Late Malapposition After Bare-Metal Stent, But Not Bioresorbable Scaffold: Insights on Intraindividual Heterogeneity in Plaque and Device Response

Abstract: We present a case of late acquired bare-metal stent malapposition and uncovered struts, visible at angiography and confirmed by optical frequency domain imaging. In the same patient, an everolimus-eluting biovascular scaffold in another vessel was well apposed and all struts were covered. This case highlights the potential heterogeneity in the evolution of atherosclerotic plaques and response to different devices in the same patient.

J INVASIVE CARDIOL 2015;27(8):E171-E172

Key words: cardiac imaging, optical frequency domain imaging, bioresorbable vascular scaffolds, malapposition

_____________________

Case Report

A 55-year-old patient with inferior ST-elevation myocardial infarction was admitted for primary percutaneous coronary intervention (PCI). After several thrombectomy runs, a 3.0 x 16 mm titanium-nitride-oxide coated Titan2 stent (Hexacath) was implanted in the mid-portion of the right coronary artery (RCA), achieving satisfactory result. Two days later, he underwent elective PCI with a 3.0 x 18 mm Absorb bioresorbable vascular scaffold (Abbott Vascular) placed in the left anterior descending artery.

The patient was discharged uneventfully. Twelve months later, at repeat coronary angiography performed as part of a routine quality control protocol, a significant aneurysm was evident at the site of the Titan2 stent. The aneurysm was confirmed by optical frequency domain imaging (OFDI; Terumo Corporation). In addition, OFDI showed the presence of several uncovered struts. Conversely, the angiographic and OFDI results of the bioresorbable vascular scaffold appeared entirely satisfactory, with all struts completely covered and no area of malapposition. Platelet function testing showed no evidence of clopidogrel unresponsiveness; thus, we opted for life-long clopidogrel monotherapy and careful clinical follow-up despite the lack of valid and precise clinical data on the optimal management of coronary aneurysms. Indeed, adequate stent expansion, even at OFDI, proved reassuring considering that the true prognostic impact of stent malapposition remains unclear.

This clinical vignette highlights the potential heterogeneity in the evolution of different plaques and the response to different devices in the same patient, and underscores the need for caution when applying simple and apparently reassuring paradigms, ie, that the use of a bare-metal stent may be safer than drug-eluting stent or bioresorbable scaffold in thrombotic and unstable coronary lesions.¹ Indeed, it remains unclear whether the aneurysm was already present (but filled with thrombus) during the index procedure, or whether the nitric-oxide releasing effects of the Titan2 stent may have contributed to its development or worsening.

References

1. Kubo T, Tanaka A, Kitabata H, Ino Y, Tanimoto T, Akasaka T. Application of optical coherence tomography in percutaneous coronary intervention. Circ J. 2012;76:2076-2083.

_____________________

From ¹Interventional Cardiology, Fatebenefratelli Hospital, Milan, Italy; ²the Cardiac Department, P. Giaccone Hospital, Palermo, Italy; and ³the Department of Medico-Surgical-Sciences/Biotechnologies, Sapienza University, Latina, Italy.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Cortese and Dr Biondi-Zoccai report consultation and lecture fees from Abbott Vascular. Dr Cortese reports consultation fees from Hexacath. The authors report no conflicts of interest regarding the content herein.

Manuscript submitted January 30, 2015 and accepted February 2, 2015.

Address for correspondence: Bernardo Cortese, MD, Fatebenefratelly Hospital, Corso di Porta Nuova 23, 20121 Milano, Italy. Email: bcortese@gmail.com