Complex Lesions, Thrombus During PCI May Spell Trouble After DES Implantation

Certain angiographic characteristics are strongly linked to greater risk of stent thrombosis in the 2 years after DES implantation, an analysis of the ADAPT-DES study shows.

Having American College of Cardiology/American Heart Association (ACC/AHA) type C lesions and thrombus present during the index PCI were both associated with about double the likelihood of developing stent thrombosis, Philippe Généreux, MD, of the Hôpital du Sacré-Coeur de Montréal (Montréal, Canada) and the Cardiovascular Research Foundation (New York, NY), and colleagues report.

The findings, recently published online in Catheterization and Cardiovascular Interventions, are consistent with prior studies and underscore “the central role of baseline angiographic assessment in risk prediction,” they say. A previous analysis of ADAPT-DES identified a relationship between platelet reactivity and stent thrombosis. “However,” the authors note, “the role of angiographic lesion characteristics, while also taking into account platelet reactivity, has yet to be examined.”

In this prespecified analysis, an independent core lab took a detailed look at all stent thrombosis cases through 2 years follow-up in the main trial, which prospectively assessed all-comers patients who had successful PCI with DES at 11 centers in the United States and Germany.

Of the 8,582 patients in ADAPT-DES, 1.1% developed stent thrombosis. Academic Research Consortium-defined definite or probable target lesion-related stent thrombosis was seen in 77 patients (82 lesions), who were matched to 153 patients (196 lesions) who did not develop stent thrombosis. In all, 2.6% of stent thrombosis cases occurred within 24 hours, 45.5% between 24 hours and 30 days, 36.4% between 30 days and 1 year, and 15.6% beyond 1 year.

After adjustment for several variables, including high platelet reactivity, 2 angiographic and 3 clinical predictors of stent thrombosis emerged.

“The present study is the first and largest study to specifically address the association between baseline angiographic pre-PCI targeted-lesion characteristics, platelet reactivity, and the risk of subsequent [stent thrombosis] among patients undergoing contemporary DES PCI,” Généreux and colleagues write, noting that most prior studies had low patient numbers, were performed in the BMS era, included mostly low-risk patients, or lacked assessment by an angiographic core lab.

“Our analysis, by assessing an all-comers population that underwent contemporary PCI with more than 75% second-generation DES, and by accounting for the potential interplay between platelet reactivity, clinical characteristics, and angiographic target lesion features, adds meaningful information to the relationship between baseline coronary anatomy and [stent thrombosis] risk after PCI,” they say.

Implications for Treatment Strategies

Considering the strong relationships found between complex lesions, thrombus, and stent thrombosis, “it is concerning that few studies have looked at how the effects of current treatment strategies are influenced by lesion complexity,” they say. “While it is generally accepted that more potent antiplatelet therapy can reduce the risk of [stent thrombosis] for patients with complex coronary lesions, whether more potent antiplatelet therapy can completely overcome the detrimental effect of lesion complexity remains to be prospectively demonstrated.”

They point out that recent studies have suggested that a shorter duration of dual antiplatelet therapy (DAPT) might be possible with newer-generation DES.

“Whether these findings can be extrapolated to patients with complex lesions (such as ACC/AHA type C or the presence of thrombus) remains to be proven,” they say, adding, however, that “in the absence of convincing evidence, shorter DAPT duration across the entire spectrum of lesion complexity may be hazardous for some patients and is debatable. We argue that angiographic lesion characteristics should be taken into consideration when deciding on the optimal DAPT duration. Similarly, the choice of antiplatelet agent should also be influenced by angiographic lesion complexity.”

“Future studies,” they conclude, “are required to identify effective pharmacoinvasive strategies to reduce [stent thrombosis] in high-risk lesions.”

Note: Généreux and several coauthors are faculty members of the Cardiovascular Research Foundation, which owns and operates TCTMD.

Source: 
Généreux P, Redfors B, Witzenbichler B, et al. Angiographic predictors of 2-year stent thrombosis in patients receiving drug-eluting stents: insights from the ADAPT-DES study. Catheter Cardiovasc Interv. 2016;Epub ahead of print.

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• ADAPT-DES: Risk of Early Stent Thrombosis in DES Predicted by Platelet Inhibition
• ADAPT-DES Substudy: Practice Changes May Decrease Already Low Stent Thrombosis Rates Even Further
• ADAPT-DES: Stent Thrombosis Increased During First 30 Days After PCI in High-Risk Patients