Registry Study Suggests Absorb BVS Matches DES in Diabetic All-Comers


Bioresorbable scaffolds (BRS) provide acceptable mid-term outcomes in high-risk diabetic patients with complex lesions, according to a small registry study published online August 13, 2015, ahead of print in Catheterization and Cardiovascular Interventions.

Take Home: Registry Study Suggests Absorb BVS Matches DES in Diabetic All-Comers

Investigators led by Jens Wiebe, MD, of the University of Giessen (Giessen, Germany), looked at 120 diabetic patients (median age 67 years; 26.7% women)—35% of them insulin dependent—who received an Absorb BVS (Abbott Vascular) in 127 lesions at a single center between October 2012 and September 2014.

Absorb consists of a poly-L-lactic acid frame coated with a poly-D, L-lactic acid matrix and everolimus; the struts are 150 µm thick. According to the authors, the device is completely resorbed within approximately 24 months.

Predilation of the target lesion was mandatory and postdilation after implantation was highly recommended. Unfractionated heparin at 70 U/kg body weight was administered immediately before the procedure. Glycoprotein IIb/IIIa inhibitors (GPIs) were used at the operator’s discretion.

Nearly half of patients presented with ACS. The predominant stenosis site was the LAD (47.2%), and 60.6% of lesions were classified as B2 or C. A scoring balloon was used for lesion preparation in 6.7% of cases.

Implantation Feasible, Postprocedural Complications Rare

Implantation was successful in 98.4% of lesions. Slow flow was observed in 2 patients, who were subsequently treated with GPIs and had no in-hospital complications. In another 2 patients, OCT revealed evidence of edge dissection, which required implantation of an additional BRS.

At discharge, 96.6% of patients with successful implantation received aspirin, 44.9% clopidogrel, 28.8% ticagrelor (Brilinta; AstraZeneca), and 26.3% prasugrel (Effient; Eli Lilly/Daiichi Sankyo). In addition, 21.2% of patients were taking a vitamin K antagonist or new oral anticoagulant for A-fib.

During hospitalization (median 3 days) there was 1 STEMI due to Academic Research Consortium (ARC)-defined definite scaffold thrombosis, 1 non-target-vessel MI, and 1 death due to severe heart failure.

Over a median follow-up of 248 days, 4 patients had an MI unrelated to the implanted BRS, 3 experienced in-scaffold restenosis that was treated with DES, 2 patients died of heart failure, and 1 patient each had a STEMI and a NSTEMI, both due to scaffold thrombosis (the NSTEMI most likely because of DAPT discontinuation). Kaplan-Meier rates of MACE, target vessel failure (TVF; death from known cardiac cause, target-vessel MI, and TVR), TVR, target lesion failure (TLF), TLR, target-vessel MI, ARC-defined scaffold thrombosis, and cardiac death at 30 days and 6 months are shown in table 1.

Table 1. Outcomes at 30 days and 6 months

There were no noncardiac deaths.

“BRS constitute a prudent alternative to DES,” the authors say, citing a recent randomized trial that provided equivalent clinical results and benefits like late lumen enlargement and restoration of vasomotion. They note that diabetics in particular might benefit from BRS dissolution because no metallic remnants are left behind to cause chronic inflammation or aggravate existing inflammation.

Another potential advantage of BRS resorption is that future CABG is not precluded, Dr. Wiebe and colleagues add.

BRS Appear Comparable to DES in Diabetics

A recent pooled analysis of diabetic patients from the ABSORB and SPIRIT trials found similar rates of a device-oriented composite endpoint for the Absorb BVS and EES, and a lower rate of definite/probable device thrombosis for both groups (0.7%) than was seen in the current study. However, the investigaors note, their study included patients with acute MI and a higher prevalence of complex lesions.

Additionally, the authors point out, all cases of scaffold thrombosis in the current analysis occurred in patients with B2 or C lesions, and in 2 of 3 cases the patients had discontinued DAPT immediately after PCI. “Thus, DAPT seems to be essential to avoid these events, especially when considering that BRS strut thickness may cause turbulent flow,” they say.

Moreover, although the 6-month incidence of cardiac mortality was relatively high, only 1 of 4 such deaths was related to the scaffold, the researchers observe.

TLR rates were similar to those seen with everolimus- and zotarolimus-eluting stents in all-comers registries, the authors write, adding that any advantages for BRS are likely to be seen on longer-term follow-up during or after resorption.

The authors acknowledge certain downsides to BRS. They note, for example, that mandatory predilation and frequent postdilation entails extra contrast, which can have adverse effects in patients with diabetic nephropathy, and that diabetics’ CAD is often severely calcified, which increases the risk of scaffold fracture.   

Overall, the findings suggest that BRS “can be considered as a reasonable alternative [to DES] for use in daily clinical practice, since they offer benefits beyond scaffolding a stenosis,” Dr. Weibe and colleagues conclude. However, they caution, “patients and lesions should be selected carefully.” Further randomized trials and long-term data are needed to test this hypothesis, they add.

 


Source: 
Wiebe J, Gilbert F, Dörr O, et al. Implantation of everolimus-eluting bioresorbable scaffolds in a diabetic all-comers population. Catheter Cardiovasc Interv. 2015;Epub ahead of print.

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Registry Study Suggests Absorb BVS Matches DES in Diabetic All-Comers

Disclosures
  • Dr. Wiebe reports no relevant conflicts of interest.

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