LAUSR

BACKGROUND This study compared aortic pressures estimated using a SphygmoCor XCEL PWA device (ATCOR, Naperville, IL, USA) noninvasively with aortic pressures obtained using pressure catheters during catheterization procedures and analyzed the impact of a linear-fit function on the estimated pressure values. METHODS 136 patients scheduled for cardiac catheterization procedure were enrolled in IRB approved studies. Catheterization procedures were performed according to standard-of-care to acquire aortic pressure measurements. Immediately after the catheterization procedure and the pressure catheters removed, while the patients were still in the catheterization laboratory, central aortic pressures were estimated with the SphygmoCor device (using its inbuilt transfer function). The error between measured and estimated aortic pressures was evaluated using Bland-Altman analysis (n=93). A linear-fit was performed between the measured and estimated pressures, and using the linear equation the error measurements were repeated. A bootstrap analysis was performed to test the generalizability of the linear-fit function. In a subset of cases (n=13), central aortic pressure values were also obtained using solid-state high-fidelity catheters (Millar Inc., Houston, TX, USA), and the error measurements were repeated. RESULTS The magnitude of errors between the measured and estimated aortic pressures (mean errors > 6.4 mmHg; mean errors > 8.0 mmHg in the subset) reduced to less than 1 mmHg after using the linear-fit function derived in this study. CONCLUSIONS For the population examined in this study, the SphygmoCor data must be used with the linear-fit function in order to obtain aortic pressures that are comparable to the measurements obtained using pressure catheters.