Ambulatory heart rate and target organ damage in never-treated essential hypertensives

Limited evidence is available about the relationship between ambulatory heart rate (HR) and target organ damage (TOD) in uncomplicated hypertension. We sought to investigate the association between ambulatory HR and subclinical cardiac, vascular and renal markers of TOD in never-treated essential hypertensives. A total of 580 subjects with recently diagnosed (≤1 year) grade 1 and 2 hypertension, categorized by tertiles of HR levels, assessed by two 24-h ambulatory blood pressure monitoring at 1- to 4-week interval, sex and the presence or absence of TOD were considered for this analysis. All subjects also underwent laboratory and ultrasonographic investigations searching for microalbuminuria (MA), left ventricular hypertrophy (LVH) and carotid atherosclerosis (carotid thickening/plaque). In the whole population, as well as in both genders, LVH, carotid atherosclerosis and MA prevalence rates did not significantly increase with 48-h HR tertiles. When patients were categorized according to the presence or absence of TOD (that is, LVH, carotid atherosclerosis or MA) no significant intergroup differences in 48-h HR were found. Furthermore, average 48-h HR was similar in patients without organ involvement as in those with one, two or three TOD signs. Finally, in a multivariate analysis age, 48-h systolic blood pressure and metabolic syndrome assessed by ATP III criteria, but not HR were independently associated with TOD. Our findings showing that 48-h ambulatory HR is not associated with markers of TOD do not support the view that a faster HR may have an additive value in predicting organ damage in the early phases of essential hypertension.