Influence of Different ß-Blockers on Platelet Aggregation in Patients With Coronary Artery Disease on Dual Antiplatelet Therapy.

INTRODUCTION: The use of ß-blockers in the treatment of patients with coronary heart disease is associated with a decrease in the frequency of angina pectoris and mortality of patients. Due to the severity of the disease and previous cardiovascular interventions, many patients with coronary artery disease (CAD) use dual antiplatelet therapy to achieve greater inhibition of platelet aggregation. The influence of ß-blockers on platelet aggregation in patients using antiplatelet therapy is not well understood. OBJECTIVE: To examine the effect of different ß-blockers on platelet aggregation in patients on dual antiplatelet therapy. METHODOLOGY: The study included 331 patients who were treated at the Department of Cardiology, Clinical Center Kragujevac during 2011. Patients were divided into 4 groups depending on the type of ß-blockers that were used (bisoprolol, nebivolol, metoprolol, and carvedilol). Platelet aggregation was measured using the multiplate analyzer and expressed through the value of adenosine diphosphate (ADP) test (to assess the effect of clopidogrel), ASPI test (to assess the effect of acetyl salicylic acid), TRAP test (to assess baseline platelet aggregation), and the ratio of ADP/TRAP and ASPI/TRAP ASPI/TRAP (ASPI - aranchidonic acid induced aggregation, TRAP - thrombin receptor activating peptide) representing the degree of inhibition of platelet aggregation compared to the basal value. In consideration were taken the representation of demographic, clinical characteristics, laboratory parameters, and cardiovascular medications between the groups. RESULTS: Patients who used nebivolol had a significantly lower value of the ratio of ADP/TRAP (0.39 ± 0.30) compared to patients who used bisoprolol (0.48 ± 0.26; P = .038), and trend toward the lower values of ADP test (328.0 ± 197.3 vs 403.7 ± 213.2; P = .059), while there was no statistically significant difference in values of other laboratory parameters of platelet function between other groups. CONCLUSION: Patients with CAD on dual antiplatelet therapy who used nebivolol had significantly lower levels of residual ADP-induced platelet aggregation compared to baseline than patients who used bisoprolol.

Is there a link between Hashimoto's thyroiditis and primary hyperparathyroidism? A study of serum parathormone and anti-TPO antibodies in 2267 patients.

According to various authors, thyroid disorders like Hashimoto's thyroiditis (HT), diffuse goiter or multinodular goiter, Graves' disease, medullary or papillary carcinoma could be found in a number of patients with primary hyperparathyroidism (PHPT). This association is more common in elderly women. Neck irradiation, lithium treatment and elevated TSH levels have been suggested as some of the possible causes of this co-existance. The aim of this study was to investigate and determine the prevalence of patients having both HT and PHPT, and the possible relation between these two diseases. We conducted a prospective study during three and a half years. This study included 45,231 patients, which were referred by their general practitioner or endocrinologist, under suspicion of having thyroid and/or parathyroid disease. In these patients we measured serum levels of the following parameters: anti-thyroid peroxidase antibodies (antiTPO-Ab), anti-thyroglobulin antibodies (Tg-Ab), anti-TSH-receptor antibodies (TSHR-Ab), thyroid-stimulating hormone (TSH), parathyroid hormone (PTH) and calcium (Ca). In 2,267 of these 45,231 patients (5.01%) we noticed elevated antiTPO-Ab (3542±3407IU/mL), with statistical significant difference from normal values (normal range 0-70IU/mL), P<0.05, and normal levels of other antithyroid antibodies (Tg-Ab, TSHR-Ab). All patients with elevated antiTPO-Ab were assumed to have HT. Within this group, 43 patients (1.89%) also had elevated serum levels of PTH (112.4±33.2pg/mL, normal range 8-76pg/mL) as well as elevated serum levels of calcium (2.92±0.06mmol/L, normal range 2.2-2.65mmol/L). These laboratory findings, accompanied with clinical symptoms, satisfied the criteria for PHPT. The mean age in this subgroup was 60.5±12.2 years. All 2,267 patients had normal or slightly elevated TSH levels. In conclusion, although the reported rate of prevalence of PHPT in the general population is about 0.3%, our results indicated a 1.89% occurrence of PHPT in 2267 patients with HT in central Serbia. This may be due to the autoimmune inflammatory process in HT supporting PHPT to PTH or calcium supporting HT or to common genetical predisposition of both entities.