Validity of Aortic Pulse Wave Velocity in Predicting the 6- Minute Walking Test Before Major Non-cardiac Surgery

Methods: Prospective observational study in adult patients requiring preoperative evaluation Objectives: To determine the correlation between the aortic pulse wave velocity (AoPWV) and the distance walked in the 6-minute walk test (6MWT) Sample Size: For a desired precision of estimate of ± 0.10 (95% confidence interval) around a postulated validity correlation coefficient of r = 0.70 (for an AoPWV in the distance prediction of 6MWT) a sample of 100 patients. By allowing a 25% wear rate, a final sample size of 125 participants is required Inclusion criteria: Patients older than 18 years undergoing any surgery and who require pre-anesthesia Statistical analysis If the variables have a normal distribution, the Pearson correlation coefficient (r2) is used, which is between -1 and 1. Where -1 indicates the highest possible negative linear relationship (increasing the value of a variable decreases the another), 0 that there is no association, +1 positive correlation. From 0.7 negative or positive, it is said that the association is strong. Linear regression models of ordinary least squares will be applied to obtain the validity coefficient (r) and the standard error of the estimate (SEE): the typical error associated with the prediction the AoPWV with the distance traveled in the 6MWD test in each individual patient. The analysis of the receiver operating characteristic curve (ROC) will be used to derive cutoff points for an AoPWV value for the prediction of a 6MWD less than 427 meters