Rafal Nizankowski

Impaired responsiveness to clopidogrel and aspirin in patients with recurrent stent thrombosis following percutaneous intervention for peripheral artery disease

Patients with peripheral artery disease (PAD) following peripheral percutaneous transluminal angioplasty (PTA) with stent implantation are prone to stent thrombosis despite treatment with aspirin and clopidogrel. Impaired clopidogrel responsiveness is associated with increased risk of ischemic events in patients following coronary stent implantation. We sought to assess platelet responsiveness to clopidogrel and aspirin in patients with PAD and recurrent stent thrombosis. Platelet aggregation induced by 5 and 20 µmol/l adenosine diphosphate (ADP) and 0.5 mmol/l arachidonic acid (AA), together with platelet reactivity index (PRI) and serum thromboxane B2 (TXB2), were determined in 11 patients with PAD and a history of stent thrombosis (mean, 3.1 ± 1.14) after PTA and in 15 patients with PAD with no such history, also in 11 controls with coronary artery disease (CAD) and previous stent thrombosis. Platelet aggregation to 5 µmol/l ADP was higher in subjects with PAD and stent thrombosis than in those without stent thrombosis (p = 0.0003) and CAD subjects (p = 0.002). Aggregation induced by 20 µmol/l ADP was higher in PAD group with stent thrombosis than in PAD subjects without thrombosis (p = 0.004). The PAD group with stent thrombosis had higher AA-induced platelet aggregation than CAD controls (p = 0.007) and serum TXB2 concentrations higher than PAD group without thrombosis (p = 0.002) and CAD group (p = 0.02). Concluding, platelet responsiveness to clopidogrel and aspirin is impaired in patients with PAD and recurrent stent thrombosis following PTA, as compared with similar individuals with CAD, and PAD with no history of stent thrombosis. This indicates that atherosclerosis burden affects platelet function and might contribute to stent thrombosis following percutaneous intervention in peripheral arteries.

Influence of air pollution on exhaled carbon monoxide levels in smokers and non-smokers. A prospective cross-sectional study

Background The poor air quality and cigarette smoking are the most important reasons for increased carbon monoxide (CO) level in exhaled air. However, the influence of high air pollution concentration in big cities on the exhaled CO level has not been well studied yet. Objectives To evaluate the impact of smoking habit and air pollution in the place of living on the level of CO in exhaled air. Methods Citizens from two large cities and one small town in Poland were asked to complete a survey disclosing their place of residence, education level, work status and smoking habits. Subsequently, the CO level in their exhaled air was measured. Air quality data, obtained from the Regional Inspectorates of Environmental Protection, revealed the differences in atmospheric CO concentration between locations. Results 1226 subjects were divided into 4 groups based on their declared smoking status and place of living. The average CO level in exhaled air was significantly higher in smokers than in non‐smokers (p<0.0001) as well as in non‐smokers from big cities than non‐smokers from small ones (p<0.0001). Created model showed that non‐smokers from big cities have odds ratio of 125.3 for exceeding CO cutoff level of 4 ppm compared to non‐smokers from small towns. Conclusions The average CO level in exhaled air is significantly higher in smokers than non‐smokers. Among non‐smokers, the average exhaled CO level is significantly higher in big city than small town citizens. These results suggest that permanent exposure to an increased concentration of air pollution and cigarette smoking affect the level of exhaled CO. HighlightsThere is increased exhaled carbon monoxide in big, polluted cities citizens.Higher level of CO in exhaled air in smokers than non‐smokers has been observed.Increased exhaled CO level is 125 times more likely in big cities than small towns.

Involvement of CD8+ T cell subsets in early response to vascular injury in patients with peripheral artery disease in vivo

AIMS Adaptive immunity is critical in vascular remodelling following arterial injury. We hypothesized that acute changes in T cells at a percutaneous transluminal angioplasty (PTA) site could serve as an index of their potential interaction with the injured vascular wall. METHODS AND RESULTS T cell subsets were characterised in 45 patients with Rutherford 3-4 peripheral artery disease (PAD) undergoing PTA. Direct angioplasty catheter blood sampling was performed before and immediately after the procedure. PTA was associated with an acute reduction of α/β-TcR CD8+ T cells. Further characterisation revealed significant reduction in pro-atherosclerotic CD28nullCD57+ T cells, effector (CD45RA+CCR7-) and effector memory (CD45RA-CCR7-) cells, in addition to cells bearing activation (CD69, CD38) and tissue homing/adhesion markers (CD38, CCR5). CONCLUSIONS The acute reduction observed here is likely due to the adhesion of cells to the injured vascular wall, suggesting that immunosenescent, activated effector CD8+ cells have a role in the early vascular injury immune response following PTA in PAD patients.

Endovascular treatment of dysfunctional arteriovenous fistula in hemodialyzed patients — the results of one year follow-up

Introduction. The arteriovenous fistula (AVF) dysfunction is a common reason for vascular access problem in chronically hemodialyzed patients. It is caused by stenosis or occlusion located either in inflow artery, anastomosis or outflow vein. Revascularization of these pathologies can be achieved in surgical or endovascular (PTA) manner. The aim of this study was to evaluate both immediate and late endovascular treatment results of dysfunctional fistulas in chronically hemodialyzed patients. Material and methods. We included in our observation 106 patients with end stage renal disease, who un-derwent PTA within arteriovenous fistulas. We used conventional and unified techniques of endovascular therapy. Procedural results were evaluated after 1, 3, 6 and 12 months based on fistula sufficiency during hemodialysis. Results. In 96 (90.6%) cases the initial result of PTA was good. We achieved improvement in blood flow through AVF and successful hemodialysis. In 10 cases (9.4%) results were not satisfactory. None of our patients developed neither worsening in the blood flow through AVF nor compromised blood circulation distally to AVF. No serious complications (MI, stroke, death) occurred during procedure or hospital stay. After 12 months, in 52 patients AVF were functioning properly. In 20 cases, because of fistula dysfunction, reintervention was necessary (primary patency 66%). Considering all patients, also these with successful reintervention, 69 AVF were functioning properly after 12 months (secondary patency 86%). Conclusions. To conclude, the immediate and long-term PTA outcomes of arteriovenous fistulas with currently available techniques and equipment are satisfying. PTA is a safe manner of prolonging patency rate of AVF in patients requiring permanent hemodialysis.

The relationship between pulse waveform analysis indices, endothelial function and clinical outcomes in patients with peripheral artery disease treated using percutaneous transluminal angioplasty during a one-year follow-up period

BACKGROUND The aim of the current study was to assess the relationship between potential predictors of clinical outcomes after percutaneous transluminal angioplasty (PTA) of peripheral arteries during a one-year follow-up. Indices of endothelial function (EF), arterial pulse waveform analysis (aPWA) and markers of peripheral arteries ischemia were among those mostly examined. METHODS The study comprised of 72 individuals with PAD who underwent PTA of the peripheral arteries. During the first visit and 1 and 6 months after PTA, endothelial function and aPWA measurements were performed. Ankle-brachial index (ABI), toe-brachial index (TBI) and physical evaluation of the limbs took place during the first visit and 1, 6 and 12 months after the PTA. The study endpoints included myocardial infarction, amputation, death, stroke and reintervention. All subjects included into the study were observed for 386 days after the PTA. RESULTS We noticed significant improvement in walking distance after PTA, as well as transient improvement of ABI and flow-mediated dilatation (FMD), and no significant changes in aPWA indices or reactive-hyperemia index (RHI). There were 25 study endpoints which occurred in 16 patients during the follow-up period (22.2%). Patients with CLI, hypercholesterolemia, lower diastolic blood pressure, higher subendocardial viability ratio, greater number of pack-years and lower TBI at baseline presented significantly poorer clinical outcomes in terms of endpoint events. CONCLUSIONS Endothelial function assessed as FMD and RH-PAT before PTA in patients with advanced PAD does not predict clinical outcomes during the one-year follow-up. < p > < /p >.