Abstract
Background
Due to the inherent limitations of current generation BVSs, complex coronary artery disease often contains BVS unsuitable segments. Our aim was to assess the feasibility of a hybrid approach using bioresorbable vascular scaffolds (BVSs) and drug-eluting stents (DESs) for the treatment of complex coronary artery lesions not suitable for a scaffolding only approach.
Methods
A retrospective multicenter cohort analysis was performed on patients with complex de novo or in-stent restenosis lesions treated with a hybrid BVS (Absorb BVS, Abbott Vascular, Santa Clara, CA) and DES strategy. The primary endpoint was target lesion failure (TLF) defined as a composite of cardiac death, target-vessel myocardial infarction (MI) and target lesion revascularization (TLR).
Results
A total of 98 patients (105 lesions) were treated with the hybrid strategy. Isolated long lesions in which either proximal or distal reference vessel diameters were not suitable for BVS were an indication in 36.2% (n = 38) of cases. In contrast, 28% (n = 29) of lesions treated with the hybrid strategy were bifurcations in which the side branch was predominantly treated with DES (n = 28). DES bailout after BVS implantation was an indication in 21.9% (n = 23 lesions). The rates of type B2/C and long lesions (>28 mm) were 95.2% and 74.3% respectively. The mean total BVS and DES lengths implanted were 37.5 ± 24.1 mm and 25.0 ± 14.7 mm respectively. The rate of TLF in the overall cohort of patients (median follow-up 405 days [interquartile range 189–658]) was 11.4% at 1-year. This was primarily driven by TLR (9.5%), with rates of cardiac death and target vessel MI of 2.1% and 1.4% respectively. No cases of definite or probable BVS/DES thrombosis occurred.
Conclusion
In conclusion, the use of a hybrid BVS/DES strategy was feasible and associated with acceptable outcomes at 1-year, considering the length and complexity of lesions treated. Further, larger studies with longer follow-up are needed to confirm our findings.
Highlights
- •
We assessed the feasibility of a hybrid approach using bioresorbable vascular scaffolds (BVSs) and drug-eluting stents (DESs) for the treatment of complex coronary artery lesions not suitable for a scaffolding only approach.
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A total of 98 patients (105 lesions) were treated with the hybrid strategy. Isolated long lesions in which either proximal or distal reference vessel diameters were not suitable for BVS were an indication in 36.2% (n = 38) of cases. In contrast, 28% (n = 29) of lesions treated with the hybrid strategy were bifurcations in which the side branch was predominantly treated with DES (n = 28). DES bailout after BVS implantation was an indication in 21.9% (n = 23 lesions).
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The rate of TLF in the overall cohort of patients (median follow-up 405 days [interquartile range 189–658]) was 11.4% at 1-year. This was primarily driven by TLR (9.5%), with rates of cardiac death and target vessel MI of 2.1% and 1.4% respectively. No cases of definite or probable BVS/DES thrombosis occurred.
1
Introduction
Bioresorbable vascular scaffolds (BVSs) are an attractive option for percutaneous coronary interventions (PCIs) and have been shown in randomized trials to be non-inferior to metallic drug-eluting stents (DESs) in relatively simple lesions , with signals of applicability to more complex lesions appearing from real world data . However, due to the limitations of current generation BVSs, certain lesion characteristics may limit pure scaffolding PCIs (e.g. long lesions with proximal or distal reference vessel diameters unsuitable for BVSs). Limiting the permanent metallic length implanted may still be beneficial since total metallic stent length is a continuous risk factor associated with an increased risk of restenosis and stent thrombosis . In addition, a metallic cage permanently impairs restoration of vasomotion, may promote neoatherosclerosis and limits the option for future coronary artery bypass graft surgery. Therefore, a hybrid DES/BVS approach may be an attractive alternative. Accordingly, we analyzed the immediate and mid-term outcomes following the treatment of patients with complex coronary artery disease (CAD) not suitable for a pure BVS approach.
2
Methods
A retrospective, multicenter (5 centers), cohort analysis was performed on 98 consecutive patients (105 lesions) who underwent PCI with a “hybrid strategy” for stable or unstable CAD between May 2012 and May 2016. The indications for a hybrid strategy were decided by the individual operator in each center. The hybrid strategy was defined as overlapping or slightly superimposing BVS (Absorb BVS 1.1, Abbott Vascular, Santa Clara, CA) and a new generation DES for a complex de novo or in-stent restenotic (ISR) lesion unsuitable for a pure BVS approach. In general, extensive lesion preparation with semi-compliant and/or non-compliant balloons and post-dilatation with non-oversized 1:1 non-compliant balloons (max 0.5 mm above scaffold nominal diameter) was standard practice in participating centers. Whenever possible, intravascular imaging was used both pre-deployment to help guide sizing and post-deployment to confirm optimal scaffold expansion, exclude strut malapposition or edge dissections. During BVS deployment, inflation pressures were slowly increased (2 atm per 5 s), followed by prolonged inflation (more than 30 s) at nominal pressure. When implanting multiple BVSs, a “scaffold to scaffold” implantation technique was preferred to minimize overlap, which is achieved by placing the distal balloon marker of the proximal scaffold just before (~1–2 mm) the proximal radiopaque marker of the distal scaffold. In case of hybrid scaffold/DES overlap, the DES edge was positioned adjacent (~1–2 mm) to the scaffold radiopaque marker. The overlapping sites were post-dilated specifically to embed the devices as much as possible into the vessel wall. All patients were administered dual antiplatelet therapy for at least 12 months after the procedure. All patients provided written informed consent for both the procedure and subsequent data collection and analysis.
2.1
Endpoints and definitions
The primary endpoint was target lesion failure (TLF) defined as a composite of cardiac death, target-vessel myocardial infarction (MI) and target lesion revascularization (TLR). Additionally, all patients were followed-up for incidences of all-cause mortality, target vessel revascularization (TVR), and definite/probable BVS/DES thrombosis (ST). Procedural success was defined as successful BVS and DES implantation at the target site with a residual diameter stenosis less than 30% at the BVS or DES treated segment. Follow-up angiography was performed only when clinically necessary: for recurrent anginal symptoms or suspected myocardial ischemia. TLR was defined as repeat percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) for the previously treated segment (in-BVS, in-DES or at the BVS/DES overlap site) or in the adjacent proximal or distal 5 mm. Periprocedural myocardial infarction (<48 h) post PCI was defined as per Table 1 in the publication by Vranckx et al. . MI was defined as the presence of pathological and new Q waves on an electrocardiogram, or an increase in creatinine kinase-myocardial band level to >5× the upper limit of the normal range . TVR was defined as repeat PCI or CABG in the target vessel. ST was defined according to the Academic Research Consortium criteria . The SYNTAX score was calculated for patients without previous CABG . The investigators of each center were required to complete a patient-level database, including clinical, procedural data and outcome data. Data were anonymized and sent to the study coordinators (A.I. and R.J.) for analysis. Source verification and queries generation from the coordinating center to the participating sites were undertaken to partly account for the unavoidable bias of site-reported event adjudication.
| All patients | |
|---|---|
| N = 98 | |
| Age (years) | 62.6 ± 10.9 |
| Male gender | 85 (86.7%) |
| Hypertension | 63 (64.3%) |
| Diabetes mellitus | 26 (26.5%) |
| Insulin dependent | 11 (11.2%) |
| Dyslipidemia | 57 (58.2%) |
| Smoking history | 28 (28.6%) |
| eGFR <60 mL/min/1.73 m 2 | 6 (6.1%) |
| Previous myocardial infarction | 20 (20.4%) |
| Previous percutaneous coronary intervention | 33 (33.7%) |
| Previous coronary artery bypass graft | 1 (1.0%) |
| Left ventricular ejection fraction (%) | 53.1 ± 9.0 |
| SYNTAX score | 22.4 ± 11.4 |
| Clinical presentation | |
| Stable angina | 59 (60.2%) |
| Acute coronary syndrome | |
| Unstable angina / NSTEMI | 23 (23.5%) |
| STEMI | 16 (16.3%) |
| Antiplatelet therapy at discharge | |
| Clopidogrel | 50 (51.0%) |
| Prasugrel | 40 (40.8%) |
| Ticagrelor | 8 (8.2%) |
2.2
Statistical analysis
Continuous data are expressed either as mean ± SD or median and interquartile range depending on distribution, and categorical data as number and percentages. Cumulative event rates were analyzed using the Kaplan–Meier methods, and the rate differences among the groups estimated using the log-rank test. All analyses were performed using the SPSS 21.0 software package (SPSS, Chicago, IL, USA).
2
Methods
A retrospective, multicenter (5 centers), cohort analysis was performed on 98 consecutive patients (105 lesions) who underwent PCI with a “hybrid strategy” for stable or unstable CAD between May 2012 and May 2016. The indications for a hybrid strategy were decided by the individual operator in each center. The hybrid strategy was defined as overlapping or slightly superimposing BVS (Absorb BVS 1.1, Abbott Vascular, Santa Clara, CA) and a new generation DES for a complex de novo or in-stent restenotic (ISR) lesion unsuitable for a pure BVS approach. In general, extensive lesion preparation with semi-compliant and/or non-compliant balloons and post-dilatation with non-oversized 1:1 non-compliant balloons (max 0.5 mm above scaffold nominal diameter) was standard practice in participating centers. Whenever possible, intravascular imaging was used both pre-deployment to help guide sizing and post-deployment to confirm optimal scaffold expansion, exclude strut malapposition or edge dissections. During BVS deployment, inflation pressures were slowly increased (2 atm per 5 s), followed by prolonged inflation (more than 30 s) at nominal pressure. When implanting multiple BVSs, a “scaffold to scaffold” implantation technique was preferred to minimize overlap, which is achieved by placing the distal balloon marker of the proximal scaffold just before (~1–2 mm) the proximal radiopaque marker of the distal scaffold. In case of hybrid scaffold/DES overlap, the DES edge was positioned adjacent (~1–2 mm) to the scaffold radiopaque marker. The overlapping sites were post-dilated specifically to embed the devices as much as possible into the vessel wall. All patients were administered dual antiplatelet therapy for at least 12 months after the procedure. All patients provided written informed consent for both the procedure and subsequent data collection and analysis.
2.1
Endpoints and definitions
The primary endpoint was target lesion failure (TLF) defined as a composite of cardiac death, target-vessel myocardial infarction (MI) and target lesion revascularization (TLR). Additionally, all patients were followed-up for incidences of all-cause mortality, target vessel revascularization (TVR), and definite/probable BVS/DES thrombosis (ST). Procedural success was defined as successful BVS and DES implantation at the target site with a residual diameter stenosis less than 30% at the BVS or DES treated segment. Follow-up angiography was performed only when clinically necessary: for recurrent anginal symptoms or suspected myocardial ischemia. TLR was defined as repeat percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) for the previously treated segment (in-BVS, in-DES or at the BVS/DES overlap site) or in the adjacent proximal or distal 5 mm. Periprocedural myocardial infarction (<48 h) post PCI was defined as per Table 1 in the publication by Vranckx et al. . MI was defined as the presence of pathological and new Q waves on an electrocardiogram, or an increase in creatinine kinase-myocardial band level to >5× the upper limit of the normal range . TVR was defined as repeat PCI or CABG in the target vessel. ST was defined according to the Academic Research Consortium criteria . The SYNTAX score was calculated for patients without previous CABG . The investigators of each center were required to complete a patient-level database, including clinical, procedural data and outcome data. Data were anonymized and sent to the study coordinators (A.I. and R.J.) for analysis. Source verification and queries generation from the coordinating center to the participating sites were undertaken to partly account for the unavoidable bias of site-reported event adjudication.
| All patients | |
|---|---|
| N = 98 | |
| Age (years) | 62.6 ± 10.9 |
| Male gender | 85 (86.7%) |
| Hypertension | 63 (64.3%) |
| Diabetes mellitus | 26 (26.5%) |
| Insulin dependent | 11 (11.2%) |
| Dyslipidemia | 57 (58.2%) |
| Smoking history | 28 (28.6%) |
| eGFR <60 mL/min/1.73 m 2 | 6 (6.1%) |
| Previous myocardial infarction | 20 (20.4%) |
| Previous percutaneous coronary intervention | 33 (33.7%) |
| Previous coronary artery bypass graft | 1 (1.0%) |
| Left ventricular ejection fraction (%) | 53.1 ± 9.0 |
| SYNTAX score | 22.4 ± 11.4 |
| Clinical presentation | |
| Stable angina | 59 (60.2%) |
| Acute coronary syndrome | |
| Unstable angina / NSTEMI | 23 (23.5%) |
| STEMI | 16 (16.3%) |
| Antiplatelet therapy at discharge | |
| Clopidogrel | 50 (51.0%) |
| Prasugrel | 40 (40.8%) |
| Ticagrelor | 8 (8.2%) |
2.2
Statistical analysis
Continuous data are expressed either as mean ± SD or median and interquartile range depending on distribution, and categorical data as number and percentages. Cumulative event rates were analyzed using the Kaplan–Meier methods, and the rate differences among the groups estimated using the log-rank test. All analyses were performed using the SPSS 21.0 software package (SPSS, Chicago, IL, USA).
3
Results
3.1
Baseline characteristics
Baseline clinical characteristics are depicted in Table 1 . The mean age of patients was 62.6 ± 10.9 years, 86.7% (n = 85) were male and 26.5% (n = 26) diabetic. The mean SYNTAX score of the cohort was 22.4 ± 11.4. The majority of patients underwent PCI for stable CAD (n = 59; 60.2%), followed by 23.5% (n = 23) and 16.3% (n = 16) for unstable angina/non-ST elevation myocardial infarction (UA/NSTEMI) and ST-elevation myocardial infarction (STEMI).
3.2
Indications for hybrid strategy
Indications for a hybrid BVS/DES strategy are described in Fig. 1 . Long lesions in which either the proximal or distal reference vessel diameters were not suitable (>3.7 mm or <2.5 mm) for BVS made up most lesions requiring a hybrid strategy (n = 38; 36.2%). In contrast, 28% (n = 29) of lesions treated with a hybrid strategy were bifurcations. DES bailout was an indication in 21.9% (n = 23) and reasons included edge dissection (n = 12; 52.2%) and failure of device delivery due to calcification and/or tortuosity (n = 11; 47.8%). The remaining lesions treated with a hybrid approach involved an ostial segment (5.7%, n = 6) or were lesions that involved a bifurcation lesion which was unsuitable for BVS implantation (8.6%, n = 9; e.g. BVS bifurcation PCI unsuitable due to large diameter difference proximal and distal to bifurcation).
