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Oral anticoagulant therapy remains one of the most frequent options for treatment and prevention in patients with arterial and venous thromboembolism. Clinical guidelines have been updated in recent years by various associations such as the American Heart Association (AHA), the American College of Cardiology (ACC) and the European Society of Cardiology (ESC), as well as organizations in several other countries. The authors present a review of therapy with vitamin K antagonists, focusing on their mechanism of action and metabolism, as well as on the fundamentals of such therapy. Clinical recommendations for the most frequent indications are described. One of the most important issues is the use of these drugs for atrial fibrillation therapy, which is a common indication. Prosthetic valvular disease is a compelling indication for anticoagulation, for which there is a broad consensus. Ischemic heart disease is another indication described for oral anticoagulation. Several practical issues in cardiac patients are discussed. These include the appropriate initial dose, schemes for reversal of anticoagulation, and management of surgical patients. Finally, risk factors for deep venous thrombosis and pulmonary embolism are detailed in this review, presenting current clinical recommendations for oral anticoagulation of these patients.

We stimulated human erythrocytes obtained from patients with hypercholesterolemia (HC; n = 42), renal transplantation (RT; n = 18) and hypertension (HT; n = 10) with acetylcholine (ACh 10 microM) and measured the amperometric NO production, comparing with the NO levels achieved on erythrocytes of healthy persons (n = 27). We also measured the hemoglobin, hematocrit, erythrocyte aggregation, erythrocyte deformability, plasma viscosity and fibrinogen concentration from human blood samples. The erythrocytes NO levels were of 2.5 +/- 0.7 nM (P = 0.038, HC), 2.4 +/- 1.1 nM (RT) and 2.2 +/- 0.8 nM (HT) against the 2.0 +/- 0.8 nM for the control groups. For each group and at each shear stress value, the erythrocytes deformability decreases with the increase of the NO concentration after ACh stimulation. We observed a significant increase of the control values on the erythrocyte aggregation results on each patient group. Besides the lower erythrocyte deformability obtained on HC, RT and HT blood samples, the erythrocytes produced higher NO levels after ACh stimulation than the healthy ones. The power of erythrocyte hemorheological behaviour could be compensated by the NO production at the presence of acetylcholine. We can hypothesises that cholinergic drugs could be used as co-adjuvants of specific therapeutics compounds on these studied diseases.

Background and Aim: In hypertensive patients tight blood pressure (BP) control during the critical morning and evening periods may be relevant for preventing cardiovascular events, which most frequently occur at these times of the day., Methods: In a prospective study we evaluated 24h ambulatory BP (ABP) values (24h, daytime, nighttime, morning period between 6-10 am and evening period between 6-10 pm), in 103 hypertensive patients (HTs), aged between 18-79 years, considered to be controlled in the office in the previous two months (office BP < 140/90 mmHg, 2 x 3 readings, before taking medication), who were being treated with antihypertensive drugs taken once daily in the morning. Based on ABP data, HTs were considered to have good BP control if daytime BP values were < 135/85 mmHg, < 133.1/85.4 mmHg during the morning period, and < 138.1/89.3 mmHg during the evening period. Otherwise control of ABP was considered poor. These limits correspond to the upper 95% confidence limits of BP calculated for each period in a normotensive control population of 210 subjects age-matched to the HTs., Results: Of the 103 HTs, 39 were under monotherapy and the remaining 64 on combination regimens (34 with two drugs, 29 with three and one with four). Based on ABP data of the 103 HTs, poor ABP control was observed in 36 (35%) in the morning period, in 24 (23%) in the evening period and in 29 (28%) for daytime BP values. ABP values during both the morning and evening periods correlated significantly with daytime values (r = 0.72 and r = 0.89 respectively, p < 0.01) but not with office values., Conclusions: A significant proportion of treated HTs who are considered to be controlled in the office present abnormally high ABP levels, particularly in the critical early morning period, but also during the evening and throughout the daytime period.

Left ventricular hypertrophy (LVH) is a well-known cardiovascular risk factor. Left ventricular mass reduction following anti-hypertensive treatment has also been demonstrated. However, few prospective and systematic clinical trials have analyzed whether regression of LVH is associated with improved prognosis. Two recently published LIFE substudies consistently show that the greater the reduction of LVH, assessed by ECG or by echocardiography in the setting of a prospective trial of anti-hypertensive treatment, the greater the reduction in cardiovascular event rates, independent of treatment modality and of decreases in blood pressure. These results support LVH regression as a therapeutic target in hypertension.

Stroke is a serious complication associated with hypertension. Because cytochrome P450 1A1 (CYP1A1) is involved in the production of arachidonic acid-derived vasoactive substances, we hypothesized that CYP1A1 functional polymorphisms (linked to changes in enzyme activity) might be related to pathological conditions associated with essential hypertension. We genotyped 32 patients with hypertension for three CYP1A1 polymorphisms, and individuals with or without history of previous stroke were compared. These results were also compared with a control population sample of 152. The distributions of T6235C (m1) CYP1A1 genotypes in patients with (TT: 44.4%;, Tc/cc: 55.6%; n = 9) and without stroke (TT: 82.6%;, Tc/cc: 17.4%; n = 23) indicate that the C allele is associated with stroke (OR = 5.94; 95% C = 1.46 - 24.23). No association was found between the polymorphism studied and essential hypertension. Our results suggest a relationship between CYP1A1 activity and incidence of stroke in patients with essential hypertension, but no conclusion can be drawn regarding an association with essential hypertension.

Introduction: A decrease in blood pressure (BP) 30 to 60 minutes after food ingestion is a physiologic and asymptomatic event, and is about 10 to 16 mm Hg in elderly subjects, but only 3 to 4 mm Hg in youths., Patients and Methods: Sixteen women referred to our hospital with complains of lipothymia were studied. They were compared with a control population of 20 healthy subjects. Clinical, laboratory and electrocardiographic (12 leads and 24 hour "Holter" monitoring) evaluation, and 24 hour BP monitoring were performed. In the BP register, the period between the beginning and until 4 hours after the meal was analysed separately., Results: The systolic and diastolic BP between the two populations was not significantly different (120.6 +/- 14.6 mm Hg and 76.5 +/- 8.9 mm Hg in the study group and 126.8 +/- 10.9 mm Hg and 77.8 +/- 7.2 mm Hg in the controls). The average of the mean BP was also not significantly different (78.7 +/- 11.7 mm Hg vs. 86.8 +/- 5 mm Hg, patients and controls). During the 4 hours after the meal there was a significant decrease (p < 0.01) in the average of the mean BP of the patients, which did not occur in the controls (65.4 +/- 7.3 mm Hg vs. 88.5 +/- 2.5 mm Hg, patients and controls). This postprandial decrease in BP correlated with the patients' symptomatology., Conclusions: Although physiologic in some individuals, the decrease in postprandial BP can be exaggerated and symptomatic. Outpatient BP monitoring can become a useful instrument in the evaluation of syncope/lipothymia.