Angiographically Based Direct Implantation of the Bioresorbable Vascular Scaffold in Non-ST Segment Elevation Acute Coronary Syndrome: Feasibility and Outcome

Background: Direct implantation of metallic drug-eluting stents is recommended for lesions with high thrombotic burden; however, this can't be applied to bioresorbable scaffold for which adequate lesion preparation is recommended.

Aim: We aimed at assessing the feasibility and safety of direct scaffold implantation based only on angiographic assessment in patients presented with non-ST segment elevation acute coronary syndrome.

Methods: The study was a retrospective two-centre study conducted over patients diagnosed with NSTE-ACS presented to cardiology department at Juan Ramon Hospital, Spain and critical care department, Cairo University in the period between February 2016 to May 2017. We included patients for whom we depend only on angiographic assessment for decision making whether to directly implant the scaffold or predilate the lesion and we excluded patients for whom intracoronary imaging was used at the index procedure either for pre or post-implantation. The primary outcome of interest was the device-oriented composite endpoints (DOCE) including cardiac death, and MI attributed to the target vessel and TLR. The secondary endpoints were the broader patient-oriented composite outcome (POCE) and scaffold/stent thrombosis. POCE includes all-cause mortality, any MI and any revascularisation (including TLR, TVR and revascularisation of non- target vessel).

Results: Among 46 patients with NSTE-ACS treated with BVS, we did direct implantation in 20 patients (group A), and we used pre dilatation in 26 patients (group B). The two groups have similar demographics and clinical criteria. Procedural success was obtained in all study population. Mean follow up duration was 12 months. We have total of 10% device-oriented composite endpoints in group A versus 15% in group B (p-value = 0.684). We didn't document any cardiac death in both groups. In group B we had one (3.8%) non-fatal MI while there was no MI in group A (P-value = 1). In group A we had 2 cases (10%) of TLR while in group B there were 3 cases (11.5%) TLR (P-value = 1). We have two cases (7.7%) of TVR in group B and one in group A p-value = 1. All cases were planned staged PCI. Scaffold thrombosis occurred in one case in group A (5%) and two cases in group B (7.7%) p-value = 1.

Conclusion: With proper lesion selection, direct BVS implantation in all-comers NSTE-ACS patients is feasible and safe even without the aid of intracoronary imaging.