Cardiovascular characteristics in normotensive subjects with or without family history of hypertension

Left Ventricular Myocardial Performance in Normotensive Offspring of Hypertensive Parents

INTRODUCTION

Early alterations in the cardiovascular system have been described in offspring of hypertensive parents, but with conflicting results.

AIM

To evaluate the influence of genetic predisposition to hypertension on left ventricular (LV) geometry and function, 30 normotensive male offspring of hypertensive parents (EH+) and 30 matched offspring of normotensive families (EH-), were studied.

METHODS

All subjects underwent office and 24-h ambulatory blood pressure monitoring (ABPM), conventional and Tissue Doppler Echocardiography (TDE), including assessment of myocardial performance index (MPI).

RESULTS

EH+ showed an increase in office BP with statistical significance in diastolic BP (84 ± 7 vs 73 ± 6 mmHg; p < 0.05). Relative wall thickness (RWT) was greater in EH+ (0.37 ± 0.05 vs 0.31 ± 0.03; p < 0.05) and significantly related to the EH+ condition at the univariate analysis (p < 0.003), whilst the LV mass index was unchanged (84.3 ± 14 vs 80 ± 17 g/m²; p = NS), suggesting a trend towards concentric remodeling. Systolic and diastolic function, in both ventricles, were superimposable in the two groups. The MPI was higher in EH+ (0.49 ± 0.10 vs 0.45 ± 0.08; p = NS) and significantly correlated to RWT (r = 0.47, p < 0.01). However, at the stepwise multiple regression analysis, only the condition of EH + was independently associated with RWT (p <0.006). RWT, according to ROC curves analysis, predicted the condition of EH+ (cutoff 0.359, specificity 89%, sensitivity 82%).

CONCLUSION

Current results provide information about LV myocardial performance in EH+ subjects, related to a LV concentric remodeling and to endothelial dysfunction.

Arterial stiffness and peripheral vascular resistance in offspring of hypertensive parents: influence of sex and other confounders

AIM

Established essential hypertension is associated with increased arterial stiffness and peripheral resistance, but the extent of vascular changes in persons genetically predisposed for essential hypertension is uncertain.

METHODS

Participants from the Danish Hypertension Prevention Project (DHyPP) (both parents hypertensive) (n = 95, 41 ± 1 years, 53% men) were compared with available spouses (n = 45, 41 ± 1 years) using measurements of ambulatory blood pressure (BP), left ventricular mass index (LVMI), pulse wave velocity, central BP and augmentation index (AIx) in addition to forearm resting and minimal resistance [forearm resting vascular resistance (Rrest) and forearm minimal vascular resistance (Rmin)].

RESULTS

DHyPP patients with participating spouses had higher 24-h mean BP (94 ± 1 vs. 88 ± 1 mmHg, P < 0.01), LVMI (94 ± 3 vs. 80 ± 2 g/m, P < 0.01), central SBP (121 ± 2 vs. 111 ± 2 mmHg, P < 0.01) and AIx (16.0 ± 1.2 vs. 10.5 ± 1.7%, P < 0.01), but similar carotid-femoral pulse wave velocity (7.5 ± 0.2 vs. 7.1 ± 0.2 m/s), Rrest (53 ± 3 vs. 51 ± 3 mmHg/ml/min/100 ml) and log Rmin (0.58 ± 0.02 vs. 0.55 ± 0.02 mmHg/ml/min/100 ml) when compared with spouses. Using multiple linear regression analysis (adjusting for sex, age, BMI, creatinine clearance and 24-h BP, heart rate and sodium excretion) AIx and LVMI remained elevated in DHyPP patients [4.2% (0.7; 7.7), P = 0.02 and 6.3 g/m (0.7; 11.9), P = 0.03]. For the entire DHyPP cohort AIx, Rrest and Rmin were higher in women than men (P < 0.01), and the same was true for AIx and Rmin among spouses (P < 0.05). Furthermore, AIx was linearly associated with Rrest and Rmin.

CONCLUSION

Young to middle-aged individuals genetically predisposed for essential hypertension display increased AIx and LVMI, although vascular stiffness and peripheral resistance are still normal.

Association of parental blood pressure with retinal microcirculatory abnormalities indicative of endothelial dysfunction in children

OBJECTIVE

Microcirculatory abnormalities precede the onset of hypertension and may explain its familial nature. We examined the relationship between parental blood pressure (BP) and offspring retinal microvasculature in Pakistani trios [father, mother, and child (aged 9-14 years)].

METHODS

This is a substudy of a population-based trial of BP reduction. Data were available on 358 normotensive, and 410 offspring of at least one hypertensive parent. Retinal vessel characteristics were measured from digital images. Multivariable linear regression models were built to assess the associations between maternal and paternal BP and offspring retinal microvasculature.

RESULTS

Optimality deviation was greatest in offspring of two hypertensive parents, compared with those with one or no hypertensive parent (P=0.030 for trend). Paternal SBP and DBP were each significantly associated with optimality deviation in offspring (P=0.023 and P=0.006, respectively). This relationship persisted after accounting for offspring cardiovascular risk factors [increase in optimality deviation (95% confidence interval, CI) 0.0053 (0.0001-0.0106, P=0.047) and 0.0109 (0.0025-0.0193, P=0.011), for each 10 mmHg increase in paternal SBP and DBP, respectively]. Maternal DBP was inversely associated with offspring arteriovenous ratio -0.0102 (-0.0198 to -0.0007, P=0.035).

CONCLUSION

Microvascular endothelial dysfunction in children is associated with increasing levels of parental hypertension. The association with paternal BP is independent of other cardiovascular risk factors, including the child's BP. Higher maternal DBP is associated with evidence of arteriolar narrowing in offspring. These early microcirculatory changes may help explain familial predisposition to hypertension in people of Pakistani origin at an early age.

VIDEO ABSTRACT

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The lord of the ring: mandatory role of the kidney in drug therapy of hypertension

Strong evidence supports the idea that total peripheral resistance (TPR) is increased in all forms of human and experimental hypertension. Although the etiological participation of TPR in the origin and long-term maintenance of hypertension has been extensively debated, it now seems clear that the renal, nonadaptive, infinite gain-working, pressure-sensitive natriuresis and diuresis is the main mechanism of blood pressure control in the long term. The tissue, cellular, biochemical, and genetic sensors and executors of this process have not been fully identified yet, but the role of the renal medulla has gained growing attention as the physiopathological scenario in which the key regulatory elements reside. Specifically, the functionality of the renomedullary vasculature seems to be highly responsible for blood pressure control. The vasculature of the renal medulla becomes a new and more specific target for the therapeutic intervention of hypertension. Recent data on the effect of baroreceptor-controlled renal sympathetic activity on the long-term regulation of blood pressure are integrated. The renomedullary effects of the main antihypertensive drugs are discussed, and new perspectives for the therapeutic intervention of hypertension are outlined. Comparison of the genetic program of the renal medulla before and after the development of hypertension in spontaneously hypertensive and experimentally induced animal models might provide a mechanism for identifying the key genes that become activated or suppressed in the development of high blood pressure. These genes, their encoded proteins, or other elements related to their signalling and genetic pathways might serve as new and more specific targets for the pharmacological treatment of abnormally elevated blood pressure. Besides, proteins specifically located to the luminal side of the renomedullary vascular endothelium may serve as potential targets for site-directed drug and gene therapy.

Early Target Organ Damage and Its Reversibility: The Heart

Left ventricular hypertrophy (LVH) represents not only an adaptation to increased load, but also a risk factor and a marker of risk of cardiovascular diseases. It may be detected early in the development of the disease by electrocardiography or echocardiography. LVH is often associated to abnormalities of systolic and diastolic function, and its presence clearly predisposes not only to cardiac ischemia and to congestive heart failure, but also to a higher incidence of stroke. A large number of clinical and experimental studies have shown that long-term antihypertensive treatment may be associated with regression of LVH. Long-term antihypertensive treatment is associated with a progressive decrease of LV mass. Differences on reduction of LV mass using different classes of antihypertensive drugs for the same decrease of blood pressure are usually mild, although the effect on cardiac structure and tissue composition are probably not the same. In fact, not only the quantity of left ventricular mass, but also its quality (i.e., collagen content, contractile machinery) should be evaluated and improved by treatment. The incidence of cardiovascular events in hypertensive patients is clearly related to the value of LV mass achieved during treatment; in fact, a reduction in LVH by antihypertensive treatment is associated with improvement in outcome and with decrease of the risk of cardiovascular morbidity and mortality, even independently from changes of other risk factors, including blood pressure. In patients with LVH at baseline, the decrease of LV mass is associated with a number of pathophysiological changes such as 1) improved systolic performance at the midwall, 2) possible improvement of diastolic filling, 3) autonomic nervous system changes toward normalization, 4) possible reduction or ventricular arrhythmias and 5) coronary reserve improvement. All these changes might explain an improvement of clinical prognosis in hypertensive patients. Ongoing studies will more precisely assess the quantitative relation between development or regression of LV mass, improvement of systolic and diastolic function and incidence of cardiovascular events. At present time detection, prevention and reversal of LVH represent a major goal in the management of hypertensive patients.

Therapeutic profile of manidipine and lercanidipine in hypertensive patients

Manidipine and lercanidipine are considered effective and safe in the treatment of chronic arterial hypertension and are equipotent in reducing blood pressure (BP) levels. Their main side effect is ankle-foot edema. After a 2-week placebo run-in period, these 2 drugs were compared in a controlled parallel-group study lasting 3 months, involving 53 patients with mild-to-moderate essential hypertension (26 assigned to manidipine and 27 to lercanidipine). At the end of the active treatment period, BP was significantly reduced in comparison with the end of the placebo phase in both the manidipine and the lercanidipine groups, without significant differences between the 2 drugs. Daytime BP was significantly reduced by 5.5%/5.6% with manidipine and by 3.8%/6.6% with lercanidipine, while smaller reductions were seen at nighttime. The smoothness index was the same with both drugs. Unlike lercanidipine, manidipine significantly reduced both basal (-30%) and minimal vascular resistance (-39%), qualifying it as a potent vasodilator. Despite vasodilation, heart rate was not increased but was even slightly reduced by treatment. Ankle-foot edema was observed with both drugs but was less pronounced with manidipine, probably because of greater postcapillary dilatation. In conclusion, manidipine and lercanidipine are both effective and safe in mild-to-moderate essential hypertension, although the former seems to have a more favorable tolerability profile than the latter.