Circadian autonomic disturbances in resistant hypertension with and without white coat phenomenon

Resumo

BACKGROUND AND OBJECTIVES: The current definition of resistant hypertension includes both patients whose blood pressure is uncontrolled on three or more medications and those whose blood pressure is controlled when using four or more antihypertensive medications. Ambulatory blood pressure monitoring is an indispensable method to diagnose resistant hypertension and classify it into 2 groups: resistant hypertension without white-coat response and resistant hypertension with white-coat response. The aim of this study was to evaluate the circadian autonomic profile of resistant hypertension with and without white-coat phenomenon. METHODS: Forty four resistant hypertension patients were divided into two groups: resistant hypertension with white-coat phenomenon (n=25) and resistant hypertension without white-coat (n=19) phenomenon. All patients underwent  office blood pressure measurement, ambulatory blood pressure monitoring, and 24-hour Holter monitoring. RESULTS: No differences were observed between the resistant hypertension with white-coat phenomenon and resistant hypertension without white-coat phenomenon groups regarding age, body mass index or gender. The group of resistant hypertension with white-coat phenomenon had greater autonomic imbalance evaluated by heart rate variability parameters in frequency domain compared to resistant hypertension patients without white-coat phenomenon. Moreover, nighttime frequency domain parameters of resistant hypertension group with white-coat phenomenon correlated positively with office resistant hypertension  and office pulse pressure (r=0.57, p<0.05 and r=0.55, p<0.05, respectively). CONCLUSION: The presence of the white-coat response in resistant hypertension patients implies worse autonomic imbalance.