Low On-Treatment Platelet Reactivity Predicts Long-Term Risk of Bleeding After Elective PCI.

BACKGROUND: Bleeding after percutaneous coronary interventions (PCI) is an important complication with impact on prognosis. AIM: To evaluate the predictive value of enhanced platelet responsiveness to dual antiplatelet therapy with aspirin and clopidogrel, for bleeding, after elective PCI. METHODS AND RESULTS: We performed multiple electrode aggregometry (MAE) platelet functional tests induced by arachidonic acid (ASPI) and adenosine-diphosphate (ADP) before PCI, and 24 hours after PCI, in 481 elective PCI patients who were followed-up for an average of 15.34 ± 7.19 months. Primary end point was the occurrence of any bleeding, while ischemic major adverse cardiovascular event (MACE) was a secondary endpoint. The incidence of total, BARC ≤ 2, and BARC ≥ 3 bleeding, according to BARC classification, was 19, 18, and 1%, respectively. Groups with any, and BARC ≤ 2 bleeding, had a lower average value of MAE ADP test after 24 hours, compared to the group without bleeding: 45.30 ± 18.63 U versus 50.99 ± 19.01 U; P = 0.005; and 45.75 ± 18.96 U versus 50.99 ± 18.99 U; P = 0.01; respectively. Female gender (HR 2.11; CI 1.37-3.25; P = 0.001), previous myocardial infarction (HR 0.56; CI 0.37-0.85; P = 0.006), lower body mass (HR 0.78; CI 0.62-0.98; P = 0.03), and MAE ADP test after 24 hours (HR 0.75; CI 0.61-0.93; P = 0.009) were the independent predictors for any bleeding by Cox univariate analysis. After adjustment, MAE ADP test after 24 hours, was the only independent predictor for any (HR 0.7; CI 0.56-0.87; P = 0.002), and BARC ≤ 2 (HR 0.71; CI 0.56-0.89; P = 0.003) bleeding, by Cox multivariate analysis. CONCLUSION: MAE ADP test before and after PCI, was associated with any, and BARC ≤ 2 bleeding after elective PCI.

The pharmacokinetics of Biolimus A9 after elution from the Nobori stent in patients with coronary artery disease: the NOBORI PK study.

OBJECTIVES: The aim of this study was to assess the pharmacokinetics and tolerability of Biolimus A9 eluted from Nobori coronary stents. BACKGROUND: : The release kinetics and pharmacokinetics of drugs delivered via coronary stents have been shown to play an essential role in the efficacy and safety of drug eluting stents. METHODS: Twenty patients with coronary artery disease were treated with single 14-mm (10 patients) or 28-mm long stent (10 patients). Blood samples were drawn at 16 time points to determine the pharmacokinetics of Biolimus A9. At seven time points, complete laboratory and toxicology panels were assessed to screen for potential Biolimus A9 toxicity. The primary endpoint of the study was the systemic blood concentrations of Biolimus A9 after 28 days and 6 months as measured using highly specific and sensitive liquid chromatography- tandem mass spectrometry assay. RESULTS: At 28 days, 6 patients (30%) had quantifiable Biolimus A9 concentrations in blood. The highest Biolimus A9 blood concentration measured in any sample was 32.2 pg/mL. The median time to maximum concentration was 2 hr, ranging from 0.05 hr to 3 months. Six months after stent implantation, only 1 of 20 patients had measurable Biolimus A9 concentrations at the lowest level of quantification, while at 9 months no sample had quantifiable Biolimus A9 concentrations. Laboratory and toxicology assessments did not indicate any impact of Biolimus A9 on the evaluated parameters. CONCLUSION: Results of this study suggest that systemic exposure to Biolimus A9 was very low and that Biolimus A9 was well tolerated.

Differential effects of drug-eluting stents on local endothelium-dependent coronary vasomotion.

OBJECTIVES: The aim of our study was to compare coronary vasomotion after implantation of a second-generation biolimus A9-eluting stent (BES) and of a sirolimus-eluting stent (SES). BACKGROUND: Drug-eluting stents (DES) have been associated with impaired local coronary vasomotion, delayed endothelialization, and increased late thrombotic risk. New DES with different drugs, pharmacokinetics, and polymers have been developed. METHODS: Nineteen patients with a BES and 15 patients with a SES were studied 9 months after stent implantation. Endothelium-dependent and -independent coronary vasomotion were tested proximally and distally to the stent as well as at a reference segment during right atrial pacing at increasing heart rates. Quantitative coronary angiographic measurements were performed offline. RESULTS: Of the patients with BES, 2 showed vasoconstriction with increased heart rate and 17 showed vasodilatation. Of the patients with a SES, 9 showed vasoconstriction while 6 showed vasodilatation. The SES showed significant vasoconstriction at both the proximal (-2.3 +/- 10% vs. 7.9 +/- 10%) and the distal (-5.4 +/- 9% vs. 6.1 +/- 8%) segments to the stent compared with the BES (p = 0.003 for proximal, p < 0.001 for distal segment). Endothelium-independent vasomotion after intracoronary nitrates did not differ significantly between the 2 groups (p = NS for proximal and distal segment). CONCLUSIONS: Unlike the case with the SES, endothelium-dependent vasomotion at adjacent stent segments seems to be preserved after BES implantation. This result may be explained by the different drug release kinetics, DES design, or characteristics of polymer used in the stent system.

First clinical comparison of Nobori -Biolimus A9 eluting stents with Cypher- Sirolimus eluting stents: Nobori Core nine months angiographic and one year clinical outcomes.

AIM: To compare clinical efficacy and safety of stents eluting limus drugs from biodegradable polymer - Nobori, or durable polymer - Cypher. METHODS AND RESULTS: From May to August 2006, 107 patients with 142 coronary artery lesions were treated with either Nobori, Biolimus A9 eluting stent (54) or Cypher, Sirolimus eluting stent (53) in five centres. The two groups were well matched for baseline clinical and angiographic characteristics. The in-stent late loss at nine months, the primary endpoint of the study, was 0.10+/-0.26 mm in Nobori, and 0.13+/-0.44 mm in Cypher arm (p=0.660) confirming the hypothesis of the similarity between the two stents. In-stent diameter stenosis of 13+/-10% with Nobori was significantly lower than 20+/-12% with Cypher stent (p=0.002) without significant difference in binary restenosis (1.7% in Nobori and 6.3% in Cypher arm; p=0.32). The rate of major adverse cardiac events at 12 months was 1.9% with Nobori and 4.1% with Cypher stent. CONCLUSIONS: The nine months angiographic data from Nobori Core study demonstrate that Biolimus A9 has similar anti-proliferative efficacy to Sirolimus as judged by in-stent late loss and restenosis rate. Low frequency of adverse cardiac events at 12 months indicates that both stents are safe and effective in the studied population.