Domenico Prisco

Acute T-cell activation is detectable in unstable angina.

BACKGROUND Recent studies suggest a role for inflammation in the pathophysiology of unstable angina. This study was designed to investigate whether circulating lymphocytes are involved in the inflammatory reaction associated with the episodes of unstable angina. METHODS AND RESULTS Twenty-nine patients with proven unstable angina, 36 with stable angina, and 30 healthy subjects were studied. Both early and short-lived (interleukin-2 receptor [IL-2R], alpha-chain CD25, and transferrin receptor CD71) and late antigen (HLA-DR) expression were investigated by flow cytometric analysis. Soluble IL-2R (sIL-2R) was also measured in plasma by ELISA. Lymphocyte activation was studied at day 1 of hospital admission and after 7, 15, 30, 60, and 90 days. In patients with unstable angina, the number of HLA-DR+ CD3 lymphocytes and levels of sIL-2R were higher (P < .001) than in patients with stable angina and control subjects. Both CD4+ and CD8+ lymphocytes expressed HLA-DR antigens. No differences were found among the different groups of subjects in regard to the expression of CD25 and CD71. Lymphocyte activation was more marked in patients with urgent revascularization. No relationships were found between the number of HLA-DR+ lymphocytes and either the severity of coronary angiographic lesions or the number of ischemic episodes. Observations over time showed a gradual decrease in the number of HLA-DR+ lymphocytes and sIL-2R levels from weeks 3 through 8 to 12. CONCLUSIONS The present results indicate that (1) CD4+ and CD8+ circulating lymphocytes are activated in patients with unstable angina, and their activation state lasts 6 to 8 weeks; and (2) activation of lymphocytes is not a consequence of myocardial ischemia. These results support the immune system-mediated inflammatory nature of unstable angina.

Different methodologies for evaluating the effect of clopidogrel on platelet function in high-risk coronary artery disease patients.

Summary.  Background: Two point‐of‐care (POC) systems have been recently proposed as rapid tools with which to evaluate residual platelet reactivity (RPR) in coronary artery disease (CAD) patients. Objectives and Methods: We compared Platelet Function Analyzer‐100 (PFA‐100) closure times (CTs) by collagen/adenosine 5´‐diphosphate (ADP) (C/ADP CT) cartridge and the VerifyNow P2Y12 Assay (VerifyNow) with light transmission aggregation (LTA) induced by 2 and 10 μmol L–1 ADP in 1267 CAD patients on dual antiplatelet therapy who underwent percutaneous coronary intervention. We also performed the vasodilator‐stimulated phosphoprotein (VASP) phosphorylation assay by cytofluorimetric analysis in a subgroup of 115 patients. Results: Cut‐off values for identifying RPR were: ≥ 54% and ≥ 66% for LTA induced by 2 and 10 μmol L–1 ADP respectively, and ≥ 264 P2Y12 Reaction Units (PRU) for VerifyNow. The cut‐off for PFA‐100 C/ADP CT was ≥ 68 s. RPR was detected in 25.1% of patients by 2 μmol L–1 ADP‐induced LTA (ADP‐LTA), in 23.2% by 10 μmol L–1 ADP‐LTA, in 24.4% by PFA‐100, and in 24.7% by VerifyNow. PFA‐100 results did not parallel those obtained with LTA. VerifyNow showed a significant correlation (ρ = 0.62, P < 0.001) and significant agreement (k = 0.34, P < 0.001) with LTA induced by 2 μmol L–1 ADP. The correlation was similar but the agreement was better between VerifyNow and 10 μmol L–1 ADP‐LTA (ρ =  0.64, P < 0.0001; k = 0.43, P < 0.001). Significant relationships were found between VASP platelet reactivity index and both ADP‐LTA and VerifyNow. PFA‐100 C/ADP CT did not significantly correlate with any of the other assays. Conclusions: Our results show a significant correlation between LTA and VerifyNow but not the PFA‐100 C/ADP assay. Clinical validation studies for POC systems are necessary.

Standardized Low–Molecular-Weight Heparin Bridging Regimen in Outpatients on Oral Anticoagulants Undergoing Invasive Procedure or Surgery An Inception Cohort Management Study

Background— Bridging therapy with low–molecular-weight heparin is usually recommended in patients who must stop oral anticoagulants before surgical or invasive procedures. To date, there is no universally accepted bridging regimen tailored to the patient’s thromboembolic risk. This prospective inception cohort management study was designed to assess the efficacy and safety of an individualized bridging protocol applied to outpatients. Methods and Results— Oral anticoagulants were stopped 5 days before the procedure. Low–molecular-weight heparin was started 3 to 4 days before surgery and continued for 6 days after surgery at 70 anti–factor Xa U/kg twice daily in high-thromboembolic-risk patients and prophylactic once-daily doses in moderate- to low-risk patients. Oral anticoagulation was resumed the day after the procedure with a boost dose of 50% for 2 days and maintenance doses afterward. The patients were followed up for 30 days. Of the 1262 patients included in the study (only 15% had mechanical valves), 295 (23.4%) were high-thromboembolic-risk patients and 967 (76.6%) were moderate- to low-risk patients. In the intention-to-treat analysis, there were 5 thromboembolic events (0.4%; 95% confidence interval, 0.1 to 0.9), all in high-thromboembolic-risk patients. There were 15 major (1.2%; 95% confidence interval, 0.7 to 2.0) and 53 minor (4.2%; 95% confidence interval, 3.2 to 5.5) bleeding episodes. Major bleeding was associated with twice-daily low–molecular-weight heparin administration (high-risk patients) but not with the bleeding risk of the procedure. Conclusions— This management bridging protocol, tailored to patients’ thromboembolic risk, appears to be feasible, effective, and safe for many patients, but safety in patients with mechanical prosthetic valves has not been conclusively established.

Bleeding Risk During Oral Anticoagulation in Atrial Fibrillation Patients Older Than 80 Years

OBJECTIVES We sought to evaluate the rate of bleeding in relation to age (<80 and > or =80 years), the quality of anticoagulation (expressed as time spent in international normalized ratio therapeutic range), and factors associated with bleeding events. BACKGROUND Stroke prevention in patients with atrial fibrillation (AF) is an increasingly crucial public health target, particularly in patients ages > or =80 years. METHODS We conducted a prospective observational study on 783 patients with AF on oral anticoagulant treatment (OAT). RESULTS Patients spent a median 14%, 71%, and 15% of time below, within, and above the intended therapeutic range, respectively. No difference in OAT quality was found between patients age <80 and > or =80 years. During follow-up, 94 patients experienced bleeding complications (rate 3.7 x 100 patient/years), 37 major (rate 1.4 x 100 patient/years), and 57 minor (rate 2.2 x 100 patient/years). Different rates of major hemorrhage were observed between patients age <80 and > or =80 years (0.9 vs. 1.9 x 100 patient/years; p = 0.004). Bleeding risk also was greater in patients with a history of previous cerebral ischemic event (odds ratio [OR]: 2.5; 95% confidence interval: 1.3 to 4.8; p = 0.007). A Cox regression analysis confirmed age > or =80 years associated with bleeding risk (OR: 2.0). CONCLUSIONS These results indicate that the rate of major bleeding complications may be kept acceptably low also in very elderly AF patients on OAT, provided a careful management of anticoagulation is obtained.

Usefulness of repeated D-dimer testing after stopping anticoagulation for a first episode of unprovoked venous thromboembolism: the PROLONG II prospective study

The PROLONG randomized trial showed that a normal D-dimer (D-d) 1 month after anticoagulation suspension for unprovoked venous thromboembolism (VTE) was associated with a low risk of late recurrences (4.4% patient years). However, it is unknown whether D-d changes subsequently. The aim of this prospective multicenter study was to assess D-d time course and its relation with late recurrences in patients with normal D-d 1 month after anticoagulation suspension for a first episode of unprovoked VTE. D-d was measured with a qualitative method (Clearview Simplify D-dimer; Inverness Medical Professional Diagnostics). Patients with a normal D-d 1 month after stopping anticoagulation repeated D-d testing every 2 months for 1 year. D-d was normal in 68% (243/355) of patients 1 month after anticoagulation suspension. Patients in whom D-d became abnormal at the third month and remained abnormal afterward had a higher risk of recurrence (7/31; 27% patient years; 95% confidence interval [CI]: 12-48) than patients in whom D-d remained normal at the third month and afterward (4/149; 2.9% patient years; 95% CI: 1-7; adjusted hazard ratio: 7.9; 95% CI: 2.1-30; P = .002). Repeated D-d testing after anticoagulation suspension for a first episode of unprovoked VTE could help tailor the duration of treatment. This trial is registered at http://clinicaltrials.gov as NCT00266045.

D-DIMER CONCENTRATIONS DURING NORMAL PREGNANCY, AS MEASURED BY ELISA

In pregnant women a number of changes in blood clotting and fibrinolysis proteins have been reported so indicating the existence of a state of hypercoagulability. In addition to fibrinogen and antithrombin III (AT), D-dimer is frequently checked during pregnancy, in particular during at risk pregnancy, but the exact pattern of D-dimer modifications during uncomplicated pregnancy is not definitively described. The aim of this study was to establish the range values in three different periods of uncomplicated pregnancy (A: 1-20 wks; B: 21-30 wks; C: 31-40 wks). We measured plasma levels of D-dimer, clottable fibrinogen and AT in 108 consecutive normal pregnant women aged 16 to 42 years. In period A, the range of D-dimer values was 43-211 ng/mL, not different from controls, while fibrinogen levels were significantly higher (p < 0.05) than in matched non pregnant women. Mean D-dimer levels were higher in periods B (p < 0.05) and C (p < 0.05) vs period A. Similarly, mean fibrinogen levels were found more elevated in periods B and C vs period A (p < 0.05). A significant correlation was found between fibrinogen and D-dimer levels (p < 0.001). No differences in AT levels were found among the three periods of pregnancy. The results of this study indicate that levels of D-dimer up to 685 micrograms/L may be reached at the end of physiological pregnancy. This fact should be taken into account in the evaluation of hemostatic studies performed in uncomplicated and complicated pregnant women.

Assessment of platelet function on whole blood by multiple electrode aggregometry in high-risk patients with coronary artery disease receiving antiplatelet therapy.

This study sought to compare Multiplate impedance platelet aggregometry (IPA) with light transmission aggregometry (LTA) and the PFA-100 for determining the prevalence of residual platelet reactivity (RPR) by the Multiplate IPA in 297 patients with acute coronary syndrome receiving dual antiplatelet therapy. Aggregations were induced by adenosine-5 diphosphate (ADP), arachidonic acid, and collagen. PFA-100 closure times were measured by collagen and ADP and epinephrine (CEPI) cartridges. Significant correlations were observed between Multiplate IPA and LTA after all stimulations (P < .0001) and between Multiplate IPA (arachidonate and collagen) and PFA-100 CEPI closure time (P < .0001 for both). Cutoff values of Multiplate IPA (for all stimulations) were calculated for the identification of RPR. Between the Multiplate IPA and LTA good agreement was found with all 3 agonists (P < .0001 for all). Multiplate IPA might represent a reliable, handy, rapid tool to monitor antiplatelet therapy in clinical practice and for clinical investigations.

Effect of Medium-term Supplementation with a Moderate Dose of n-3 Polyunsaturated Fatty Acids on Blood Pressure in Mild Hypertensive Patients

Several studies have shown that n-3 polyunsaturated fatty acids (n-3 PUFA) are able to lower blood pressure (BP) in humans, but large doses of fish oils have been often used. Moreover, most of the studies available in the literature were not able to evaluate the specific effects of n-3 PUFA because they employed fish oils which contain, together with n-3 PUFA, many other different components. The aim of this preliminary study was to evaluate if medium-term supplementation with a moderate dose of highly purified eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) ethyl esters is able to reduce BP in mild hypertensive patients. Sixteen mild essential hypertensive (diastolic BP: 95-104 mm Hg), non-diabetic, normolipidemic male outpatients and 16 normotensive male controls were recruited to participate in the study. Both hypertensive and control subjects were randomly assigned to receive either EPA and DHA ethyl esters (2.04 g EPA and 1.4 g DHA) as active treatment or olive oil (4 g/day) as a placebo for a period of 4 months. These subjects were followed up with 24-hour ambulatory BP monitoring and blood chemistry analyses at 2 and 4 months of treatment and 2 months after its discontinuation. The intake of n-3 PUFA was checked by red blood cell (RBC) phosphatidylcholine (PC) fatty acid composition. The effect of n-3 PUFA on BP in the active group was maximum after 2 months. Both systolic (-6 mm Hg, p<0.05) and diastolic (-5 mm Hg, p<0.05) BP significantly decreased during the n-3 PUFA ethyl ester supplementation. No further effect was observed at 4 months with a return to baseline values during the recovery period. These data indicate that 4 g/day of highly purified EPA + DHA ethyl esters are able to favorably affect BP in mild hypertensives.

Evaluation of Clotting and Fibrinolytic Activation after Protracted Physical Exercise

The behavior of hemostatic system activation during protracted physical exercise is well known, but the duration of its modification is not yet defined. In order to evaluate the time of hemostatic system activation after prolonged strenuous endurance physical exercise (typical marathon race: 42.195 km, v=15.35 km/h; mean length of time run 2.45+/-0.15 hours) 12 well-trained long-distance male runners (mean age: 35+/-7, range 25-47 years) were investigated. Blood samples were drawn in the morning on the day before the performance, immediately after the race, and 24 hours and 48 hours after the end of run. With respect of baseline, immediately after the race, a significant decrease of fibrinogen (-25%) and significant increases of prothrombin fragment 1+2 (+633%) and thrombin-antithrombin complex (+848%) were observed. A significant acceleration of euglobulin lysis time (-41%), and rises of plasma levels of tissue plasminogen activator antigen (+361%), plasminogen activator inhibitor type 1 antigen (+235%), d-dimer (+215%), and plasma fibrinogen degradation products (+1200%) were also found. Only a slight, yet not significant, decrease in plasminogen activator inhibitor type 1 activity was observed. One day after the end of marathon different parameters were still unchanged. Forty-eight hours after the competition all parameters investigated returned to baseline values. These results indicate a persistence of clotting as well as fibrinolysis activation up to 24 hours after the end of the race.

Prevention and treatment of bleeding complications in patients receiving vitamin K antagonists, Part 1: Prevention

Oral anticoagulant therapy with coumarins is widelyused for the prevention and treatment of venous andarterial thrombosis. The most common complication ofvitamin K antagonist therapy is bleeding, with majorbleeding events occurring in 1–3% of patients annually.Although a number of potential predictors for bleedinghave been described, little research is available to pro-vide evidence-based guidelines for the prevention ofbleeding. To address this knowledge gap, we assembleda panel of international experts and posed a series offocused clinical questions. The experts were asked toperform a systematic literature review and summarize theresults of that review within the context of their clinicalquestion. In many cases, data were lacking and theexperts were asked to supplement their answer with clin-ical expertise. To minimize bias the reviews were vettedby three internationally recognized scholarly bodies. Ourgoal in this project is to provide ‘‘best evidence’’ forclinicians faced with the problem of minimizing the riskof bleeding in patients on vitamin K antagonist therapy.The number of patients receiving vitamin K antagonisttherapy increases annually and probably exceeds three mil-lion in the United States. Despite monitoring and carefuldose adjustment, the time spent in the therapeutic Interna-tional Normalized Ratio (INR) range varies from below 47%to a maximum of 81% of the time [1]. Major bleedingevents occur in up to 3% of ‘‘standard risk’’ patients treatedwith an oral vitamin K antagonist in one year. Despite thehigh frequency of use of vitamin K antagonists, very littleresearch has been performed examining techniques toreduce the risk of bleeding. In particular, the role of clinicalbleeding prediction rules is uncertain and further study ofthe role of drug and food interactions, the impact of patienteducation, the risk to benefit ratio of combining differentantithrombotic drugs, the role of pharmacogenomic testing,and on the optimal management of patients presentingwith elevated INR values is required. However, despitethese needs clinicians are still required to initiate andmonitor vitamin K antagonists while mitigating the risks ofbleeding and thrombosis. This article provides recommen-dations designed to assist clinicians in estimating andmanaging bleeding risk in patients receiving oral vitamin Kantagonists.Clinical questions were formulated by three of theauthors (WA, MC, DG) and authors were selected basedon their published experience. In each case, a North Ameri-can and Italian expert were asked to co-author theresponse to the question. The authors were asked to per-form a comprehensive literature review and make specificrecommendations on the basis of this review in concertwith their clinical experience. Given the anticipated lack ofevidence, the recommendations are largely opinion-based.To increase the rigor of the recommendations, each sectionwas carefully reviewed by members of the Italian Societyfor Studies on Haemostasis and Thrombosis, the Federa-tion of Centers for the Diagnosis of Thrombosis and Sur-veillance of Antithrombotic Therapies, and the Anticoagula-tion Forum.To provide readers with information on the strength of therecommendations, we have asked the authors to use theAmerican College of Chest Physicians GRADE system toevaluate the quality of the recommendations [2]. In thissystem, grades of 1A, 1B, 1C, 2A, 2B, and 2C are possible.A 1A recommendation is a strong recommendation basedon evidence from randomized trials or exceptional qualityobservational data which is thought to apply to mostpatients, in most circumstances. A 2C recommendation is avery weak recommendation, based on poor quality evi-dence, and for which there is doubt as to which patientsthe recommendation applies. Our goal with this project is toboth provide guidance to clinicians and to stimulate addi-tional research designed to improve the quality of evidenceon which treatments for vitamin K antagonist associatedbleeding are based.Clinical Scenario 1A 79-year-old woman with atrial fibrillation and well-con-trolled hypertension is assessed for anticoagulant therapy.She has no history of diabetes, congestive heart failure,stroke, or transient ischemic attack (TIA). Two years agoshe had an upper gastrointestinal bleed treated with a pro-