Clinical outcomes after unprotected left main coronary artery occlusion: A retrospective multicentre cohort analysis

AIMS

Unprotected left main coronary artery (ULMCA) occlusion is a rare and disastrous condition with scarce data on presentation and outcomes. Herein, we report data on patients presenting with acute coronary syndrome due to ULMCA occlusion at four different institutions.

METHODS

This is an international multicentre observational study. Baseline characteristics were retro- and prospectively collected. Clinical follow-up was prospective. The primary outcome was in-hospital death. Patients surviving the index hospitalization were compared with nonsurvivors to find predictors of survival.

RESULTS

The study population consisted of 55 patients. Eight patients (15%) died in the cath lab, and 23 (42%) died in hospital. Three (6%) deaths were noncardiac and due to major bleeding. Thirty-two (58%) patients survived the index hospitalization and were discharged. These patients were followed for a median of 17.5 months during which three cardiac deaths occurred. Repeat revascularization was performed in 25% (n = 8). Overall mortality at maximum follow-up was 47% (n = 26). The only significant predictor for hospital survival was left ventricular ejection fraction (odds ratio [OR]: 1.10 (per 1 point increase); 95% confidence interval [CI]: 1.02-1.19; p = 0.02).

CONCLUSION

ULMCA occlusion carries a high short-term mortality. Patients who survive index hospitalization have similar mortality rates as compared with other st elevation myocardial infarction patients.

Bioabsorbable polymer drug-eluting stents with 4-month dual antiplatelet therapy versus durable polymer drug-eluting stents with 12-month dual antiplatelet therapy in patients with left main coronary artery disease: the IDEAL-LM randomised trial

BACKGROUND

Improvements in drug-eluting stent design have led to a reduced frequency of repeat revascularisation and new biodegradable polymer coatings may allow a shorter duration of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI).

AIMS

The Improved Drug-Eluting stent for All-comers Left Main (IDEAL-LM) study aims to investigate long-term clinical outcomes after implantation of a biodegradable polymer platinum-chromium everolimus-eluting stent (BP-PtCr-EES) followed by 4 months DAPT compared to a durable polymer cobalt-chromium everolimus-eluting stent (DP-CoCr-EES) followed by 12 months DAPT in patients undergoing PCI of unprotected left main coronary artery (LMCA) disease.

METHODS

This is a multicentre randomised clinical trial study in patients with an indication for coronary artery revascularisation who have been accepted for PCI for LMCA disease after Heart Team consultation. Patients were randomly assigned in a 1:1 ratio to receive either the BP-PtCr-EES or the DP-CoCr-EES. The primary endpoint was a non-inferiority comparison of the rate of major adverse cardiovascular events (MACE), defined as all-cause death, myocardial infarction, or ischaemia-driven target vessel revascularisation at 2 years.

RESULTS

Between December 2014 and October 2016, 818 patients (410 BP-PtCr-EES and 408 DP-CoCr-EES) were enrolled at 29 centres in Europe. At 2 years, the primary endpoint of MACE occurred in 59 patients (14.6%) in the BP-PtCr-EES group and 45 patients (11.4%) in the DP-CoCr-EES group; 1-sided upper 95% confidence interval (CI) 7.18%; p=0.04 for non-inferiority; p=0.17 for superiority. The secondary endpoint event of BARC 3 or 5 bleeding occurred in 11 patients (2.7%) in the BP-PtCr-EES group and 2 patients (0.5%) in the DP-CoCr-EES group (p=0.02).

CONCLUSIONS

In patients undergoing PCI of LMCA disease, after two years of follow-up, the use of a BP-PtCr-EES with 4 months of DAPT was non-inferior to a DP-CoCr-EES with 12 months of DAPT with respect to the composite endpoint of all-cause death, myocardial infarction or ischaemia-driven target vessel revascularisation.

Leaflet stress quantification of porcine vs bovine surgical bioprostheses: an in vitro study

Calcified aortic stenoses are among the most prevalent form of cardiovascular diseases in the industrialized countries. This progressive disease, with no effective medical therapy, ultimately requires aortic valve replacement - either a surgical or very recently transcatheter aortic valve implantation. Increase leaflet mechanical stress is one of the main determinants of the structural deterioration of bioprosthetic aortic valves. We applied a coupled in vitro/in silico method to compare the timing, magnitude, and regional distribution of leaflet mechanical stress in porcine versus pericardial bioprostheses (Mosaic and Trifecta). A double activation simulator was used for in vitro testing of a bioprosthesis with externally mounted pericardium (Abbott, Trifecta) and a bioprosthesis with internally mounted porcine valve (Medtronic, Mosaic). A non-contact system based on stereophotogammetry and digital image correlation (DIC) with high spatial and temporal resolution (2000 img/s) was used to visualize the valve leaflet motion and perform the three-dimensional analysis. A finite element model of the valve was developed, and the leaflet deformation obtained from the DIC analysis was applied to the finite element model calculate local leaflet mechanical stress throughout the cardiac cycle. The maximum leaflet stress was higher with the pericardial versus the porcine bioprosthesis (2.03 vs. 1.30 MPa) For both bioprostheses the highest values of leaflet stress occurred during diastole and were primarily observed in the upper leaflet edge near the commissures and to a lesser extent in the mid-portion of the leaflet body. In conclusion, the coupled in vitro/in silico method described in this study shows that the highest levels of leaflet stress occur in the regions of the commissures and mid-portion of the leaflet body. This method may have important insight with regard to bioprosthetic valve durability. Our results suggest that, compared to porcine bioprostheses, those with externally mounted pericardium have higher leaflet mechanical stress, which may translate into shorter durability.

First-in-Man trial of a drug-free bioresorbable stent designed to minimize the duration of coronary artery scaffolding

For the last two decades, various degradable stents have been proposed to treat coronary artery diseases and replace metallic stents to avoid residual foreign material after healing. To date, the right balance between suitable scaffolding and loss of radial strength soon after endothelium restoration is still an unmet need. The present article reports on the First-in-Man trial of a drug-free bioresorbable stent based on a lactic acid stereocopolymer composed of 98% l-lactyl units selected to release stress shielding earlier than in the case of homopoly(l-lactic acid). Thirty patients with single de novo coronary lesions were included in the trial. The fate of scaffolds was monitored by clinical and imaging follow-ups to assess rate of adverse events, acute recoil, late luminal loss, and late lumen recovery. There was no death, no myocardial infarction, and no stent thrombosis observed over the 36 months trial. Dismantling occurred about 3 months after implantation. Bioresorption was almost completed at 2 years. The late lumen loss observed at the end of the first year was partly compensated one year later by enlarging remodeling. At one year, a neointimal hyperplasia slightly greater than for drug-eluting metallic and bioresorbable stents was shown using optical coherence tomography. The excess of hyperplasia was discussed relative to struts thickness, absence of anti-proliferative drug, and release of degradation by-products.

Comparison of a Novel Biodegradable Polymer Sirolimus-Eluting Stent With a Durable Polymer Everolimus-Eluting Stent: 5-Year Outcomes of the Randomized BIOFLOW-II Trial

OBJECTIVES

The authors aimed to compare long-term data of an ultrathin cobalt-chromium stent with passive silicon carbide coating and an active biodegradable polymer that releases sirolimus (O-SES) (Orsiro, BIOTRONIK, Bülach, Switzerland) with the durable polymer-based Xience Prime everolimus-eluting stent (X-EES) (Abbott Vascular, Santa Clara, California).

BACKGROUND

Biodegradable polymer stents have been developed aiming to overcome long-term detrimental effects of durable polymer stents, ultimately leaving a bare-metal stent in the vessel.

METHODS

This multicenter, assessor-blinded trial randomized 452 patients with 505 lesions to either O-SES or X-EES in a 2:1 fashion. Endpoints at 5 years were target lesion failure (TLF), its components, and stent thrombosis.

RESULTS

TLF occurred in 10.4% (n = 30) of O-SES patients versus 12.7% (n = 19) of X-EES patients (p = 0.473), overall stent thrombosis occurred in 0.7% (n = 2) versus 2.8% (n = 4) (p = 0.088), and definite stent thrombosis in 0% versus 0.7% (n = 1) (p = 0.341). Post hoc analysis was performed in diabetic patients (n = 128) and vessels ≤2.75 mm (n = 259). In diabetic patients, the O-SES group had numerically more target lesion revascularizations (13.5% vs. 4.5%; p = 0.138), but fewer cardiac deaths (1.3% vs. 6.9%; p = 0.089) and stent thrombosis (0% vs. 6.9%; p = 0.039). In small vessels, the O-SES group had a significantly lower 5-year mortality (3.7% vs. 11.3%; p = 0.022).

CONCLUSIONS

At 5 years, the biodegradable polymer O-SES demonstrated low TLF rates comparable to the durable polymer X-EES, confirming its long-term safety and performance. Particularly encouraging is the absence of definite stent thrombosis.

A novel method to quantitate bioprosthetic valve leaflet mechanical stress: a numerical and in vitro study

An original in vitro/in silico method was developed to estimate the local and global mechanical stress applied on the bioprosthetic valve leaflet, which can be important for better understanding of the valve durability. A non-contact system based on stereophotogammetry and digital image correlation enabled filming and studying the valve leaflet movement frame by frame and performing three-dimensional analysis. The deformation was applied in a finite element model in order to calculate the local mechanical stress applied. High stress regions were primarily observed in the upper leaflet edge and belly and to a lesser extent at the free leaflet edge.

6- Versus 24-Month Dual Antiplatelet Therapy After Implantation of Drug-Eluting Stents in Patients Nonresistant to Aspirin: Final Results of the ITALIC Trial (Is There a Life for DES After Discontinuation of Clopidogrel)

OBJECTIVES

The aim of this study was to test the hypothesis that 6-month dual antiplatelet therapy (DAPT) is noninferior to 24-month DAPT in aspirin-sensitive patients.

BACKGROUND

The ITALIC (Is There a Life for DES After Discontinuation of Clopidogrel) trial showed that rates of bleeding and thrombotic events at 1 year were much the same with 6 versus 12 months of DAPT after percutaneous coronary intervention with second-generation drug-eluting stents. In this report, 2-year follow-up is presented.

METHODS

In a multicenter randomized study, patients with confirmed nonresistance to aspirin undergoing drug-eluting stent implantation were allocated to 6 or 24 months of DAPT. The primary endpoint was a composite of death, myocardial infarction, urgent target vessel revascularization, stroke, and major bleeding at 12 months post-percutaneous coronary intervention. The secondary endpoints comprised the same composite endpoint at 24 months and each individual component.

RESULTS

Overall, 2,031 patients from 70 centers were screened; 926 were randomized to 6-month and 924 to 24-month DAPT. Noninferiority was demonstrated for 6- versus 12-month DAPT, with an absolute risk difference of 0.11% (95% confidence interval: -1.04% to 1.26%; p = 0.0002). At 2 years, the composite endpoint was unchanged, at 3.5% for 6 months and 3.7% for 24 months (p = 0.79), and rates of myocardial infarction (1.3% vs. 1.0%; p = 0.51), stroke (0.6% vs. 0.8%; p = 0.77), and target vessel revascularization (1.0% vs. 0.3%; p = 0.09) were likewise similar. There was a trend toward higher mortality with longer DAPT (2.2% vs. 1.2%; p = 0.11). Four patients (0.4%) in the 24-month group and none in the 6-month group had major bleeding.

CONCLUSIONS

Two-year outcomes in the ITALIC trial confirmed the 1-year results and showed that patients receiving 6-month DAPT after percutaneous coronary intervention with second-generation drug-eluting stent have similar outcomes to those receiving 24-month DAPT.

Reduced duration of dual antiplatelet therapy using an improved drug-eluting stent for percutaneous coronary intervention of the left main artery in a real-world, all-comer population: Rationale and study design of the prospective randomized multicenter IDEAL-LM trial

BACKGROUND

Continuous improvements in stent technology make percutaneous coronary intervention (PCI) a potential alternative to surgery in selected patients with unprotected left main coronary artery (uLMCA) disease. The optimal duration of dual antiplatelet therapy (DAPT) in these patients remains undetermined, and in addition, new stent designs using a bioabsorbable polymer might allow shorter duration of DAPT.

STUDY DESIGN

IDEAL-LM is a prospective, randomized, multicenter study that will enroll 818 patients undergoing uLMCA PCI. Patients will be randomized in a 1:1 fashion to intravascular ultrasound-guided PCI with the novel everolimus-eluting platinum-chromium Synergy stent with a biodegradable polymer (Boston Scientific, Natick, MA) followed by 4 months of DAPT or the everolimus-eluting cobalt-chromium Xience stent (Abbott Vascular, Santa Clara, CA) followed by 12 months of DAPT. The total follow-up period will be 5 years. A subset of 100 patients will undergo optical coherence tomography at 3 months.

END POINTS

The primary end point will be major adverse cardiovascular events (composite of all-cause mortality, myocardial infarction, and ischemia-driven target vessel revascularization) at 2 years. Secondary end points will consist of the individual components of the primary end point, procedural success, a device-oriented composite end point, stent thrombosis as per Academic Research Consortium criteria, and bleeding as per Bleeding Academic Research Consortium criteria.

SUMMARY

IDEAL-LM is designed to assess the safety and efficacy of the novel Synergy stent followed by 4 months of DAPT vs the Xience stent followed by 12 months of DAPT in patients undergoing uLMCA PCI. The study will provide novel insights regarding optimal treatment strategy for patients undergoing PCI of uLMCA disease (www.clinicaltrials.gov, NCT 02303717).

Comparison of a novel biodegradable polymer sirolimus-eluting stent with a durable polymer everolimus-eluting stent: results of the randomized BIOFLOW-II trial

BACKGROUND

Biodegradable polymers for release of antiproliferative drugs from drug-eluting stents aim to improve vascular healing. We assessed noninferiority of a novel ultrathin strut drug-eluting stent releasing sirolimus from a biodegradable polymer (Orsiro, O-SES) compared with the durable polymer Xience Prime everolimus-eluting stent (X-EES) in terms of the primary end point in-stent late lumen loss at 9 months.

METHODS AND RESULTS

A total of 452 patients were randomly assigned 2:1 to treatment with O-SES (298 patients, 332 lesions) or X-EES (154 patients, 173 lesions) in a multicenter, noninferiority trial. The primary end point was in-stent late loss at 9 months. O-SES was noninferior to X-EES for the primary end point (0.10±0.32 versus 0.11±0.29 mm; difference=0.00063 mm; 95% confidence interval, -0.06 to 0.07; Pnoninferiority<0.0001). Clinical outcome showed similar rates of target-lesion failure at 1 year (O-SES 6.5% versus X-EES 8.0%; hazard ratio=0.82; 95% confidence interval, 0.40-1.68; log-rank test: P=0.58) without cases of stent thrombosis. A subgroup of patients (n=55) underwent serial optical coherence tomography at 9 months, which demonstrated similar neointimal thickness among lesions allocated to O-SES and X-EES (0.10±0.04 mm versus 0.11±0.04 mm; -0.01 [-0.04, -0.01]; P=0.37). Another subgroup of patients (n=56) underwent serial intravascular ultrasound at baseline and 9 months indicating a potential difference in neointimal area at follow-up (O-SES, 0.16±0.33 mm(2) versus X-EES, 0.43±0.56 mm(2); P=0.04).

CONCLUSIONS

Compared with durable polymer X-EES, novel biodegradable polymer-based O-SES was found noninferior for the primary end point in-stent late lumen loss at 9 months. Clinical event rates were comparable without cases of stent thrombosis throughout 1 year of follow-up.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT01356888.

Cyclosporine before PCI in Patients with Acute Myocardial Infarction

BACKGROUND

Experimental and clinical evidence suggests that cyclosporine may attenuate reperfusion injury and reduce myocardial infarct size. We aimed to test whether cyclosporine would improve clinical outcomes and prevent adverse left ventricular remodeling.

METHODS

In a multicenter, double-blind, randomized trial, we assigned 970 patients with an acute anterior ST-segment elevation myocardial infarction (STEMI) who were undergoing percutaneous coronary intervention (PCI) within 12 hours after symptom onset and who had complete occlusion of the culprit coronary artery to receive a bolus injection of cyclosporine (administered intravenously at a dose of 2.5 mg per kilogram of body weight) or matching placebo before coronary recanalization. The primary outcome was a composite of death from any cause, worsening of heart failure during the initial hospitalization, rehospitalization for heart failure, or adverse left ventricular remodeling at 1 year. Adverse left ventricular remodeling was defined as an increase of 15% or more in the left ventricular end-diastolic volume.

RESULTS

A total of 395 patients in the cyclosporine group and 396 in the placebo group received the assigned study drug and had data that could be evaluated for the primary outcome at 1 year. The rate of the primary outcome was 59.0% in the cyclosporine group and 58.1% in the control group (odds ratio, 1.04; 95% confidence interval [CI], 0.78 to 1.39; P=0.77). Cyclosporine did not reduce the incidence of the separate clinical components of the primary outcome or other events, including recurrent infarction, unstable angina, and stroke. No significant difference in the safety profile was observed between the two treatment groups.

CONCLUSIONS

In patients with anterior STEMI who had been referred for primary PCI, intravenous cyclosporine did not result in better clinical outcomes than those with placebo and did not prevent adverse left ventricular remodeling at 1 year. (Funded by the French Ministry of Health and NeuroVive Pharmaceutical; CIRCUS ClinicalTrials.gov number, NCT01502774; EudraCT number, 2009-013713-99.).

Presentation and revascularization patterns of patients admitted for acute coronary syndromes in France between 2004 and 2008 (from the National Observational Study of Diagnostic and Interventional Cardiac Catheterization [ONACI])

Patients with acute coronary syndrome (ACS) comprise a heterogeneous group. Despite clear guidelines, the management of ACS in clinical practice is variable. We aimed to evaluate clinical characteristics and myocardial revascularization patterns of patients presenting with ACS from a large French nationwide registry. The National Observational Study of Diagnostic and Interventional Cardiac Catheterization is a multicenter registry including all interventional cardiology procedures performed since 2004. Patient demographics and co-morbidities, invasive parameters, treatment options, and procedural techniques were prospectively collected. The present study is focused on data collected between 2004 and 2008. Patients were recruited in 99 hospitals (55% in private clinics, 45% in public institutions). Over a 5-year period, 64,932 patients with ACS were included (mean age 65.7 ± 13.3; 73% men, 31% ST-elevation myocardial infarction [STEMI]). Patients presenting with unstable angina pectoris and non-ST-elevation myocardial infarction weresimilar with regards to clinical presentation and coronary artery disease (CAD) extension. Overall, these patients were older, had a higher cardiovascular risk profile, and had more severe CAD compared with STEMI patients. In-hospital mortality during the first 24 hours was higher in STEMI patients. Patient's characteristics and CAD were highly dependent on the type of ACS. Patients with unstable angina/non-STEMI were older and had a more severe CAD. In-hospital complications were higher in STEMI patients.

Six-month IVUS and two-year clinical outcomes in the EVOLVE FHU trial: a randomised evaluation of a novel bioabsorbable polymer-coated, everolimus-eluting stent

Aims: The EVOLVE FHU trial demonstrated non-inferiority of six-month late loss with two dose formulations of SYNERGY, a novel bioabsorbable polymer everolimus-eluting stent (EES) compared with the durable polymer PROMUS Element (PE) EES. The current analysis describes the six-month IVUS and clinical results through two years from the EVOLVE FHU trial. Methods and results: EVOLVE recruited 291 patients from 29 centres. At six months, IVUS-assessed in-stent net volume obstruction was 3.40±5.06% for PROMUS Element (PE) vs. 2.68±4.60% for SYNERGY (p=0.34) and 3.09±4.29% for SYNERGY ½ dose (p=0.68 vs. PE). There were no significant differences between groups for any other measured IVUS parameter including resolved, persistent, and late-acquired incomplete stent apposition (ISA). At two years, target lesion failure (TLF) was 6.1% for PE vs. 5.5% for SYNERGY (p=0.87) and 5.2% for SYNERGY ½ dose (p=0.81). There were no significant differences between groups for cardiac death, repeat revascularisation, MI or stent thrombosis through two years. Conclusions: At six months, everolimus delivered from an ultrathin bioabsorbable abluminal polymer resulted in equivalent net volume obstruction and ISA compared with a permanent polymer EES. There were no significant differences between PE and either SYNERGY stent for any major cardiac endpoint through two years. Clinical trials number: NCT01135225.

SeQuentPlease World Wide Registry: clinical results of SeQuent please paclitaxel-coated balloon angioplasty in a large-scale, prospective registry study

OBJECTIVES

This study sought to assess the safety and efficacy of paclitaxel-coated balloon (PCB) angioplasty in an international, multicenter, prospective, large-scale registry study.

BACKGROUND

In small randomized trials, PCB angioplasty was superior to uncoated balloon angioplasty for treatment of bare-metal stent (BMS) and drug-eluting stent (DES) restenosis.

METHODS

Patients treated with SeQuent Please PCBs were included. The primary outcome measure was the clinically driven target lesion revascularization (TLR) rate at 9 months.

RESULTS

At 75 centers, 2,095 patients with 2,234 lesions were included. The TLR rate was 5.2% after 9.4 months. Definite vessel thrombosis occurred in 0.1%. PCB angioplasty was performed in 1,523 patients (72.7%) with DES or BMS restenosis and 572 patients (27.3%) with de novo lesions. The TLR rate was significantly lower in patients with PCB angioplasty for BMS restenosis compared with DES restenosis (3.8% vs. 9.6%, p < 0.001). The TLR rate did not differ for PCB angioplasty of paclitaxel-eluting stent and non-paclitaxel-eluting sten restenosis (8.3% vs. 10.8%, p = 0.46). In de novo lesions (small vessels), the TLR rate was low and did not differ between PCB angioplasty with and without additional BMS implantation (p = 0.31).

CONCLUSIONS

PCB angioplasty in an all-comers, prospective, multicenter registry was safe and confirmed in a large population the low TLR rates seen in randomized clinical trials. PCB angioplasty was more effective in BMS restenosis compared with DES restenosis, with no difference regarding the type of DES.

Comparison of twelve-month outcomes after percutanous coronary intervention with everolimus-eluting versus zotarolimus-eluting or sirolimus-eluting stents from the PROENCY (PROmus ENdeavor CYpher) registry

OBJECTIVES

We compared safety and efficacy outcomes of 3 limus-based drug-eluting stents in the 'all-comers' PROENCY (PROmus/ENdeavor/CYpher) registry.

BACKGROUND

Limited data are available on head-to-head comparisons of the everolimus-eluting stent (EES) with the zotarolimus-eluting stent (ZES) or the sirolimus- eluting stent (SES) in the treatment of patients with coronary artery disease.

METHODS

PROENCY was a prospective, open-label, multicenter, observational study including consecutive patients undergoing planned treatment with EES, ZES, or SES. Seventeen centers were designated to place an EES or SES, 14 other centers were designated to place EES or ZES. The primary endpoint was the composite of cardiac death, myocardial infarction, and target vessel revascularization (TVR) at 12 months. Unadjusted and propensity-adjusted outcomes were compared between groups.

RESULTS

A total of 1921 patients were enrolled in the study from February to December 2008, of which 1704 patients received only study stents and were analyzed. At 12 months, the unadjusted major adverse event rate was significantly lower in the EES group versus the ZES group (3.1% vs 8.7%; P=.001) and the SES group (5.2% vs 9.6%; P=.01). This was mainly driven by lower TVR rates [2.6% with EES vs 8.2% with ZES [P<.001] and 4.1% with EES vs 7.0% with SES [P=.05]. Stent thrombosis rates were low and comparable. Adjusted analyses confirmed the unadjusted results.

CONCLUSION

There were no differences in safety outcomes of EES, ZES, and SES at 12 months in PROENCY. However, differences in efficacy were observed between the 3 "limus"-based stents in a real-world patient population.

Biological efficacy of a 600 mg loading dose of clopidogrel in ST-elevation myocardial infarction

Optimal platelet reactivity (PR) inhibition is critical to prevent thrombotic events in primary percutaneous coronary intervention (PCI). We aimed to determine the relationship between high on-treatment platelet reactivity (HTPR) and ST-elevation myocardial infarction (STEMI) following a 600 mg loading dose (LD) of clopidogrel. We performed a prospective monocentre study enrolling patients on clopidogrel undergoing PCI. The VASP index was used to assess PR inhibition after clopidogrel LD. HTPR was defined according to the consensus as a VASP index ≥50%. The present study included 833 patients undergoing PCI. Most patients had PCI for an acute coronary syndrome (58.7%). The mean VASP index was 50 ± 23% with a large inter-individual variability (range: 1-94%). Patients with a VASP index ≥50% were significantly older (p= 0.03), with a higher body mass index (BMI) (p<0.001), more often diabetic (p=0.03), taking omeprazole (p=0.03), admitted for an acute coronary syndrome (ACS) and with a high fibrinogen level compared to good responders (VASP <50%). In multivariate analysis BMI, omeprazole use, ACS and high fibrinogen level (p<0.001) remained significantly associated with HTPR. Of importance, in this analysis STEMI was independently associated with HTPR when compared with the other forms of ACS (NSTEMI and unstable angina) with an odd ratio of 2.14 (95% CI: 1.3 -3.5; p=0.003). In conclusion, STEMI is associated with high on-treatment platelet reactivity following 600 mg of clopidogrel. The present results suggest that 600 mg of clopidogrel may not be able to achieve an optimal PR inhibition in STEMI patients undergoing PCI and more potent drugs may be preferred.

Comparison of a new ELISA assay with the flow cytometric assay for platelet vasodilator-associated stimulated phosphoprotein (VASP) phosphorylation in whole blood to assess P2Y(12) inhibition

Thienopyridines and other agents target the platelet P2Y(12) receptor and inhibit several platelet activities mediated by adenosine diphosphate (ADP). The measurement of vasodilator-associated stimulated phosphoprotein (VASP) phosphorylation, expressed as platelet reactivity index (PRI), mirrors the degree of P2Y(12) receptor inhibition and can detect the well-known variable response to clopidogrel. The commercially available VASP assay uses flow cytometry (FC) and requires that the test be run within 48 hours of blood collection. A new ELISA VASP assay offers the advantages of using more widely available technology and the potential to freeze and store samples before analysis. The objectives of the present study were to compare the performance of the ELISA and FC methods and to describe the relative flexibility of the ELISA-based assay. Human blood samples encompassing a wide range of levels of P2Y(12) blockade achieved in vitro by preincubation with P2Y(12) antagonists or in vivo from patients treated with clopidogrel were included, reflecting the wide spread of values reported in clinical studies. The correlation between the PRI measured by ELISA and FC was highly significant (r=0.95, p<0.001), (n=80). After the initial activation, samples were stable for at least four weeks when frozen (-20°C) prior to analysis by ELISA. Frozen samples from patients treated with clopidogrel appeared stable for up to nine weeks. Based on these results, the ELISA-based assay appears to provide a reliable and more flexible alternative to the FC method to determine P2Y(12) receptor blockade and may enable more extensive utilisation of the VASP assay in clinical studies.

[Role of angioplasty in the treatment of renal artery stenosis]

Atherosclerotic renal artery stenosis is frequent and is associated with a high incidence of morbidity and mortality, with a strong correlation with coronary artery disease, (Kalra et al., 2005; Cheung et al., 2002; Guo et al., 2007 [1-3]). The atherosclerotic renal artery stenosis is an independent predictive factor of death (Conlon et al., 1998 [4]). The treatment of this lesion does not have strong evidence. A lot of studies in this area suggest the angioplasty is superior in a big majority between surgery, and angioplasty with stent is superior between balloon angioplasty, but some studies fail to prove the superiority of angioplasty versus medical treatment. These studies have sadly a lot of mistakes and nowadays we don't know what is the treatment for our patients in a lot of cases. The angioplasty is indicated when there is a failure of antihypertensive medications for control of blood pressure, when it is associated with a renal insufficiency quickly progressive or when there is a lesion on each renal artery. Other studies must be organized for prove the superiority of angioplasty when there is a real stenosis, maybe with the use of fractional flow reserve.

Clopidogrel loading dose adjustment according to platelet reactivity monitoring in patients carrying the 2C19*2 loss of function polymorphism

OBJECTIVES

We aimed to investigate the biological impact of a tailored clopidogrel loading dose (LD) according to platelet reactivity monitoring in carriers of the cytochrome (CYP) 2C19*2 loss-of-function polymorphism undergoing percutaneous coronary intervention for an acute coronary syndromes.

BACKGROUND

CYP2C19*2 polymorphism is associated with reduced clopidogrel metabolism and a worse prognosis after percutaneous coronary intervention.

METHOD

A prospective multicenter study enrolling 411 patients with non-ST-segment elevation acute coronary syndrome undergoing percutaneous coronary intervention was performed. Platelet reactivity was measured using the vasodilator-stimulated phosphoprotein (VASP) index, and a cutoff value of ≥ 50% was used to define high on-treatment platelet reactivity (HTPR). The genetic polymorphism of CYP2C19 was determined by allele-specific polymerase chain reaction. In patients carrying CYP2C19*2 and exhibiting HTPR after a first 600-mg LD of clopidogrel, dose adjustment was performed by using up to 3 additional 600 mg LDs to obtain a VASP index <50%.

RESULTS

One hundred thirty-four patients (35.3%) carried at least one 2C19*2 allele (11 homozygotes [2.7%] and 123 heterozygotes [32.6%]). The VASP index in these patients was significantly higher than in homozygotic patients for the wild-type alleles (61.7 ± 18.4% vs. 49.2 ± 24.2%; p < 0.001). Of the 134 carriers of the loss-of-function polymorphism, 103 were considered to have HTPR. After a second clopidogrel LD, the VASP index was significantly decreased in these patients (69.7 ± 10.1% vs. 50.6 ± 17.6%; p < 0.0001). Finally, dose adjustment according to platelet reactivity monitoring, enabled 88% of 2C19*2 carriers exhibiting HTPR to reach a VASP index <50%.

CONCLUSIONS

Increased and tailored clopidogrel loading dose according to platelet reactivity monitoring overcome HTPR in carriers of the loss-of-function CYP2C19*2 polymorphism.

Relation of body mass index to high on-treatment platelet reactivity and of failed clopidogrel dose adjustment according to platelet reactivity monitoring in patients undergoing percutaneous coronary intervention

High on-treatment platelet reactivity (HTPR) after a clopidogrel loading dose predicts the risk of thrombotic events after percutaneous coronary intervention. We have demonstrated that HTPR could be overcome in most cases using dose adjustment according to PR monitoring resulting in an improved clinical outcome. However, this strategy failed in nearly 10% of patients with HTPR. Cytochrome P450 (CYP) 2C19 polymorphism was a major determinant of the response to clopidogrel and could be responsible for a failure of dose adjustment. We aimed to determine the clinical and genetical predictors of a failure of the dose-adjustment strategy. Seventy-three patients undergoing percutaneous coronary intervention were included in this prospective multicenter study. A vasodilator phosphoprotein index >or=50% after a 600-mg loading dose of clopidogrel defined HTPR. Dose adjustment was performed according to PR monitoring to reach a vasodilator phosphoprotein index <50%. Genetic polymorphism of CYP2C19 was determined by direct sequencing. Clinical predictors of HTPR were body mass index (BMI; p = 0.01), diabetes mellitus (p = 0.03), and acute coronary syndrome (p = 0.02). The mutant 2 allele of CYP2C19 681A > G loss of function polymorphism was also significantly associated with HTPR (p = 0.04). The rate of successful dose adjustment was similar in carriers of the CYP2C19 2 allele and carriers of the wild-type allele. The only independent predictor of a failed dose adjustment was a high BMI (p = 0.01). In conclusion, high BMI, acute coronary syndrome, diabetes mellitus, and CYP2C19 2 are associated with HTPR after a 600-mg loading dose of clopidogrel. Dose adjustment overcomes HTPR in carriers of the CYP2C19 2 allele. BMI is the only independent predictor of failed dose adjustment. Thus, drug underdosage seems to be the main determinant of HTPR.

Tailored clopidogrel loading dose according to platelet reactivity monitoring to prevent acute and subacute stent thrombosis

Stent thrombosis remains a significant pitfall of percutaneous coronary intervention (PCI). A recent trial observed that an adjusted loading dose (LD) of clopidogrel according to platelet monitoring decreases the rate of major adverse cardiovascular events after PCI. We investigated if such a strategy of a tailored clopidogrel LD according to platelet reactivity monitoring could decrease the rate of stent thrombosis. This multicenter prospective randomized study included 429 patients with a low clopidogrel response after a 600-mg LD undergoing PCI. Patients were randomized to a control group (n = 214) and to a vasodilator-stimulated phosphoprotein (VASP)-guided group (n = 215). In the VASP-guided group, patients received up to 3 additional 600-mg LDs of clopidogrel to obtain a VASP index <50% before PCI. The primary end point was the rate of stent thrombosis at 1 month. Secondary end points were rates of major adverse cardiovascular events and bleeding. Patients in the 2 groups had a high body mass index and were often diabetic (control vs VASP-guided group 28 +/- 5.1 vs 27.9 +/- 4.7 kg/m(2), p = 0.8, and 39% vs 33%, p = 0.2, respectively). PCI was performed in most patients for acute coronary syndrome in the 2 groups (52.3% vs 50.7%, p = 0.8). Despite a 2,400-mg LD of clopidogrel, 8% of patients in the VASP-guided group remained low responders. The rate of stent thrombosis was significantly lower in the VASP-guided group (0.5% vs 4.2%, p <0.01). The rate of major adverse cardiovascular events was also higher in the control group (8.9% vs 0.5%, p <0.001). There was no difference in the rate of bleeding (2.8% vs 3.7%, p = 0.8). In conclusion, a tailored clopidogrel LD according to platelet reactivity monitoring decreases the rate of early stent thrombosis after PCI without increasing bleeding.