Antiplatelet Therapy After Implantation of Bioresorbable Vascular Scaffolds: A Review of the Published Data, Practical Recommendations, and Future Directions

Impact of perioperative low-molecular-weight heparin therapy on clinical events of elderly patients with prior coronary stents implanted > 12 months undergoing non-cardiac surgery: a randomized, placebo-controlled trial

BACKGROUND

Little is known about the safety and efficacy of discontinuing antiplatelet therapy via LMWH bridging therapy in elderly patients with coronary stents implanted for > 12 months undergoing non-cardiac surgery. This randomized trial was designed to compare the clinical benefits and risks of antiplatelet drug discontinuation via LMWH bridging therapy.

METHODS

Patients were randomized 1:1 to receive subcutaneous injections of either dalteparin sodium or placebo. The primary efficacy endpoint was cardiac or cerebrovascular events. The primary safety endpoint was major bleeding.

RESULTS

Among 2476 randomized patients, the variables (sex, age, body mass index, comorbidities, medications, and procedural characteristics) and percutaneous coronary intervention information were not significantly different between the bridging and non-bridging groups. During the follow-up period, the rate of the combined endpoint in the bridging group was significantly lower than in the non-bridging group (5.79% vs. 8.42%, p = 0.012). The incidence of myocardial injury in the bridging group was significantly lower than in the non-bridging group (3.14% vs. 5.19%, p = 0.011). Deep vein thrombosis occurred more frequently in the non-bridging group (1.21% vs. 0.4%, p = 0.024), and there was a trend toward a higher rate of pulmonary embolism (0.32% vs. 0.08%, p = 0.177). There was no significant difference between the groups in the rates of acute myocardial infarction (0.81% vs. 1.38%), cardiac death (0.24% vs. 0.41%), stroke (0.16% vs. 0.24%), or major bleeding (1.22% vs. 1.45%). Multivariable analysis showed that LMWH bridging, creatinine clearance < 30 mL/min, preoperative hemoglobin < 10 g/dL, and diabetes mellitus were independent predictors of ischemic events. LMWH bridging and a preoperative platelet count of < 70 × 109/L were independent predictors of minor bleeding events.

CONCLUSIONS

This study showed the safety and efficacy of perioperative LMWH bridging therapy in elderly patients with coronary stents implanted > 12 months undergoing non-cardiac surgery. An alternative approach might be the use of bridging therapy with half-dose LMWH.

TRIAL REGISTRATION

ISRCTN65203415.

One-Month Dual Antiplatelet Therapy in Patients With Chronic and Acute Coronary Syndromes Treated With Bioresorbable Polymer Everolimus-Eluting Stents

There is a paucity of data regarding the safety of a 1-month dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) in patients at high bleeding risk (HBR) presenting with acute coronary syndromes (ACS). We aimed to compare the clinical outcomes of patients at HBR with chronic coronary syndrome (CCS) or ACS treated with PCI using bioresorbable polymer everolimus-eluting stent (BP-EES) followed by 1-month DAPT. Patients at HBR who underwent PCI with BP-EES were prospectively enrolled in 10 Italian centers. All patients were treated with 1-month DAPT. In case of need for anticoagulation, patients received an oral anticoagulant in addition to a P2Y12 inhibitor for 1 month, followed by oral anticoagulation only after that. The primary end point was a composite of cardiac death, myocardial infarction, or definite/probable stent thrombosis at 12 months. Overall, 263 patients (59.4%) with CCS and 180 patients (40.6%) with ACS were enrolled. No significant difference was evident between patients with CCS and ACS for the primary end point (4.3% vs 5.6%, respectively, p = 0.497) and for each isolated component. The risk for Bleeding Academic Research Consortium (BARC) type 1 to 5 or type 3 to 5 bleedings was also similar between patients with CCS and ACS (4.3% vs 5.2%, p = 0.677, and 1.6% vs 2.9%, p = 0.351, respectively). In conclusion, among HBR patients with ACS who underwent PCI with BP-EES, a 1-month DAPT strategy is associated with a similar risk of ischemic and bleeding events compared with those with CCS.

Coronary bioresorbable stents: Non-invasive quantitative evaluation of intra- and juxta-stent plaque composition-A computed tomography longitudinal study

PURPOSE

Coronary bioresorbable stents (BRS) do not produce blooming artifacts on computed tomography (CT), in contrast to metallic stents, as they are made of a bioresorbable polymer and are radiolucent. They allow to evaluate the coronary plaque beneath. The low-attenuation plaque (LAP) suggests plaque vulnerability and is CT assessable. The aim of our study was to show the possibility of a non-invasive CT evaluation of the volume and the LAP composition of the intra- and juxta-stent plaque.

METHODOLOGY

In our prospective longitudinal study, we recruited 27 consecutive patients (35 BRS stents total; mean age 60 +/- 9 years) with bioresorbable stents for a 256-slice ECG-synchronized CT evaluation at 1- and 12-months post stent implantation. Total plaque volume (mm3), absolute and relative (%) LAP volume per block in the pre- intra- and post-stent zones were analyzed; comparison 1- and 12-months post-implantation of BRS. Changes in the previously mentioned variables were assessed by the mixed effects models with and without spline, which also accounted for the correlation between repeated measurements.

RESULTS

Our block or spline model analysis has shown no significant difference in plaque or absolute LAP volumes in pre- intra- and post-stent zones between 1 and 12 months. Interestingly, % LAP volume increases near-significantly in the distal block of the intrastent at 12-mo follow-up (from 23.38 ± 1.80% to 26.90 ± 2.22% (increase of 15%), p = 0.052).

CONCLUSION

Our study demonstrates the feasibility of the repeated non-invasive quantitative analysis of the intrastent coronary plaque and of the in-stent lumen by CT scan.

Outcomes of the two generations of bioresorbable scaffolds (Magmaris vs. Absorb) in acute coronary syndrome in routine clinical practice

BACKGROUND

Acute coronary syndrome (ACS) as a clinical manifestation of coronary artery disease (CAD) remains a significant cause of mortality and morbidity, as reported worldwide annually. The second generation of drug-eluting stents (DES) is a gold standard in percutaneous interventions in ACS patients however, permanent caging of the vessel with metallic DES has some drawbacks. Bioresorbable vascular scaffolds (BRS) were designed as a temporal vessel-supporting technology allowing for anatomical and functional restoration. Nevertheless, following the initial encouraging reports, numerous concerns about the safety of BRS occurred.

METHODS

In this study, a 1-year performance of 193 patients with magnesium BRS - Magmaris (Biotronik, Berlin, Germany) was evaluated in comparison to 160 patients with polymer BRS - Absorb (Abbott-Vascular, Chicago, USA) in the non-ST-segment elevation-ACS setting.

RESULTS

The Magmaris, when compared to Absorb showed a significantly lower rate of primary endpoint (death from cardiac causes, myocardial infarction, stent thrombosis) as well as target lesion failure in 30-day and 1 year follow-up. In the Absorb group, a significantly higher rate of stent thrombosis was observed.

CONCLUSIONS

Data from the present study suggests encouraging safety a profile and more favorable clinical outcomes of Magnesium BRS in comparison to the polymer Absorb - BRS.

Long-term results of long segment coronary artery lesions overlapped with novolimus-eluting DESolve scaffold: Disappointment or futuristic?

OBJECTIVE

The data on using novolimus-eluting DESolve bioresorbable scaffolds (BVS) for long-segment coronary artery lesions remains insufficient. In this study, our main objective was to assess the long-term effects of the overlapping applications of both DESolve-DESolve and the drug-eluting stent (DES)-DESolve.

METHODS

A single-centered study of 103 patients scheduled for DESolve placement for long-segment lesions (>28 mm) was conducted (October 2013 to November 2016). A DESolve-DESolve overlap was used on 43 patients and a DES-DESolve overlap on 60 patients. Acute procedural success and major adverse cardiac events (MACE) (stent thrombosis, targeted vessel revascularization, targeted lesion revascularization, and cardiac death) were evaluated. The patients were followed up for 48 months.

RESULTS

Revascularization was performed on 4 (6.7%) patients in the DES-DESolve group and 5 (11.6%) patients in the DESolve-DESolve group for target lesion revascularization. Among the study population, 10 (9.7%) patients had MACE, including 5 (8.3%) patients in the DES-DESolve group and 5 (11.6%) patients in the DESolve-DESolve group.

CONCLUSION

The positive results of our study concerning the use of DESolve for the treatment of long coronary lesions demonstrate that BVS will emerge with new platforms and become non-inferior to the DES.

Bioresorbable Scaffolds in Percutaneous Coronary Intervention: Facing Old Problems, Raising New Hopes

PURPOSE OF REVIEW

In this review, we discuss about the reasons behind the failure of the Absorb bioresorbable vascular scaffold (BVS) device and about the challenges the future holds for the next generation of the bioresorbable scaffold (BRS) technology.

RECENT FINDINGS

Absorb BVS was burdened by intrinsic structural limitations which resulted in augmented rates of device thrombosis and clinical adverse events compared to current-generation metallic stent. Nevertheless, new generation devices with novel design and materials are in development. Second generation BRS have enhanced mechanical strength, smaller footprints, less thrombogenicity and modified bioresorption. These features, paired with proper patient and lesion selection and optimal "user-friendly" implant techniques, could possibly overcome the previous BRS generation limitations, rekindling physicians, and industry interest on this promising technology.

Mid-term outcomes of bioresorbable vascular scaffolds vs second-generation drug-eluting stents in patients with acute coronary syndromes: A systematic review and meta-analysis

BACKGROUND

Everolimus-eluting bioresorbable vascular scaffolds (BVS), which have the characteristics of scaffold absorption and vascular function recovery, are the latest innovation in the treatment of coronary artery disease. This new concept has become a hot topic in the field of interventional cardiology. Data regarding mid-term clinical outcomes of BVS in acute coronary syndromes are currently scarce. The aim of this systematic review and meta-analysis is to compare mid-term outcome data for BVS and second-generation drug-eluting stents (DES) in the treatment of acute coronary syndromes.

METHODS

We searched PubMed, Embase, the Cochrane Library, Web of Science, and relevant web sites for studies with a follow-up of ≥ 1 years that studied percutaneous coronary interventions with BVS vs second-generation DES in acute coronary syndromes. A meta-analysis was performed with the software RevMan following the standards of the Cochrane Handbook for Systematic Reviews of Interventions 5.1.0.

RESULTS

Five studies, 2 randomized controlled trials, and 3 observational studies, with a total of 1758 patients (BVS n = 917; DES n = 841) and a median follow-up duration of 24 months, were included. BVS, when compared with DES, resulted in higher rates of target lesion revascularization (TLR) (OR, 2.20; 95% CI, 1.12-3.64; P = .02) and stent/scaffold thrombosis (ST/ScT) (OR = 2.35, 95% CI: 1.13-4.89, P = .02). When TLR due to device thrombosis were excluded, the difference in risk estimates between the 2 groups was no longer significant (OR: 1.67, 95% CI: 0.73-3.82, P = .22). The risk for all-cause death (OR = 1.32 95% CI: 0.61-2.88, P = .48), cardiac death (OR = 1.29, 95% CI: 0.58-2.86 P = .52), target vessel myocardial infarction (OR = 1.50, 95% CI: 0.86-2.61, P = .15), and target lesion failure (OR = 1.34, 95% CI: 0.76-2.35, P = .31) did not differ between BVS and DES groups.

CONCLUSION

At mid-term follow-up, BVS had a higher risk of TLR and ST/ScT than the second-generation DES in patients with acute coronary syndromes. ST/ScT was the key factor indicating the decreased safety and effectiveness of BVS relative to DES.

Comparison of the everolimus-eluting bioresorbable vascular scaffold versus the everolimus-eluting metallic stent in real-world patients with ST-segment elevation myocardial infarction

INTRODUCTION

Despite the withdrawal of the ABSORB bioresorbable vascular scaffold (BVS) from clinical use, continuous observation of BVS-treated patients is necessary. In the vast majority of clinical trials, patients with ST-segment elevation myocardial infarction (STEMI) were excluded from the analysis.

AIM

To compare the early and long-term outcomes of the BVS with the everolimus-eluting metallic stent (EES) in patients with STEMI.

MATERIAL AND METHODS

Consecutive patients treated with BVS or EES in our center were screened. For analysis, only patients with STEMI were enrolled. The primary endpoint was a comparison of the target lesion failure at 12 and 24 months. The secondary endpoints encompass occurrence of the patient-oriented cardiovascular endpoint (PoCE), stent thrombosis (ST), device, and procedural success.

RESULTS

Between 2012 and 2016, 2,137 patients were hospitalized for STEMI. Of these, 123 patients received the BVS (163 scaffolds; 151 lesions), whereas in 141 patients the EES (203 stents; 176 lesions) was implanted. The median follow-up was 931 ±514 days. The primary endpoint at 12 months occurred in 9.7% in the BVS group and in 8.5% in the EES group (hazard ratio (HR) = 2.61; 95% confidence interval (CI): 0.90-7.56; p = 0.076). At 24 months the incidence of the primary endpoint was 15.2% in the BVS group and 14.9% in the EES group (HR = 2.46; 95% CI: 0.85-7.07; p = 0.095). The rates of PoCE, ST, device, and procedural success were also comparable in both groups.

CONCLUSIONS

STEMI patients treated with the BVS showed statistically similar rates of primary and secondary endpoints compared with the EES.

A Multidisciplinary Approach on the Perioperative Antithrombotic Management of Patients With Coronary Stents Undergoing Surgery: Surgery After Stenting 2

Perioperative management of antithrombotic therapy in patients treated with coronary stents undergoing surgery remains poorly defined. Importantly, surgery represents a common reason for premature treatment discontinuation, which is associated with an increased risk in mortality and major adverse cardiac events. However, maintaining antithrombotic therapy to minimize the incidence of perioperative ischemic complications may increase the risk of bleeding complications. Although guidelines provide some recommendations with respect to the perioperative management of antithrombotic therapy, these have been largely developed according to the thrombotic risk of the patient and a definition of the hemorrhagic risk specific to each surgical procedure, key to defining the trade-off between ischemia and bleeding, is not provided. These observations underscore the need for a multidisciplinary collaboration among cardiologists, anesthesiologists, hematologists and surgeons to reach this goal. The present document is an update on practical recommendations for standardizing management of antithrombotic therapy management in patients treated with coronary stents (Surgery After Stenting 2) in various types of surgery according to the predicted individual risk of thrombotic complications against the anticipated risk of surgical bleeding complications. Cardiologists defined the thrombotic risk using a "combined ischemic risk" approach, while surgeons classified surgeries according to their inherent hemorrhagic risk. Finally, a multidisciplinary agreement on the most appropriate antithrombotic treatment regimen in the perioperative phase was reached for each surgical procedure.

Bioactive peptides and proteins as alternative antiplatelet drugs

Antiplatelet drugs reduce the risks associated with atherothrombotic events and show various applications in diverse cardiovascular diseases including myocardial infarctions. Efficacy of the current antiplatelet medicines including aspirin, clopidogrel, prasugrel and ticagrelor, and the glycoprotein IIb/IIIa antagonists, are limited due to their increased risks of bleeding, and antiplatelet drug resistance. Hence, it is important to develop new effective antiplatelet drugs, with fewer side-effects. The vast repertoire of natural peptides can be explored towards this goal. Proteins and peptides derived from snake venoms and plants represent exciting candidates for the development of novel and potent antiplatelet agents. Consequently, this review discusses multiple peptides that have displayed antiplatelet aggregation activity in preclinical drug development stages. This review also describes the antiplatelet mechanisms of the peptides, emphasizing the signaling pathways intervened by them. Also, the hurdles encountered during the development of peptides into antiplatelet drugs have been listed. Finally, hitherto unexplored peptides with the potential to prevent platelet aggregation are explored.

Dual Antiplatelet Therapy Duration: Reconciling the Inconsistencies

Dual antiplatelet therapy (DAPT) prevents recurrent ischemic events after an acute coronary syndrome (ACS) as well as stent thrombosis (ST) in patients with prior stent implantation. Nevertheless, these benefits are counterbalanced by a significant bleeding hazard, which is directly related to the treatment duration. Although DAPT has been extensively studied in numerous clinical trials, optimal treatment duration is still debated, mostly because of apparent inconsistencies among studies. Shortened treatment duration of 6 or 3 months was shown to mitigate bleeding risk compared with consensus-grounded 12-month standard duration, without any apparent excess of ischemic events. However, recent trials showed that a >12-month course of treatment reduces ischemic events but increases bleeding compared with 12 months. The inconsistent benefit of a longer DAPT course compared with shorter treatment durations is puzzling, and requires a careful appraisal of between-studies differences. We sought to summarize the existing evidence aiming at reconciling apparent inconsistencies among these studies, as well as thoroughly discuss the possible increased risk of fatal events associated with long-term DAPT. Benefits and risks of prolonging or shortening DAPT duration will be discussed, with a focus on treatment individualization. Finally, we will provide an outlook for possible future directions in the field.

Lights and shadows of long-term dual antiplatelet therapy in "real life" clinical scenarios

Dual antiplatelet therapy (DAPT) is a cornerstone of treatment for patients with acute coronary syndromes (ACS). Mounting evidences have opened the debate about the optimal DAPT duration. Considering the ACS-pathophysiology, the most recent guidelines recommend DAPT in all ACS patients for at least 12 months unless there are contraindications such as excessive risk of bleeding. Thus, it can be considered acceptable earlier discontinuation if the risk of morbidity from bleeding outweighs the anticipated benefit. On the other hand, several studies have clearly indicated that a significant burden of platelet related-events, such as stroke and new ACS might occur after this period, suggesting that potential benefits might derive by prolonging DAPT beyond 12 months (Long DAPT). Indeed, although current guidelines give some indications about patients eligible for Long DAPT, they do not embrace several real-life clinical scenarios. Thus, in such scenarios, how to decide whether a patient is eligible for Long DAPT or not might be still challenging for clinicians. This position paper presents and discusses various "real-life" clinical scenarios in ACS patients, in order to propose several possible recommendations to overcome guidelines potential limitations.

The optimal duration of dual antiplatelet therapy after coronary stent implantation: to go too far is as bad as to fall short

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is key for secondary prevention of recurrent coronary ischemic events and stent thrombosis. For this purpose, DAPT showed superior efficacy compared to aspirin alone, but it is also associated with an increased risk of major, and potentially fatal, bleeding. Hence, while secondary prevention with aspirin monotherapy is generally maintained for an indefinite period, the duration of DAPT after the index event is still debated. Multiple trials have challenged the guideline recommended standard of care of 12 months of DAPT duration. These studies tested on one side a treatment reduction to 6 or 3 months, and on the other side an extension of treatment beyond 12 months in order to define the optimal DAPT duration maximizing the anti-ischemic protection and minimizing bleeding. In this document we sought to summarize the existing evidence from more than 18 randomized controlled trials in the field, and discuss the benefit and risks of prolonging/shortening DAPT duration. In addition, a specific focus on treatment individualization will outline the current, evidence-based, decision-making process for optimal DAPT duration selection after coronary stenting.

State of the art: duration of dual antiplatelet therapy after percutaneous coronary intervention and coronary stent implantation - past, present and future perspectives

Evidence from studies published more than 10 years ago suggested that patients receiving first-generation drug-eluting stents (DES) needed dual antiplatelet therapy (DAPT) for at least 12 months. Current evidence from randomised controlled trials (RCT) reported within the past five years suggests that patients with stable ischaemic heart disease who receive newer-generation DES need DAPT for a minimum of three to six months. Patients who undergo stenting for an acute coronary syndrome benefit from DAPT for at least 12 months, but a Bayesian network meta-analysis confirms that extending DAPT beyond 12 months confers a trade-off between reduced ischaemic events and increased bleeding. However, the network meta-analysis finds no credible increase in all-cause mortality if DAPT is lengthened from three to six months to 12 months (posterior median odds ratio [OR] 0.98; 95% Bayesian credible interval [BCI]: 0.73-1.43), from 12 months to 18-48 months (OR 0.87; 95% BCI: 0.64-1.17), or from three to six months to 18-48 months (OR 0.86; 95% BCI: 0.63-1.21). Future investigation should focus on identifying scoring systems that have excellent discrimination and calibration. Although predictive models should be incorporated into systems of care, most decisions about DAPT duration will be based on clinical judgement and patient preference.

Longer Inflation Duration and Predilation-Sizing-Postdilation Improve Bioresorbable Scaffold Outcomes in a Long-term All-Comers Canadian Registry

BACKGROUND

Real-world long-term safety and efficacy of the ABSORB (Abbott Vascular, Santa Clara, CA) bioresorbable vascular scaffold has not been well characterized in the literature, particularly in the setting of acute coronary syndromes (ACS). Herein, we report outcomes up to 4 years in such a high-risk cohort, with identification of parameters associated with better outcomes.

METHODS

ReABSORB is a Canadian dual-centre, prospective, nonrandomized, all-comers registry consisting of 125 consecutively enrolled nontrial patients between October 2012 and December 2016. Angiographic and clinical follow-up is now available up to 4 years.

RESULTS

Average age was 59 ± 11 years and 69% were male. Most (70.4%) presented with ACS and the median available follow-up was 1330 days (interquartile range, 1035-1483). Treated lesions (n = 163) were type A in 23%, type B (1 or 2) in 64%, and type C in 13%. Procedural success and device success were 98.2% and 98.8%, respectively. Using Kaplan-Meier methods, major adverse cardiac event-free survival (EFS) up to 4 years of clinical follow-up was 90.7% overall. However, use of a predilation-sizing-postdilation (PSP) technique was associated with an EFS rate of 95.8% vs 74.0% without PSP (P = 0.001). No significant differences in major adverse cardiac EFS rates were found between patients with or without ACS (92.7% vs 86.0%, respectively, P = 0.239). Use of PSP as well as inflation time ≥ 60 seconds were independent predictors of EFS at 2 years.

CONCLUSIONS

In this prospective, real-world registry with mostly ACS patients, use of the recommended PSP implantation technique and longer inflations times were associated with significantly higher EFS.

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.

Biodegradable coronary scaffolds: their future and clinical and technological challenges

Angioplasty and stenting are standard treatment options for both stabile occlusive coronary artery disease and acute myocardial infarctions. Over the last years, several biodegradable stent systems have entered pre-clinical and clinical evaluation and into clinical practice. A strong supporting scaffold is necessary after angioplasty to prevent elastic recoil of the vessel but in the long term a permanent metallic stent will only impair normal physiology of the artery wall. Thus, the main advantage of a resorbable system is the potential for better vessel recovery and function in the long term. The new stent systems differ from traditional stents in size and biological responses and questions have risen regarding their mechanical strength and increased risk of stent thrombosis. Here, we present current treatment options with biodegradable scaffolds, discuss further key areas for improvements and review novel technological advances in the context of all up-to-date clinical trial information. New material choices are also covered as well as special considerations for pre-clinical testing.

Sustained safety and clinical performance of a drug-eluting absorbable metal scaffold up to 24 months: pooled outcomes of BIOSOLVE-II and BIOSOLVE-III

AIMS

We aimed to assess the safety and performance of the DREAMS 2G scaffold up to 24 months post implant.

METHODS AND RESULTS

The present study population comprises a total of 184 patients with 189 lesions who were enrolled in the prospective, multicentre BIOSOLVE-II and BIOSOLVE-III trials. Clinical follow-up was scheduled at one, six, 12, 24 and 36 months. The present report includes pooled follow-up data at six months and BIOSOLVE-II data at 24 months. Patients were 65.5±10.8 years old, and lesions were 12.5±5.1 mm long with reference diameters of 2.7±0.4 mm. Procedural success was obtained in 97.8%. At six months, the composite clinical endpoint target lesion failure was 3.3% (95% CI: 1.2-7.1), based on two cardiac deaths (1.1%, one unknown and one not device-related), one target vessel myocardial infarction (0.6%), and three clinically driven target lesion revascularisations (1.7%). For BIOSOLVE-II at 24 months, the target lesion failure rate was 5.9% (95% CI: 2.4-11.8), based on two cardiac deaths (1.7%), one target vessel myocardial infarction (0.9%) and four target lesion revascularisations (3.4%). There was no definite or probable scaffold thrombosis.

CONCLUSIONS

The present analysis provides additional evidence on the safety of a drug-eluting absorbable metal scaffold with promising clinical outcomes up to 24 months and absence of definite or probable scaffold thrombosis.

Impact of PSP Technique on Clinical Outcomes Following Bioresorbable Scaffolds Implantation

Bioresorbable scaffolds (BRS) were introduced in clinical practice to overcome the long-term limitations of newer-generation drug-eluting stents. Despite some initial promising results of the Absorb BRS, safety concerns have led to the discontinuation of the commercialization of this device. Several retrospective studies have assessed the impact of the so-called Pre-dilation, Sizing and Post-dilation (PSP) technique concluding that an optimal PSP technique can improve clinical outcomes following BRS implantation. In this article, the definition of the PSP technique, and the current evidence of its impact on clinical outcomes are put in perspective. Additionality, the relationship between the PSP technique and the dual-antiplatelet therapy to prevent scaffold thrombosis is addressed. Finally, the future perspectives of BRS technology in clinical practice are commented.

Decision Analytic Markov Model Weighting Expected Benefits and Current Limitations of First-Generation Bioresorbable Vascular Scaffolds: Implications for Manufacturers and Next Device Iterations

BACKGROUND

Relative benefits of bioresorbable vascular scaffolds (BVS) compared with everolimus-eluting stents (EES) are expected to accrue after complete bioresorption.

METHODS AND RESULTS

We built a decision analytic Markov model comparing BVS and EES for a contemporary percutaneous coronary intervention population. Procedure-related morbidity and outcome data from the available literature were used to derive model probabilities. The net benefit of BVS and EES was estimated in terms of quality-adjusted life expectancy. Under the assumption of no risk for device thrombosis and target lesion revascularization with BVS beyond 3 years, the equipoise in quality-adjusted life expectancy (12.86) between BVS and EES was achieved 19 years after implantation. The maximum tolerable excess risk of 3-year BVS thrombosis equalizing the model-predicted quality-adjusted life expectancy of BVS and EES at 10 years was 1.40, corresponding to an absolute tolerable rate of 1.45%.

CONCLUSIONS

At the currently observed relative increase in device thrombosis and under the extreme hypothesis of no scaffold thrombosis and target lesion revascularization beyond 3 years, the incremental benefit of BVS over EES becomes apparent only after 19 years. This simulation suggests that there is a small degree of benefit that clinicians and decision-makers may expect from the first-generation BVS at the current risk of device thrombosis. Manufacturers should target scaffold thrombosis rates <1.45% at 3 years to make their technologies attractive during a 10-year horizon.

Bioresorbable Scaffolds in Coronary Intervention: Unmet Needs and Evolution

Bioresorbable scaffolds (BRS) represent a novel paradigm in the 40-year history of interventional cardiology. Restoration of cyclic pulsatility and physiologic vasomotion, adaptive vascular remodeling, plaque regression, and removal of the trigger for late adverse events are expected BRS benefits over current metallic drug-eluting stents. However, first-generation BRS devices have significant manufacturing limitations and rely on optimal implantation technique to avoid experiencing an excess of clinical events. There are currently at least 22 BRS devices in different stages of development, including many trials of device iterations with thinner (<150 µm) struts than first-generation BRS. This article reviews the outcomes of commercially available and potentially upcoming BRS, focusing on the most recent stages of clinical development and future directions for each scaffold type.

Impact of calcium on procedural and clinical outcomes in lesions treated with bioresorbable vascular scaffolds - A prospective BRS registry study

BACKGROUND

There is limited data on the impact of calcium (Ca) on acute procedural and clinical outcomes in patients with lesions treated with bioresorbable vascular scaffolds (BRS). We sought to evaluate the effect of calcium on procedural and clinical outcomes in a 'real world' population.

METHODS

Clinical outcomes were compared between patients with at least 1 moderately or heavily calcified lesion (Ca) and patients with no/mild calcified lesions (non-Ca) enrolled in our institutional BRS registry.

RESULTS

455 patients (N) with 548 lesions (L) treated with 735 BRS were studied. Patients in the Ca group (N=160, L=200) had more complex (AHA B2/C lesion: 69.0% in Ca vs 14.9% in non-Ca, p<0.001) and significantly longer lesions (27.80±15.27 vs 19.48±9.92mm, p<0.001). Overall device success rate was 99.1% with no significant differences between the groups. Despite more aggressive lesion preparation and postdilation compared to non Ca, acute lumen gain was significantly less in Ca lesions (1.50±0.66 vs 1.62±0.69mm, p=0.040) with lower final MLD (2.28±0.41 vs 2.36±0.43, p=0.046). There were no significant differences in all-cause mortality, total definite scaffold thrombosis (ST), target lesion revascularization and myocardial infarction between the 2 groups. Late ST was more frequent in the Ca group compared to non Ca group (late ST: 2.1 vs 0%, p=0.02).

CONCLUSIONS

Clinical outcomes after BRS implantation in calcified and non-calcified lesions were similar. A remarkable difference in timing of thrombosis was observed, with an increased rate of late thrombosis in calcified lesions.

Mid- and Long-Term Outcome Comparisons of Everolimus-Eluting Bioresorbable Scaffolds Versus Everolimus-Eluting Metallic Stents: A Systematic Review and Meta-analysis

BACKGROUND

Percutaneous coronary interventions to implant bioresorbable vascular scaffolds (BVSs) were designed to reduce the late thrombotic events that occur with metallic stents.

PURPOSE

To estimate the incidence of scaffold thrombosis after BVS implantation and compare everolimus-eluting BVSs with everolimus-eluting metallic stents (EESs) in terms of safety and efficacy at mid- and long-term follow-up in adults who had a percutaneous coronary intervention.

DATA SOURCES

PubMed, EMBASE, the Cochrane Library, conference proceedings, and relevant Web sites from inception until 20 May 2017, without language restriction.

STUDY SELECTION

7 randomized trials and 38 observational studies (each with a minimum of 6 months and 100 patient-years of follow-up) in adults with coronary artery disease who had a BVS or an EES and reported scaffold or stent thrombosis (main outcome) or other secondary outcomes (such as death, myocardial infarction, or revascularization).

DATA EXTRACTION

2 reviewers independently extracted study data, rated study quality, and assessed strength of evidence.

DATA SYNTHESIS

The pooled incidence of definite or probable scaffold thrombosis after BVS implantation was 1.8% (95% CI, 1.5% to 2.2%) at a median follow-up of 1 year (41 studies, 21 884 patients) and 0.8% (CI, 0.5% to 1.3%) beyond 1 year (14 studies, 4688 patients). Seven trials involving 5578 patients that directly compared BVSs with EESs showed an increased risk for definite or probable scaffold thrombosis (odds ratio [OR], 3.40 [CI, 2.01 to 5.76]) with BVSs at a median follow-up of 25 months. Increased risks were present at early (prominently subacute), late, and very late stages, and odds beyond 1 year were almost double those seen within 1 year. Bioresorbably vascular scaffolds increased risks for myocardial infarction (OR, 1.63 [CI, 1.26 to 2.10]), target lesion revascularization (OR, 1.31 [CI, 1.03 to 1.67]), and target lesion failure (OR, 1.37 [CI, 1.12 to 1.66]); the odds for these 3 end points also increased over time. The incidences of all-cause, cardiac, and noncardiac death and of target vessel and any revascularization did not differ.

LIMITATION

Quality of observational studies was unclear, and some data were unpublished.

CONCLUSION

Compared with EESs, BVSs increased the risks for scaffold thrombosis and other thrombotic events at mid- and long-term follow-up, and risks increased over time.

PRIMARY FUNDING SOURCE

National Natural Science Foundation of China.

Bioresorbable Vascular Scaffold Korean Expert Panel Report

Bioresorbable vascular scaffold (BRS) is an innovative device that provides structural support and drug release to prevent early recoil or restenosis, and then degrades into nontoxic compounds to avoid late complications related with metallic drug-eluting stents (DESs). BRS has several putative advantages. However, recent randomized trials and registry studies raised clinical concerns about the safety and efficacy of first generation BRS. In addition, the general guidance for the optimal practice with BRS has not been suggested due to limited long-term clinical data in Korea. To address the safety and efficacy of BRS, we reviewed the clinical evidence of BRS implantation, and suggested the appropriate criteria for patient and lesion selection, scaffold implantation technique, and management.

Effectiveness and safety of the ABSORB bioresorbable vascular scaffold for the treatment of coronary artery disease: systematic review and meta-analysis of randomized clinical trials

BACKGROUND

In the last years bioresorbable vascular scaffold (BVS) become a new therapeutic option for interventional cardiologists, with the advantage of a scaffold inducing a possible vessel wall restoration. Nevertheless, several trials tried to prove the safety and efficacy profile of scaffolds, but with conflicting results.

METHODS

A systematic review and meta-analysis was performed. The search was carried out in PubMed, Google Scholar, Biomed Central and Cochrane Library between January and March 2017. Inclusion criteria: randomized clinical trials (RCT) comparing the Absorb BVS versus durable polymer cobalt-chromium Everolimus Eluting Stent. The outcomes analysed were all-cause mortality, cardiac death, ischemia-driven target lesion revascularization, target vessel myocardial infarction (MI), target lesion failure (TLF)/device oriented composite endpoints (DOCE), and device thrombosis. Fixed-effect meta-analysis was performed. Data were expressed as odds ratio (OR).

RESULTS

Overall 5,674 patients were included (mean age 62.2±1.31 in drug eluting stents (DES) group vs. 62±1,47 in BVS group; P=0.942). DOCE (OR 1.16, 95% CI: 0.90-1.48; P=0.259, I2=0%), cardiac death (OR 0.86, 95% CI: 0.52-1.40; P=0.537, I²=0%) and all-cause death (OR 0.78, 95% CI: 0.53-1.15; P=0.205, I²=15%) did not differ between BVS and DES. Conversely, ischemia-driven target lesion revascularization was more frequent in the BVS group (OR 1.32, 95% CI: 1.01-1.73; P=0.039, I²=0%), as well as device thrombosis (2.2% vs. 0.6%, OR 2.94, 95% CI: 1.71-5.05, P=0.0001, I²=0%) and target-vessel MI (5.4% vs. 3%, OR 1.66, 95% CI: 1.25-2.21, P=0.001, I²=0%).

CONCLUSIONS

The implantation of BVS is associated with an increased risk of device thrombosis, ischemia-driven target lesion revascularization and target vessel MI. If longer follow-up or different implantation technique may change these findings should be addressed in future trials.

Very late bioresorbable scaffold thrombosis and reoccurrence of dissection two years later chronic total occlusion recanalization of the left anterior descending artery

We describe the case of a patient presenting with ST-segment elevation myocardial infarction due to very late scaffold thrombosis. The patient was already admitted for an elective percutaneous recanalization of a chronically occluded left anterior descending artery (LAD). The procedure was performed according the sub-intimal tracking and re-entry (STAR) technique with 4 bioresorbable vascular scaffolds implantation. However, even though the coronary flow was preserved at the end of the procedure, the dissected segment was only partially sealed at the distal segment of the LAD. After 18 mo of regular assumption, dual antiplatelet therapy was discontinued for 10 mo before his presentation at the emergency room. This is the first reported case of a very late scaffold thrombosis after coronary chronic total occlusion (CTO) recanalization performed according to the STAR technique. This case raises concerns about the risk of very late scaffold thrombosis after complex CTO revascularization.