Remote ischemic preconditioning in myocardial protection in hemodialysis patients.

BACKGROUND: Remote ischemic preconditioning (RIPC) is a procedure that generates a brief period of ischemia followed by reperfusion. The role of RIPC in protecting myocardial ischemia during hemodialysis is not yet established. The aim of the study was to evaluate RIPC myocardial protection as evaluated by ultrasensitive I troponin in hemodialysis outpatients. PATIENTS AND METHODS: A double-blind randomized trial with two groups: intervention submitted to RIPC and control group without RIPC. Intervention group received RIPC in three consecutive hemodialysis sessions. Blood samples were taken before and after each session. Blood urea nitrogen for calculation of single-pool Kt/v and ultrasensitive I troponin were measured to evaluate dialysis adequacy and myocardial injury. RESULTS: A total of 47 patients were randomized. About 60.8% were men and 54% were diabetic. The mean single-pool Kt/v was 1.51 in the intervention group and 1.49 in control. The ultrasensitive troponin I measured no significant change from the time of collection: before or after dialysis. CONCLUSION: The RIPC applied in three consecutive sessions did not demonstrate superiority to control, therefore another study tested RIPC in 12 consecutive sessions with a positive result in myocardial protection. In our study, more than half of the patients were diabetic. Diabetic patients have a trend to show a lower response to RIPC because of the greater presence of collateral coronary circulation. In summary, in this model there was no interference of RIPC in ultrasensitive troponin I values, but troponin had a high negative predictive value for myocardial infarction in all tested models.

Obstructive sleep apnea syndrome and sleep quality in hypertensive patients / Síndrome da apneia obstrutiva do sono e qualidade do sono em hipertensos

Summary Introduction: Obstructive sleep apnea and hypopnea syndrome (OSAHS) is one of the developmental factors of high blood pressure (HBP), a relevant global public health problem. OSAHS is characterized by the reduction or complete cessation of respiratory airflow due to intermittent airway collapse. Additionally, significant changes in sleep rhythm and pattern are observed in these patients. Objective: To evaluate the association between OSAHS and sleep quality in essential and resistant hypertensives. Method: A cross-sectional, observational study evaluated 43 hypertensive patients treated at the outpatient clinics of the Faculdade de Medicina do ABC (FMABC) who were medicated with two or more antihypertensive drugs and divided into nonresistant or resistant to treatment. Results: Group I (using up to two antihypertensive agents - 60.47% of the sample) presented mean systolic blood pressure (SBP) of 127.5±6.4 mmHg, mean diastolic blood pressure (DBP) of 79.6±5.2 mmHg, mean body mass index (BMI) of 27.2±5.3 kg/m2 and mean age of 51.2±15.1 years. Group II (using more than two antihypertensive drugs - 37.2% of the sample) presented mean SBP of 132.1±9.3 mmHg, mean DBP of 84.5±5.8 mmHg, mean BMI of 27.2±7.2 kg/m2 and mean age of 55.5±13.4 years. The patients presented low quality of sleep/sleep disorder evaluated by the Pittsburgh Sleep Quality Index (PSQI), which represents a preponderant factor for OSAHS. Conclusion: Patients at high risk for OSAHS had poor sleep quality and high levels of DBP, suggesting a causal relation between these parameters. However, they did not present a higher prevalence of resistant high blood pressure (RHBP).

Resumo Introdução: A síndrome da apneia e a hipopneia obstrutiva do sono (SAHOS) estão inseridas entre os fatores de desenvolvimento da hipertensão arterial sistêmica (HAS), um relevante problema de saúde pública mundial. A SAHOS é caracterizada pela redução ou cessação completa do fluxo aéreo respiratório, decorrente do colapso intermitente das vias respiratórias. Adicionalmente, observam-se nos pacientes importantes alterações no ritmo e padrão do sono. Objetivo: Avaliar a associação entre SAHOS e qualidade de sono em hipertensos essenciais e resistentes. Método: Estudo observacional, transversal avaliou 43 pacientes hipertensos provenientes dos ambulatórios da Faculdade de Medicina do ABC (FMABC) medicados com dois ou mais anti-hipertensivos, divididos em não resistentes ou resistentes ao tratamento. Resultados: Grupo I (que utilizava até dois anti-hipertensivos - 60,47% da amostra) apresentou pressão arterial sistêmica (PAS) média de 127,5±6,4 mmHg, pressão arterial diastólica (PAD) média de 79,6±5,2 mmHg, índice de massa corpórea (IMC) médio de 27,2± 5,3 kg/m2 e idade média de 51,2±15,1 anos. Grupo II (que utilizava mais que dois anti-hipertensivos - 37,2% da amostra) apresentou PAS média de 132,1±9,3 mmHg, PAD média de 84,5±5,8 mmHg, IMC médio de 27,2±7,2 kg/m2 e idade média de 55,5±13,4 anos. Os pacientes apresentaram baixa qualidade de sono/distúrbio do sono avaliada pelo PSQI, o que representa um fator preponderante para SAHOS. Conclusão: Os pacientes com alto risco para SAHOS tiveram pior qualidade de sono e elevados níveis de PAD, sugerindo uma relação causal entre esses parâmetros. Contudo, não apresentaram maior prevalência de hipertensão arterial resistente.

Obstructive sleep apnea syndrome and sleep quality in hypertensive patients.

INTRODUCTION: Obstructive sleep apnea and hypopnea syndrome (OSAHS) is one of the developmental factors of high blood pressure (HBP), a relevant global public health problem. OSAHS is characterized by the reduction or complete cessation of respiratory airflow due to intermittent airway collapse. Additionally, significant changes in sleep rhythm and pattern are observed in these patients. OBJECTIVE: To evaluate the association between OSAHS and sleep quality in essential and resistant hypertensives. METHOD: A cross-sectional, observational study evaluated 43 hypertensive patients treated at the outpatient clinics of the Faculdade de Medicina do ABC (FMABC) who were medicated with two or more antihypertensive drugs and divided into nonresistant or resistant to treatment. RESULTS: Group I (using up to two antihypertensive agents - 60.47% of the sample) presented mean systolic blood pressure (SBP) of 127.5±6.4 mmHg, mean diastolic blood pressure (DBP) of 79.6±5.2 mmHg, mean body mass index (BMI) of 27.2±5.3 kg/m2 and mean age of 51.2±15.1 years. Group II (using more than two antihypertensive drugs - 37.2% of the sample) presented mean SBP of 132.1±9.3 mmHg, mean DBP of 84.5±5.8 mmHg, mean BMI of 27.2±7.2 kg/m2 and mean age of 55.5±13.4 years. The patients presented low quality of sleep/sleep disorder evaluated by the Pittsburgh Sleep Quality Index (PSQI), which represents a preponderant factor for OSAHS. CONCLUSION: Patients at high risk for OSAHS had poor sleep quality and high levels of DBP, suggesting a causal relation between these parameters. However, they did not present a higher prevalence of resistant high blood pressure (RHBP).

Cardioprotection conferred by exercise training is blunted by blockade of the opioid system.

OBJECTIVES: To investigate the effect of opioid receptor blockade on the myocardial protection conferred by chronic exercise and to compare exercise training with different strategies of myocardial protection (opioid infusion and brief periods of ischemia-reperfusion) preceding irreversible left anterior descending coronary ligation. INTRODUCTION: The acute cardioprotective effects of exercise training are at least partly mediated through opioid receptor-dependent mechanisms in ischemia-reperfusion models. METHODS: Male Wistar rats (n = 76) were randomly assigned to 7 groups: (1) control; (2) exercise training; (3) morphine; (4) intermittent ischemia-reperfusion (three alternating periods of left anterior descending coronary occlusion and reperfusion); (5) exercise training+morphine; (6) naloxone (a non-selective opioid receptor blocker) plus morphine; (7) naloxone before each exercise-training session. Myocardial infarction was established in all groups by left anterior descending coronary ligation. Exercise training was performed on a treadmill for 60 minutes, 5 times/week, for 12 weeks, at 60% peak oxygen (peak VO2). Infarct size was histologically evaluated. RESULTS: Exercise training significantly increased exercise capacity and ΔVO2 (VO2 peak - VO2 rest) (p < 0.01 vs. sedentary groups). Compared with control, all treatment groups except morphine plus naloxone and exercise training plus naloxone showed a smaller infarcted area (p < 0.05). No additional decrease in infarct size occurred in the exercise training plus morphine group. No difference in myocardial capillary density (p = 0.88) was observed in any group. CONCLUSIONS: Exercise training, morphine, exercise training plus morphine and ischemia-reperfusion groups had a smaller infarcted area than the control group. The effect of chronic exercise training in decreasing infarct size seems to occur, at least in part, through the opioid receptor stimulus and not by increasing myocardial perfusion.

Effect of exercise training on plasma levels and functional properties of high-density lipoprotein cholesterol in the metabolic syndrome.

Intense lifestyle modifications can change the high-density lipoprotein (HDL) cholesterol concentration. The aim of the present study was to analyze the early effects of short-term exercise training, without any specific diet, on the HDL cholesterol plasma levels and HDL functional characteristics in patients with the metabolic syndrome (MS). We studied 30 sedentary subjects, 20 with and 10 without the MS. The patients with the MS underwent moderate intensity exercise training for 3 months on bicycle ergometers. Blood was sampled before and after training for biochemical analysis, paraoxonase-1 activity, and HDL subfraction composition and antioxidative capacity. Lipid transfer to HDL was assayed in vitro using a labeled nanoemulsion as the lipid donor. At baseline, the MS group had greater triglyceride levels and a lower HDL cholesterol concentration and lower paraoxonase-1 activity than did the controls. Training decreased the plasma triglycerides but did not change the low-density lipoprotein or HDL cholesterol levels. Nonetheless, exercise training increased the HDL subfractions' antioxidative capacity and paraoxonase-1 activity. After training, the MS group had compositional changes in the smallest HDL subfractions associated with increased free cholesterol and cholesterol ester transfers to HDL, reaching normal values. In conclusion, the present investigation has added relevant information about the dissociation between the quantitative and qualitative aspects of HDL after short-term exercise training without any specific diet in those with the MS, highlighting the importance of evaluating the functional aspects of the lipoproteins, in addition to their plasma levels.

Cardioprotection conferred by exercise training is blunted by blockade of the opioid system

OBJECTIVES: To investigate the effect of opioid receptor blockade on the myocardial protection conferred by chronic exercise and to compare exercise training with different strategies of myocardial protection (opioid infusion and brief periods of ischemia-reperfusion) preceding irreversible left anterior descending coronary ligation. INTRODUCTION: The acute cardioprotective effects of exercise training are at least partly mediated through opioid receptor-dependent mechanisms in ischemia-reperfusion models. METHODS: Male Wistar rats (n = 76) were randomly assigned to 7 groups: (1) control; (2) exercise training; (3) morphine; (4) intermittent ischemia-reperfusion (three alternating periods of left anterior descending coronary occlusion and reperfusion); (5) exercise training+morphine; (6) naloxone (a non-selective opioid receptor blocker) plus morphine; (7) naloxone before each exercise-training session. Myocardial infarction was established in all groups by left anterior descending coronary ligation. Exercise training was performed on a treadmill for 60 minutes, 5 times/week, for 12 weeks, at 60 percent peak oxygen (peak VO2). Infarct size was histologically evaluated. RESULTS: Exercise training significantly increased exercise capacity and ΔVO2 (VO2 peak - VO2 rest) (p<0.01 vs. sedentary groups). Compared with control, all treatment groups except morphine plus naloxone and exercise training plus naloxone showed a smaller infarcted area (p<0.05). No additional decrease in infarct size occurred in the exercise training plus morphine group. No difference in myocardial capillary density (p = 0.88) was observed in any group. CONCLUSIONS: Exercise training, morphine, exercise training plus morphine and ischemia-reperfusion groups had a smaller infarcted area than the control group. The effect of chronic exercise training in decreasing infarct size seems to occur, at least in part, through the opioid receptor stimulus and not by increasing ...

Ezetimiba: farmacocinética e terapêutica / Ezetimibe: pharmacokinetics and therapeutics

Ezetimiba é um inibidor da absorção do colesterol que é glucuronidado no fígado após sua rápida absorção nos enterócitos, onde juntamente com os seus metabólitos, exerce as suas ações hipolipidêmicas, reduzindo a absorção do colesterol através da inibição do transporte do colesterol por enzimas transportadoras específicas. Esta droga pode ser utilizada uma vez ao dia, em função de sua meia-vida plasmática prolongada e normalmente é muito bem tolerada. A eliminação da ezetimiba e de seus metabólitos é feita principalmente pela excreção fecal. Em geral, o uso da ezetimiba isolada promove modestos efeitos no LDL plasmático, entretanto, quando combinada às estatinas, importantes mudanças no perfil lipídico podem ser observadas.

[Ezetimibe--pharmacokinetics and therapeutics]. / Ezetimiba--farmacocinética e terapêutica.

Ezetimibe is an inhibitor of cholesterol absorption that is liver glucuronized after its rapid absorption, and is mobilized to the enterocytes, where together with its metabolites it exerts hypolipidemic effects, avoiding the absorption of cholesterol, through the reduction of specific cholesterol-transporter enzymes in the gut. This drug can be given once daily due to its prolonged plasma half-life, and is usually very well-tolerated. Elimination of ezetimibe and its metabolites is mainly via fecal excretion. In general, the use of ezetimibe alone promotes modest effects on plasma LDL-c, however, when combined with statins, a remarkable change in the lipid profile can be observed.

Cirurgia näo-cardíaca no idoso: Avaliaçäo do risco e recomendaçöes / Non cardic surgery in the elderly: risk evaluation and recommendations

Estima-se que das cirurgias gerais realizadas anualmente, 3% iräo apresentar problemas relacionados com o sistema cardiovascular, sendo que este índice é mais relevante nos idosos. O envelhecimento dos orgäos, as doenças crônicas e as seqüelas adquiridas, associadas à diminuiçäo da reserva orgânica, explicam o incremento da morbimortalidade nesta faixa etária. Para diminuir o risco, säo fundamentais a avaliaçäo pré-operatória e controles intra e pós-operatórios adequados, considerando-se as peculiaridades inerentes aos gerontes. A atuaçäo do clínico se destaca nos períodos pré e pós-operatório, particularmente no controle da isquemia miocárdica e da insuficiência cardíaca

Infarct-sparing effect of propranolol in an occlusion-reperfusion dog model

To test the hypothesis that early pharmacological protection of the ischemic myocardium can enhance the effects of late reperfusion, 32 mongrel dogs were submitted to 6 h of left anterior descending coronary (LAD) occlusion and 18 h of reperfusion. Arterial pressure and ECG were monitored. Area at risk was determined with methylene blue during coronary occlusion. Myocardial infarct size, measured with triphenyl tetrazolium chloride and by planimetry, was reported as percent of the area at risk of necrosis. Ten dogs received no treatment and were used as controls (Group I); Group II (9 dogs) and Group III (13 dogs) received 2.0 and 4.0 mg/kg propranolol, iv, respectively, 30 min after LAD occlusion. The hemodynamic effects of propranolol were not significantly different among groups during ischemia or reperfusion. Area at risk was similar in the 3 groups. Following reperfusion, salvage of ischemic myocardium was 13 + or - 3% of area at risk in Group I, and 18 + or - 8% (Group II) and 25 + or - 5% (Group III) in propranolol-treated animals. The differences between Groups I and II or II and III were not significant. However, preservation was significantly greater in Group III than in Group I (P<0.05). Therefore, early propranolol administration during ischemia improves the effects of subsequent reperfusion

Lack of correlation between anatomic infarct size and ventriculographic variables following coronary occlusion in closed-chest dogs

1. Although the effects of therapeutic interventions upon infarct size are frequently assessed on the basis of left ventricular ejection fraction and segmental contraction, the correlation of these variables with infarct size has not been thoroughly evaluated. To explore such relationship, we occluded the left antior descending coronary artery of 22 closed-chest dogs and performed contrast ventriculography one week later. Regional myocardial functionwas evaluated by a computer in 60 radial segments. 2. Infarct size, measured by triphenyl-tetrazolium chloride staining, ranged 1.4 to 43.6% of the left ventricle. Infarcted dogs were arbitrarily divided into 3 groups by percentage of necrotic area: Group 1 (< ou = 15%, N = 5), Group 2 (15 to 30%, N = 10) and Group 3 (> ou = 30%, N = 7). 3. Although the ejection fraction was significantly reduced in infarcted animals as compared to preselected normal controls (38.9 ñ 11.6 [SD] vs 74.1 ñ 7.5%, P < 0.001), it was similar within each infarct subgroup. 4. There was a linear inverse correlation between ejection fraction and percentage of abnormally contractiong segments ( R = -0.63, - = 0.0017). However, neither ejection fraction nor abnormally contracting segments were correlated with infarct size (R = 0.17 and R = 0.11, respectively). 5. A more detailed analysis revealed that infarcted or infarct-adjacent segments were less depressed in Group 1 than in Group 2 or 3 and extent of depression was similar between Groups 2 and 3. Conversely, the extent of shortening of non- infarcted inferior wall segments increased from Group 1 to Group 3. 6. Thus, regional myocardial contration is significantly affected by non-necrotic infarct-adjacent segments and the ejection fraction is significantly influenced by non-ischemic myocardium. For infarcted areas up to 40% of the left ventricle, a single post-infarction determination of ejection fraction or the percentual of abnormally contracting segments seems unreliable, on a population basis, to judge the effects of infarct-sparing interventions