Radial late-SBP as a surrogate for central SBP

Background: Recent studies indicated that central SBP could be estimated by radial late-SBP (rSBP2) with a small disparity. However, most of these studies were conducted by SphygmoCor with a transfer function. The agreement between rSBP2 and central SBP was also tested in several invasive studies, but with inconsistent results. The objective of the present study was, therefore, to investigate whether rSBP2, from commercially available noninvasive devices, could practically indicate central SBP in current clinical care. Methods: We assessed carotid SPB (cSBP) and aortic SBP (aSBP) and rSBP2 by two broadly used tonometry-based devices, SphygmoCor and PulsePen, in 106 patients (57.5 ± 14.1 years) from our cardiovascular department. Results: In SphygmoCor and PulsePen, rSBP2 correlated well with aSBP and cSBP (R > 0.80, P < 0.001), but significantly underestimated them with a discrepancy ranging from 1.2 ± 5.1 to 13.9 ± 10.9 mmHg. The slopes of regression line in the correlation plots between the PulsePen rSBP2 and cSBPs from SphygmoCor and PulsePen were 0.91 and 0.99, respectively, and did not significantly differ from 1. Conclusion: PulsePen rSBP2 underestimated cSBP with a systematical but clinically substantial discrepancy, whereas SphygmoCor rSBP2 underestimated aSBP and cSBP with a nonsystematical but much smaller disparity. From a practical point of view, neither of these noninvasive devices can be applied for the precise estimation of central SBP with rSBP2 in clinical practice. © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins.