Relationship between radial and central arterial pulse wave and evaluation of central aortic pressure using the radial arterial pulse wave

Since a decrease of central aortic pressure contributes to the prevention of cardiovascular events, simple measurement of not only brachial blood pressure but: also central aortic pressure may be useful in the prevention and treatment of cardiovascular diseases. In this study, we simultaneously measured radial artery pulse waves non-invasively and ascending aortic pressure invasively, before and after the administration of nicorandil. We then compared changes in central aortic pressure and radial arterial blood pressure calibrated with brachial blood pressure in addition to calculating the augmentation index (At) at the aorta and radial artery. After nicorandil administration, the reduction in maximal systolic blood pressure in the aorta (Delta a-SBP) was -14 +/- 15 mmHg, significantly larger than that in early systolic pressure in the radial artery (Delta r-SBP) (-9 +/- 12 mmHg). The reduction in late systolic blood pressure in the radial artery (Delta r-SBP2) was -15 +/- 14 mmHg, significantly larger than Delta r-SBP, but not significantly different from Delta a-SBP. There were significant relationships between Delta a-SBB and Delta r-SBP (r=0.81, p < 0.001), and between Delta a-SBP and Delta r-SBP2 (r=0.91, p < 0.001). The slope of the correlation regression line with Delta r-SBP2 (0.83) was larger and closer to 1 than that with Delta r-SBP (0.63), showing that the relationship was close to 1:1. Significant correlations were obtained between aortic At (a-Al) and radial At (r-Al) (before nicorandil administration: r=0.91, p < 0.001; after administration: r=0.70, p < 0.001). These data suggest that the measurement of radial artery pulse wave and observation of changes in the late systolic blood pressure in the radial artery (r-SBP2) in addition to the ordinary measurement of brachial blood pressure may enable a more accurate evaluation of changes in maximal systolic blood pressure in the aorta (a-SBP).