Very Late Stent Thrombosis Remains an Important Clinical Target


The frequency of very late stent thrombosis and associated mortality has declined in recent years, but outcomes of very late stent thrombosis remain an important clinical target, according to a speaker at TCT 2015.

About half of all stent thrombosis cases occur very late, Donald E. Cutlip, MD, of Beth Israel Deaconess Medical Center, Boston, Mass., said during a presentation. Recent data show a decline in very late cases, to a rate of approximately 1% over 5 years, he said. Early and late mortality associated with Academic Research Consortium (ARC)-defined very late stent thrombosis ranges from 10% to 20% and is lower than mortality associated with early stent thrombosis, which ranges from 20% to 50%.

“Very late stent thrombosis remains important. It’s great that we reduced the frequency of very late stent thrombosis … but a mortality of about 10% is still quite high and worrisome,” Cutlip said.

In the BASKET-LATE study, which examined outcomes of late thrombosis-related events in patients treated with DES vs. BMS after clopidogrel discontinuation, the rate of cardiac mortality was 19% and that of nonfatal MI was 75% in those with late or very late stent thrombosis.

More recent observational studies suggest outcomes for late events have improved in the years since that study, however, Cutlip said. He referenced a single-center study published in 2014 that showed a mortality rate of 23.7% for early stent thrombosis, 14.8% for late stent thrombosis and 9.6% for very late stent thrombosis. Furthermore, data from the National Cardiovascular Data Registry, which included more than 7,000 cases of stent thrombosis from 2009 to 2010 showed an overall stent thrombosis rate of 1.8%. About 60% of those cases were very late stent thrombosis, most likely stemming from first-generation devices, Cutlip said. Additionally, in-hospital death was higher in those with early vs. very late stent thrombosis (7.9% vs. 3.6%; P < 0.001).

Trials needed for new stent types

During another presentation, Stefan K. James, MD, of Uppsala Clinical Research Center, Uppsala, Sweden, said data indicate that the overall rate of stent thrombosis is low with modern DES and potent platelet inhibition. Most clinical trials and registries show an early stent thrombosis rate of less than 1%, he said.

“The risk of stent thrombosis appears not to be higher with DES compared with BMS,” he said.

James presented new results from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR) showing the cumulative risk of stent thrombosis for individual newer-generation devices beyond 1 year (Figure).

Image Stent Thrombosis

“I’m not saying that one stent is worse than another, but it is an important and interesting observation that [can be examined] in an all-comers registry,” James said about the SCAAR data. “New stent types need to be evaluated in trials and in post-marketing surveillance studies and registries.”

Disclosures:

  • Cutlip reports receiving grant/research support from Boston Scientific Corporation, CeloNova and Medtronic.
  • James reports relationships with multiple pharmaceutical and device companies.

 

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