Robert J. Gil

Quantitative assessment with intracoronary ultrasound of the mechanisms of restenosis after percutaneous transluminal coronary angioplasty and directional coronary atherectomy

The mechanisms of immediate and late changes after percutaneous transluminal coronary angioplasty (PTCA) and directional coronary atherectomy (DCA) were assessed by serial ultrasound imaging in 18 patients treated with PTCA and 16 treated with DCA before, immediately after, and 6 months after coronary interventions. A reduction in plaque area was the main operative mechanism of DCA, explaining 66% of lumen enlargement. In the PTCA group, the increase in lumen area was the result of a more balanced combination of plaque reduction (52% of lumen increase) and increase in total lumen area (48%); p < 0.05 versus DCA. In the PTCA group, this last mechanism was prevalent (p < 0.05) in the lesions showing wall fracture or dissection after treatment and in the lesions with a mixed or calcific composition. In the PTCA group, concentric lesions showed a greater plaque compression than eccentric lesions (p < 0.02). Plaque increase was responsible for 92% and 32% of the late lumen loss after DCA and after PTCA, respectively (p < 0.05). In PTCA patients, a chronic reduction in total vessel area was the main operative mechanism of lumen reduction (67%) and was prevalent in lesions with a mixed or calcific composition. (p < 0.05).

Stenting of Culprit Lesions in Unstable Angina Leads to a Marked Reduction in Plaque Burden: A Major Role of Plaque Embolization? A Serial Intravascular Ultrasound Study

Background—Intravascular ultrasound (IVUS) studies have shown that a mechanism of plaque compression/embolization contributes toward the poststenting increase in lumen area. The aim of this IVUS study was to compare the mechanisms of lumen enlargement after coronary stenting in 54 consecutive patients with unstable angina (UA) (group 1) and 56 with stable angina (group 2) to verify whether plaque embolization plays a major role in the former. Methods and Results—Both groups underwent the IVUS assessment (speed, 0.5 mm/sec) before the intervention and after stent implantation. The lumen area, the external elastic membrane area, and the plaque+media area (PA) were measured at 0.5-mm intervals. PA reduction in the lesion site was significantly greater in group 1 (−2.50±1.97 versus −0.53±1.43 mm2, P <0.001). After stenting, 47% of the lumen area increase in group 1 was obtained by means of PA reduction, and 53% was attributable to external elastic membrane area increase; the corresponding figures in group 2 were 13% and 87% (P <0.05). Decrease in PA after stenting was the only significant predictor of the MB fraction of creatinine kinase (CK-MB) release in a multiple regression model (P =0.047). Conclusions—Serial volumetric IVUS assessment revealed in UA lesions a marked poststenting reduction in plaque volume, which is significantly greater than in stable angina and is associated with postprocedural CK-MB release. The decrease in PA during the procedure predicts CK-MB release in a multiple regression model. These findings suggest that stent deployment is often associated with plaque embolization in patients with UA.

A randomized placebo-controlled study on the effect of nifedipine on coronary endothelial function and plaque formation in patients with coronary artery disease: the ENCORE II study.

Aims Endothelial dysfunction and plaque formation are features of atherosclerosis. Inhibition of L-type calcium channels or HMG-CoA pathway improves endothelial function and reduces plaque size. Thus, we investigated in stable coronary artery disease (CAD) the effects of a calcium antagonist on coronary endothelial function and plaque size. Methods and results In 454 patients undergoing PCI, acetylcholine (10−6 to 10−4 M) was infused in a coronary segment without significant CAD. Changes in coronary diameter were measured and an intravascular ultrasound examination (IVUS) was performed. On top of statin therapy, patients were randomized in a double-blind fashion to placebo or nifedipine GITS 30–60 mg/day and followed for 18–24 months. Blood pressure was lower on nifedipine than on placebo by 5.8/2.1 mmHg (P < 0.001) as was total and LDL cholesterol (4.8 mg/dL; P = 0.495), while HDL was higher (3.6 mg/dL; P = 0.026). In the most constricting segment, nifedipine reduced vasoconstriction to acetylcholine (14.0% vs. placebo 7.7%; P < 0.0088). The percentage change in plaque volume with nifedipine and placebo, respectively, was 1.0 and 1.9%, ns. Conclusion The ENCORE II trial demonstrates in a multi-centre setting that calcium channel blockade with nifedipine for up to 2 years improves coronary endothelial function on top of statin treatment, but did not show an effect of nifedipine on plaque volume.

Local delivery versus intracoronary infusion of abciximab in patients with acute coronary syndromes.

OBJECTIVES We investigated whether local abciximab delivery to the site of intracoronary thrombus is more effective than intracoronary bolus infusion in patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention and downstream clopidogrel administration. BACKGROUND The intracoronary route of administration does not allow an optimal contact between the plaque components and abciximab, which is rapidly washed out by the coronary flow. METHODS A total of 50 patients with ACS and a significant lesion in the culprit artery indicative of local thrombosis were randomly assigned to receive local intracoronary delivery of abciximab through a dedicated perfusion catheter or intracoronary infusion through the guiding catheter. The primary end point was the change in thrombus score after angioplasty by optical coherence tomography. RESULTS After the intervention, the mean percentage change of the thrombus score was significantly higher among patients of the local delivery group compared with those of the intracoronary infusion group (33.8% vs. 3.9%, p = 0.002). Post-procedural corrected Thrombolysis in Myocardial Infarction frame count was shorter in the local delivery group compared with the intracoronary infusion group (15.3 ± 10.2 vs. 21.1 ± 9.9, p = 0.049). Procedure-related myocardial infarction was observed in 10% and 43% of patients in the local delivery and intracoronary infusion groups, respectively (p = 0.018). At 1 year, MACE were observed in 5.9% and 27.2% of patients in the local delivery and intracoronary infusion groups, respectively (p = 0.046). CONCLUSIONS Local intracoronary delivery of abciximab by means of a dedicated perfusion catheter reduces thrombus burden with the potential to improve coronary microcirculation.

Novel paclitaxel-eluting, biodegradable polymer coated stent in the treatment of de novo coronary lesions: a prospective multicenter registry.

Objectives: The purpose of the present study was to evaluate the efficacy and safety of a biodegradable polymer coated, paclitaxel eluting stent (Luc‐Chopin2) based on 9‐months angiographic and 12‐months clinical follow‐up results. Background: First‐generation drug‐eluting stents utilize nonbioabsorbable polymeric coatings, whose persistent presence in the arterial wall may negatively affect long‐term outcomes. Bioabsorbable coatings with a degradation period matched to that of the drug elution may be a better alternative, clinically and economically. Methods: We conducted a prospective, multicenter first‐in‐man registry of a novel, locally developed, bioabsorbable‐coated, paclitaxel‐eluting coronary stent in 116 patients with single‐lesion de novo coronary disease. Results: Major adverse cardiac events occurred in 7.8% patients within 12 months. There were no late thrombotic events, death, stroke, or surgical revascularization in that period. There were two myocardial infarctions, one related to recent subacute stent thrombosis and another associated with restenosis. By 12 months, target vessel revascularization was performed in 7.8%; 2.9% were ischemia‐driven and the rest were mandated at 9 months in accordance with a control angiography protocol. Core‐lab assessed binary in‐stent restenosis (≥50% DS) was noted in 11.9% patients and mean late loss was 0.46 ± 0.47 mm. Conclusions: This first‐in‐man experience obtained in a multicenter registry of real‐world de novo lesions (almost half of lesions were class B2 or C by AHA classification) showed a favorable safety profile and acceptable efficacy through 12 months. Randomized comparison with a benchmark nonbioabsorbable polymer coated paclitaxel eluting stent should be undertaken to validate this initial positive experience.

Impact of diabetes on survival in patients with ST-segment elevation myocardial infarction treated by primary angioplasty: Insights from the POLISH STEMI registry

BACKGROUND It has been shown that, among patients with ST-segment elevation myocardial infarction (STEMI), diabetes is associated with a significantly higher mortality. The aim of this study was to investigate in a large cohort of patients the impact of diabetes on mortality in a large cohort of patients with STEMI treated with primary angioplasty. METHODS Our population is represented by consecutive patients with STEMI treated by primary angioplasty and enrolled in the POLISH registry in 2003. All clinical, angiographic, and follow-up data were prospectively collected. Diagnosis of diabetes was based on history of diabetes at admission. RESULTS Among 7193 patients, 877 (12.2%) had diabetes at admission. Diabetes was associated with more advanced age (p<0.0001), higher prevalence of female gender (p<0.0001), hyperlipidemia (p<0.0001), shock at presentation (p<0.0001), renal failure (p<0.0001), previous myocardial infarction (p<0.0001), more often treated after 6h from symptom onset (p<0.0001). Diabetes was associated with more extensive coronary artery disease (p<0.0001), less often treated with stenting (p<0.0001). Diabetes was significantly associated with impaired epicardial reperfusion (TIMI 0-2: OR [95% CI]=1.81 [1.5-2.18], p<0.0001), that persisted after correction for baseline confounding factors (OR [95% CI]=1.33 [1.075-1.64], p=0.009). At a mean follow-up of 524+/-194 days, diabetes was associated with higher mortality (unadjusted cumulative mortality: 23.5% vs. 12.6%, unadjusted HR=1.95 [1.66-2.3], p<0.0001), that persisted after correction for confounding factors (adjusted cumulative mortality: 13.3% vs. 10.7%, adjusted HR=1.23 [1.04-1.46], p=0.013). CONCLUSIONS This study shows that among STEMI treated by primary angioplasty diabetes is independently associated with impaired epicardial reperfusion and higher mortality.

Usefulness of three-dimensional reconstruction for interpretation and quantitative analysis of intracoronary ultrasound during stent deployment

We examined 49 coronary stents in 33 patients after angiographically guided optimization of the deployment by intracoronary ultrasound, and compared the findings of a conventional 2-dimensional analysis approach with the results obtained from an automatic lumen recognition provided by a 3-dimensional reconstruction system. The automatic lumen analysis demonstrated that only 15 stents (31%) fulfilled defined ultrasound criteria of adequate stent deployment, and that 5 of these cases were missed by the conventional approach, which systematically overestimated the dimensions of the minimal stent lumen.

Dedicated paclitaxel-eluting bifurcation stent BiOSS® (bifurcation optimisation stent system): 12-month results from a prospective registry of consecutive all-comers population.

AIMS Dedicated bifurcation stents seem to be the most promising solution for treating bifurcations. The aim of our study was to present the 12 months results of a new dedicated stent for coronary bifurcation lesions -the paclitaxel-eluting stent- BiOSS® Expert (Bifurcation Optimisation Stent System, Balton, Warsaw, Poland). METHODS AND RESULTS Sixty-three patients with 65 lesions were enrolled in the registry. Forty-six % of the patients were classified as NSTEMI or unstable angina, 27% were diabetics, 30% had previous myocardial infarction and 48% had a history of previous revascularisation. In addition, hypertension and dyslipidaemia were the most common risk factors (58% and 40%). Sixty-five stents were successfully implanted (100% device success rate). The analysis of 30 days follow-up for 63 patients revealed good clinical results showing lack of death, target lesion revascularisation procedures (TLR) and target vessel revascularisation procedures (TVR). There were six (9,5%) cases of in-hospital raised troponin, however, only one showed an additional increase in CK-MB levels and was qualified as non-Q myocardial infarction (MI). There was a need for percutaneous coronary intervention (PCI) in a non-index vessel in one patient due to exertional angina. The analysis of 12-month follow-up for 63 patients revealed good clinical results. There were two (3.2%) cases of death (three and 10 months after index procedure). The first patient, in good physical shape, drowned, while the second was found dead by his family. There were no incidents of MI or stroke in the rest of the population. At 12 months there were seven (10.8% per lesion; 11.1% per patient) cases of TLR and nine (13.8% per lesion; 14.3% per patient) TVR. There were also 15 (23.8%) cases of PCI on vessels not related to BiOSS® Expert stent implantation. CONCLUSIONS Our registry showed that bifurcation treatment with a single dedicated paclitaxel-eluting bifurcation stent, BiOSS® Expert is feasible and successful. The long-term clinical results are satisfactory in this high-risk patient population.

Dedicated Bifurcation Paclitaxel‐Eluting Stent BiOSS Expert® in the Treatment of Distal Left Main Stem Stenosis

OBJECTIVES The aim of this study was to assess prospectively the effectiveness and safety profile of distal left main stem (LMS) stenosis treatment with dedicated bifurcation paclitaxel-eluting stent BiOSS Expert®. BACKGROUND Angioplasty of distal LMS stenosis is always a high-risk procedure, and optimal treatment is uncertain. METHODS This was a prospective international 2-center study, which enrolled patients with non-ST-elevation acute coronary syndrome (NSTE-ACS) or stable angina with distal left main stenosis. All patients were treated with the dedicated bifurcation stent BiOSS Expert®. Provisional T-stenting was the obligatory strategy. Angiographic control was performed after 12 months. The primary end-point was cumulative rate of death, myocardial infarction (MI), and target lesion revascularization (TLR) at 12 months. Angiographic end-points included late lumen loss, percent diameter stenosis, and binary restenosis rate. RESULTS A total of 54 patients with distal LMS stenosis were enrolled. Seven patients (13%) were enrolled during NSTE-ACS, 77.8% were hypertensive, 27.8% were diabetic, 51.9% had previous MI, 53.7% underwent prior percutaneous coronary intervention, and 16.7% coronary artery bypass graft. The mean SYNTAX score was 21.52 ± 6.50. The device success rate was 100%. The mean BiOSS Expert stent parameters were as follows: 4.07 ± 0.26 mm × 3.36 ± 0.26 mm × 16.61 ± 1.72 mm and in side branch the other stent (classical drug-eluting stent) was implanted in 25.9% of cases. The overall TLR was 9.3%. There were no death, stent thrombosis, or acute MI. In the univariate regression analysis, the only factor associated with higher risk for TLR was the SYNTAX score value. CONCLUSIONS The dedicated bifurcation stent BiOSS Expert® proved to be a feasible device, with promising safety and long-term clinical effectiveness in the treatment of distal LMS stenosis.

Bifurcation Optimisation Stent System (BiOSS Lim) with sirolimus elution: results from porcine coronary artery model.

AIMS The optimal treatment strategy for coronary bifurcation lesions is still unknown. The BiOSS Lim stents (Bifurcation Optimisation Stent System) is a novel dedicated bifurcation stent introduced over a single wire in to the main vessel, covered with biodegradable polymer and sirolimus. It has wider proximal and narrower distal parts. The aim of the study was to assess applicability of the the BiOSS Lim stent in a porcine coronary model. METHODS AND RESULTS A total of 14 BiOSS Lims were implanted in normal non-atherosclerotic porcine coronary bifurcations of 14 animals (six stents for 28 days, eight stents for 90 days) using 1.1:1.0 stent-to-artery ratio. Stent geometry and morphology were evaluated by Faxitron imagery (Faxitron Bioptics, LLC, IL, USA). Vascular effects were assessed based on angiographic and histological analysis. Analysis of Faxitron images revealed no major abnormalities except two struts fractures at the place of connection between the mid-portion and proximal wider part of the stent. Histomorphometry showed decreased area stenosis and intimal thickness at 90 days compared with the 28 days cohort. The inflammatory scores were low (<1) at both time points and struts endothelialisation was completed at 28 days. CONCLUSIONS The novel BiOSS Lim stent demonstrates good short- and mid-term vascular effects in a porcine coronary bifurcation model.