Background: Oscillometric central blood pressure (CBP) monitors have emerged as a new technology for blood pressure (BP) measurements. With a newly proposed diagnostic threshold for CBP, we investigated the diagnostic performance of a novel CBP monitor.
Methods: We recruited a consecutive series of 138 subjects (aged 30-93 years) without previous use of antihypertensive agents for simultaneous invasive and noninvasive measurements of BP in a catheterization laboratory. With the cutoff (CBP ≥130/90 mm Hg) for high blood pressure (HBP), the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the novel CBP monitor were calculated with reference to the measured CBP. In comparison, the diagnostic performance of the conventional cuff BP was also evaluated.
Results: The noninvasive CBP for detecting HBP in a sample with a prevalence of 52% showed a sensitivity of 93% (95% confidence interval (CI) = 91-95), specificity of 95% (95% CI = 94-97), PPV of 96% (95% CI = 94-97), and NPV of 93% (95% CI = 90-95). In contrast, with cuff BP and the traditional HBP criterion (cuff BP ≥140/90 mm Hg), the sensitivity, specificity, PPV, and NPV were 49% (95% CI = 44-53), 94% (95% CI = 92-96), 90% (95% CI = 86-93), and 63% (95% CI 59-66), respectively.
Conclusions: A stand-alone oscillometric CBP monitor may provide CBP values with acceptable diagnostic accuracy. However, with reference to invasively measured CBP, cuff BP had low sensitivity and NPV, which could render possible management inaccessible to a considerable proportion of HBP patients, who may be identifiable through noninvasive CBP measurements from the CBP monitor.
Keywords: Microlife WatchBP Office Central; blood pressure; central blood pressure; diagnostic accuracy; hypertension; oscillometric signals; pulse volume plethysmography; sensitivity and specificity; sphygmomanometer.