Need of more frequent International Normalized Ratio monitoring in elderly patients on long-term anticoagulant therapy after influenza vaccination.

Previous findings suggest the safety of influenza vaccination for patients on oral anticoagulant therapy (OAT). However, some studies reported a moderate reduction or increase of the anticoagulation. We assessed the effect of influenza vaccination on anticoagulation levels. Seventy-three patients on stable long-term OAT were recruited. Patients were compared with a control group of 72 patients observed during the same period. No differences in the anticoagulation levels were found in patients and in controls during the 3 months before and after the vaccination. However, in patients older than 70 years we observed a reduction of anticoagulation intensity achieved in the month after the vaccination, with a prolonged time spent below the therapeutic range (10% before and 27% after, P = 0.001), and this behaviour was still observed 3 months after vaccination. Influenza vaccination is safe in patients on OAT, but it is associated with a slight reduction in warfarin effect in the elderly, suggesting the need of more frequent International Normalized Ratio monitoring after vaccination in these subjects.

Postprocedural PAI-1 activity is a risk marker of subsequent clinical restenosis in patients both with and without stent implantation after elective balloon PTCA.

Stent implantation after balloon dilation of coronary arteries has improved clinical prognosis in patients undergoing transluminal coronary angioplasty (PTCA), but late restenosis remains a relevant problem. A previous study has indicated that PAI-1 activity changes immediately after PTCA without stent implantation are predictive of clinical restenosis. The present study was aimed to investigate the early PAI-1 changes and fibrin formation in patients undergoing elective PTCA with stent implantation. PAI-1 activity and D-dimer plasma levels were evaluated in two groups of patients (G1 underwent only elective balloon PTCA and G2 underwent elective PTCA with stent implantation) before and after the procedure. At the end of the procedure, PAI-1 activity significantly decreased, while D-dimer levels significantly increased in both groups. Post-PTCA D-dimer levels in the group with stent implantation were significantly higher than in the other group (P<.05). In both groups of patients, the post-PTCA PAI-1 activity was higher in patients with subsequent clinical recurrence with restenosis (P<.005 in G1 and P<.0005 in G2) than in those without, whereas no differences were found in D-dimer levels. In conclusion, our results demonstrate that fibrin formation assessed by D-dimer levels is enhanced by stent implantation. However, this behaviour is not related, differently from PAI-1 changes, to subsequent occurrence of clinical restenosis.

Lipoprotein (a) and anticardiolipin antibodies are risk factors for clinically relevant restenosis after elective balloon percutaneous transluminal coronary angioplasty.

Recent reports have shown the importance of new risk factors for cardiovascular disease. We investigated the relationship between Lp(a), fibrinolytic parameters and anticardiolipin antibodies (aCL) and the occurrence of clinical recurrence owing to restenosis after elective balloon percutaneous transluminal coronary angioplasty (PTCA) without stenting. In 167 patients, undergoing PTCA, Lp(a) plasma levels, aCL, euglobulin lysis time (ELT), plasminogen activator inhibitor-1 (PAI-1) activity and tissue-type plasminogen activator (t-PA) plasma levels were evaluated before the procedure. During follow-up 29 patients underwent clinical recurrence due to restenosis. Lp(a) levels were significantly higher in patients with restenosis in comparison to those without (P<0.05); an earlier restenosis was observed in patients with Lp(a) values >450 mg/L. Kaplan-Meier survival estimate showed an earlier occurrence of restenosis in patients with base-line Lp(a)>300 mg/l associated with aCL positivity. High Lp(a) plasma levels play a role in the occurrence of clinical recurrence due to restenosis after elective balloon PTCA without stenting; the association with aCL accelerates the development of restenosis.

The pre-procedural platelet state predicts clinical recurrence after coronary angioplasty.

Percutaneous transluminal coronary angioplasty is an established therapy for coronary artery disease, but restenosis still occurs at a rate of 25%-40%. The aim of this study was to investigate the acute effect of percutaneous transluminal coronary angioplasty on platelet function and the relationship between platelet function and clinical recurrence. Spontaneous platelet aggregation was assessed before and after successful coronary angioplasty in 155 patients (120 men, 35 women). Patients were followed for a mean time of 20 months; follow-up angiography was performed only in patients with clinical recurrence. In 122 of 155 patients (79%) a significant increase in spontaneous platelet aggregation was observed immediately after coronary angioplasty. Baseline spontaneous platelet aggregation in platelet-rich plasma was significantly lower in patients with clinical recurrence than in those without (P<0.05). Kaplan-Meier event-free survival estimate showed a significant difference in clinical recurrence between patients with spontaneous platelet aggregation in platelet-rich plasma below and above the first quintile (P<0.05) with a relative risk of 2.5. In conclusion. these results indicate that percutaneous transluminal coronary angioplasty enhances spontaneous platelet aggregation and that the platelet state before coronary angioplasty affects the risk of clinical recurrence after the procedure.

The influence of smoking on von Willebrand factor is already manifest in healthy adolescent females: the Floren-teen (Florence Teenager) Study.

The early onset of atherosclerosis and the involvement of physiological biochemical, and environmental factors in its pathogenesis is well documented. Few data are available on the role of risk factors related to hemostasis in the pathogenesis of atherosclerosis in the young and, in particular, little information is available on adolescent populations. In the Study of Preventive Medicine and Education Program (Floren-teen Study), von Willebrand factor, a risk factor for cardiovascular disorder, was studied, together with classical cardiovascular risk factors, in apparently healthy students from two high schools in Florence. Familial and personal history, physical examination, and cardiovascular risk factors were evaluated in 144 students (aged 17-19 years). Blood was withdrawn to assess von Willebrand factor (ELISA) and lipid parameters. Levels of von Willebrand factor were significantly higher (P<0.044) in smokers than in nonsmokers and were correlated with the number of cigarettes per day in the whole group (P=0.01) and in females (P=0.006). In females a positive correlation was observed between von Willebrand factor and high-density lipoprotein cholesterol (P=0.0365). There was no significant correlation between von Willebrand factor and blood pressure or between von Willebrand factor and physical activity. In conclusion, this study shows an association between levels of von Willebrand factor and smoking habits and is the first show that even a brief period of smoking affects levels of von Willebrand factor in healthy adolescent females independently of other risk factors. These results stress the relevance of extending prevention programs to reduce smoking in high school students.

Elevated tissue factor and tissue factor pathway inhibitor circulating levels in ischaemic heart disease patients.

Several studies have shown that thrombosis and inflammation play an important role in the pathogenesis of Ischaemic Heart Disease (IHD). In particular, Tissue Factor (TF) is responsible for the thrombogenicity of the atherosclerotic plaque and plays a key role in triggering thrombin generation. The aim of this study was to evaluate the TF/Tissue Factor Pathway Inhibitor (TFPI) system in patients with IHD. We have studied 55 patients with IHD and not on heparin [18 with unstable angina (UA), 24 with effort angina (EA) and 13 with previous myocardial infarction (MI)] and 48 sex- and age-matched healthy volunteers, by measuring plasma levels of TF, TFPI, Prothrombin Fragment 1-2 (F1+2), and Thrombin Antithrombin Complexes (TAT). TF plasma levels in IHD patients (median 215.4 pg/ml; range 72.6 to 834.3 pg/ml) were significantly (p<0.001) higher than those found in control subjects (median 142.5 pg/ml; range 28.0-255.3 pg/ml). Similarly, TFPI plasma levels in IHD patients were significantly higher (median 129.0 ng/ml; range 30.3-316.8 ng/ml; p<0.001) than those found in control subjects (median 60.4 ng/ml; range 20.8-151.3 ng/ml). UA patients showed higher amounts of TF and TFPI plasma levels (TF median 255.6 pg/ml; range 148.8-834.3 pg/ml; TFPI median 137.7 ng/ml; range 38.3-316.8 ng/ml) than patients with EA (TF median 182.0 pg/ml; range 72.6-380.0 pg/ml; TFPI median 115.2 ng/ml; range 47.0-196.8 ng/ml) and MI (TF median 213.9 pg/ml; range 125.0 to 341.9 pg/ml; TFPI median 130.5 ng/ml; range 94.0-207.8 ng/ml). Similar levels of TF and TFPI were found in patients with mono- or bivasal coronary lesions. A positive correlation was observed between TF and TFPI plasma levels (r = 0.57, p<0.001). Excess thrombin formation in patients with IHD was documented by TAT (median 5.2 microg/l; range 1.7-21.0 microg/l) and F1+2 levels (median 1.4 nmol/l; range 0.6 to 6.2 nmol/l) both significantly higher (p<0.001) than those found in control subjects (TAT median 2.3 microg/l; range 1.4-4.2 microg/l; F1+2 median 0.7 nmol/l; range 0.3-1.3 nmol/l). As in other conditions associated with cell-mediated clotting activation (cancer and DIC), also in IHD high levels of circulating TF are present. Endothelial cells and monocytes are the possible common source of TF and TFPI. The blood clotting activation observed in these patients may be related to elevated TF circulating levels not sufficiently inhibited by the elevated TFPI plasma levels present.