Serban Puricel

Bioresorbable Coronary Scaffold Thrombosis : Multicenter Comprehensive Analysis of Clinical Presentation, Mechanisms, and Predictors

BACKGROUND Recent reports suggest an elevated incidence of bioresorbable vascular scaffold (BVS) thrombosis (scaffold thrombosis [ScT]). OBJECTIVES This study investigated occurrence rates, clinical and angiographic characteristics, and possible mechanisms of ScT in all-comer patients undergoing BVS implantation at 2 German and 2 Swiss hospitals. METHODS A total of 1,305 consecutive patients (mean age 64 years, 78% male) who received 1,870 BVS (mean 1.4 ± 0.8 BVS/patient) were enrolled. Clinical/procedural characteristics, mortality, and ScT data at 485 days (range 312 to 652 days) were examined. RESULTS ScT occurred in 42 patients. The incidence of probable and definite ScT was 1.8% at 30 days and 3.0% at 12 months, without differences among centers (p = 0.60). A total of 22 (52%) ScTs presented as ST-segment elevation myocardial infarction and 6 (17%) as sudden cardiac death. In multivariable analysis, ostial lesions (p = 0.049) and impaired left ventricular ejection fraction (p = 0.019) were independently associated with ScT. Nine (21%) of the ScTs occurred in patients who had suspended dual antiplatelet therapy, in 6 cases prematurely. Lower post-procedural minimum lumen and reference vessel diameters were hallmarks of ScT (all p < 0.0001). The risk of ScT appeared to rapidly increase for post-procedural minimum lumen diameters below 2.4 mm (for the 2.5- to 3.0-mm BVS) and 2.8 mm (for the 3.5-mm BVS). When a BVS-specific implantation strategy was implemented, 12-month ScT rates fell from 3.3% to 1.0%, an effect that remained significant when adjusted for multivariable propensity score (p = 0.012; hazard ratio: 0.19; 95% confidence interval: 0.05 to 0.70). CONCLUSIONS The 12-month incidence of ScT reached 3% and could be significantly reduced when an optimized implantation strategy was employed. (retrospective multicentric registry and Mainz Intracoronary Database. The Coronary Slow-flow and Microvascular Diseases Registry [MICAT]; NCT02180178).

Optical Coherence Tomography Findings in Bioresorbable Vascular Scaffolds Thrombosis

Background—Everolimus-eluting bioresorbable vascular scaffolds have been developed to improve late outcomes after coronary interventions. However, recent registries raised concerns regarding an increased incidence of scaffold thrombosis (ScT). The mechanism of ScT remains unknown. Methods and Results—The present study investigated angiographic and optical coherence tomography findings in patients experiencing ScT. Fifteen ScT (14 patients, 79% male, age 59±10 years) occurred at a median of 16 days (25%–75% interquartile range: 1–263 days) after implantation. Early ScT (<30 days) occurred in 8 cases (53%). Possible causal factors in these patients included insufficient platelet inhibition in 2 cases and procedural factors (scaffold underexpansion, undersizing, or geographical miss) in 4 cases. No obvious cause could be found in 2 early ScT. In late (>1 month) and very late (>1 year) ScT (respectively, 5 and 2 cases), 5 scaffolds showed intimal neovessels or marked peristrut low-intensity areas. Scaffold fractures were additionally found in 2 patients, and scaffold collapse was found in 1 patient with very late ScT. Extensive strut malapposition was the presumed cause for ScT in 1 case. One scaffold did not show any morphological abnormality. Thrombectomy specimens were analyzed in 3 patients and did not demonstrate increased numbers of inflammatory cells. Conclusions—The mechanisms of early ScT seem to be similar to metallic stents (mechanical and inadequate antiplatelet therapy). The predominant finding in late and very late ScT is peristrut low-intensity area.

Late thrombotic events after bioresorbable scaffold implantation: a systematic review and meta-analysis of randomized clinical trials

Aims To compare the long-term safety and efficacy of bioresorbable vascular scaffold (BVS) with everolimus-eluting stent (EES) after percutaneous coronary interventions. Methods and results A systematic review and meta-analysis of randomized clinical trials comparing clinical outcomes of patients treated with BVS and EES with at least 24 months follow-up was performed. Adjusted random-effect model by the Knapp-Hartung method was used to compute odds ratios (OR) and 95% confidence intervals (CI). The primary safety outcome of interest was the risk of definite/probable device thrombosis (DT). The primary efficacy outcome of interest was the risk of target lesion failure (TLF). Five randomized clinical trials (n = 1730) were included. Patients treated with Absorb BVS had a higher risk of definite/probable DT compared with patients treated with EES (OR 2.93, 95%CI 1.37-6.26, P = 0.01). Very late DT (VLDT) occurred in 13 patients [12/996 (1.4%, 95%CI: 0.08-2.5) Absorb BVS vs. 1/701 (0.5%, 95%CI: 0.2-1.6) EES; OR 3.04; 95%CI 1.2-7.68, P = 0.03], 92% of the VLDT in the BVS group occurred in the absence of dual antiplatelet therapy (DAPT). Patients treated with Absorb BVS had a trend towards higher risk of TLF (OR 1.48, 95%CI 0.90-2.42, P = 0.09), driven by a higher risk of target vessel myocardial infarction and ischaemia-driven target lesion revascularization. No difference was found in the risk of cardiac death. Conclusion Compared with EES, the use of Absorb BVS was associated with a higher rate of DT and a trend towards higher risk of TLF. VLDT occurred in 1.4% of the patients, the majority of these events occurred in the absence of DAPT.

Clinical outcomes after PCI for acute coronary syndrome in unprotected left main coronary artery disease: insights from the Swiss Acute Left Main Coronary Vessel Percutaneous Management (SALVage) study.

AIMS Unprotected left main (ULM) coronary artery disease is encountered in 3%-10% of coronary angiograms and is associated with high mortality. The survival of patients with ULM disease presenting with acute coronary syndromes (ACS) depends on different variables and is lowest in those with cardiogenic shock (CS). The aim of the present study was to estimate the impact of baseline characteristics on the subsequent clinical outcome in patients treated by percutaneous coronary intervention (PCI) of ULM for ACS. METHODS AND RESULTS One hundred and thirty-four patients were retrieved from our database and followed by phone or physician visit. Patients were classified into two groups according to their presentation (CS/STEMI group: patients presenting with CS or ST-elevation myocardial infarction; NSTEMI/UA group: patients with non-STEMI or unstable angina). Data collected were baseline characteristics, procedural information, and clinical outcome. The primary endpoint was all-cause mortality at 6-month follow-up. The secondary end point was a composite of cardiac death, myocardial infarction, and any repeat revascularisation, i.e., major adverse cardiac events (MACE). Kaplan-Meier curves were computed for survival. Logistic regression determined that hypercholesterolaemia (OR 6.22, p=0.03), high pre-procedural TIMI score (OR 3.89, p=0.01), preserved left ventricular ejection fraction (OR 1.07, p=0.01) and LM as culprit lesion (OR 8.57, p=0.01) protected against development of CS. Primary outcome occurred in 44% of patients in the CS/STEMI group compared to 6% in the NSTEMI/UA group (p<0.001). MACE were observed in 30 patients (48%) of the CS/STEMI group and in 12 patients (19%) of the NSTEMI/UA group (p=0.001). CONCLUSIONS Acute coronary syndrome due to critical ULM stenosis is associated with high mortality even after successful PCI. Patients presenting with CS or STEMI are at particular risk.

Comparison of everolimus- and biolimus-eluting coronary stents with everolimus-eluting bioresorbable vascular scaffolds: Two-year clinical outcomes of the EVERBIO II trial.

BACKGROUND Data from randomized controlled trials have shown that the ABSORB BVS is non-inferior to Cobalt Chromium everolimus-eluting stents at 2years. METHODS & RESULTS The EVERBIO II trial (Comparison of Everolimus- and Biolimus-Eluting Coronary Stents with Everolimus-Eluting Bioresorbable Vascular Scaffold) is a single-center, assessor-blind, randomized controlled trial enrolling 240 patients with an allocation ration of 1:1:1 conducted at University and Hospital Fribourg, Switzerland. The studied devices were an everolimus-eluting persistent polymer stent (EES), a biolimus-eluting stent with bioabsorbable polymer (BES) and a fully bioresorbable vascular scaffold (BVS). Clinical end points collected at 9months, 12months, and 2years, were academic research consortium defined composites, device thrombosis and target-vessel revascularization. Clinical follow-up at 2years was available in 96% (N=77) of patients in the EES group, in 100% (N=80) in the BES and 99% (N=77) in the BVS group. The device-oriented composite end point of cardiac death, target-vessel myocardial infarction and target-lesion revascularization occurred in 13 (16%) patients treated with EES, in 7 (9%) patients treated with BES and in 16 (21%) patients treated with BVS. There was no significant difference when the metallic stents were compared to the BVS (p=0.12). There was one late scaffold thrombosis throughout the trial in the BVS group, and no definite stent thrombosis in either EES or BES treated patients. CONCLUSIONS The current analysis shows no significant differences with regard to clinical outcomes at 2years between BVS and the best-in-class metallic DES. Event rates were numerically higher in BVS-treated patients. However, when BVS were compared to BES alone, the occurrence of device related adverse events was significantly increased.

A randomized comparison of platelet reactivity in patients after treatment with various commercial clopidogrel preparations: the CLO-CLO trial.

BACKGROUND The salt linked to the clopidogrel molecule in generic preparations is suspected to affect its clinical efficacy. There is a lack of information about inhibition of platelet reactivity by generic preparations. AIMS To compare the effect of original clopidogrel (clopidogrel bisulphate [Plavix(®)]), generic clopidogrel preparations (clopidogrel hydrochloride [Clopidogrel-Mepha(®)]; clopidogrel besylate [Clopidogrel Sandoz(®)]) and prasugrel (Efient(®)) on platelet reactivity in patients with coronary artery disease. METHODS Patients with coronary artery disease treated with stents received, in a random sequence, original clopidogrel bisulphate, clopidogrel hydrochloride and clopidogrel besylate. Platelet function was assessed with the Multiplate analyser after an initial loading dose (600 mg) and at day 10 after each treatment period. Prasugrel was given for another 10 days. An adenosine diphosphate (ADP) test value<46 antiaggregation units (U) was defined as therapeutic platelet inhibition. RESULTS Sixty patients (mean age 69 ± 10 years; 50 men) were randomized. Original clopidogrel bisulphate, clopidogrel hydrochloride and clopidogrel besylate provided similar inhibition of platelet reactivity with values of 31 ± 25, 33 ± 28 and 28 ± 23 U, respectively (P not significant). Prasugrel provided better inhibition of platelet function (10 ± 11 vs. 31 ± 25 U for clopidogrel bisulphate; P<0.001). An ADP test value>46 U was measured in 11 patients (18%) with clopidogrel bisulphate, 13 (22%) with clopidogrel besylate and 13 (22%) with clopidogrel hydrochloride compared with only one (2%) with prasugrel. CONCLUSION Generic clopidogrel preparations provided similar inhibition of platelet reactivity to original clopidogrel bisulphate, although prasugrel was more efficient.

Long-term comparison of everolimus-eluting and biolimus-eluting stents

AIMS Second-generation everolimus-eluting stents (EES) are safer and more efficient than first-generation paclitaxel-eluting stents (PES). Third-generation biolimus-eluting stents (BES) have been found to be non-inferior to PES. To date, there is no available comparative study between EES and BES. We aimed to investigate the safety and efficacy of BES with biodegradable polymer compared to EES with durable polymer at a follow-up of two years in an unselected population of consecutively enrolled patients. METHODS AND RESULTS A group of 814 consecutive patients undergoing percutaneous coronary intervention (PCI) was enrolled between 2007 and 2010, of which 527 were treated with EES and 287 with BES implantation. Clinical outcome was compared in 200 pairs using propensity score matching. The primary endpoint was a composite of death, myocardial infarction (MI) and target vessel revascularisation (TVR) at two-year follow-up. Median follow-up was 22 months. The primary outcome occurred in 11.5% of EES and 10.5% of BES patients (HR 1.11, 95% CI: 0.61-2.00, p=0.74). At two years, there was no significant difference with regard to death (HR 0.49, 95% CI: 0.18-1.34, p=0.17), cardiac death (HR 0.14, 95% CI: 0.02-1.14, p=0.66) or MI (HR 6.10, 95% CI: 0.73-50.9, p=0.10). Stent thrombosis (ST) incidence was evenly distributed between EES (n=2) and BES (n=2) (p-value=1.0). CONCLUSIONS This first clinical study failed to demonstrate any significant difference regarding safety or efficacy between these two types and generations of drug-eluting stents (DES).

Comparison of endothelium-dependent and -independent vasomotor response after abluminal biodegradable polymer biolimus-eluting stent and persistent polymer everolimus-eluting stent implantation (COMPARE-IT)

BACKGROUND Drug-eluting stents (DES) have been associated with local endothelial dysfunction in the segments proximal and distal to the stent (peristent segments) and increased thrombotic risk in long term follow-up. Little data exists on endothelial function post-implantation of new DES with biodegradable polymer. The aim of our study was to compare the local endothelial function assessed by exercise induced coronary vasomotion after implantation of a biolimus A9-eluting stent with biodegradable polymer (BES) with an everolimus-eluting stent with durable polymer (EES). METHODS Coronary vasomotion was evaluated with quantitative coronary angiography at rest and during supine bicycle exercise in nine patients with EES and thirteen patients with BES, 16 months after stent implantation. Mean luminal diameter of the stent, peristent segments, and of a control vessel were determined at rest, during exercise, and after the administration of nitroglycerine. RESULTS The control vessel showed exercise-induced vasodilatation in both groups (EES: +6.4±5.5%, p=0.07; BES: +7.8±10.1%, p=0.07). Vasomotion in the stented vessel segment was abolished. There was exercise-induced vasoconstriction in both groups in the segments proximal (EES: -9.6±4.5%; p=0.03; BES: -4.3±5.4%, p=0.02) and distal to the stent (EES: -3.2±9.3%; p=0.41, BES -8.6±8.0%, p<0.01). Sublingual nitroglycerin was associated with maximal vasodilatation of the peristent segments in both groups. CONCLUSION Alike DES with durable polymer, stents with a biodegradable polymer are associated with exercise-induced paradoxical coronary vasoconstriction of the peristent segments. This data suggests that endothelial dysfunction after DES implantation is not primarily caused by the durability of the polymer coating.

Biolimus-eluting versus everolimus-eluting stents in coronary artery disease: a pooled analysis from the NEXT (NOBORI biolimus-eluting versus XIENCE/PROMUS everolimus-eluting stent) and COMPARE II (Abluminal biodegradable polymer biolimus-eluting stent versus durable polymer everolimus-eluting stent) randomised trials

AIMS This study sought to investigate the safety and efficacy of a biolimus-eluting stent with biodegradable polymer (BP-BES) (Nobori; Terumo Corp.) compared to an everolimus-eluting stent with durable polymer (DP-EES) (XIENCE V or Prime; Abbott Vascular, or PROMUS; Boston Scientific). METHODS AND RESULTS The all-comers NEXT and COMPARE II clinical trials randomly assigned 5,942 patients to BP-BES (N=3,412) or DP-EES (N=2,530). We conducted a patient level pooled analysis at three-year follow-up with specified study endpoints: definite stent thrombosis (ST), the combined safety endpoint cardiac death or target vessel myocardial infarction (TV-MI), and the efficacy endpoint target lesion revascularisation (TLR). At three-year follow-up, all endpoints, namely definite stent thrombosis (BP-BES 0.8% vs. 0.4%, p=0.20), death or TV-MI (BP-BES 7.8% vs. 6.7%, p=0.07), as well as TLR (BP-BES 6.4% vs. 6.4%, p=0.78) were similar between groups. Interestingly, unadjusted (BP-BES 5.6% vs. 4.5%, p=0.02) and adjusted (HR 1.36; 1.01-1.82, p=0.04) TV-MI rates were higher in the BP-BES group than in the DP-EES group. CONCLUSIONS In this large-scale patient level pooled analysis of the NEXT and COMPARE II randomised trials, the use of BP-BES compared with DP-EES resulted in similar outcomes, but with an observed higher rate of TV-MI in the BP-BES group.

Bioresorbable vascular scaffolds—time to vanish?

The fully bioabsorbable vascular scaffold (BVS) has been developed to reduce late adverse events after coronary stenting such as device thrombosis. The device consists of polylactic acid, which is gradually absorbed within the first few years after its implantation. The initial experience with the device in low-risk patients presenting with simple lesions was satisfying and generated optimism among interventional cardiologists by promising better patient outcomes. However, the unrestricted use of the device in patients presenting with a higher baseline risk and more complex lesions came at the cost of alarmingly high rates of early device thrombosis. The performance of the device largely depends on an optimal implantation technique, which differs from that employed with metallic drug-eluting stents due to the devices distinct physical propensity. Mid-term outcomes in large-scale randomized clinical trial were disappointing. Although its non-inferiority compared to metallic everolimus-eluting stents was formally met, there was a clear trend towards an increased occurrence of myocardial infarction and device thrombosis during the first year after device implantation. However, the BVSs putative advantages are expected to manifest themselves at long-term, that is 3 to 5 years after the device has been implanted. Evidence pertaining to these long-term outcomes is eagerly awaited.