OCT predicted incomplete stent apposition, associated outcomes

Optical coherence tomography demonstrated that second-generation DES show greater capacity to heal acute incomplete stent apposition than first-generation DES and can provide useful information to optimize PCI, new data concluded.

Researchers of the study aimed to compare first-generation sirolimus-eluting stents (SES) with second-generation everolimus-eluting stents (EES) for the natural course of incomplete stent apposition and used OCT to assess outcomes.

The analysis included 77 patients from the OCT subset of the RESET trial. Thirty-nine patients received SES and 38 received EES. Eligible participants underwent serial OCT examination after stenting and at 8 to 12 months follow-up.

Clinicians determined the presence of incomplete stent apposition and the distance from the center of the strut blooming to the adjacent lumen border.

All stents demonstrated incomplete stent apposition at post-stenting. This persisted at 8 to 12 months follow-up in 38% of SES and 26% of EES.

Other results indicated significant decreases in maximum incomplete stent apposition distance in both SES (post-stenting, 308 ± 119 mcm vs. follow-up, 143 ± 195 mcm; P<.001) and EES (post-stenting, 315 ± 94 mcm vs. follow-up, 110 ± 165 mcm; P<.001).

The optimal cut-off value of OCT-estimated incomplete stent apposition distance after implantation for predicting late-persistent apposition at 8 to 12 months was >285 mcm for SES and >355 mcm for EES, according to results of a receiver-operating curve analysis.

“The second-generation EES showed better healing of acute [incomplete stent apposition] in comparison with the first-generation SES,” the researchers concluded. “Optical coherence tomography can predict late-persistent [incomplete stent apposition] after DES implantation and provide useful information to optimize PCI.”

Gary S. Mintz

In an accompanying editorial, Gary S. Mintz, MD, of the Cardiovascular Research Foundation, New York, raised the question of why the clinical community places such importance on acute incomplete stent apposition. He noted that the most recent Cardiac Catheterization and Interventional Cardiology Self-Assessment Program described stent apposition as “the most important determinant of freedom from subacute stent thrombosis with DES.”

“To the contrary, the predictors of early [stent thrombosis] that have been identified with intravascular imaging are primarily stent underexpansion and secondarily inflow/outflow problems such as a larger plaque burden, a small lumen area, and/or a large dissection at either stent edge,” Mintz continued. “Given the nearly ubiquitous finding of acute [incomplete stent apposition], it is not surprising that studies using IVUS or OCT have shown no relationship between acute [incomplete stent apposition] and early, late or very late stent thrombosis after DES implantation.”

Mintz stressed that adequately powered studies should be conducted to assess whether incomplete stent apposition actually can predict stent thrombosis, and what the extent of that stent thrombosis is.

“Until information is available to the contrary, the misguided emphasis on avoiding [incomplete stent apposition] should be replaced with renewed attention to what is known to be important —stent expansion and proper lesion coverage,” Mintz wrote.

For more information:

Shimamura K. Eur Heart J Cardiovasc Imaging. 2014;doi:10.1093/ehjci/jeu174.

Mintz GS. Eur Heart J Cardiovasc Imaging. 2014;doi:10.1093/ehjci/jeu199.

Disclosure: The researchers report financial disclosures with Abbott Vascular. Mintz reports financial disclosures with Acist, Boston Scientific, Infraredx, St. Jude Medical and Volcano Corp.