Hypertension in perspective.

Decisions about the management of hypertensive patients should not be based on the level of blood pressure alone, but also on the presence of other risk factors, target organ damage and cardiovascular and renal disease. The results of echocardiography and carotid ultrasonography aids in the stratification of absolute cardiovascular risk as recently advocated by the guidelines of the European Society of Hypertension 2003. Therefore, the detection of target organ damage by ultrasound techniques allows an accurate identification of high-risk patients. Cardiovascular risk stratification only based on a simple routine work-up can often underestimate overall risk, thus leading to a potentially inadequate therapeutic management especially of low-medium risk patients.

Arteriolar constriction in mild-to-moderate essential hypertension: an old concept requiring reconsideration?

OBJECTIVE: To investigate differences between in-vivo properties of a vascular bed in hypertensive patients and normotensive controls. DESIGN: Despite the controversy about the origin of essential hypertension and its accompanying vascular changes, it is generally assumed that the characteristic increase in peripheral resistance when hypertension progresses is caused by arteriolar constriction. Yet, there is little experimental evidence that this assumption generally holds in vivo. METHODS: A non-invasive technique was used for studying properties of the complete vascular bed of an upper arm segment under an occluding cuff in 23 previously untreated hypertensive patients and their matched normotensive controls. The method used the segment's electrical impedance to assess the volumes of extravascular fluid and of arterial and venous blood under varying arterial transmural pressures. RESULTS: Compared with that of matched normotensive controls, the compliance of the large arteries of the vascular bed was on average 50.9% lower (P < 0.001) in the hypertensive patients. The compliance of the complete arterial bed at the operating blood pressure level was also lower (40.0%, P < 0.01), but appeared to be significantly higher (45.9%, P < 0.05) at the normotensive blood pressure level. On the venous side, the patients had a higher blood volume (60.0%, P < 0.01) and an increased myogenic response (68.5%, P < 0.05). CONCLUSIONS: The increase in vascular resistance in the hypertensive patients is due primarily to changes in the large and small vessels of the arterial bed. We found no evidence for a generally increased arteriolar constriction.

Long-term effects of amlodipine and lisinopril on left ventricular mass and diastolic function in elderly, previously untreated hypertensive patients: the ELVERA trial.

OBJECTIVE: To compare the effects of a calcium antagonist (amlodipine) and an angiotensin converting enzyme inhibitor (lisinopril) on left ventricular mass and diastolic function in elderly, previously untreated hypertensives. DESIGN: A double-blind randomized parallel group trial. Effects of amlodipine and lisinopril on left ventricular mass and diastolic function (E/A Ratio) (The ELVERA trial). SETTING: Rural northern Netherlands: population screening new diagnosed hypertensive subjects. PATIENTS: The study population comprised 166 newly diagnosed hypertensive (aged 60-75) with diastolic blood pressure between 95-115 mmHg and/or systolic blood pressure between 160-220 mmHg. INTERVENTION: Patients were randomly allocated to receive 5-10 mg amlodipine or 10-20 mg lisinopril for 2 years. MAIN OUTCOME MEASURES: Prior and after 1 and 2 years of treatment left ventricular mass, indexed by body surface (LVMI) was estimated by 2-D mode echocardiography according to Devereux with use of Penn convention. Early to atrial filling ratio (E/A) was assessed by transmitral flow. Change from baseline of LVMI and E/A ratio was evaluated by repeated measurement analysis of the treatment effect in an intention-to-treat analysis. RESULTS: Both amlodipine and lisinopril led to equivalent reduction in systolic and diastolic blood pressure. At the end of the study the amlodipine group led to LVMI decrease by 21.8 g/m < or = [95% confidence interval (CI), 18.3-25.3] and E/A ratio increased by 0.08 (95% CI, 0.05-0.11). In the lisinopril group LVMI decreased by 22.4 g/m < or = (95%, CI, 19.0-25.8) and E/A ratio increased by 0.07 (95% CI, 0.04-0.10). No statistically significant differences were found in changes in LVMI and E/A ratio between amlodipine and lisinopril. CONCLUSION: A long-term study, the ELVERA trial proves that amlodipine and lisinopril reduce left ventricular mass and improve diastolic function to a similar extent in elderly newly diagnosed hypertensive patients.

Home blood pressure measurement: reproducibility and relationship with left ventricular mass.

OBJECTIVE: To evaluate the reproducibility and relationship with left ventricular mass index of home blood pressure in comparison with ambulatory and office blood pressures. METHODS: We measured home, ambulatory and office blood pressures of 84 previously untreated hypertensive patients, aged 60-74 years, from primary care, at baseline and after 12 weeks, without active intervention in between. Left ventricular mass index was determined echocardiographically during week 12. RESULTS: Decreases in systolic and diastolic blood pressures were found after 12 weeks for mean home and office blood pressures (P<0.05), but not for mean ambulatory blood pressure. The coefficients of reproducibility for systolic and diastolic ambulatory blood pressures were 26.4 and 16.0, respectively. Correlation coefficients for correlation of left ventricular mass index to ambulatory blood pressure (0.51 and 0.36) were higher than the correlation coefficients for home (0.31 and 0. 16) and office (0.32 and 0.21) blood pressures, for systolic and diastolic values, respectively. However, we could find no statistically significant difference among the correlation coefficients for all three types of measurements. CONCLUSIONS: Home blood pressure was considerably less reproducible than ambulatory blood pressure and no different from office blood pressure in this respect. The relationship with left ventricular mass index appeared to be stronger for ambulatory than it was for home and office blood pressures, although not statistically significant so.

Carotid intima-media thickness: influence of drug treatment and clinical implications.

With B-mode ultrasound measurements of the intima-media thickness (IMT) of the carotid arterial wall (asymptomatic) atherosclerosis can be detected. In this article several studies are reviewed in which IMT was used as a surrogate endpoint to assess effects of lipid-lowering or antihypertensive drugs on peripheral atherosclerosis, and the clinical implications are discussed. After 1 year of treatment with lipid-lowering drugs an improvement of the blood lipid profile and retarded progression of the carotid IMT was seen. No incontrovertible evidence can be provided for a correlation between induced changes in the carotid and coronary arteries. Carotid IMT appears to be of prognostic value for cardiovascular events. The range of treatment-induced changes in IMT do not support the use of IMT in an individual patient to monitor treatment effects. However, with increased IMT as independent cardiovascular risk factor, IMT measurements are valuable in risk assessment in the individual patient in clinical practice. Looking forward to some ongoing studies, there is so far insufficient evidence that treating hypertension also inhibits progression of the IMT.

Investigation of the arterial and venous upper arm vascular bed.

Studies concerning vascular changes in hypertension and exercise have shown an increasing need to investigate the properties of a complete vascular bed in vivo. In this study, the repeatability of a non-invasive method for quantifying properties of the vascular bed of an upper arm segment, was investigated in two groups of volunteers (age 22-55 years). One group of subjects (n = 9) were measured twice at a 15 min interval. The other group (n = 8) were measured 4 times with each subject measured daily at the same time. The estimated quantities included the arterial and venous blood volume, the static arterial compliance, the myogenic response of the arm veins and the extravascular fluid volume of the tissue under an occluding cuff at the upper arm. They not only describe properties of the arterial vascular bed as a whole but also of different sized arteries functioning at different intra-arterial pressure. They were derived from the fluid shifts under the occluding cuff that arise when cuff pressure changes, as determined by electrical impedance and blood pressure measurements. The repeatability of the method was well within the physiologically acceptable range and of the same order of magnitude as that of established methods. Established methods however, provide less information about the properties of a vascular bed and result in controversial estimates of the dynamic arterial compliance. Furthermore, the method eliminates the need to match subjects in comparative studies for arterial blood pressure. These features and the sensitivity of the method for (patho)physiological changes, offer the possibility to investigate in vivo many still unknown aspects of the peripheral circulation.

Microalbuminuria is related to marked end organ damage in previously untreated, elderly hypertensive patients.

We wondered whether, in an elderly hypertensive population in a primary prevention setting, free from diabetes mellitus and clinical atherosclerosis, differences between end organ damage and microalbuminuria (MA) could be found using a lower level of urinary albumin excretion than that of classically defined MA. From a population survey of 173 previously untreated hypertensive patients (4x blood pressure systolic > or = 160 and < or = 220 mmHg, and/or diastolic > or = 95 and < or = 115 mmHg), mean age 67 +/- 4 years, were screened for MA (defined as albumin excretion between 20 and 300 mg/24 h). End organ damage was determined by B-mode ultrasound scanning of carotid and femoral arteries and echocardiography. Out of 173 hypertensives, 14 showed MA (8%). These hypertensives had a significantly higher intima media thickness (IMT; 1.01 +/- 0.21 vs 0.88 +/- 0.6 mm, p < 0.05) and increased left ventricular mass index (118 +/- 31 vs 103 +/- 22 g/m2, p < 0.05) than hypertensives without MA. Linear regression analysis showed that MA, age, male gender and diastolic blood pressure were independently related to IMT, while systolic blood pressure, male gender and body mass index were independently related to left ventricular mass. Even using lower levels of urinary albumin excretion rate, patients with MA had significantly higher IMT and increased left ventricular mass. Moreover, MA was independently related to IMT in these elderly hypertensives. These results suggest that the threshold value for MA should be reconsidered in hypertension.

Silent ST depression and cardiovascular end-organ damage in newly found, older hypertensives.

In hypertension, both reduced vascular supply and increased cardiac demand contribute to the development of (silent) myocardial ischemia. Our aim was to determine the prevalence of ST-segment depression and to analyze contributing factors in asymptomatic, previously untreated, older hypertensives. From a population survey, in 184 patients with mild hypertension (4 times systolic blood pressure >/=160 mm Hg and/or diastolic blood pressure >/=95 mm Hg), 60 to 75 years of age, cardiovascular end-organ damage was measured. Episodes of ST-segment depression were measured by 48-hour ambulatory Holter monitoring and were observed in 21 hypertensives (12%). They showed a significantly higher combined far-wall intima-media thickness of carotid and femoral arteries and more arterial plaques as measured by B-mode ultrasound compared with hypertensives without ST depression (0.00098+/-0.00021 versus 0.00088+/-0.00016 mm and 5.2+/-3.7 versus 3.7+/-2.8 plaques, P<0.05, respectively), whereas left ventricular mass index was not different (111+/-18 versus 104+/-24 g/m(2); P=0.18, respectively). In hypertensives with transient ST-segment depression, a significant relation was found between left ventricular mass and ischemic burden (r=0.51, P=0.02). Approximately 1 of 8 unselected and previously untreated older hypertensives show asymptomatic ST-segment depression, suggestive of silent myocardial ischemia. These data suggest that vascular factors mainly determine the occurrence of ischemic ST-segment depression and cardiac factors determine the ischemic burden in older hypertensives.