Abstract Introduction Coronary artery bypass grafting (CABG) surgery is associated with a decline in ventilatory muscle strength and lung function. Inspiratory muscle training (IMT) based on anaerobic threshold (AT) has been used to minimize the impact of CABG on these parameters, but the long-term impact is unknown. Objective To test the hypothesis that AT-based IMT improves inspiratory muscle strength and lung function even six months after CABG. Methods This is a randomized controlled clinical trial. In the preoperative period, maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), vital capacity (VC) and peak expiratory flow (PEF) rate were assessed. On the first postoperative day, patients were randomized into two groups: AT-based IMT (IMT-AT) (n=21) where the load was prescribed based on glycemic threshold and conventional IMT (IMT-C) (n=21), with load of 40% of MIP. Patients were trained during hospitalization until the day of discharge and were assessed at discharge and six months later. For within-group comparison, paired Student's t-test or Wilcoxon test was used, and independent Student's t-test or the Mann-Whitney test was used to analyze the different time points. A p<0.05 was considered significant. Results At six months after CABG surgery, statistical difference was found between the IMT-AT and the IMT-C groups in MIP (difference between the means of -5cmH2; 95% CI=- 8.21to-1.79) and VC (difference between the means of -2ml/kg;95%CI=-3.87to-0.13). No difference was found between groups in the other variables analyzed. Conclusion IMT-AT promoted greater recovery of inspiratory muscle strength and VC after six months of CABG when compared to conventional training.

Abstract Background The European Heart Surgery Risk Assessment System (EuroSCORE) and InsCor have been used to predict complications of cardiac surgery. However, their application to predict lung function and functionality is still uncertain. Objective To correlate surgical risk scales with functional independence and pulmonary function in patients undergoing coronary artery bypass grafting. Methods This was a prospective cohort study. In the preoperative period, the two surgical scales were applied, the maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and peak expiratory flow (PEF) were measured, and functionality was assessed using the functional independence measure (FIM). On the seventh postoperative day, the pulmonary function and functionality variables were reevaluated, compared with the preoperative values (delta) and correlated with the risk scales. Correlations of pulmonary function, functional independence and muscle strength variables with the surgical scales were made by Pearson correlation test. The significance level adopted was 5%. Results Thirty-one patients were studied; most were male (77%), with a mean age of 56±8 years. Mean EuroSCORE was 2.3±0.5 and mean InsCOR was 1.2±0.5. MIP, MEP, and PEF reduced 30% (p<0.001), 33% (p<0.001) and 10% (p=0.23), respectively. The EuroSCORE correlated with MIP (r-0.78; p = 0.02) and FIM (r-0.79; p <0.01), and the InsCor correlated with MIP (r-0.77), MEP (r-0.73) and MIF (r-0.89; p=0.02). Conclusion The EuroSCORE showed a strong negative correlation with MIP and FIM, while InsCor had a strong negative correlation with MIP, MEP and FIM. (Int J Cardiovasc Sci. 2020; [online].ahead print, PP.0-0)

Abstract Introduction: Cardiac surgery is a highly complex procedure which generates worsening of lung function and decreased inspiratory muscle strength. The inspiratory muscle training becomes effective for muscle strengthening and can improve functional capacity. Objective: To investigate the effect of inspiratory muscle training on functional capacity submaximal and inspiratory muscle strength in patients undergoing cardiac surgery. Methods: This is a clinical randomized controlled trial with patients undergoing cardiac surgery at Instituto Nobre de Cardiologia. Patients were divided into two groups: control group and training. Preoperatively, were assessed the maximum inspiratory pressure and the distance covered in a 6-minute walk test. From the third postoperative day, the control group was managed according to the routine of the unit while the training group underwent daily protocol of respiratory muscle training until the day of discharge. Results: 50 patients, 27 (54%) males were included, with a mean age of 56.7±13.9 years. After the analysis, the training group had significant increase in maximum inspiratory pressure (69.5±14.9 vs. 83.1±19.1 cmH2O, P=0.0073) and 6-minute walk test (422.4±102.8 vs. 502.4±112.8 m, P=0.0031). Conclusion: We conclude that inspiratory muscle training was effective in improving functional capacity submaximal and inspiratory muscle strength in this sample of patients undergoing cardiac surgery.