Dario C. Sobral Filho

Exercício físico e o controle da pressão arterial

Physical exercise causes a series of physiological responses resulting from autonomic and hemodynamic adaptation that affect the cardiovascular system. Many studies have demonstrated its beneficial effect on blood pressure. Bearing in mind that hypertension is a very prevalent condition causing high morbidity and mortality rate, the physical exercise plays an important role as a nondrug measure for its control or as an adjuvant to drug treatment.RESUMENEjercicio fisico y el control de la presion arterial El ejercicio fisico provoca una serie de respuesta fisiologicas,resultantes de adaptaciones autonomicas y hemodinamicas quevan a influenciar en el sistema cardiovascular. Diversos estudiosdemonstraron el efecto benefico sobre la presion arterial. Siendoasi, la hipertension arterial sistemica una entidad de alta prevalen-cia y elevada morbi-mortalidad en la poblacion, el ejercicio fisicotiene un papel muy importante como elemento no medicamento-so para su control y como adyuvante al tratamiento farmacologicotambien. INTRODUCAO O exercicio fisico e uma atividade realizada com repeticoes sis-tematicas de movimentos orientados, com consequente aumentono consumo de oxigenio devido a solicitacao muscular, gerando,portanto, trabalho (1) . O exercicio representa um subgrupo de ativi-dade fisica planejada com a finalidade de manter o condicionamen-to (2) . Pode tambem ser definido como qualquer atividade muscularque gere forca e interrompa a homeostase

Prevention of hypertension in patients with pre-hypertension: protocol for the PREVER-prevention trial

BackgroundBlood pressure (BP) within pre-hypertensive levels confers higher cardiovascular risk and is an intermediate stage for full hypertension, which develops in an annual rate of 7 out of 100 individuals with 40 to 50 years of age. Non-drug interventions to prevent hypertension have had low effectiveness. In individuals with previous cardiovascular disease or diabetes, the use of BP-lowering agents reduces the incidence of major cardiovascular events. In the absence of higher baseline risk, the use of BP agents reduces the incidence of hypertension. The PREVER-prevention trial aims to investigate the efficacy, safety and feasibility of a population-based intervention to prevent the incidence of hypertension and the development of target-organ damage.MethodsThis is a randomized, double-blind, placebo-controlled clinical trial, with participants aged 30 to 70 years, with pre-hypertension. The trial arms will be chlorthalidone 12.5 mg plus amiloride 2.5 mg or identical placebo. The primary outcomes will be the incidence of hypertension, adverse events and development or worsening of microalbuminuria and of left ventricular hypertrophy in the EKG. The secondary outcomes will be fatal or non-fatal cardiovascular events: myocardial infarction, stroke, heart failure, evidence of new sub-clinical atherosclerosis, and sudden death. The study will last 18 months. The sample size was calculated on the basis of an incidence of hypertension of 14% in the control group, a size effect of 40%, power of 85% and P alpha of 5%, resulting in 625 participants per group. The project was approved by the Ethics committee of each participating institution.DiscussionThe early use of blood pressure-lowering drugs, particularly diuretics, which act on the main mechanism of blood pressure rising with age, may prevent cardiovascular events and the incidence of hypertension in individuals with hypertension. If this intervention shows to be effective and safe in a population-based perspective, it could be the basis for an innovative public health program to prevent hypertension in Brazil.Trial RegistrationClinical Trials NCT00970931.

Effectiveness of Chlorthalidone Plus Amiloride for the Prevention of Hypertension: The PREVER‐Prevention Randomized Clinical Trial

Background Prehypertension is associated with higher cardiovascular risk, target organ damage, and incidence of hypertension. The Prevention of Hypertension in Patients with PreHypertension (PREVER‐Prevention) trial aimed to evaluate the efficacy and safety of a low‐dose diuretic for the prevention of hypertension and end‐organ damage. Methods and Results This randomized, parallel, double‐blind, placebo‐controlled trial was conducted in 21 Brazilian academic medical centers. Participants with prehypertension who were aged 30 to 70 years and who did not reach optimal blood pressure after 3 months of lifestyle intervention were randomized to a chlorthalidone/amiloride combination pill or placebo and were evaluated every 3 months during 18 months of treatment. The primary outcome was incidence of hypertension. Development or worsening of microalbuminuria, new‐onset diabetes mellitus, and reduction of left ventricular mass were secondary outcomes. Participant characteristics were evenly distributed by trial arms. The incidence of hypertension was significantly lower in 372 study participants allocated to diuretics compared with 358 allocated to placebo (hazard ratio 0.56, 95% CI 0.38–0.82), resulting in a cumulative incidence of 11.7% in the diuretic arm versus 19.5% in the placebo arm (P=0.004). Adverse events; levels of blood glucose, glycosylated hemoglobin, creatinine, and microalbuminuria; and incidence of diabetes mellitus were no different between the 2 arms. Left ventricular mass assessed through Sokolow‐Lyon voltage and voltage‐duration product decreased to a greater extent in participants allocated to diuretic therapy compared with placebo (P=0.02). Conclusions A combination of low‐dose chlorthalidone and amiloride effectively reduces the risk of incident hypertension and beneficially affects left ventricular mass in patients with prehypertension. Clinical Trial Registration URL: http://www.ClinicalTrials.gov, www.ensaiosclinicos.gov. Unique identifiers: NCT00970931, RBR‐74rr6s.

Treadmill stress test in children and adolescents: higher tolerance on exertion with ramp protocol

OBJECTIVE: Compare exercise tolerance by children and adolescents submitted to treadmill stress test (TST) following Bruce Protocol (BP) or Ramp Protocol (RP), as well as describe velocity and inclination reached with ramp protocol to help set protocol exercise standards. METHODS: Observational, case-based study, with history control of 1,006 children and adolescents in the 4 to 17-year-old range who were submitted to TST between October, 1986 and February, 2003, and who concluded one of the two protocols. Those who interrupted their ET for other reasons rather than physical exhaustion, those on medication that interfered in HR and those with physical constraints to exercise were excluded. Statistical analysis of data considered p<0.05 as significance level; with confidence interval at 95%. RESULTS: Exercise time close to 10 minutes in RP was significantly higher than in BP. HR max reached was higher than 180 bpm in both protocols. Inclination showed to be slightly higher in younger girls in Bruce Protocol. Velocity and VO2 max showed to be higher for all age ranges for those in the Ramp Protocol. CONCLUSION: Velocity and inclination reached with ramp protocol may be used as reference to help set ramp protocol exercise, which showed superior on exertion tolerance as compared to Bruce protocol.

A single bout of resistance exercise does not modify cardiovascular responses during daily activities in patients with peripheral artery disease.

ObjectiveTo analyze the posteffects of a single bout of resistance exercise on cardiovascular parameters in patients with peripheral artery disease (PAD). DesignRandomized cross-over. Materials and methodsSeventeen PAD patients performed two experimental sessions: control (C) and resistance exercise (R). Both sessions were identical (eight exercises, 3×10 repetitions), except that the R session was performed with an intensity between 5 and 7 in the OMNI-RES scale and the C session was performed without any load. Systolic blood pressure (BP), diastolic BP, heart rate, and rate–pressure product (RPP) were measured for 1 h after the interventions in the laboratory and during 24-h using ambulatory BP monitoring. ResultsAfter the R session, systolic BP (greatest reduction: −6±2 mmHg, P<0.01) and RPP (greatest reduction: −888±286 mmHg×bpm; P<0.01) decreased until 50 min after exercise. From the second hour until 23 h after exercise, BP, heart rate, and RPP product were similar (P>0.05) between R and C sessions. BP load, nocturnal BP fall, and morning surge were also similar between R and C sessions (P>0.05). ConclusionA single bout of resistance exercise decreased BP and cardiac work for 1 h after exercise under clinical conditions, and did not modify ambulatory cardiovascular variables during 24 h in patients with PAD.

Physical exercise and blood pressure control

Physical exercise causes a series of physiological responses resulting from autonomic and hemodynamic adaptation that affect the cardiovascular system. Many studies have demonstrated its beneficial effect on blood pressure. Bearing in mind that hypertension is a very prevalent condition causing high morbidity and mortality rate, the physical exercise plays an important role as a nondrug measure for its control or as an adjuvant to drug treatment.RESUMENEjercicio fisico y el control de la presion arterial El ejercicio fisico provoca una serie de respuesta fisiologicas,resultantes de adaptaciones autonomicas y hemodinamicas quevan a influenciar en el sistema cardiovascular. Diversos estudiosdemonstraron el efecto benefico sobre la presion arterial. Siendoasi, la hipertension arterial sistemica una entidad de alta prevalen-cia y elevada morbi-mortalidad en la poblacion, el ejercicio fisicotiene un papel muy importante como elemento no medicamento-so para su control y como adyuvante al tratamiento farmacologicotambien. INTRODUCAO O exercicio fisico e uma atividade realizada com repeticoes sis-tematicas de movimentos orientados, com consequente aumentono consumo de oxigenio devido a solicitacao muscular, gerando,portanto, trabalho (1) . O exercicio representa um subgrupo de ativi-dade fisica planejada com a finalidade de manter o condicionamen-to (2) . Pode tambem ser definido como qualquer atividade muscularque gere forca e interrompa a homeostase

Hemodynamic profile of severity at pulmonary vasoreactivity test in schistosomiasis patients

BACKGROUND The pulmonary vasoreactivity rate of Schistosomal Pulmonary Artery Hypertension (SPAH) is not known. Hemodynamic data obtained by cardiac catheterization are associated with the most commonly used clinical criteria of severity. OBJECTIVE To estimate the percentage of positive vasoreactivity to nitric oxide in schistosomal pulmonary arterial hypertension and verify the association of hemodynamic parameters with WHO functional classification and the six-minute walk test in these patients. METHODS A total of 84 patients with schistosomal pulmonary hypertension were selected from a database, who had been submitted to the right and left cardiac catheterization and pulmonary vasoreactivity test with nitric oxide. Data on WHO functional classification and six-minute walk test were collected for comparison with invasive data. RESULTS Of the 84 patients with SPAH, 3 (3.5%) had positive criteria for pulmonary vasoreactivity. The increase in pulmonary vascular resistance was significantly associated with lower exercise capacity measured by the six-minute walk test (p = 0.045) and greater symptom severity by higher functional classifications (WHO class III/IV) (p = 0.013). The decrease in oxygen saturation in the pulmonary artery was significantly associated with higher functional classifications (p = 0.041). CONCLUSION The pulmonary response rate to the vasodilation test of schistosomiasis patients is below the values found for idiopathic pulmonary hypertension. Pulmonary vascular resistance and oxygen saturation in the pulmonary artery are hemodynamic data that can be used as markers of severity in schistosomal pulmonary hypertension.

Low-intensity resistance exercise does not affect cardiac autonomic modulation in patients with peripheral artery disease

OBJECTIVE: To analyze the effect of a single bout of resistance exercise on cardiac autonomic modulation in patients with peripheral artery disease. METHODS: Fifteen patients with peripheral artery disease (age: 58.3±4.0 years) underwent the following sessions in a random order: resistance exercise (three sets of 10 repetitions of the six resistance exercises with a workload of 5–7 in the OMNI-RES scale) and control (similar to the resistance session; however, the resistance exercises were performed with no load). The frequency domain (low frequency, high frequency and sympathovagal balance) and symbolic analysis (0V, 1V and 2V patterns) of heart rate variability were obtained before and until one hour after the interventions. RESULTS: After the resistance exercise and control sessions, similar increases were observed in the consecutive heartbeat intervals (control: 720.8±28.6 vs. 790.9±34.4 ms; resistance exercise: 712.9±30.1 vs. 756.8±37.9 ms; p<0.05) and in the pattern of the symbolic analysis with no variation (0V) (control: 25.1±3.5 vs. 33.4±4.1%; resistance exercise: 26.1±3.2 vs. 29.7±3.5%; p<0.05) until 50 min after both interventions. The pattern of two variations (2V) decreased similarly (control: 11.2±2.1 vs. 8.3±2.1%; resistance exercise: 9.5±1.7 vs. 7.8±1.7%; p<0.05). In contrast, the pattern of one variation (1V), the low and high frequency bands and sympathovagal balance did not change after the interventions (p>0.05). CONCLUSION: A single bout of resistance exercise did not alter cardiac autonomic modulation in patients with peripheral artery disease.

A comparison between diuretics and angiotensin- receptor blocker agents in patients with stage I hypertension (PREVER-treatment trial): study protocol for a randomized double-blind controlled trial

BackgroundCardiovascular disease is the leading cause of death in Brazil, and hypertension is its major risk factor. The benefit of its drug treatment to prevent major cardiovascular events was consistently demonstrated. Angiotensin-receptor blockers (ARB) have been the preferential drugs in the management of hypertension worldwide, despite the absence of any consistent evidence of advantage over older agents, and the concern that they may be associated with lower renal protection and risk for cancer. Diuretics are as efficacious as other agents, are well tolerated, have longer duration of action and low cost, but have been scarcely compared with ARBs. A study comparing diuretic and ARB is therefore warranted.Methods/designThis is a randomized, double-blind, clinical trial, comparing the association of chlorthalidone and amiloride with losartan as first drug option in patients aged 30 to 70 years, with stage I hypertension. The primary outcomes will be variation of blood pressure by time, adverse events and development or worsening of microalbuminuria and of left ventricular hypertrophy in the EKG. The secondary outcomes will be fatal or non-fatal cardiovascular events: myocardial infarction, stroke, heart failure, evidence of new subclinical atherosclerosis and sudden death. The study will last 18 months. The sample size will be of 1200 participants for group in order to confer enough power to test for all primary outcomes. The project was approved by the Ethics committee of each participating institution.DiscussionThe putative pleiotropic effects of ARB agents, particularly renal protection, have been disputed, and they have been scarcely compared with diuretics in large clinical trials, despite that they have been at least as efficacious as newer agents in managing hypertension. Even if the null hypothesis is not rejected, the information will be useful for health care policy to treat hypertension in Brazil.Clinical trials registration numberClinicalTrials.gov: NCT00971165

Nucleated Red Blood Cells as Predictors of All-Cause Mortality in Cardiac Intensive Care Unit Patients: A Prospective Cohort Study

Background The presence of nucleated red blood cells (NRBCs) in the peripheral blood of critically ill patients is associated with a poorer prognosis, though data on cardiovascular critical care patients is lacking. The aim of the present study was to assess the role of NRBCs as a predictor of intensive care unit (ICU) and in hospital all-cause mortality among cardiologic patients. Methods NRBCs were measured daily in consecutive cardiac ICU patients, including individuals with both coronary and non-coronary acute cardiac care. We excluded patients younger than 18 years, with cancer or hematological disease, on glucocorticoid therapy, those that were readmitted after hospital discharge and patients who died in the first 24 hours after admission. We performed a multiple logistic analysis to identify independent predictors of mortality. Results We included 152 patients (60.6 ± 16.8 years, 51.8% female, median ICU stay of 7 [4–11] days). The prevalence of NRBCs was 54.6% (83/152). The presence of NRBC was associated with a higher ICU mortality (49.4% vs 21.7%, P<0.001) as well as in-hospital mortality (61.4% vs 33.3%, p = 0.001). NRBC were equally associated with mortality among coronary disease (64.71% vs 32.5% [OR 3.80; 95%CI: 1.45–10.0; p = 0.007]) and non-coronary disease patients (61.45% vs 33.3% [OR 3.19; 95%CI: 1.63–6.21; p<0.001]). In a multivariable model, the inclusion of NRBC to the APACHE II score resulted in a significant improvement in the discrimination (p = 0.01). Conclusions NRBC are predictors of all-cause in-hospital mortality in patients admitted to a cardiac ICU. This predictive value is independent and complementary to the well validated APACHE II score.