Biomolecules Responsible for the Total Antioxidant Capacity (TAC) of Human Plasma in Healthy and Cardiopathic Individuals: A Chemical Speciation Model.

(1) Background: Much effort has been expended to investigate the antioxidant capacity of human plasma, attempting to clarify the roles of both metabolic and food substances in determining defenses against oxidative stress. The relationship between the total antioxidant capacity (TAC) and the concentrations of redox-active biomolecules in the human plasma of healthy and cardiopathic individuals was investigated in the present study to develop a chemical speciation model. (2) Methods: Plasma was collected from 85 blood donors and from 25 cardiovascular surgery patients. The TAC was measured using the CUPRAC-BCS (CUPric Reducing Antioxidant Capacity - Bathocuproinedisulfonic acid) method. Biomolecule concentrations were determined via visible spectrophotometry or HPLC/RP techniques. The relationship between the TAC and the concentrations was defined by applying a multiple regression analysis. The significance of the variables was first tested, and chemical models were proposed for the two datasets. The model equation is ßTAC=∑ißi·Ai, where ßi and [Ai] are the electronic exchange and the molar concentrations of the ith antioxidant component, respectively. (3) Results: The major contributions to the TAC, ~80%, come from endogenous compounds in both healthy and cardiopathic individuals, whereas the contributions from exogenous compounds were different between the two datasets. In particular, γ-tocopherol showed a different role in the chemical models developed for the two groups.

The Prevalence of Thyroid Autoimmunity in Children with Developmental Dyslexia.

METHODS: We enrolled pediatric subjects with developmental dyslexia and, as a control group, healthy age- and sex-matched subjects without developmental dyslexia. Thyroid function was evaluated in subjects with developmental dyslexia measuring serum concentrations of thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), and free thyroxine (fT4). Thyroid autoimmunity was evaluated in all subjects measuring antithyroid peroxidase (TPO-Ab) and antithyroglobulin (TG-Ab) antibodies. In subjects with developmental dyslexia, thyroid ultrasonography (US) was also performed. RESULTS: We enrolled 51 subjects with developmental dyslexia (M : F = 39 : 12, mean age 12.4 ± 9 years) and 34 controls (M : F = 24 : 10, mean age 10.8 ± 4 years). TPO-Ab positivity was significantly higher in subjects with developmental dyslexia compared to controls (60.8% vs. 2.9%, p < 0.001), while no significant difference was found in TG-Ab positivity (16% vs. 5.8%). Thyroid US performed in 49 subjects with developmental dyslexia revealed a thyroiditis pattern in 60%. CONCLUSIONS: We found an extremely high prevalence of thyroid autoimmunity in children with developmental dyslexia. Further studies are needed to confirm our observations, but our findings may change the approach to this disorder and eventually lead to a systematic determination of thyroid autoimmunity in children with developmental dyslexia.

Kidney-Detrimental Factors and Estimated Glomerular Filtration Rate in Preterm Newborns: The Role of Nutrition.

: Background: Kidney function in preterm newborns may be impaired by many factors. METHODS: 71 newborns with gestational age (GA) < 32 weeks were enrolled. Serum creatinine (sCr), cystatin C (CysC), beta-trace protein (BTP) and urea were measured at T0 (3rd day of life) and T36 (GA 36 weeks), and estimated glomerular filtration rate (eGFR) was calculated according to different formulas at T36. Pre-natal and post-natal kidney injury risk scores were calculated. RESULTS: Newborns with GA ≤ 28 weeks had higher sCr at T0, and lower sCr, BTP and higher urea levels at T36 (p = 0.007, p = 0.005 and p = 0.029, respectively). eGFR values were not different according to GA when calculated by the formulas using only CysC, but were higher in subjects with GA ≤ 28 weeks according to the other formulas. The post-natal score was positively correlated with eGFR according to sCr-based formulas, but the correlations did not persist when adjusted for urea levels and GA. CONCLUSIONS: CysC-based eGFR values are not influenced by GA. Post-natal score shows a direct correlation with eGFR according to sCr-based formulas, not persisting after adjustment for GA and urea levels, implying the importance of the nutritional status, since more premature subjects receive a more aggressive nutritional regimen, testified by higher urea levels.

Impact of adenosine A2a receptor polymorphism rs5751876 on platelet reactivity in ticagrelor treated patients.

Dual antiplatelet therapy constitutes a key point in the management of patients with acute coronary syndromes. In particular, ticagrelor, an ADP-antagonist, can provide a more potent and predictable platelet inhibition as compared to clopidogrel, and adenosine-mediated pathways have been involved in its beneficial effects on mortality and myocardial perfusion. However, a quote of patients still displays a suboptimal platelet inhibition on ticagrelor, and, while the role of genetics in conditioning clopidogrel resistance is well established, few data have been reported for ticagrelor. We investigated the impact of rs5751876 C > T polymorphism of adenosine A2a receptor (ADORA2a) on platelet reactivity in patients during chronic treatment with ticagrelor. We included patients treated with ASA and ticagrelor for a recent ACS or elective coronary revascularization. Platelet reactivity was assessed at 30-90 days post-discharge by multiple-electrode aggregometry. HRPR for ticagrelor was defined as ADP-test results >417 AU*min. Genetic analysis was performed to assess the presence of rs5751876 C > T polymorphism of ADORA2a receptor. We included 244 patients in our study, 174 (71.3%) patients carried the polymorphism (T allele), 51 (20.9%) of them in homozygosis (T/T). C-allele carriers (homozygotes C/C and heterozygotes C/T) showed no difference in baseline characteristics but for lower HDL-cholesterol (p = 0.01). An absolute lower rate of HRPR on ticagrelor was observed in homozygotes T/T (p = 0.03). At multivariate analysis, C allele carriage was independently associated with the rate of HRPR on ticagrelor (adjusted OR[95%CI] = 4.63[1.02-21.01], p = 0.048). Our study results showed a significant independent association between rs5751876 allele C carriage and a higher rate of high residual platelet reactivity in patients on ticagrelor after a recent ACS or PCI.

Impact of Long-Term Dual Antiplatelet Therapy on Immature Platelet Count and Platelet Reactivity.

The immature platelet count (IPC) is a potential marker of platelet reactivity. We assessed the relationship between IPC during chronic dual antiplatelet therapy (DAPT) and the response to antiplatelet drugs (acetylsalycilic acid + clopidogrel/ticagrelor). We included 286 patients: 167 (58.4%) patients received ticagrelor and 119 (41.6%) received clopidogrel. At a median follow-up of 46.5 days, the variation in IPC displayed an absolute median (interquartile range [IQR]) of -11.9 × 103/µL (-182.7 to 160.8), corresponding to a median percentage change in IPC ([%ΔIPC] IQR) of -0.3% (-21.9% to 35.5%), with an increase in IPC levels in those on ticagrelor and a decrease in IPC levels in those on clopidogrel. We observed an inverse association of lower platelet reactivity at different tests and a higher increase in IPC ( r = -0.14, P = .04 for arachidonic acid test; r = -0.12, P = .05 for collagen test; and r = -0.13, P = .02 for adenosine diphosphate test [ADP]). The rate of poor effectiveness of ADP antagonists was the only independent predictor of a ΔIPC above the third tertile (odds ratio [95% confidence interval] = 0.55 [0.32-0.99]; P = .048). We showed that in patients treated with chronic DAPT, an increase in IPC is significantly related to lower levels of platelet reactivity.

Vitamin D Binding Protein rs7041 polymorphism and high-residual platelet reactivity in patients receiving dual antiplatelet therapy with clopidogrel or ticagrelor.

BACKGROUND: Vitamin D deficiency represents a major health problem in general population, especially for its association with cardiovascular disorders and thrombotic risk, even in patients on dual antiplatelet therapy (DAPT). Vitamin D Binding Protein (VDBP) is the main transporter of vitamin D in the bloodstream and genetic polymorphisms of this protein have been shown to account for a significant variability of vitamin D levels and its systemic effects. Contrasting data have linked the rs7041 T→G substitution with cardiovascular disease. However, no study has so far addressed the role of rs7041 polymorphism on platelet reactivity in patients on DAPT, that was the aim of the present study. METHODS: Patients treated with DAPT (ASA and clopidogrel or ticagrelor) for an ACS or elective PCI were scheduled for platelet function assessment at 30-90days post-discharge. Platelet function was assessed by Multiplate® (Roche Diagnostics AG), and VDBP genetic status by polymerase chain reaction and restriction fragment length polymorphism technique. Fasting samples were obtained for main chemistry parameters and vitamin D levels assessment. RESULTS: We included 400 patients, 187 (46.8%) receiving clopidogrel and 213 (53.2%) ticagrelor. The genetic polymorphism rs7041 (T→G) was observed in 318 patients, (79.5%), in 38.7% of them in homozygosis. Main clinical and chemistry features did not significantly differ according to genetic status, but for a higher rate of ACE-inhibitors and beta-blockers use among the carriers of the G allele (p=0.04 and p=0.01, respectively). VDBP genetic status did not affect the rate of HRPR with ADP-antagonists (25.6% vs 24.6% vs 28.5%, p=0.59; adjusted OR[95%CI]=0.94[0.52-1.7], p=0.83 for T/G patients; adjusted OR[95%CI]=1.14[0.6-2.2], p=0.67 for G homozygotes). However, the rate of HRPR with ADP-antagonists was influenced by severe hypovitaminosis D (< 10ng/ml) only in patients carrying the G allele, especially in homozygosis (T/T: 25.9% vs 26.1%, p=0.99; G carriers: 22.1% vs 35.3%, p=0.02, pinteraction=0.019; adjusted OR[95%CI]=1.93[1.11-3.34], p=0.02 for G carriers). CONCLUSION: The present study shows that rs7041 polymorphism of Vitamin D Binding Protein does not affect platelet reactivity or the rate of HRPR among patients receiving DAPT. However the carriage of the G allele could condition the impact of hypovitaminosis D on the response to antiplatelet agents, increasing the occurrence of HRPR especially in homozygotes, thus suggesting a more significant role of vitamin D deficiency among these patients.

Vitamin D levels and high-residual platelet reactivity in patients receiving dual antiplatelet therapy with clopidogrel or ticagrelor.

BACKGROUND: Suboptimal platelet inhibition still represents an important challenge, especially for patients undergoing percutaneous coronary interventions (PCIs). However, very few are known so far on the predictors of high-residual platelet reactivity (HRPR) despite antiplatelet strategies. Increasing attention has been paid in the last years to the role of vitamin D in atherothrombosis. Therefore, the aim of our study was to evaluate the impact of vitamin D levels on platelet function in patients treated with dual antiplatelet therapy (DAPT). Patients treated with DAPT (ASA and clopidogrel or ticagrelor) after a recent acute coronary syndrome (ACS) or elective PCI were scheduled for platelet function assessment at 30-90 days post-discharge. Platelet function was assessed by whole blood impedance aggregometry (Multiplate®-Roche Diagnostics AG), HRPR was considered for ASPI test values > 862 AU*min (for ASA) and adenosine diphosphate (ADP) test values ≥417 AU*min (for ADP-antagonists). Fasting samples were obtained for main chemistry parameters and vitamin D level assessment. Our population is represented by 503 patients, who were divided according to vitamin D quartiles (≤9.1; 9.2-14.4; 14.5-21.7; >21.7 ng/ml). Lower vitamin D levels related with age (p = 0.04), diabetic status (p = 0.05), and previous coronary surgery (p = 0.007), therapy with beta-blockers and statins (p = 0.01 and p = 0.02). Vitamin D inversely related to the levels of total cholesterol (p = 0.01), triglycerides (p < 0.001), hemoglobin (p = 0.05), and HbA1c (p < 0.001). Significantly higher platelet reactivity was observed after platelet stimulation with ADP (p = 0.01), but not with other platelet activators. The prevalence of HRPR for ASA was low (1.2%) and not conditioned by Vitamin D levels (adjusted OR[95%CI] = 1.56[0.71-3.5], p = 0.27). HRPR with ADP-antagonists was observed in 26% of patients, and the rate increased with lower vitamin D quartiles (37.3% vs 22.2% vs 24.4% vs 20.2%, p = 0.005, adjusted OR[95%CI] = 1.23[1.02-1.49], p = 0.04). An absolute increase in HRPR with lower vitamin D levels was similarly observed among patients receiving ticagrelor (adjusted OR[95% CI] = 1.40[0.95-2.06], p = 0.08), and those on clopidogrel (adjusted OR[95%CI] = 1.31[0.99-1.75], p = 0.06). Thus, lower vitamin D levels are associated with higher platelet reactivity and impaired effectiveness of ADP-antagonists, while not influencing the effectiveness of ASA. Future studies will tell whether vitamin D supplementation can reduce platelet reactivity, overcoming the phenomenon of resistance to antiplatelet agents.

Impact of renal function on mean platelet volume and its relationship with coronary artery disease: A single-centre cohort study.

BACKGROUND: Mean platelet volume (MPV) has been proposed as a marker of platelet reactivity and cardiovascular disease. Chronic kidney disease (CKD) significantly favors the occurrence of cardiovascular events, by increasing the circulating levels of a wide spectrum of pro-oxidant and pro-thrombotic mediators. However, opposite alterations of platelet function, both enhanced aggregability and increased bleeding diathesis have been reported in these patients, with contrasting results on the effects of renal function on MPV and coronary artery disease, that were assessed in present study. METHODS: In patients undergoing coronary angiography, MPV and renal function (serum creatinine and estimated Glomerular Filtration Rate, eGFR, by MDRD formula) were assessed at admission. Coronary artery disease (CAD) was defined as a stenosis >50% in at least 1 coronary vessel, while severe CAD as left main or trivessel disease. RESULTS: Among 3712 patients, 1044 (28.1%) had chronic kidney disease. CKD was related with age, female gender, diabetes and glycemic control, history of myocardial infarction, cerebrovascular accidents, coronary artery bypass grafting and left ventricular dysfunction or arrhythmias as indication to angiography, therapy with angiotensin-receptor blockers, nitrates, diuretics and calcium-antagonists, but lower rate of smoking, lower fibrinogen levels, haemoglobin, total and HDL cholesterol (p<0.001, respectively). CKD patients displayed increased severity and complexity of CAD (p<0.001) and significantly larger platelet volume (p<0.001), with CKD resulting as independent predictor of MPV above the median (≥10.85fl; Adjusted OR[95%CI]=1.56[1.23,1.99], p=0.002). Moreover, in the 1044 patients with renal failure, higher platelet volume (above the median value; ≥10.85fl) was associated with age (p=0.05), haemoglobin levels and platelet count (p<0.001), but not to a higher prevalence or extent of coronary artery disease (CAD: adjusted OR[95%CI]=0.80[0.58-1.09], p=0.16; severe CAD, adjusted OR[95%CI]=1.07[0.81-1.41], p=0.65). CONCLUSIONS: Higher values of MPV are observed among patients with chronic kidney disease, inversely relating to eGFR. However, larger platelet size does not contribute to explain the increased severity of coronary artery disease observed among these patients.

Parathyroid Hormone Levels and High-Residual Platelet Reactivity in Patients Receiving Dual Antiplatelet Therapy With Acetylsalicylic Acid and Clopidogrel or Ticagrelor.

BACKGROUND: High-residual-on-treatment platelet reactivity still represents a challenging issue, potentially vanishing the benefits of dual antiplatelet treatment in patients with coronary artery disease. However, very few is known on the determinants of suboptimal response to antiplatelet agents. Recent interests have emerged on the potential prothrombotic effect of parathyroid hormone (PTH). Therefore, the aim of the present study was to assess the impact of parathyroid hormone (PTH) on platelet reactivity in patients receiving DAPT after an acute coronary syndrome or PCI. METHODS: Patients treated with DAPT (ASA and clopidogrel or ticagrelor) were scheduled for platelet function assessment at 30- to 90-days postdischarge. By whole blood impedance aggregometry, HRPR was considered for ASPI test >862 AU*min (for ASA) and ADP test values ≥417 AU*min (for ADP antagonists). RESULTS: We included 362 patients on DAPT, 125 (34.5%) receiving clopidogrel, and 237 (65.5%) on ticagrelor. Patients were divided according to PTH quartiles values (<45.8; 45.8-60.3; 60.4-88; ≥88.1 pg/mL). Higher PTH was associated with older age (P = 0.001); renal failure (P < 0.001), higher HDL cholesterol (P = 0.006) and creatinine (P < 0.001) and lower 25-OH cholecalciferol (P < 0.001). Suboptimal response to ASA was infrequent (2.8%), and not influenced by the levels of PTH (P = 0.57). ADP-mediated platelet aggregation was significantly increased in patients with higher PTH (P = 0.03), with an absolute increase in the prevalence of HRPR to ADP antagonists for higher PTH (24.7% vs. 40%, P = 0.007 for 4th vs. 1-3rd quartiles, adjusted OR[95%CI] = 2.04[1.14-3.64], P = 0.02). By the use of the ROC curve, we identified PTH levels above 96.7 pg/mL as the best predictor of HRPR with ADP antagonists (adjusted OR[95%CI] = 2.52[1.31-4.87], P = 0.006). Higher rate of HRPR was confirmed for PTH >96.7 pg/mL among the subgroup of patients on clopidogrel (51.5 vs. 85.7%, P = 0.001; adjusted OR[95%CI] = 12.5[2.6-60.9], P = 0.002), but not among ticagrelor-treated patients (11.3 vs. 16.7%, P = 0.31; adjusted OR[95%CI] = 1.55[0.56-4.6], P = 0.42). CONCLUSION: In patients receiving dual antiplatelet therapy for coronary artery disease, higher PTH levels are associated with an increased ADP-mediated platelet reactivity and suboptimal response to clopidogrel, especially for values above 96.7 pg/mL, while not influencing the effectiveness of ASA and ticagrelor.

Impact of diabetes on immature platelets fraction and its relationship with platelet reactivity in patients receiving dual antiplatelet therapy.

Contrasting data have been reported so far on the role of reticulated platelets in suboptimal response to antiplatelet therapies. In particular, still unexplored is whether they may contribute to explain the higher risk of thrombotic complications observed in diabetic patients. Aim of the present study was to evaluate the impact of diabetes on the levels of reticulated platelets and its relationship with high residual on-treatment platelet reactivity (HRPR) in patients receiving dual antiplatelet therapy. In patients treated with ASA (100-160 mg) and clopidogrel (75 mg daily) or ticagrelor (90 mg twice a day) platelet reactivity and the reticulated platelets fraction (immature platelets fraction, IPF) were assessed at 30-90 days post-discharge for an acute coronary syndrome or elective PCI. Aggregation was assessed by multiple-electrode aggregometry. We included 386 patients, 158 (40.9 %) diabetics. The percentage of IPF was similar in diabetic and non diabetic patients, both at baseline (3.5 ± 2.5 vs 3.6 ± 2.7 %, p = 0.91) and at 30-90 days re-assessment (3.3 ± 2.1 vs 3.5 ± 2.5 %, p = 0.30), with diabetes not emerging as an independent predictor of IPF above III tertile (adjusted OR [95 %CI] = 0.58 [0.30-1.09], p = 0.10). Diabetic patients displayed an enhanced platelet reactivity and a higher rate of HRPR with ADP antagonists (32.8 vs 22.5 %, p = 0.009). However, no association was found between the percentage of IPF and platelet function (r = -0.004; p = 0.95 for ASPI test, r = -0.04; p = 0.59 for ADP-mediated aggregation), or the rate of HRPR for ADP antagonsist across IPF tertiles. Results were similar for diabetics both receiving clopidogrel and ticagrelor. Diabetic patients display a higher platelet reactivity and suboptimal response to ADP-antagonists. However, the rate of reticulated platelets is neither influenced by diabetic status nor associated with an increased platelet reactivity among diabetic patients receiving dual antiplatelet therapy for a recent acute coronary syndrome or PCI.

Gender Differences in Platelet Reactivity in Patients Receiving Dual Antiplatelet Therapy.

BACKGROUND: Cardiovascular risk is still underestimated in women, experiencing higher mortality and worse prognosis after acute cardiovascular events. Gender differences have been reported in thrombotic and hemorrhagic risk during dual antiplatelet therapy (DAPT), thus suggesting a potential variability in platelet reactivity according to sex. The aim of the present study was to assess the role of gender on platelet function and the prevalence of high-on treatment residual platelet reactivity (HRPR) during DAPT in patients with recent acute coronary syndrome or percutaneous coronary revascularization. METHODS: Patients treated with DAPT (ASA and clopidogrel or ticagrelor) were scheduled for platelet function assessment at 30-90 days post-discharge. By whole blood impedance aggregometry, HRPR was considered for ASPI test >862 AU*min (for ASA) and ADP test values ≥417 AU*min (for ADP-antagonists). RESULTS: We included 541 patients on DAPT, 122 (22.6 %) of whom were females. Females were older (p < 0.001), displayed more frequently hypercholesterolemia (p = 0.003), renal failure (p = 0.04), acute presentation (p < 0.001), higher cholesterol levels and platelets count (p < 0.001). Inverse association was demonstrated with smoking (p < 0.001), previous PCI (p = 0.04) and statin use (p = 0.03), creatinine and haemoglobin (p < 0.001). Female gender did not influence mean platelet reactivity or the prevalence of HRPR for ASA (1.7 % vs 1.4 %, OR[95%CI] = 1.14[0.17-4.36], p = 0.99, adjusted OR[95%CI] = 1.54[0.20-11.6], p = 0.68) or ADP-antagonists (26.3 % vs 22.8 %, OR[95%CI] = 1.17[0.52-1.34], p = 0.45, adjusted OR[95%CI] = 1.05[0.59-1.86], p = 0.87). Results did not change when considering separately the 309 patients treated with clopidogrel (34 % vs 31.3 %, OR[95%CI] = 1.13[0.62-2.07], p = 0.76, adjusted OR[95%CI] = 1.35[0.63-2.9], p = 0.44 for females vs males), or patients (n = 232) on ticagrelor (20.4 % vs 11.1 %, OR[95%CI] = 2.27[0.99-5.17], p = 0.06 for females vs males), confirmed after correction for baseline differences (adjusted OR[95%CI] = 1.21[0.28-2.29], p = 0.68). CONCLUSION: In patients receiving dual antiplatelet therapy, gender does not impact on the prevalence of high-on treatment residual platelet reactivity (HRPR) with the major antiplatelet agents ASA, clopidogrel or ticagrelor.

Immature platelet fraction and high-on treatment platelet reactivity with ticagrelor in patients with acute coronary syndromes.

Residual high-on treatment platelet reactivity (HRPR) has been associated with a 2-9 fold increased risk of acute ischemic events in patients with acute coronary syndromes or coronary stenting. However, the mechanism of suboptimal platelet inhibition are still poorly understood. Aim of present study was to evaluate the role of the percentage of reticulated platelets on HRPR with ticagrelor. In patients treated with ASA (100-160 mg) and ticagrelor (90 mg twice a day) platelet reactivity and the reticulated platelets fraction (immature platelets fraction, IPF) were assessed at 30-90 days after acute coronary syndrome. Aggregation was assessed by multiple-electrode aggregometry. HRPR was defined as ADP test >417 AU*min. Our population is represented by 190 patients, divided according to tertiles values of IPF (<2.5; 2.5-3.99; ≥4 %). Higher IPF was associated to a larger platelet volume and lower platelets count (p < 0.001), and inversely related with a history of previous coronary revascularization (p = 0.03). Twenty-one out of 190 (11.0 %) patients displayed HRPR. No difference in the levels of circulating IPF was found in patients with or without HRPR (p = 0.25), with no correlation between the rate of reticulated platelets and platelet reactivity at ADP test (r = -0.084, p = 0.26). In fact no association was observed between high levels of IPF and the occurrence of HRPR (adjusted OR[95 % CI] = 0.69[0.34-1,37], p = 0.28), even after correction for baseline differences. In patients treated with ticagrelor, the levels of circulating reticulated platelets assessed at 30-90 days post-ACS are not associated with platelet reactivity or the occurrence of HRPR.

Platelet reactivity in patients with impaired renal function receiving dual antiplatelet therapy with clopidogrel or ticagrelor.

BACKGROUND: Suboptimal platelet inhibition still represents an important challenge, especially for patients undergoing percutaneous coronary interventions (PCI). Chronic kidney disease (CKD) is a common comorbidity of patients with coronary artery disease, and may potentially influence platelet reactivity. So far only few studies have assessed the role of CKD on response to dual antiplatelet therapy (DAPT) with conflicting results. Therefore, the aim of our study was to evaluate the impact of CKD on platelet function in patients treated with DAPT after a recent acute coronary syndrome (ACS) or PCI. METHODS: Patients treated with DAPT, acetylsalicylic acid (ASA)+adenosine diphosphate antagonist (ADP-antagonist) such as clopidogrel or ticagrelor, for ACS or elective patients undergoing PCI were scheduled for platelet function assessment at 30-90 days post-discharge. Platelet function was assessed by whole blood impedance aggregometry (Multiplate®- Roche Diagnostics AG), high residual platelet reactivity (HRPR) was considered for ASPI test >862 AU*min (for ASA) and ADP test values ≥ 417 AU*min (for ADP-antagonists). Chronic renal failure was defined as an estimated glomerular filtration rate of 60 mol/min/1.73 m(2) or less, calculated by applying MDRD (Modification of Diet in renal Disease) formula. RESULTS: Our population included a total of 537 patients of which 308 (57.3%) received ASA and clopidogrel and 229 (42.6%) received ASA and ticagrelor. Patients with renal failure at baseline (101 out of 537, 18.8%) were older, with higher prevalence of hypertension, previous myocardial infarction and coronary artery bypass graft surgery. Moreover, they had a lower ejection fraction at baseline and were more often in therapy with diuretics, but less often with statins at admission. They had lower haemoglobin and higher glycated haemoglobin. HRPR was observed in 1.5% of patients treated with ASA with no difference according to renal function (p=0.18). HRPR for ADP-antagonists was observed in 23.7% of patients, with no difference according to renal function (p=0.50). This result was confirmed either with clopidogrel (31.9% versus 38%, p=0.41) and ticagrelor (13.1% versus 10.8%, p=0.99), also after correction for all baseline confounders (clopidogrel: adjusted OR[95%CI]=1.26 [0.60-2.63], p=0.54) (ticagrelor: adjusted OR[95%CI]=0.95 [0.54-1.65], p=0.84). The absence of association between renal function and platelet reactivity was confirmed at linear regression analysis both with clopidogrel (r=-0.04, p=0.52) and ticagrelor (r=0.006, p=0.92). CONCLUSION: In patients receiving DAPT, chronic renal failure did not influence ADP-mediated platelet reactivity, with both ticagrelor or clopidogrel. No influence of chronic renal failure was found on the effectiveness of ASA.

Prevalence and predictors of high-on treatment platelet reactivity with ticagrelor in ACS patients undergoing stent implantation.

BACKGROUND: Residual high-on treatment platelet reactivity (HRPR) predicts outcomes and major cardiovascular events. Ticagrelor has provided pharmacological and clinical evidence of more predictable and more potent antiplatelet effect as compared to clopidogrel. However, so far, few data have investigated the prevalence and predictors of HRPR in unselected patients treated with ticagrelor, that is therefore the aim of the current study. METHODS AND RESULTS: Our population is represented by 195 patients undergoing coronary stenting for ACS and receiving ASA and ticagrelor. Platelet function was assessed by multiplate impedance aggregometry (MEA) between 1 and 3months after stenting. Main clinical features and biochemistry parameters were collected. HRPR for ticagrelor was defined for aggregation>417 AUC after MEA-ADP stimulation. A total of 26 patients, (13.3%), displayed HRPR with ticagrelor. Older age (≥70years, p=0.002), hypertension (p=0.02) previous myocardial infarction (p=0.04), therapy with nitrates and beta-blockers (p=0.02), diuretics (p=0.03) and fasting glycaemia (p=0.05) were associated to HRPR with ticagrelor. By multivariate analysis, age≥70years (OR [95%CI]=4.6[1.55-13.8], p=0.006), concomitant therapy with beta-blockers (OR [95%CI]=3.2[1.06-9.6], p=0.04) and platelets count (OR[95%CI]=1.0007 [1-1.016], p=0.05) were identified as independent predictors of HRPR with ticagrelor. CONCLUSION: The present study firstly demonstrates that the occurrence of HRPR in patients treated with ticagrelor is not so futile, as it was observed in 13% of patients treated with ticagrelor. Older age, beta-blockers administration and platelets count are independent predictors of HRPR with ticagrelor.

Impact of atorvastatin or rosuvastatin co-administration on platelet reactivity in patients treated with dual antiplatelet therapy.

BACKGROUND: Residual high-on treatment platelet reactivity (HRPR) still represents a challenging matter in patients with coronary artery disease. Drug-to-drug interaction has been suggested between some statin and antiplatelet agents, despite their co-administration is mandatory in patients after an acute cardiovascular event or coronary stenting. Therefore, the aim of the current study was to investigate any impact of rosuvastatin or atorvastatin co-administration on platelet reactivity in patients receiving dual antiplatelet therapy (DAPT). METHODS: Our population is represented by patients on DAPT (ASA and either clopidogrel 75 mg or ticagrelor 90 mg b.i.d) after an ACS or percutaneous revascularization, and receiving rosuvastatin or atorvastatin. Platelet function was assessed by Multiplate Impedance Aggregometry (Roche Diagnostics AG). RESULTS: We included a total of 374 patients, 240 (64.2%) receiving atorvastatin, 134 (35.8%) rosuvastatin. Rosuvastatin treated patients were more often using beta-blockers (p = 0.05), diuretics (p = 0.04) and displayed higher HDL (p < 0.001) and lower LDL cholesterol (p < 0.001). The prevalence of HRPR for ASA was low, with no difference according to statin type (0.8% vs 1.5%, p = 0.62, adjusted OR[95%CI] = 2[0.23-16.6], p = 0.52). Concerning ADP-antagonists, in the 163 patients treated with clopidogrel, rosuvastatin co-administration was associated with a significantly increased rate of HRPR (55.6%vs 32%, p = 0.01, adjusted OR[95%CI] = 2.69[1.22-5.96], p = 0.015) with higher ADP-mediated platelet reactivity (p = 0.01) and TRAP-test results (p = 0.04). On the contrary, in the 211 ticagrelor treated patients, statin type did not affect mean platelet reactivity or the prevalence of HRPR with ticagrelor (10.5% vs 11.2%, p = 0.99, adjusted OR[95%CI] = 0.86[0.34-2.22], p = 0.76) CONCLUSIONS: Among patients receiving DAPT, rosuvastatin but not atorvastatin is associated with an increased rate of HRPR for clopidogrel, without any influence on the antiplatelet effect of ASA or ticagrelor. Therefore, cautiousness should be exerted for clopidogrel and rosuvastatin therapeutic association.

Platelet Larger Cell Ratio and High-on Treatment Platelet Reactivity During Dual Antiplatelet Therapy.

BACKGROUND: Low response to antiplatelet agents has been associated to an increased risk of thrombotic complications and recurrent ischemic events. Platelet size has been proposed as a potential marker of platelet reactivity. Therefore, the aim of the present study was to evaluate the impact of platelet Larger Cell Ratio (p-LCR) on platelet aggregation and the prevalence of residual high-on treatment platelet reactivity (HRPR) in patients receiving dual antiplatelet therapy (DAPT) after a recent acute coronary syndrome or coronary revascularization. METHODS: Patients treated with DAPT (ASA and clopidogrel or ticagrelor) were scheduled for platelet function assessment at 30-90 days post-discharge. HRPR was considered for ASPI test >862 AU*min (for ASA) or ADP test values ≥417 AU*min (for ADP-antagonists) using impedance aggregometry. RESULTS: Our population consisted of 530 patients receiving DAPT, who were divided in tertiles according to values of p-LCR (< 27.6; 27.6-34.7; ≥34.7 l). p-LCR was related with use of beta-blockers (p = 0.02) and statins (p = 0.002), and inversely with acute presentation (p = 0.05). Higher platelet count (p < 0.001) and haemoglobin levels (p = 0.001) were observed in higher p-LCR tertiles. The prevalence of HRPR for ASA was low and not significantly different across tertiles of p-LCR (1.1 vs 1.1 vs 1.7%, p = 0.66; adjusted OR[95%CI] = 1.68[0.66-4.29], p = 0.27). Moreover, p-LCR did not influence the occurrence of HRPR for ADP-antagonists (24.4% vs 20.9% vs 25.6 %%, p = 0.80, adjusted OR[95%CI] = 0.88[0.67-1.17], p = 0.38) and similar results were obtained when considering separately patients receiving clopidogrel (adjusted OR[95%CI] = 1.21[0.86-1.69], p = 0.29) or ticagrelor (adjusted OR[95%CI] = 1.17[0.69-2], p = 0.56). CONCLUSION: In patients receiving DAPT for coronary artery disease, p-LCR does not impact platelet reactivity. Larger platelets did not influence the prevalence of high-on treatment platelet reactivity with the antiplatelet agents ASA, clopidogrel or ticagrelor.

Impact of diabetes on fibrinogen levels and its relationship with platelet reactivity and coronary artery disease: A single-centre study.

BACKGROUND: Previous reports have suggested an association between elevated fibrinogen and CAD. Few studies have so far investigated the impact of diabetes on fibrinogen levels and its association with coronary artery disease (CAD) and platelet reactivity in diabetic patients that are therefore the aims of the current study. METHODS: We measured fibrinogen in 3280 consecutive patients undergoing coronary angiography. Samples were collected at admission for fibrinogen levels assessment. Coronary disease was defined for at least 1 vessel stenosis >50% as evaluated by QCA. RESULTS: Diabetes was observed in 1201 out of 3280 patients. Diabetic patients were older with more hypercholesterolemia, hypertension, higher BMI, more renal failure, previous MI or coronary revascularization (p<0.001, respectively) and smoking (p=0.001). Diabetic patients were more often on ACE-inhibitors, ARBs, b-blockers, calcium-antagonists, diuretics, statins (p<0.001, respectively), and ASA (p=0.004). Diabetic patients displayed higher glycaemia and HbA1c (p<0.001), higher creatinine and triglycerides (p<0.001) but lower total and HDL cholesterol (p<0.001) and haemoglobin (p<0.001). Diabetic patients had higher fibrinogen levels (p=0.003), however neither diabetes nor glucose homeostasis parameters resulted as independent predictors of hyperfibrinogenemia. Furthermore, among diabetic patients, higher fibrinogen levels did not affect platelet reactivity and were not associated with the prevalence of CAD (adjusted OR[95%CI]=0.99 [0.82-1.19], p=0.9). Similar results were found for severe CAD (adjusted OR[95%CI]=0.94 [0.82-1.08], p=0.40). CONCLUSIONS: Our study showed that diabetes and glycaemic control are not independent predictors of hyperfibrinogenemia. Among diabetic patients, elevated fibrinogen is not associated with platelet reactivity and the prevalence and extent of CAD.

Mean platelet volume and high-residual platelet reactivity in patients receiving dual antiplatelet therapy with clopidogrel or ticagrelor.

OBJECTIVE: High on-treatment platelet reactivity (HRPR) is associated with a two- to ninefold increased risk of recurrent ischemic events among patients receiving dual antiplatelet therapy (DAPT) for coronary artery disease. However, its determinants are still poorly understood. The aim of the present study was to assess the impact of mean platelet volume (MPV) on platelet reactivity in patients receiving DAPT after an acute coronary syndrome or PCI. METHODS: Patients treated with DAPT (acetylsalicylic acid [ASA] and clopidogrel or ticagrelor) were scheduled for platelet function assessment at 30 - 90 days post-discharge. By whole blood impedance aggregometry, HRPR was considered for ASPI test > 862 aggregation units (AU)*min (for ASA) and ADP test values ≥ 417 AU*min (for ADP-antagonists). RESULTS: Our population is represented by a total of 487 patients on DAPT, divided according to MPV tertiles (< 10.4 fl; 10.4 - 11.29 fl; ≥ 11.3 fl). Larger-sized platelets were associated with use of statins (p < 0.001) and beta-blockers (p = 0.03), higher hemoglobin levels (p = 0.002) and lower platelets count (p < 0.001). Higher platelet reactivity was observed at ASPI test in patients with higher MPV (r = 0.12, p = 0.008), but not for ADP-mediated aggregation (r = -0.007, p = 0.88). However, a low prevalence of HRPR was observed with ASA, with no impact of MPV tertiles (1.2 vs 1.1 vs 1.6%, p = 0.70, adjusted OR [95% CI] = 1.05 [0.51 - 1.77], p = 0.87). MPV did not influence the prevalence of HRPR for ADP-antagonists (25.9 vs 1 vs 26.5%, p = 0.89; adjusted OR [95% CI] = 1.1 [0.84 - 1.45], p = 0.50) with similar results among the 259 patients receiving clopidogrel (adjusted OR [95% CI] = 1.15 [0.82 - 1.62], p = 0.43) and the 228 patients on ticagrelor (adjusted OR [95% CI] = 1.46 [0.84 - 2.55], p = 0.18). CONCLUSION: In patients receiving DAPT, MPV does not affect the response to major antiplatelet therapies. In fact, MPV elevation does not influence the risk of HRPR with clopidogrel, ticagrelor or ASA.

High Prevalence of Vitamin D Deficiency in Native versus Migrant Mothers and Newborns in the North of Italy: A Call to Act with a Stronger Prevention Program.

BACKGROUND: Vitamin D status during pregnancy is related to neonatal vitamin D status. Vitamin D deficiency has been associated with an increased risk of rickets in children and osteomalacia in adults. Aim of this study was to investigate 25OHD levels in maternal serum and in neonatal blood spots in native and migrant populations living in Novara (North Italy, 45°N latitude). METHODS AND FINDINGS: We carried out a cross sectional study from April 1st 2012 to March 30th 2013, in a tertiary Care Center. Maternal blood samples after delivery and newborns' blood spots were analyzed for 25OHD levels in 533 pairs. Maternal country of origin, skin phototype, vitamin D dietary intake and supplementation during pregnancy were recorded. Multivariate regression analysis, showed a link between neonatal and maternal 25OHD levels (R-square:0.664). Severely deficient 25OHD values (<25 nmol/L) were found in 38% of Italian and in 76.2% of migrant's newborns (p <0.0001), and in 18% of Italian and 48,4% of migrant mothers (p <0.0001) while 25OHD deficiency (≥25 and <50 nmol/L) was shown in 40.1% of Italian and 21.7% of migrant's newborns (p <0.0001), and in 43.6% of Italian and 41.3% of migrant mothers (p <0.0001). Italian newborns and mothers had higher 25OHD levels (34.4±19.2 and 44.9±21.2 nmol/L) than migrants (17.7±13.7 and 29.7±16.5 nmol/L; p<0.0001). A linear decrease of 25OHD levels was found with increasing skin pigmentation (phototype I 42.1 ±18.2 vs phototype VI 17.9±10.1 nmol/l; p<0.0001). Vitamin D supplementation resulted in higher 25OHD values both in mothers and in their newborns (p<0.0001). CONCLUSIONS: Vitamin D insufficiency in pregnancy and in newborns is frequent especially among migrants. A prevention program in Piedmont should urgently be considered and people identified as being at risk should be closely monitored. Vitamin D supplementation should be taken into account when considering a preventative health care policy.