BP-DES for risk of all-cause death (0.831; 0.752); cardiac death (0.685; 0.613); recurrent MI (0.662; 0.611); and heart failure readmission (0.625; 0.584).

No significant between-group differences were detected in the incidences of any revascularization, stroke, or definite or probable stent thrombosis.

Several U.S. cardiologists commented on the findings in emails to Reuters Health.

Dr. Ryan Madder, Section Chief, Interventional Cardiology at Spectrum Health in Michigan, said, "The findings are interesting, but should not yet lead to a change in clinical practice. Owing to the observational design of the study, possible confounding cannot be excluded. I therefore agree with the authors that their observations should only be considered hypothesis-generating."

Dr. Dmitriy Feldman, Director of Endovascular Services at Weill Cornell Medicine and NewYork-Presbyterian in New York City, commented that the findings "should be interpreted with caution due to several important limitations of this analysis: 1) possibility of selection bias and uncorrected confounders, where the BP-DES population had more favorable baseline characteristics; 2) BP-DES were grouped together and included stent platforms with differences in drugs, polymers, polymer distribution, and, importantly, strut thickness. Therefore, differences in clinical outcomes may be related to individual aspects of DES platform designs rather than from a class effect of a BP-DES; and 3) outcomes examined in the study are reflective of patient-specific rather than stent-specific outcomes."

"Outcomes...may be improved with the newer generation of DES that utilize ultrathin metallic stent strut platforms and biodegradable polymers," he added. "Future randomized trials are needed to compare ultrathin stent strut platforms with biodegradable polymers versus durable polymers in patients undergoing primary PCI."

Dr. Richard Kovach, Director, Interventional Cardiology at Deborah Heart and Lung Center in Brown Mills, New Jersey, commented, "Although this study contributes significantly to our understanding of the science, it is only one step in advancing our knowledge about the advantages/disadvantages or benefits of BD-DES versus DP-DES, and is unlikely to result in any broad-sweeping change in the choice of DES or evidence-based recommendations for clinical practice."

In addition to some of the points raised by others, Dr. Kovach noted that "the study group consists of patients with ST elevation or non-ST elevation MI; the results therefore cannot necessarily be extrapolated to patients with stable angina undergoing elective procedures."

Further, "The BD-DES used in this study is not currently available in the U.S.; more specifically, the drug on this stent is biolimus, while the drug on the currently available BD-DES in the U.S. is everolimus. The differences in the anti-restenotic drug may influence the outcomes of any similar trial. We also don't know if the BD polymers used on these different BD stents are comparable and cannot assume that they have a class effect or lack of effect on the outcomes. And, the stent design can also influence outcomes."

"More information and randomized, controlled studies are needed - ideally, randomized controlled studies with the same stent and same drug, but with a BD versus DP coating on the stent as the only difference between the two treatment arms," he concluded.

SOURCE: and JACC Cardiovascular Interventions, online January 6, 2020.