Blood Pressure Variability (page 625)
There is increasing evidence that greater visit-to-visit variability of blood pressure is associated with a higher risk of stroke, an association that is independent of average blood pressure over time. Previous studies reporting on visit-to-visit variability of blood pressure and stroke have been relatively small and included select patients who were already at high cardiovascular disease risk. In addition, scarce data exist as to whether the relation of visit-to-visit variability of blood pressure and stroke is explained by an increase in blood pressure over time. The present study examined these associations in 58228 postmenopausal women with a wide range of cardiovascular disease risk enrolled in the Women's Health Initiative. Over a median follow-up of 5.4 years, a higher risk of stroke was associated with greater SD for the participant's mean systolic blood pressure (SBP) across visits (SD). The increased risk of stroke was similar for the SD regarding the participant's regression line when SBP regressed across visits and was independent of the temporal trend in SBP. The association was strongest for lower levels of average SBP across visits, particularly among individuals with average SBP <120 mmHg. Therefore, visit-to-visit variability of blood pressure contributes to stroke in a manner that is independent of blood pressure trends, particularly in individuals who otherwise would be considered to be low risk based on their average SBP.
Renal Resistive Index in Hypertension (page 770)
The renal restive index (RI) measured using Doppler ultrasonography has been shown to correlate with the degree of renal impairment in hypertensive patients, but the status of RI as an independent cardiovascular risk marker remains to be elucidated. The present study evaluated the prognostic role of RI in 426 essential hypertensive subjects with no previous cardiovascular disease. The primary study end point included combined cardiovascular and renal events. During an average of 3.1 years, RI was an independent predictor of worse outcome in the whole cohort, as well as in patients with estimated glomerular filtration rate (eGFR) <60 mL/min per 1.73 m2. When divided into 4 groups based on the respective sex-specific median levels of RI in the eGFR ≥60 and eGFR <60 mL/min per 1.73 m2 groups, the group with eGFR <60 mL/min per 1.73 m2 and high RI had a significantly poorer event-free survival. Evaluation of renal RI in addition to eGFR may help to assess not only renal function but also intrarenal hemodynamics, as well as intrarenal vascular resistance, and thus may provide clinically sensitive prognostic information in patients with essential hypertension. These findings corroborate the hypothesis that the impact of RI on cardiovascular and renal risk is important and that identifying renal hemodynamic abnormalities is useful for predicting cardiovascular and renal outcomes, especially in hypertensive patients with chronic kidney disease.
Exercise in Resistant Hypertension (page 653)
Regular aerobic exercise is associated with a significant reduction of blood pressure in hypertensive and normotensive subjects. Therefore, exercise is broadly recommended by current American and European hypertension guidelines. It remains elusive, however, whether exercise is able to reduce blood pressure in resistant hypertension as well. The present article describes the results of a randomized, controlled trial on the effects of regular aerobic exercise in resistant hypertension. Resistant hypertension is defined by its low responsiveness to drug therapy. The findings of this study reveal that a low responsiveness to pharmacological therapy does not inevitably go along with a low responsiveness to exercise. A moderate-intensity aerobic exercise program led to a significant and clinically relevant reduction of blood pressure. Moreover, the training increased physical performance as assessed by maximal oxygen uptake and lactate curves. In contrast to the rapidly emerging data on new invasive strategies like renal sympathetic denervation or baroreflex activation, there are only very few data on the efficacy of simple lifestyle modifications in resistant hypertension. A low responsiveness of hypertension to drug therapy may intuitively evoke the impression, “If this multitude of antihypertensive drugs is not able to provide blood pressure control, lifestyle modifications won't do anyway.” The present study shows, however, that aerobic exercise on a regular basis is a helpful adjunct to control blood pressure and should be included in the therapeutic approach to resistant hypertension.
- © 2012 American Heart Association, Inc.