Carotid Intima and Media Thickness Correlation with Central Blood Pressure Measurements by Tonometric and Oscillometric Methods: A Proof of Concept

Abstract Background The early detection of vascular damage in subclinical stages of hypertensive disease may be the key point in the prevention of cardiovascular outcomes. Objectives to correlate parameters of structural vascular damage (measurement of the carotid intima-media thickness) with parameters of functional vascular damage (central hemodynamic measurements) in pre-hypertensive and hypertensive patients taking up to two classes of anti-hypertensive drugs. Methods This was a cross-sectional descriptive study conducted with a convenience sample of patients attending the Liga de Hipertensão Arterial , a multidisciplinary program for the diagnosis and treatment of systemic hypertension, of the Federal university of Goias. Patients with arrythmia, diabetes, previous cardiovascular or cerebrovascular diseases, and end-stage diseases were excluded. Carotid Doppler test, measurements of peripheral and central blood pressure by applanation tonometry (Sphygmocor®) and oscillometry (Mobil-O-Graph®) were performed. The t-test was used for comparisons and the Pearson correlation test for correlations, considering a p<0.05 statistically significant. Results twenty patients (12 women) were evaluated, mean age 53.8 ± 14.3 years. Higher values of central pulse pressure (42.9±13.9 vs. 34.7±9.6, p=0.01) and pulse wave velocity (PWV) (9.0±1.9 vs. 7.9±1.5, p=0.01) were obtained by applanation tonometry compared with oscillometry. No difference between the methods was observed for the other measures. A significant correlation was found between carotid artery intima-media thickness (CA-IMT) and PWV (r=0.659; p=0.002) by the oscillometric test, but not with applanation tonometry. No correlation was found between central hemodynamic variables and the presence of carotid artery plaques. Conclusion PWV, estimated by oscillometry, was the only central hemodynamic parameter that correlated significantly with CA-IMT in pre-hypertensive and hypertensive patients at low cardiovascular risk. International Journal of Cardiovascular Sciences. 2020; [online].ahead print, PP.0-0

Tonometric and Oscillometric Methods for Measurement of Central Blood Pressure Parameters: a Comparison in Patients with Borderline Hypertension or Stage 1 Hypertension

Abstract Background Changes in arterial compliance are among the first changes detectable in hypertensive syndrome. Methods with good reproducibility as compared with the gold standard for identifying such changes are desirable in clinical practice. Objectives To compare central pressure measurements and arterial stiffness obtained by two non-invasive methods (tonometry and oscillometry). Methods This was a descriptive, cross-sectional study with a convenience sample of patients with borderline hypertension or stage 1 hypertension. Peripheral and central blood pressure measurements were obtained by tonometry (SphygmoCor®), considered the gold standard, and oscillometry (Mobil O´graph®). Comparisons of results were made by unpaired t-test, and p values < 0.05 were considered statistically significant. Results No difference was found in central pressure measurements obtained by SphygmoCor® (117 x 80.1 mmHg) compared with Mobil O'graph (112 x 81.4 mmHg). Mean augmentation index (AIx) was 26.1% and 21.3%, and mean pulse pressure (PP) amplification 10.7 mmHg and 10.0 mmHg by Sphygmocor® and Mobil O´graph®, respectively (p > 0.05). Mean pressure wave velocity (PWV), 8.4 m/s vs. 7.4 m/s (p = 0.013) and mean central pulse pressure, 37.7 mmmHg and 30.9 mmHg (p = 0.013) were significantly higher by SphygmoCor® than Mobil O´graph®. Conclusion Values of central systolic blood pressure, AIx and pulse pressure amplification obtained by oscillometry were not statistically different compared with tonometry; values of PWV and cPP, however, were underestimated by oscillometry. (Int J Cardiovasc Sci. 2020; 33(2):145-150)