Objective of this study was to assess the clinical performance of bioresorbable vascular scaffold (BVS) compared to everolimus-eluting stent (EES) in subjects with ST-segment elevation myocardial infarction (STEMI). We included all consecutive patients with STEMI who underwent percutaneous coronary intervention (PCI) with BVS implantation in centers participating to the Italian ABSORB Prospective Registry (BVS-RAI) and PCI with EES in the same centers during the same period. The 2 groups were compared. The primary end point was patient-oriented composite end point (POCE) including cardiac death, myocardial infarction, and target lesion revascularization (TLR) at the longest available follow-up. BVS or EES thrombosis at follow-up was also evaluated. Of the 563 patients with STEMI included, 122 received BVS and 441 EES. Procedural success was obtained in 549 (97.5%) cases without significant differences between the 2 groups (BVS 99.3% vs EES 97.0%, p = 0.2). At a median of 220-day (interquartile range 178 to 369) follow-up, no significant differences were observed in terms of POCE (BVS 4.9% vs EES 7.0%, p = 0.4); death (BVS 0.8%, EES 2.0%, p = 0.4), MI (BVS 4.1%, EES 2.0%, p = 0.2), TLR (BVS 4.1%, EES 4.5%, p = 0.8), device thrombosis (BVS 2.5%, EES 1.4%, p = 0.4). All TLR cases were successfully managed with re-PCI in both groups. A propensity matching of the study populations showed no significant differences regarding POCE at the longest available follow-up (odds ratio 0.53, 0.1 to 4.3). In conclusion, in this direct prospective comparison, BVS was associated with similar clinical results compared to EES in the STEMI setting. Larger and adequately powered randomized trials are needed to fully assess the potential clinical benefit of BVS versus the current standard of care in patients with STEMI.
Mechanical reperfusion of epicardial coronary arteries by primary percutaneous coronary intervention (PPCI) is currently the treatment of choice in patients with ST-segment elevation myocardial infarction (STEMI). Advances in interventional techniques, administration of more potent antiplatelet drugs, and the evolution from bare metal stents (BMS) to drug-eluting stents (DES) have improved the outcomes of patients with STEMI. In particular, the cobalt–chromium (Co-Cr) everolimus-eluting stent (EES-Xience; Abbott Vascular, California) has been shown to have a very favorable safety and efficacy profile and may be considered the standard of care for the treatment of patients with STEMI. Even if the current stent-based reperfusion strategies are associated with a high clinical performance, they have shortcomings related to the durable caging of the coronary wall. Indeed, the implantation of a permanent intracoronary metallic prosthesis may be associated to stent thrombosis (ST), restenosis, and malapposition. To overcome these limitations, new technologies are under investigation in the STEMI setting. The ABSORB everolimus-eluting bioresorbable vascular scaffold (BVS, Abbott Vascular) is an intracoronary prosthesis that provides temporary scaffolding and, over a period of 3 years, is fully reabsorbed by biochemical reactions, thus restoring the native pristine vessel state. The objective of this study was to assess the clinical performance of BVS compared to EES in subjects with STEMI who underwent PPCI.
Methods
Aim of this study was to assess the clinical outcomes of consecutive patients with STEMI with symptoms onset <24 hours who underwent PPCI with Absorb-BVS or EES implantation at 11 centers involved in the “Italian ABSORB Registry” (BVS-RAI), a spontaneous, prospective, ongoing multicenter Italian registry without fundings or benefits from the BVS manufacturer ( ClinicalTrials.gov identifier is CT02298413). This registry includes all consecutive patients who have successfully undergone unrestricted implantation of ≥1 BVS. Baseline patient clinical data are entered into a Web-based case report form. The conduct of the registry has been approved by the Ethics Committees of all participating centers. Written informed consent was obtained from all patients to include their data in the database. The registry started in October 2012 and will extend enrollment throughout 2015, with the aims to include 1,000 patients and assess major adverse cardiovascular events (MACE) during a 5-year follow-up. Data on PPCI patients from the BVS-RAI have already been published in part. Data from the centers contributing PPCI cases were also collected for all consecutive EES implanted during PPCI in the same time lapse. The full range of sizes and/or lengths for both BVS and EES was available during the study period in all participating centers. Although the decision to implant BVS rather than EES was the operator’s choice, vessel tortuosity and/or severe calcification proximally to the culprit lesion and infarct artery reference diameter visually exceeding the range of 2.5 to 4 mm were often considered criteria against BVS use. Available lengths for BVS during the study period were 12, 18, and 28 mm. All patients received a loading dose of commonly used antiplatelet drugs periprocedurally. The DAT regimen at discharge consisted in aspirin indefinitely, in association with clopidogrel, ticagrelor, prasugrel for 12 months. Intracoronary imaging, thrombus aspiration, lesion predilatation, and postdilatation (with a maximum diameter of 0.5 mm greater than the BVS diameter) were at the operator’s discretion.
Primary end points of this study were the cumulative occurrence of POCE (a composite of patient-oriented MACE, including death, MI, target lesion revascularization [TLR]) and device thrombosis at 6-month follow-up. Furthermore, we evaluated procedural success, defined as a final stenosis at the culprit site of <30% with thrombolysis in myocardial infarction 3 flow and without inhospital POCE. Clinical events were defined according to the Academic Research Consortium definitions. Furthermore, we differentiated POCE with device-oriented clinical outcome (DOCE). Clinical data were collected by hospital visits at 1 and 6 months. Source verification and queries generation from the coordinating center to the participating sites were undertaken to account partly for the unavoidable bias of site-reported events adjudication. An independent events adjudication was available for patients included in the Registro Absorb Italiano registry and case report form, but it was not for the cohort of patients receiving EES.
Statistical analysis
Data were summarized with counts and percentages for categorical variables, median, and interquartile range for continuous variables with skewed distribution. Mann–Whitney U and Fisher’s exact tests were computed when appropriate for bivariate analyses. Cumulative event rates were compared with the log-rank test and summarized as Kaplan–Meier estimates. Combined adverse events were evaluated on a hierarchical basis; thus, each patient could provide only one hard event per event type. All variables in Tables 1 and 2 associated with POCE at bivariate analysis (p <0.05) were simultaneously forced into a Cox regression model to identify independent outcome predictors and to calculate their adjusted hazard ratios. To compensate for potential confounding factors inherent to the nonrandomized design of the study, we calculated an individual propensity score, on the basis of the available co-variables and estimated with a nonparsimonious logistic regression model. Adjusted odd ratios (ORs) were estimated from models in which the propensity scores were entered as co-variates. In addition, as a sensitivity analysis, we also exploited the propensity score to create matched pairs with a 1:1 ratio based on greedy matching. A 2-tailed p value of 0.05 was considered statistically significant for all analyses (SPSS version 18.0).
| Variable | Overall (n=563) | BVS group (n=122) | EES group (n=441) | p |
|---|---|---|---|---|
| Age (years) ∗ | 59 (52-67) | 54 (48-60) | 61 (53-68) | 0.001 |
| Women | 125 (22.2%) | 31 (25.4%) | 94 (21.3%) | 0.401 |
| Hypertension | 327 (58.1%) | 59 (48.4%) | 268 (60.8%) | 0.019 |
| Hypercholesterolemia | 330 (58.6%) | 90 (73.8%) | 240 (54.4%) | 0.001 |
| Smoker | 253 (44.9%) | 60 (49.2%) | 193 (43.8%) | 0.336 |
| Family history of CAD | 173 (30.7%) | 49 (40.2%) | 124 (28.1%) | 0.015 |
| Diabetes mellitus | 99 (17.6%) | 12 (9.8%) | 87 (19.7%) | 0.016 |
| Insulin dependent | 52 (9.2%) | 5 (4.1%) | 47 (10.7%) | 0.042 |
| Non-insulin dependent | 47 (8.4%) | 7 (5.7%) | 40 (9.1%) | 0.321 |
| Prior myocardial infarction | 41 (7.3%) | 15 (12.3%) | 26 (5.9%) | 0.027 |
| Prior revascularization | 42 (7.5%) | 13 (10.7%) | 29 (6.6%) | 0.186 |
| Prior percutaneous coronary intervention | 39 (6.9%) | 13 (10.7%) | 26 (5.9%) | 0.103 |
| Prior coronary bypass | 5 (0.9%) | 0 (0.0%) | 5 (1.1%) | 0.525 |
| Peripheral artery disease | 44 (7.8%) | 1 (0.8%) | 43 (9.8%) | 0.002 |
| Multivessel coronary disease | 278 (49.4%) | 52 (42.6%) | 226 (51.2%) | 0.113 |
| Killip class | 0.026 | |||
| I | (82.6%) | (91.0%) | (79.9%) | 0.008 |
| II | (12.6%) | (8.2%) | (14.0%) | 0.126 |
| III | (2.9%) | (0.8%) | (3.6%) | 0.206 |
| IV | (1.9%) | (0.0%) | (2.5%) | 0.171 |
| Culprit coronary artery | ||||
| Left Anterior Descending | 334 (59.3%) | 74 (60.7%) | 260 (59.0%) | 0.815 |
| Left Circumflex | 75 (13.3%) | 16 (13.1%) | 59 (13.4%) | 1.000 |
| Right | 154 (27.4%) | 32 (26.2%) | 122 (27.7%) | 0.842 |
| Variable | Overall (n=605) | BVS group (n=135) | EES group (n= 470) | p |
|---|---|---|---|---|
| Radial approach | 417 (68.9%) | 88 (65.2%) | 329 (70.0%) | 0.337 |
| Treated coronary artery | ||||
| Left Anterior Descending | 357 (59.0%) | 82 (60.7%) | 275 (58.5%) | 0.715 |
| Left Circumflex | 80 (13.2%) | 17 (12.6%) | 63 (13.4%) | 0.919 |
| Right | 168 (27.8%) | 36 (26.7%) | 132 (28.1%) | 0.830 |
| Occluded vessel | 334 (55.2%) | 54 (40.0%) | 280 (59.6%) | 0.001 |
| Stenosis severity ∗ | 100 (95-100%) | 99 (90-100%) | 100 (99-100%) | 0.001 |
| Thrombus score ∗ | 4 (3-5) | 4 (3-5) | 4 (3-5) | 0.104 |
| Thrombectomy use | 314 (51.9%) | 67 (49.6%) | 247 (52.6%) | 0.616 |
| Direct stenting | 196 (32.4%) | 8 (5.9%) | 188 (40.0%) | 0.001 |
| Bifurcational lesions | 103 (17.0%) | 5 (3.7%) | 98 (20.9%) | 0.001 |
| Buddy wire | 27 (4.5%) | 0 (0.0%) | 27 (5.7%) | 0.009 |
| Predilation | 409 (67.6%) | 127 (94.1%) | 282 (60.0%) | 0.001 |
| Predilation balloon diameter (mm) ∗ | 2.5 (2.0-2.5) | 2.75 (2.5-3.0) | 2.5 (2.0-2.5) | 0.001 |
| Stent diameter (mm) ∗ | 3.0 (2.75-3.5) | 3.0 (3.0-3.5) | 3.0 (2.75-3.5) | 0.009 |
| Stent length (mm) ∗ | 23 (18-33) | 18 (18-28) | 23 (18-33) | 0.041 |
| Max pressure during stent implantation † | 14 (12-14) | 10 (9-14) | 14 (12-16) | 0.001 |
| Overlapping stent | 147 (24.3%) | 35 (25.9%) | 112 (23.8%) | 0.699 |
| Post-dilation | 305 (57.7%) | 127 (94.1%) | 178 (37.9%) | 0.001 |
| Postdilation balloon diameter (mm) ∗ | 3.5 (3.0-3.75) | 3.5 (3.0-4.0) | 3.5 (3.0-3.75) | 0.077 |
| Postdilation upsizing (mm) | 0.5 (0.0-0.5) | 0.5 (0.0-0.5) | 0.25 (0.0-0.5) | 0.221 |
| OCT/IVUS guidance | 8 (1.3%) | 6 (4.4%) | 2 (0.4%) | 0.045 |
| Device-related complications | 25 (4.1%) | 2 (1.5%) | 23 (4.9%) | 0.063 |
| Procedural success | 590 (97.5%) | 134 (99.3%) | 456 (97.0%) | 0.246 |
| Final TIMI 3 | 593 (98.0%) | 134 (99.3%) | 459 (97.7%) | 0.410 |
| IIB/IIIA inhibitors administration | 223 (36.9%) | 47 (34.8%) | 176 (37.4%) | 0.647 |
| Bivalirudin | 115 (19.0%) | 7 (5.2%) | 108 (23.0%) | 0.001 |
| Dual antiplatelet therapy | ||||
| ASA + Clopidogrel | 267 (44.5%) | 52 (38.5%) | 217 (46.2%) | 0.139 |
| ASA + Ticagrelor/Prasugrel | 336 (55.5%) | 83 (61.5%) | 253 (63.8%) | 0.139 |
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