Baroreflex sensitivity and carotid intima-media thickness in risk stratification of prehypertensives and hypertensives

BACKGROUNDː The aim of the study was to evaluate the clinical significance of baroreflex sensitivity (BRS) and carotid intima media thickness (IMT) in risk stratification of hypertensives and subjects with high normal blood pressure (SHNBP). METHODSː A total of 20 patients (61±13 years of age, 10 female/10 male) with essential, treated hypertension and 20 subjects (59±8 years of age, 10 female/10 male) with high normal blood pressure were enrolled. The interrelationship between BRS expressed in ms/mmHg (BRS) and IMT of common carotid artery (CCA) in hypertensives and subjects with high normal blood pressure (SHNBP, prehypertensives) was evaluated. BRS was determined by the sequence and spectral method: a five-minute non-invasive beat-to-beat recording of blood pressure (BP) and R-R interval with use of Collin CBM-7000 monitor, controlled breathing at a frequency of 0.1 Hz. Duplex ultrasonographic examination of the carotid wall and IMT of both CCA and carotid bulb were performed in all patients. RESULTSː Essential hypertension was associated with decreased BRS (r =-0.53, P<0.001). We found out that there was no significant difference between BRS and IMT CCA values in mild treated hypertensives and those in SHNBP. This finding was independent of age-dependent decrease of BRS. SHNBP and hypertensives with critical value BRS≤5 ms/mmHg have significantly increased IMT CCA. CONCLUSIONSː Decreased BRS is an early sign of autonomic dysfunction even in prehypertensive period. SHNBP and hypertensives with BRS≤5ms/mmHg have significantly increased IMT CCA. The principal result of this study showed that BRS and carotid IMT in relatively low-risk hypertensives and SHNBP could identify subjects at higher cardiovascular risk.