Can coronary CT angiography accurately evaluate bioresorbable vascular scaffolds? Experts disagree

Coronary CT angiography (CTA) is diagnostically accurate in detecting scaffold luminal obstruction, according to a team of international researchers, signaling it may become the preferred method for evaluating patients treated with bioresorbable vascular scaffold (BVS)—but not all experts agree.

In a study published in the May issue of the Journal of the American College of Cardiology (JACC), researchers tested the effectiveness of coronary CTA in evaluating angiographic outcomes after BVS implantation compared to invasive coronary angiography (ICA) and intravascular ultrasound (IVUS).

Authors analyzed CTA accuracy of 258 lesions in 238 patients enrolled in the A Bioresorbable Everolimus-Eluting Scaffold Versus a Metallic Everolimus-Eluting Stent II (ABSORB II) study at three-year follow-up. Patients treated with BVS underwent coronary CTA, ICA and IVUS.

Results showed, in comparison with IVUS, both coronary CTA and ICA underestimated the in-scaffold minimal lumen diameter and minimal lumen area. Coronary CTA and QCA produced similar diagnostic accuracy for in-scaffold evaluation compared to IVUS.

Additionally, coronary CTA criteria to predict an ICA stenosis of greater than 50 percent had an area under the curve of .88 for a sensitivity of 75 percent and a specificity of 100 percent. Compared with IVUS, coronary CTA achieved an AUC of 0.82, a sensitivity of 77 percent and a specificity of 82 percent.

“Coronary CTA has a good diagnostic accuracy to detect in-scaffold luminal obstruction and to assess luminal dimensions after BVS implantation. Coronary CTA and coronary angiography yielded similar diagnostic accuracy to identify the presence and severity of obstructive disease,” wrote Carlos Collet, MD, with the Academic Medical Center at the University of Amsterdam. “Thus, coronary CTA might become the method of choice for the evaluation of patients treated with bioresorbable scaffolds.”

However, in a corresponding JACC editorial, Joaquin E. Cigarroa, MD, with Oregon Health & Sciences University, argued the three-year follow-up mark was not appropriate for determining the diagnostic accuracy of coronary CTA to detect in-scaffold luminal obstruction in patients treated with BVS, but rather that follow-up should be done in six to twelve months— “a more clinically relevant time frame for our patients and our clinicians,” he wrote.

“The conclusion, therefore, that coronary CTA has good diagnostic accuracy to detect in-scaffold luminal obstruction is incorrect as most of the scaffold no longer exists at three years,” Cigarroa wrote.

Although he did go on to agree with Collet et al. writing, “coronary CTA at three years is an effective tool to assess the presence of a lesion and the remodeling associated with the prior BVS percutaneous coronary intervention.”