A new scoring system for evaluating coronary artery disease by using blood pressure variability.

Abstract

The aim of this study was to develop a new scoring system using ambulatory blood pressure monitoring (ABPM) to assist in the evaluation of coronary artery disease (CAD). One hundred twenty-five subjects (53.1 ± 9.6 years of age) were included. Pearson's tests were first performed to identify the parameters that correlated with Duke Treadmill Score (DTS). Blood test parameters and blood pressure variability (BPV) measures that were extracted from the ABPM were included. Next, a multiple linear regression analysis was performed to train a new scoring system in the 84 patients from the 125 patients. Then, a correlation analysis was conducted to validate the correlation between the new scoring system and DTS in the remaining 41 subjects. A further correlation analysis was used to verify the clinical value of the new scoring system using ultrasonic cardiogram (UCG) and brachial-ankle pulse wave velocity (baPWV). Our new scoring system, which had a 24.096 - 0.083 × residual standard deviation of night systolic blood pressure (SBP) - 0.130 × age - 0.206 × average real variability of night SBP, was correlated with DTS (r = 0.312, P = 0.047). Moreover, our new scoring system was also correlated with various markers of cardiac function (r = -0.290, P = 0.001; r = -0.262, P = 0.004; r = -0.303, P = 0.001; r = -0.306, P = 0.001, respectively) measured by UCG and with baPWV (r = 0.529, P = 0.001). Furthermore, the r-values for the BPV Score versus the markers were closer to -1 than the corresponding r-values for the Duke Score vs the same parameters. And the differences in r-values between Duke Score and BPV Score were statistically significant (P = 0.022). In conclusion, the new scoring system based on ABPM has potential as a non-invasive tool for evaluating CAD.