The Effectiveness And Reproducibility Of Radial Artery Subendocardial Viability Ratio

ObjectiveProposed a new index for assessment of myocardial perfusion: the radial arterysubendocardial viability ratio (SEVR).And to examine whether SEVR obtained directly from radial artery pressure waveforms (radial SEVR) can provide informationcomparable with SEVR obtained directly from carotid artery pressure waveforms（carotid SEVR）measurements. Then to assess the reproducibility of subendocardialviability ratio（SEVR） based on radial arterial waveforms. It can be used in clinicaltesting.MethodsIn a cross-sectional effectiveness study of200apparently healthy subjects (99menand101women) aged20~74years, the carotid SEVR and radial SEVR were measuredusing applanation tonometry. The arterial applanation tonometer was held on the leftcarotid artery and radial artery while pressure against the carotid artery and radial arterywas obtained. The magnification of digital volume pulse was modulated automaticallyto obtain an optimal arterial waveform. Consistent arterial waveforms were recorded for12s.In the reproducibility study, SEVR measurement was performed in30healthyvolunteers(24~59years)by two observers on the same day and repeated by the firstobserver after24h,obtaining four radial SEVRs. Then to assess the intra-observer、inter-observer and day-to-day reproducibility of radial SEVR.ResultsIn the effectiveness study, radial SEVR was strongly correlated with carotid SEVR(r=0.81, P<0.001), although carotid SEVR was much higher than radial SEVR. Malesubjects had a slightly higher radial SEVR than females. Stepwise multiple-regressionanalysis showed that heart rate was a potent predictor of radial SEVR in addition to age,pulse pressure and systolic BP. In the reproducibility study, the mean intra-observer、inter-observer and day-to-day differences(±2SD) for SEVR were1.34±26.84,1.09±23.02,-0.15±41.52; intraclass correlation coefficients were0.898,0.929,0.775, all higher than0.75;P＞0.05, no significant difference. ConclusionProposed a new radial SEVR, and found SEVR obtained directly from radial arteryblood pressure waveforms showed a significant and strong correlation with SEVRobtained directly from carotid artery blood pressure waveforms in a large populationwith a wide age range. Radial SEVR didn’t need any transfer function, and it can assesscarotid SEVR directly. Heart rate, sex, pulse pressure, systolic blood pressure had thesimilar effects on radial SEVR and carotid SEVR. These results suggested that SEVRobtained directly from radial arterial pressure waveforms could provide equivalentinformation to carotid arterial SEVR, and has potential as a surrogate marker ofcardiovascular disease. The radial SEVR showed a good intra-observer、inter-observerand day-to-day reproducibility, and can be used in clinical testing and early interventionof cardiovascular disease.