Aspirin resistance as cardiovascular risk after kidney transplantation

Sandor, Barbara,Varga, Adam,Rabai, Miklos,Toth, Andras,Papp, Judit,Toth, Kalman,Szakaly, Peter 한국유변학회 2014 Korea-Australia rheology journal Vol.26 No.2

International surveys have shown that the leading cause of death after kidney transplantation has cardiovascular origin with a prevalence of 35-40%. As a preventive strategy these patients receive aspirin (ASA) therapy, even though their rate of aspirin resistance is still unknown. In our study, platelet aggregation measurements were performed between 2009 and 2012 investigating the laboratory effect of low-dose aspirin (100 mg) treatment using a CARAT TX4 optical aggregometer. ASA therapy was considered clinically effective in case of low (i.e., below 40%) epinephrine-induced ($10{\mu}M$) platelet aggregation index. Rate of aspirin resistance, morbidity and mortality data of kidney transplanted patients (n = 255, mean age: $49{\pm}12$ years) were compared to a patient population with cardio- and cerebrovascular diseases (n = 346, mean age: $52.6{\pm}11$ years). Rate of aspirin resistance was significantly higher in the renal transplantation group (RT) compared to the positive control group (PC) (35.9% vs. 25.6%, p < 0.002). Morbidity analysis demonstrated significantly higher incidence of myocardial infarction, hypertension and diabetes mellitus in the RT group (p < 0.05). The subgroup analysis revealed significantly higher incidence of infarction and stroke in the ASA resistant RT group compared to the RT patients without ASA resistance (p < 0.05). Furthermore, the incidence of myocardial infarction and hypertension was significantly higher in the non-resistant RT group than in the group of PC patients without ASA resistance (p < 0.05). These results may suggest that the elevated rate of aspirin resistance contributes to the high cardiovascular mortality after kidney transplantation.

Aspirin resistance as cardiovascular risk after kidney transplantation

Barbara Sandor,Adam Varga,Miklos Rabai,Andras Toth,Judit Papp,Kalman Toth,Peter Szakaly 한국유변학회 2014 Korea-Australia rheology journal Vol.26 No.2

International surveys have shown that the leading cause of death after kidney transplantation has cardiovascularorigin with a prevalence of 35-40%. As a preventive strategy these patients receive aspirin (ASA)therapy, even though their rate of aspirin resistance is still unknown. In our study, platelet aggregation measurementswere performed between 2009 and 2012 investigating the laboratory effect of low-dose aspirin(100 mg) treatment using a CARAT TX4 optical aggregometer. ASA therapy was considered clinically effectivein case of low (i.e., below 40%) epinephrine-induced (10 μM) platelet aggregation index. Rate of aspirinresistance, morbidity and mortality data of kidney transplanted patients (n = 255, mean age: 49 ± 12 years)were compared to a patient population with cardio- and cerebrovascular diseases (n = 346, mean age: 52.6 ± 11years). Rate of aspirin resistance was significantly higher in the renal transplantation group (RT) compared tothe positive control group (PC) (35.9% vs. 25.6%, p < 0.002). Morbidity analysis demonstrated significantlyhigher incidence of myocardial infarction, hypertension and diabetes mellitus in the RT group (p < 0.05). Thesubgroup analysis revealed significantly higher incidence of infarction and stroke in the ASA resistant RTgroup compared to the RT patients without ASA resistance (p < 0.05). Furthermore, the incidence of myocardialinfarction and hypertension was significantly higher in the non-resistant RT group than in the groupof PC patients without ASA resistance (p < 0.05). These results may suggest that the elevated rate of aspirinresistance contributes to the high cardiovascular mortality after kidney transplantation.

In vitro hemorheological effects of parenteral agents used in peripheral arterial disease

Biro, Katalin,Sandor, Barbara,Toth, Andras,Koltai, Katalin,Papp, Judit,Rabai, Miklos,Toth, Kalman,Kesmarky, Gabor 한국유변학회 2014 Korea-Australia rheology journal Vol.26 No.2

Peripheral arterial disease (PAD) is a frequent manifestation of systemic atherosclerosis. In PAD hemorheological parameters were defined as risk factors in a number of studies and several therapeutic agents were tried in these conditions. Our study aims to investigate and compare the in vitro hemorheological effects of various drugs generally used in the parenteral treatment of intermittent claudication and critical limb ischemia. Blood samples of healthy male volunteers were incubated with iloprost, alprostadil, pentoxifylline, sulodexide or pentosan polysulfate at calculated therapeutic serum concentration. Hematocrit (Hct) was determined by microhematocrit centrifuge. Plasma and apparent whole blood viscosities (WBV) were evaluated by capillary viscometer. Red blood cell aggregation was measured by LORCA (laserassisted optical rotational cell analyzer) aggregometer, and LORCA ektacytometer was used for measuring erythrocyte deformability at $37^{\circ}C$. Iloprost, alprostadil, and pentoxifylline incubation did not have any significant effect on plasma and apparent WBV. Elongation index increased in samples incubated with alprostadil at low shear stresses 0.95 and 0.53 Pa (p < 0.05). Sulodexide significantly improved WBV and Hct/WBV ratio (p < 0.05). Incubation with pentosan polysulfate resulted in higher WBV, lower Hct/WBV ratio and deterioration in the aggregation parameters (p < 0.05). Sulodexide may have beneficial effect on a macrorheological parameter; alprostadil may improve a microrheological parameter. Hemorheological alterations could be important in PAD patients with hampered vasodilator capacity.

Hemorheological parameters in coronary artery disease detected by multi-slice CT

Andras Toth,Sandor Szukits,Edit Varady,Barbara Sandor,Miklos Rabai,Judit Papp,Istvan Juricskay,Gabor Kesmarky,Kalman Toth,Balazs Sumegi,Istvan Battyani 한국유변학회 2014 Korea-Australia rheology journal Vol.26 No.2

Epidemiological studies have confirmed that hemorheological parameters are primary risk factors in CAD;and their alterations in CAD have been described. We aimed to investigate both macro- and microrheologicalproperties of blood in patients with CAD. The data of 121 patients (mean age: 58.8 ± 9.6 years) undergoingcoronary CT were analyzed. Blood samples were obtained right before CT examinations. Hematocrit (Hct),plasma (PV) and apparent whole blood viscosity (WBV), red blood cell (RBC) aggregation and RBC deformabilitywere measured. Patients were classified into four groups according to their coronary vessel state: Negativegroup (n = 32, mean age: 56.8 ± 11.1 years) without any coronary stenosis or atherosclerotic lesion andzero calcium-score, Non-significant group (n = 27, mean age: 59.2 ± 7.5 years) below 40% area stenosis, Single-vessel group (n = 32, mean age: 58.8 ± 8.5 years) over 40% area stenosis or history of PCI or CABG onone coronary vessel, Multi-vessel group (n = 30, mean age: 62.1 ± 8.4 years) with over 40% area stenosis orhistory of PCI or CABG on multiple coronary vessels. Hct was significantly (p < 0.05) higher in all CAD(Non-significant, Single-vessel, Multi-vessel) groups compared to the Negative group. WBV was significantly(p<0.05) higher in the Multi-vessel group compared to the Negative group. No significant (p ≥ 0.05) differenceswere observed in PV. RBC aggregation was significantly (p < 0.05) increased in the Multi-vesselgroup compared to the Negative group. RBC deformability showed a decreasing tendency with the increasingnumber of atherosclerotic vessels. Our results indicate that hemorheological variables are deteriorated inpatients with CAD established by coronary CT, which is more pronounced in severe coronary disease.

In vitro hemorheological effects of parenteral agents used in peripheral arterial disease

Katalin Biro,Barbara Sandor,Andras Toth,Katalin Koltai,Judit Papp,Miklos Rabai,Kalman Toth,Gabor Kesmarky 한국유변학회 2014 Korea-Australia rheology journal Vol.26 No.2

Peripheral arterial disease (PAD) is a frequent manifestation of systemic atherosclerosis. In PAD hemorheologicalparameters were defined as risk factors in a number of studies and several therapeutic agents weretried in these conditions. Our study aims to investigate and compare the in vitro hemorheological effectsof various drugs generally used in the parenteral treatment of intermittent claudication and critical limbischemia. Blood samples of healthy male volunteers were incubated with iloprost, alprostadil, pentoxifylline,sulodexide or pentosan polysulfate at calculated therapeutic serum concentration. Hematocrit(Hct) was determined by microhematocrit centrifuge. Plasma and apparent whole blood viscosities (WBV)were evaluated by capillary viscometer. Red blood cell aggregation was measured by LORCA (laserassistedoptical rotational cell analyzer) aggregometer, and LORCA ektacytometer was used for measuringerythrocyte deformability at 37°C. Iloprost, alprostadil, and pentoxifylline incubation did not have any significanteffect on plasma and apparent WBV. Elongation index increased in samples incubated with alprostadilat low shear stresses 0.95 and 0.53 Pa (p < 0.05). Sulodexide significantly improved WBV and Hct/WBV ratio (p < 0.05). Incubation with pentosan polysulfate resulted in higher WBV, lower Hct/WBV ratioand deterioration in the aggregation parameters (p < 0.05). Sulodexide may have beneficial effect on a macrorheologicalparameter; alprostadil may improve a microrheological parameter. Hemorheological alterationscould be important in PAD patients with hampered vasodilator capacity.

Hemorheological parameters in coronary artery disease detected by multi-slice CT

Toth, Andras,Szukits, Sandor,Varady, Edit,Sandor, Barbara,Rabai, Miklos,Papp, Judit,Juricskay, Istvan,Kesmarky, Gabor,Toth, Kalman,Sumegi, Balazs,Battyani, Istvan 한국유변학회 2014 Korea-Australia rheology journal Vol.26 No.2

Epidemiological studies have confirmed that hemorheological parameters are primary risk factors in CAD; and their alterations in CAD have been described. We aimed to investigate both macro- and microrheological properties of blood in patients with CAD. The data of 121 patients (mean age: $58.8{\pm}9.6$ years) undergoing coronary CT were analyzed. Blood samples were obtained right before CT examinations. Hematocrit (Hct), plasma (PV) and apparent whole blood viscosity (WBV), red blood cell (RBC) aggregation and RBC deformability were measured. Patients were classified into four groups according to their coronary vessel state: Negative group (n = 32, mean age: $56.8{\pm}11.1$ years) without any coronary stenosis or atherosclerotic lesion and zero calcium-score, Non-significant group (n = 27, mean age: $59.2{\pm}7.5$ years) below 40% area stenosis, Single-vessel group (n = 32, mean age: $58.8{\pm}8.5$ years) over 40% area stenosis or history of PCI or CABG on one coronary vessel, Multi-vessel group (n = 30, mean age: $62.1{\pm}8.4$ years) with over 40% area stenosis or history of PCI or CABG on multiple coronary vessels. Hct was significantly (p < 0.05) higher in all CAD (Non-significant, Single-vessel, Multi-vessel) groups compared to the Negative group. WBV was significantly (p<0.05) higher in the Multi-vessel group compared to the Negative group. No significant ($p{\geq}0.05$) differences were observed in PV. RBC aggregation was significantly (p < 0.05) increased in the Multi-vessel group compared to the Negative group. RBC deformability showed a decreasing tendency with the increasing number of atherosclerotic vessels. Our results indicate that hemorheological variables are deteriorated in patients with CAD established by coronary CT, which is more pronounced in severe coronary disease.