Comparison between treatment of "established" versus complex "off-label" coronary lesions with Absorb® bioresorbable scaffold implantation: results from the GABI-R® registry

OBJECTIVES

The purpose of this study was to compare the clinical outcomes of patients treated with bioresorbable scaffold (BRS) for off-label versus approved indications.

BACKGROUND

The BRS promised some advantages in terms of complete biodegradation within 2-4 years, restored vascular physiology, and absence of potential stent-related long-term complications. However, the implication of BRS for off-label indications and further long-term follow-up of this particular patient group is not well described.

METHODS

The short- and long-term outcome after implantation of an everolimus-eluting, poly-L-lactic acid-based bioresorbable scaffold system (ABSORB, Abbott Vascular, Santa Clara, CA, USA) was evaluated in the prospective, non-interventional, multicenter real-world German-Austrian ABSORB RegIstRy (GABI-R).

RESULTS

A total of 3188 patients were enrolled. Patients were divided into two groups: on-label BRS use (33.0%) and off-label use (66.9%) if at least one off-label use criteria was met. The incidence of scaffold thrombosis in confirmed cases was significantly higher in off-label group (1.3% versus 0.5%, p = 0.04; OR 2.41 (95% CI 1.00-5.82) with also a trend toward higher myocardial infarction rate (2.3% versus 1.4%, p = 0.077; OR 1.70 (95% CI 0.95-3.03) and cardiovascular death (1.2% versus 1.1%, p = 0.76, OR 1.11 (95% CI 0.56-2.21) at 6-month follow-up.

CONCLUSIONS

In a real-world setting, the majority patients were treated with BRS for off-label indications. The off-label use of BRS compared to confirmed indications appears to be associated with a higher rate of clinical endpoints considering more complex lesions and higher morbidity in this patients' group. Comparison between treatment of "established" versus complex "off-label" coronary lesions with Absorb^® bioresorbable scaffold implantation: results from the GABI-R^® registry.

One-year clinical performance of ABSORB bioresorbable vascular scaffold in patients presenting with acute coronary syndromes: Results from the RAI registry

OBJECTIVES

To report 1-year clinical outcomes of bioresorbable vascular scaffold (BVS) in acute coronary syndromes (ACS) population.

BACKGROUND

BVS use has rapidly extended to high-risk patients as those presenting with ACS. To date limited data have been reported on BVS performance in ACS patients.

METHODS

RAI is a multicenter, prospective registry that included 1,505 patients treated with at least 1 successful BVS implantation. A subgroup analysis on ACS patients was performed and the 1-year outcomes of this cohort compared to the remaining stable coronary artery disease (SCAD) population are reported here. Coprimary endpoints were target-lesion revascularization (TLR) and scaffold thrombosis (ScT) at 1-year follow-up.

RESULTS

Fifty-nine percent of the patients presented with ACS, of whom 36.5% with ST-elevation myocardial infarctions. ACS patients were significantly younger, with a better cardiovascular risk profile, a lower rate of multivessel disease, chronic total occlusion or in-stent restenosis and a lower Syntax score. Predilation and postdilation were performed in 97.4% and in 96.5% of cases, respectively. No differences were noted in terms of TIMI 3 final flow, but acute gain was greater in ACS compared to SCAD group (P < 0.001). At one-year follow-up no differences were found in terms of TLR (3.3% vs. 3.3%, P = 0.98), and device-oriented composite end-point (4.3% vs. 3.4%, P = 0.4) between ACS and SCAD groups. The rate of definite/probable ScT was numerically higher in ACS vs. stable CAD patients (1.3% vs. 0.8%, P = 0.2).

CONCLUSIONS

Our data suggest that the use of BVS in ACS patients is associated with a numerically higher rate of ScT compared to SCAD population numerically higher, but without statistical significance.

Mid-term outcomes of the Absorb BVS versus second-generation DES: A systematic review and meta-analysis

Background

Bioresorbable Vascular Scaffolds (BVS) were introduced to overcome some of the limitations of drug-eluting stent (DES) for PCI. Data regarding the clinical outcomes of the BVS versus DES beyond 2 years are emerging.

Objective

To study mid-term outcomes.

Methods

We searched online databases (PubMed/Medline, Embase, CENTRAL), several websites, meeting presentations and scientific session abstracts until August 8^th, 2017 for studies comparing Absorb BVS with second-generation DES. The primary outcome was target lesion failure (TLF). Secondary outcomes were all-cause mortality, myocardial infarction, target lesion revascularization (TLR) and definite/probable device thrombosis. Odds ratios (ORs) with 95% confidence intervals (CIs) were derived using a random effects model.

Results

Ten studies, seven randomized controlled trials and three propensity-matched observational studies, with a total of 7320 patients (BVS n = 4007; DES n = 3313) and a median follow-up duration of 30.5 months, were included. Risk of TLF was increased for BVS-treated patients (OR 1.34 [95% CI: 1.12–1.60], p = 0.001, I² = 0%). This was also the case for all myocardial infarction (1.58 [95% CI: 1.27–1.96], p<0.001, I² = 0%), TLR (1.48 [95% CI: 1.19–1.85], p<0.001, I² = 0%) and definite/probable device thrombosis (of 2.82 (95% CI: 1.86–3.89], p<0.001 and I² = 40.3%). This did not result in a difference in all-cause mortality (0.78 [95% CI: 0.58–1.04], p = 0.09, I² = 0%). OR for very late (>1 year) device thrombosis was 6.10 [95% CI: 1.40–26.65], p = 0.02).

Conclusion

At mid-term follow-up, BVS was associated with an increased risk of TLF, MI, TLR and definite/probable device thrombosis, but this did not result in an increased risk of all-cause mortality.

Predictors of early scaffold thrombosis: results from the multicenter prospective German-Austrian ABSORB RegIstRy

BACKGROUND

In randomized clinical trials, the risk of thrombotic events with the absorb bioresorbable vascular scaffold (BVS) was significantly higher than with metallic drug-eluting stents. We evaluated predictors of scaffold thrombosis in the large-scale, multicenter German-Austrian ABSORB RegIstRy.

METHODS AND RESULTS

3178 patients with treatment of 4252 lesions using 5020 scaffolds were included. Follow-up rate at 6 months was 97.4%. Forty-five (1.42%) patients experienced definite/probable scaffold thrombosis during follow-up. Multiple regression analysis showed implantation of absorb BVS in bifurcation lesions [odds ratio (OR): 4.43; 95% confidence interval (CI): 1.69-11.59; P=0.0024] or treatment in the years 2013/2014 (OR: 1.88; 95% CI: 1.02-3.47; P=0.04) to be significant predictors of scaffold thrombosis. Excluding bifurcation lesions, the incidence of definite/probable scaffold thrombosis decreased from 1.8% (95% CI: 1.17-2.64%) in 2013/2014 to 0.89% (95% CI: 0.5-1.46%) in 2015/2016. In the latter period, absorb BVS were implanted more often in younger patients with less complex de novo lesions, and debulking devices and postdilatation were used more frequently. Between the two treatment periods, there was a significant reduction in myocardial infarction (2.73-1.24%, P<0.01; OR: 0.45; 95% CI: 0.26-0.77), definite/probable scaffold thrombosis (1.79-0.88%, P<0.05; OR: 0.49; 95% CI: 0.26-0.93), and target lesion failure and revascularization during follow-up.

CONCLUSION

Improved procedural technique and more strict patient selection may explain a significant decrease in the absorb BVS thrombosis rates during the recruitment period of the large-scale German-Austrian ABSORB RegIstRy. In addition, treatment of bifurcation lesions was identified as an independent predictor of definite/probable scaffold thrombosis.

Acute and one-year clinical outcomes following implantation of bioresorbable vascular scaffolds: the ABSORB UK Registry

AIMS

The aim of this registry was to monitor practice patterns and outcomes in patients treated with Absorb bioresorbable vascular scaffolds (BVS) during the early phase of usage in the UK.

METHODS AND RESULTS

A total of 1,005 patients with de novo coronary lesions were treated using careful implantation techniques at 24 centres. Follow-up at one year was obtained in 99%. An independent clinical events committee and angiographic core lab adjudicated all events. Patient age was 52 years and 46% presented with acute coronary syndromes. Lesion complexity was B2/C in 47.4%, with an average of 1.4±0.6 BVS implanted and a BVS length of 28±14.3 mm. A single BVS was implanted in 71.3%. High pressure post-dilatation was performed in 94.9%, with 50% using intravascular imaging. Device success was achieved in 98.7% and procedure success in 97.3% of patients. At one year, the device-oriented endpoint target lesion failure was 3.2%, and the patient-oriented endpoint major adverse cardiac events was 3.4%. Definite ST occurred in 1.4%. By multivariable analysis, scaffold size of 2.5 mm predicted ST at one year (OR 3.27, 95% CI: 1.28-8.37; p=0.014).

CONCLUSIONS

With careful patient selection and technique, TLF rates following BVS implantation in real-world practice are comparable with contemporary drug-eluting stents. ST rates remain high, with small vessel size identified as a contributory factor.

Effect of Technique on Outcomes Following Bioresorbable Vascular Scaffold Implantation: Analysis From the ABSORB Trials

BACKGROUND

Procedural technique may affect clinical outcomes after bioresorbable vascular scaffold (BVS) implantation. Prior studies suggesting such a relationship have not adjusted for baseline patient and lesion characteristics that may have influenced operator choice of technique and outcomes.

OBJECTIVES

This study sought to determine whether target lesion failure (TLF) (cardiac death, target-vessel myocardial infarction, or ischemia-driven target lesion revascularization) and scaffold thrombosis (ScT) rates within 3 years of BVS implantation are affected by operator technique (vessel size selection and pre- and post-dilation parameters).

METHODS

TLF and ScT rates were determined in 2,973 patients with 3,149 BVS-treated coronary artery lesions from 5 prospective studies (ABSORB II, ABSORB China, ABSORB Japan, ABSORB III, and ABSORB Extend). Outcomes through 3 years (and between 0 to 1 and 1 to 3 years) were assessed according to pre-specified definitions of optimal technique (pre-dilation, vessel sizing, and post-dilation). Multivariable analysis was used to adjust for differences in up to 18 patient and lesion characteristics.

RESULTS

Optimal pre-dilation (balloon to core laboratory-derived reference vessel diameter ratio ≥1:1), vessel size selection (reference vessel diameter ≥2.25 mm and ≤3.75 mm), and post-dilation (with a noncompliant balloon at ≥18 atm and larger than the nominal scaffold diameter, but not by >0.5 mm larger) in all BVS-treated lesions were performed in 59.2%, 81.6%, and 12.4% of patients, respectively. BVS implantation in properly sized vessels was an independent predictor of freedom from TLF through 1 year (hazard ratio [HR]: 0.67; p = 0.01) and through 3 years (HR: 0.72; p = 0.01), and of freedom from ScT through 1 year (HR: 0.36; p = 0.004). Aggressive pre-dilation was an independent predictor of freedom from ScT between 1 and 3 years (HR: 0.44; p = 0.03), and optimal post-dilation was an independent predictor of freedom from TLF between 1 and 3 years (HR: 0.55; p = 0.05).

CONCLUSIONS

In the present large-scale analysis from the major ABSORB studies, after multivariable adjustment for baseline patient and lesion characteristics, vessel sizing and operator technique were strongly associated with BVS-related outcomes during 3-year follow-up. (ABSORB II Randomized Controlled Trial [ABSORB II]; NCT01425281; ABSORB III Randomized Controlled Trial [RCT] [ABSORB-III]; NCT01751906; A Clinical Evaluation of Absorb Bioresorbable Vascular Scaffold [Absorb BVS] System in Chinese Population-ABSORB CHINA Randomized Controlled Trial [RCT] [ABSORB CHINA]; NCT01923740; ABSORB EXTEND Clinical Investigation [ABSORB EXTEND]; NCT01023789; AVJ-301 Clinical Trial: A Clinical Evaluation of AVJ-301 [Absorb BVS] in Japanese Population [ABSORB JAPAN]; NCT01844284).

Bioresorbable Vascular Scaffolds - Are We Facing a Time of Crisis or One of Breakthrough?

Current 2nd-generation drug-eluting stents (DES) have dramatically improved clinical outcomes after percutaneous coronary intervention for coronary artery disease. However, DES implantation has major long-term limitations related to the permanent presence of foreign material in the coronary artery. Bioresorbable vascular scaffolds (BVS) were designed to overcome this limitation of permanent metal-based DES. However, because of immature manufacturing technology, BVS have several drawbacks, such as the thicker strut, poor deliverability, poor radio-opacity, poor radial strength, and cumbersome procedure to meet the principle of PSP (Preparation, Sizing, and Post-dilatation). Initial studies indicated that BVS outcomes were non-inferior to those of current DES and recent follow-up data of trials have revealed an additional critical drawback, higher rate of scaffold thrombosis, on the top of the existing limitations of BVS. Thus attention must be paid to the appropriate BVS-specific implantation protocols (i.e., PSP), as well as adequate intensity and duration of dual antiplatelet therapy. In any case, current BVS need further technical evolution to replace current metallic DES in routine clinical use.