Correlation between estimated pulse wave velocity values from two equations in healthy and under cardiovascular risk populations

Introduction Equations can calculate pulse wave velocity (ePWV) from blood pressure values (BP) and age. The ePWV predicts cardiovascular events beyond carotid-femoral PWV. We aimed to evaluate the correlation between four different equations to calculate ePWV. Methods The ePWV was estimated utilizing mean BP (MBP) from office BP (MBP OBP ) or 24-hour ambulatory BP (MBP 24-hBP ). We separated the whole sample into two groups: individuals with risk factors and healthy individuals. The e-PWV was calculated as follows: e1−PWV=9.58748315543126−0.402467539733184*age+4.56020798207263*10−3*age2−2.6207705511664*10−5*age2*MBP+3.1762450559276*10−3*age*MBP−1.83215068503821*10−2*MBP e2−PWV=4.62−0.13*age+0.0018*age2+0.0006*age*MBP+0.0284*MBP We calculated the concordance correlation coefficient (Pc) between e1-PWV OBP vs e2-PWV OBP , e1-PWV 24-hBP vs e2-PWV 24-hBP , and mean values of e1-PWV OBP , e2-PWV OBP , e1-PWV 24-hBP and e2-PWV 24-hBP . The multilevel regression model determined how much the ePWVs are influenced by age and MBP values. Results We analyzed data from 1541 individuals; 1374 ones with risk factors and 167 healthy ones. The values are presented for the entire sample, for risk-factor patients and for healthy individuals respectively. The correlation between e1-PWV OBP with e2-PWV OBP and e1-PWV 24-hBP with e2-PWV 24-hBP was almost perfect. The Pc for e1-PWV OBP vs e2-PWV OBP was 0.996 (0.995–0.996), 0.996 (0.995–0.996), and 0.994 (0.992–0.995); furthermore, it was 0.994 (0.993–0.995), 0.994 (0.994–0.995), 0.987 (0.983–0.990) to the e1-PWV 24-hBP vs e2-PWV 24-hBP . There were no significant differences between mean values (m/s) for e1-PWV OBP vs e2-PWV OBP 8.98±1.9 vs 8.97±1.8; p = 0.88, 9.14±1.8 vs 9.13±1.8; p = 0.88, and 7.57±1.3 vs 7.65±1.3; p = 0.5; mean values are also similar for e1-PWV 24-hBP vs e2-PWV 24-hBP , 8.36±1.7 vs 8.46±1.6; p = 0.09, 8.50±1.7 vs 8.58±1.7; p = 0.21 and 7.26±1.3 vs 7.39±1.2; p = 0.34. The multiple linear regression showed that age, MBP, and age 2 predicted more than 99.5% of all four e-PWV. Conclusion Our data presents a nearly perfect correlation between the values of two equations to calculate the estimated PWV, whether utilizing office or ambulatory blood pressure.