Late Events Continue to Accrue After PCI

Debra L Beck

February 13, 2020

In a meta-analysis of individual patient data on more than 25,000 patients undergoing percutaneous coronary intervention (PCI) with bare-metal and first- and second-generation drug-eluting stents, stent-related adverse events were shown to continue to accrue at a rate of about 2% per year from postprocedure years 1 to 5.

"The data show that while we've made tremendous advances in the first year after stent implantation, we have not made any advances between 1 and 5 years. Regardless of whether it was a bare-metal stent or a first- or second-generation drug-eluting stent, we documented an approximate 2% per year target lesion failure rate coming from the stent site," said Gregg W. Stone, MD, Cardiovascular Research Foundation, New York City, in an interview with | Medscape Cardiology.

Stone and colleagues, including first author Mahesh V. Madhavan, MD, New York-Presbyterian Hospital, New York Vity, pooled individual patient data from 19 selected prospective studies that included 25,032 patients randomly assigned to treatment with bare-metal stents (n = 3,713), first-generation drug-eluting stents (DES1; n = 7,934), and second-generation DES (DES2; n = 13,380).

The findings and a related editorial were published online ahead of the February 18 issue of the Journal of the American College of Cardiology.

The researchers set their primary end point as "very-late MACE" — the composite of cardiac death, myocardial infarction (MI), and ischemia-driven target lesion revascularization (ID-TLR) — from 1 to 5 years, because that was the outcome determined in all 19 trials.

Although, strictly speaking, this was not a stent-specific end point, Stone noted that it was not far from stent-specific either. "It's a little broader than our target-lesion failure end point, but it still didn't include everything. It didn't include non-target vessel related events, so I'd say it's still mostly stent-related events."

Overall, MACE between 1 and 5 years after stenting was seen in 9.4% of patients. This included cardiac death in 2.9%, MI in 3.1%, and ID-TLR in 5.1%.

When divided by stent type, late MACE occurred in 9.7% of patients treated with BMS, 11.0% of those treated with DES1, and 8.3% of the DES2 group (< .0001).

"We know that second-generation drug-eluting stents are safer and more effective than first-generation, not only in the first year but beyond that as well, but it must be pointed out that there is still ongoing risk after the first year," commented Stone.

The rates increased in a linear fashion between 1 and 5 years, with no plateau evident, he added.

Stent-Specific Outcomes

A more stent-specific measure of target lesion failure (TLF) — defined as cardiac death, target-vessel myocardial infarction (TV-MI), or ID-TLR — was used as a key secondary end point. Patient-level findings for this end point were available in 12 trials in which TV-MI was adjudicated.

TLF in the 4-year period was 8.2%, again with a linear increasing event rate with all stent types and no sign of a plateau. It's from this number that the researchers "eye-balled" the 2% per year figure.

"There was no plateau evident; it was a straight line up to 5 years," Stone emphasized. "So, given that the patients we treat are in their 50s and 60s, it's easy to see that 10 or 20 years later, there's going to be a large percentage of patients that have events arising from the stent sites. And that is, of course, in addition to non-stent-related events, non-culprit-lesion events from advancing atherosclerosis."

Asked about the inclusion of cardiac death in the stent-related events grouping, Stone agreed that this is "not perfect by any means."

In their editorial, Manel Sabaté, MD, PhD, and Michael Mack, MD, concur that cardiac death, target-vessel MI, and ID-TLR could indeed all be considered stent related.

To this they add, however, that only about 40% of all events occurring between 1 and 5 years can be considered stent related. "Although some of the events may be related to target lesion failure, the majority of them occurred remote from the target site," Sabaté and Mack write.

Newer metallic alloys, thinner struts, and the use of biocompatible polymer coating have all been shown to reduce events, they say, but their impact can be expected to have "minimal incremental benefit to overall patient outcomes."

Said Stone: "Back when I was in training, we used to tell patients that if nothing happened in the first year, they're free, nothing is going to happen at the treated site, but I think what we've learned over the years — and this is by far the largest and most comprehensive analysis to show this — is that not only are they not done, but there's an ongoing, small, but cumulative risk of events even from the target lesion site."

This investigator-initiated study was funded in part by Abbott Vascular. Stone reports that he currently has no financial relationships with stent makers. Sabaté has received consultant fees from Abbott Vascular and IVascular outside the submitted work, and Mack has been the coprincipal investigators and study chair for trials for Abbott, Edwards Lifesciences, and Medtronic.

J Am Coll Cardiol. 2020;75:590-604, 605-607. Abstract, Editorial


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: