Antihypertensive activity of angiotensin II AT1 receptor antagonists: a systematic review of studies with 24 h ambulatory blood pressure monitoring.

OBJECTIVE: To perform a systematic review of the antihypertensive activity of the angiotensin II AT1 receptor antagonists (ARB). METHODS: Studies in which blood pressure (BP) was measured using ambulatory BP monitoring for at least 24 h were collected from MEDLINE. Data for each treatment group, ARB, placebo or the drug used for its comparison were obtained from the selected studies. Only studies with a minimum of quality criteria were selected. The final study group contained 36 publications, with a total of 47 patient cohorts receiving ARB in monotherapy, 10 with placebo, 10 with amlodipine, and five with enalapril. The reduction in clinical and ambulatory BP during 24 h, day, night and the last 4-h period for each of the drugs analysed were calculated and adjusted by age, sex, number of participants and by the initial BP level. RESULTS: The global antihypertensive activity of ARB differs from that observed with amlodipine in the sense that the magnitude of the reduction in the BP values does not essentially depend on the initial BP values nor on the dose used. When only ARB were considered, the drug used was a determinant for systolic BP reduction, whereas for diastolic BP the influence was on the BP reduction and the duration of the antihypertensive activity. The dose used had a particular influence on the duration of the antihypertensive activity for both systolic and diastolic BP. CONCLUSION: Among the ARB, the influence is on duration more than on the magnitude of BP reduction. Dose, therefore, is an important factor in the duration of antihypertensive activity.

[Factors related to the differences in blood pressure values assessed by auscultatory or oscillometric methods]. / Factores que influyen en la diferencia de medida de presión arterial entre el método auscultatorio y el oscilométrico.

BACKGROUND AND OBJECTIVE: Measurement of blood pressure by using the auscultatory method coupled with mercury sphygmomanometer is rapidly being replaced for monitor using the oscillometric one. Discrepancies between the two methods and the factors related to them were analyzed in a large subset of adults. MATERIAL AND METHOD: Blood pressure values were obtained sequentially in the same arm by using a mercury sphygmomanometer and a Spacelabs monitor devices. The relationship between both kinds of measurements was assessed by the Pearson's correlation coefficients and the concordance by using the Bland and Altman method. Differences between the two methods were calculated and the factors related to the differences were sought by multiple regression models. RESULTS: A total of 1,742 adult subjects were analyzed. Pearson's correlation coefficients were 0.927, 0.922, 0.886, 0.962 for SBP, DBP, MBP and PR, respectively. Oscillometric method overestimate and infraestimate SBP values in the two extreme of SBP values, the lowest SBP the highest the values and vice versa. A similar trend was observed for DBP although the differences were minor. Pulse wave amplitude explains the 24% of the variance observed for SBP and arm circumference the 8% for DBP. CONCLUSIONS: Blood pressure values measured by oscillometric methods are influenced for pulse wave amplitude and by the arm circumference. These need to be taken in account when blood pressure assessment is obtained by using this method.

[Factors related to the risk of thrombosis in patients with lupus and antiphospholipid antibodies]. / Factores relacionados con el riesgo de trombosis en pacientes con lupus y positividad para anticuerpos antifosfolipídicos.

BACKGROUND AND OBJECTIVE: Antiphospholipid antibodies (aPL) are frequently associated with eritematosus systemic lupus (SLE) and increases the risk of thrombosis. The aim of the study was to analize risk factors of thrombosis and its temporal profile in subjects with SLE. PATIENTS AND METHOD: One hundred and two SLE patients -mean age: 37.5 years (range: 8-85); 90 women; mean of follow-up: 72 months (range: 9-324); 41 (40.2%) with aPL positive- were included in the study. Actuarial Kaplan-Meier curves were used to assess the thrombosis risk and Cox proportional hazard model was used to evaluate factors associated with the risk. RESULTS: 13 thrombotic events occurred in the group with aPL positive (mean of follow up: 83.5 months) and 5 events in aPL negative group (mean of follow up: 72 months). The event-rates were 3.93 and 0.96/100 patients/year for each group, respectively. Survival curves showed a significantly higher risk of thrombotic events in the patients with positive aPL as compared to the aPL negative group, and the risk still present throughout the observational time. Activated partial thromboplastine time up to 37 s was significantly associated with thrombosis risk (p = 0.003). Furthermore, positivity of lupus anticoagulant and proteinuria > 2.5 g/day tended to increase thrombotic risk, although they did not achieve statistical significance. CONCLUSIONS: In patients with SLE and aPL, risk of first thrombosis remains over the years, and a large activated partial thromboplastine time was the most important risk factor.