Abstract
Background
Central blood pressure becomes increasingly accepted as an important diagnostic and therapeutic parameter in the management of cardiovascular disease. This led to development of several non-invasive techniques most commonly based on peripheral pulse wave analysis. Accuracy of widespread applanation tonometry can be affected by calibration and operator training. To overcome this, we aimed to evaluate a novel device (VascAssist 2) using automated oscillometric radial pulse wave analysis and a refined multi-compartment model of the arterial tree.
Methods
225 patients were prospectively enrolled. Invasive aortic root measurements served as reference in MEASURE-cBP 1 (n=106) whereas an applanation tonometry device (SphygmoCor) was used in MEASURE-cBP 2 (n=119).
Results
In MEASURE-cBP 1, we found a mean overestimation for systolic values of 4±12 mmHg (3±10%) and 6±10 mmHg (9±14%) for diastolic values. Diabetes mellitus and low blood pressure were associated with larger variation. In MEASURE-cBP 2, mean overestimation of systolic values was 4±4 mmHg (4±4%) and 1±4 mmHg (1±7%) of diastolic values. Arrhythmia was significantly more frequent in invalid measurements (61 vs. 18%, p<0.0001) which were most often due to a low quality index of SphygmoCor. Accuracy did not differ between patients with arrhythmia and sinus rhythm in MEASURE-cBP 1.
Conclusions
Central blood pressure estimates using VascAssist 2 can be considered at least as accurate as available techniques, even including diabetic patients. In direct comparison, automated measurement considerably facilitates application not requiring operator training and can be reliably applied even in patients with arrhythmias.
Non-invasive measurement of aortic pressure in patients: Comparing pulse wave analysis and applanation tonometry
