CANG and preoperative use of beta-blockers in patients with stable angina are associated with better cardiovascular survival

Abstract Objective: In contrast to unstable angina, optimal therapy in patients with stable angina is debated. Our aim was to evaluate the outcomes of patients with stable angina scheduled for isolated coronary artery bypass grafts and the effect of preoperative use of beta-blockers. Overall and cardiovascular survivals were our primary outcome. Operative mortality and postoperative complications along with subgroup analysis of diabetic patients were our secondary outcomes. Methods: Retrospective evaluation of patients with stable angina scheduled for isolated coronary artery bypass grafts was included. Pre- and postoperative variables were extracted from the institution database. Survival was obtained from the National Registry. Results: We included 282 patients with stable angina, with a mean age of 65.6±9.5 years. 26.6% were female and 38.7% had diabetes. Three-vessel disease was present in 76.6% of patients. Previous beta-blocker treatment was evident in 69.9% of patients. 10-year overall survival in the whole population was 60.5% (95% confidence interval [CI]: 50.3-70.7%). Operative mortality during the study period was 3.5%. Patients with preoperative use of beta-blocker therapy had better overall survival (9.0 years, 95%CI: 8.6-9.5) than those without treatment (7.9 years, 95%CI: 7.1-8.8 years; P=0.048). Predictors for overall survival were: hypertension, diabetes, and age. Predictors for cardiovascular survival in diabetic patients were: beta-blocker use, gender, and age. Conclusion: Coronary artery bypass grafts surgery in patients with stable angina carries low operative mortality, postoperative complications, and excellent long-term cardiovascular survival. The preoperative use of beta-blockers in diabetic patients is associated with better cardiovascular survival after coronary artery bypass grafts.

Effect of salbutamol on pulmonary responsiveness in chronic pulmonary allergic inflammation in guinea pigs

Beta-2-agonists have been widely used by asthmatic subjects to relieve their obstructive symptoms. However, there are reports that continuous use could lead to loss of bronchial protection and exacerbation of asthma symptoms. We evaluated the effect of two regimens of salbutamol administration (twice and five times a week) in a model of chronic airway inflammation in male Hartley guinea pigs (protocol starting weight: 286 ± 30 g) induced by repeated exposures to aerosols of ovalbumin (OVA). After sensitization, guinea pigs were exposed to aerosols of 0.1 mg/ml salbutamol solution twice a week (OVA + S2x, N = 7) or five times a week (OVA + S5x, N = 8). We studied allergen-specific (OVA inhalation time) and -nonspecific (response to methacholine) respiratory system responsiveness. Seventy-two hours after the last OVA challenge, guinea pigs were anesthetized and tracheostomized, respiratory system resistance and elastance were measured and a dose-response curve to inhaled methacholine chloride was obtained. Specific IgG1 was also quantified by the passive cutaneous anaphylactic technique. OVA-sensitized guinea pigs (N = 8) showed reduction of the time of OVA exposure before the onset of respiratory distress, at the 5th, 6th and 7th exposures (P < 0.001). The OVA + S2x group (but not the OVA + S5x group) showed a significant increase in OVA inhalation time. There were no significant differences in pulmonary responsiveness to methacholine among the experimental groups. OVA + S2x (but not OVA + S5x) animals showed a decrease in the levels of IgG1-specific anaphylactic antibodies compared to the OVA group (P < 0.05). Our results suggest that, in this experimental model, frequent administration of ß2-agonists results in a loss of some of their protective effects against the allergen.

Tratamiento del asma / Treatment of asthma

En el presente trabajo revisamos el tratamiento actual del asma bronquial, proponiendo clasificación simple para catalogarla de acuerdo a la intensidad del cuadro tanto crónico como agudo. El objetivo de esta revisión es enfocar nuestros esfuerzos hacia un buen control ambiental, sobre todo intradomiciliario. En el proceso agudo recomendar el manejo de broncodilatadores principalmente por vía inhalada, por su rápida acción y para limitar sus efectos colaterales; siempre usarlos por razón necesaria, sin olvidar que durante la crisis hay inflamación importante, existiendo la posibilidad en cuadros de estado de mal asmático. Finalmente recalcar la importancia del manejo a largo plazo con el uso de antiinflamatorios tópicos

Efeito do agonismo e antagonismo betadrenérgico sobre a homeostase extra-renal de potássio na insuficiência renal crônica terminal / Effect of beta adrenergic agonism and antagonism on potassium extrarenal potassium homeostasis in terminal chronic renal failure

O efeito da estimulaçäo beta-2 adrenérgica com terbutalina sobre a homeostase do potássio foi examinado em seis pacientes com insuficiência renal crônica mantidos em hemodiálise. Os pacientes foram estudados em três situaçöes diferentes: infusäo de terbutalina isoladamente, infusäo de terbutalina precedida de propranolol e infusäo de terbutalina precedida de metoprolol. A concentraçäo inicial de potássio sérico foi significativamente menor no primeiro estudo, quando comparada ao segundo (4,7 ñ 0,7 vs 5,6 ñ 0,6 mmol/l, p < 0,05). Durante o primeiro estudo, a concentraçäo sérica do potássio reduziu-se de 4,7 ñ 0,7 para 3,3 ñ 0,7 mmol/l (p < 0,01). No segundo estudo, a concentraçäo de potássio näo variou. Em contraste, no terceiro estudo, ela reduziu-se de 5,3 ñ 0,7 para 4,2 ñ 0,8 mmol/l (p < 0,01), sendo essa reduçäo significativamente menor que aquela observada no primeiro estudo (29,9 ñ 7,1 vs 21 ñ 6,4 por cento, p < 0,05). Esses resultados sugerem que o manejo extra-renal do potássio é mediado por receptores beta-2. Desde que houve elevaçäo do potássio sérico quando os pacientes receberam propranolol, os autores sugerem que pacientes com insuficiência renal crônica candidatos ao uso de betabloqueadores devam receber preferencialmente um betabloqueador beta-I específico. Os autores concluem ainda que a estimulaçäo betadrenérgica com terbutalina é um método rápido, seguro e eficaz na reduçäo do potássio sérico, desde que os pacientes näo estejam recebendo droga betabloqueadora näo específica