ticagrelor and Vitamin-D-Deficiency

Hypovitaminosis D represents an emerging cardiovascular risk factor, and especially among higher-risk subsets of patients, such as in those with diabetes mellitus. The anti-inflammatory and anti-thrombotic properties of vitamin D, in fact, could be even more beneficial among diabetics, where platelet hyperreactivity and suboptimal response to antiplatelet drugs has been associated with poorer outcomes. However, no study has so far evaluated the impact of vitamin D levels on platelet reactivity and high-on treatment platelet reactivity (HRPR) among diabetic patients receiving dial antiplatelet therapy (DAPT).. Our population is represented by a consecutive cohort ofdiabetic patients treated with DAPT (ASA + clopidogrel or ticagrelor or dose-adjusted prasugrel) for an acute coronary syndrome or elective PCI, undergoing platelet reactivity assessment at 30-90 days post-discharge. Aggregation was assessed by multiple-electrode aggregometry. HRPR was defined for values above the lower limit of normality (in non-treated patients).. We included 440 patients, that were divided according to quartiles values of vitamin D (< 9.4; 9.4-15.59; 15.6-21.64; ≥ 21.65 ng/ml). Among them, 31 were excluded as chronically treated with vitamin D supplementation. Lower vitamin D quartiles were associated with more advanced age (p = 0.01), female gender (p = 0.04), renal failure (p = 0.005), history of previous MI (p = 0.01), CABG and use of diuretics (p = 0.003), severe coronary disease (p = 0.002), but lower ejection fraction (p = 0.001), treatment with statins (p = 0.04) and new ADP-antagonists (p = 0.002). Vitamin D levels related with higher HbA1c (p = 0.001), cholesterol (p = 0.02) and creatinine (p = 0.004) and lower hemoglobin (p = 0.004). The prevalence of HRPR with ASA was low and not related to vitamin D quartiles (3.4% vs 2.7% vs 1.8% vs 2.1%, p = 0.44; adjusted OR[95%CI] = 1.16[0.60-2.26], p = 0.67). The prevalence of HRPR for ADP antagonists was associated to hypovitaminosis D (40.2% vs 29.1% vs 29.4% vs 25.5%, p = 0.03; (adjusted OR[95%CI] = 1.76[1.04-2.98], p = 0.036for I vs II-IV quartile). The impact of vitamin D quartiles, was significant only in patients on new ADP antagonists (n = 225, of whom 81 on prasugrel 5 mg; p = 0.03; adjusted OR[95%CI] = 3.12[1.34-7.49], p = 0.009) but not with clopidogrel (p = 0.85, adjusted OR[95%CI] = 1.05[0.49-2.24], p = 0.89).. Among diabetic patients receiving dual antiplatelet therapy for an acute coronary syndrome or elective percutaneous coronary intervention, severe vitamin D deficiency is associated with a higher ADP-mediated platelet reactivity and rate of HRPR, and especially for new ADP-antagonists over clopidogrel.

Topics: Acute Coronary Syndrome; Aged; Aged, 80 and over; Aspirin; Biomarkers; Clopidogrel; Diabetes Mellitus; Drug Therapy, Combination; Female; Humans; Male; Middle Aged; Percutaneous Coronary Intervention; Platelet Aggregation; Platelet Aggregation Inhibitors; Prasugrel Hydrochloride; Risk Factors; Ticagrelor; Time Factors; Treatment Outcome; Vitamin D; Vitamin D Deficiency

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.. 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.. 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, p. 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.

Topics: Acute Coronary Syndrome; Adenosine; Aged; Aspirin; Chi-Square Distribution; Clopidogrel; Coronary Artery Disease; Drug Resistance; Drug Therapy, Combination; Female; Gene Frequency; Genotype; Heterozygote; Homozygote; Humans; Logistic Models; Male; Middle Aged; Multivariate Analysis; Odds Ratio; Percutaneous Coronary Intervention; Pharmacogenetics; Pharmacogenomic Testing; Pharmacogenomic Variants; Phenotype; Platelet Aggregation; Platelet Aggregation Inhibitors; Platelet Function Tests; Prospective Studies; Risk Factors; Ticagrelor; Ticlopidine; Treatment Outcome; Vitamin D Deficiency; Vitamin D-Binding Protein