Gianni Luigi Iovino

A Common Variant of Endothelial Nitric Oxide Synthase (Glu298Asp) Is an Independent Risk Factor for Carotid Atherosclerosis

Background and Purpose— Endothelium-derived NO is formed from l-arginine by endothelial NO synthase (eNOS) encoded by the NOS 3 gene on chromosome 7. Because several studies have indicated that NO plays a key role in the development of the atherosclerotic process, we investigated whether common variants in the eNOS gene are associated with an increased risk of plaque on carotid arteries. Methods— We studied 375 subjects attending the hypertension center of our institution to be screened for arterial hypertension. The examined subjects were classified according to the presence of carotid plaques (intima-media thickness ≥1.5 mm), and 2 intronic (CA and 27-bp repeats) polymorphisms and 1 exonic (Glu298Asp) polymorphism of the eNOS gene were explored. Results— Only the Glu298Asp polymorphism of eNOS was associated with the presence of carotid plaques (P <0.05). In particular, there was an excess of homozygotes for the Asp298 variant among subjects with carotid plaques, whereas the number of subjects who had the Glu298 allele in exon 7 of the eNOS gene was equally distributed in both study groups. Interestingly, the risk of having carotid plaques was increased ≈3 times in subjects who were homozygotic for the Asp298 variant compared with subjects who were homozygotic for the Glu298 variant and was independent of the other common risk factors (age, blood pressure, and smoking). Conclusions— Homozygosity for Asp298, a common variant of the eNOS gene, is an independent risk factor for carotid atherosclerosis in this study population.

The use of a telematic connection for the follow-up of hypertensive patients improves the cardiovascular prognosis

Background Inadequate blood pressure (BP) control could be due to incorrect management of hypertensives caused by the lack of interaction between general practitioners (GP) and hypertension specialists. Objectives To test the effectiveness on BP and total cardiovascular risk (TCVR) control of an internet-based digital network connecting specialists and GPs. Methods We created a network among the Hypertension Clinic, Federico II University (Naples, Italy), 23 hospital-based hypertension clinics and 60 GPs from the area (CampaniaSalute Network, CS). Randomized GPs enrolled in CS could update online records of patients (n = 1979). As a control, we included 2045 patients referred to the specialist clinics by GPs from outside the network. All patients completed a 2-year follow-up. Results CS provided a larger reduction in BP [systolic/diastolic BP (SBP/DBP): 7.3 ± 0.4/5.4 ± 0.3 versus 4.1 ± 0.4/3.1 ± 0.26 mmHg, CS versus control; P < 0.001 for both] and percentage of patients with BP < 140/90 mmHg (CS versus control: baseline, 33 versus 34%, NS; end of follow-up, 51 versus 47%, χ2 = 13.371; P < 0.001). A European Society of Hypertension–European Society of Cardiology (ESH/ESC) TCVR score was calculated [from 1 (average) to 5 (very high TCVR)]. The CS group showed a reduction in the mean TCVR score (CS: from 3.5 ± 0.02 to 3.2 ± 0, P < 0.01, ANOVA; control group: 3.5 ± 0.03 to 3.4 ± 0.03, NS) and, accordingly, fatal and non-fatal major cardiovascular events (MACE) were less frequent (2.9 versus 4.3%; χ2 = 5.047, P < 0.02). CS predicts fewer MACE in multiple binary regression analysis (β:−7.27, P < 0.008) reducing the risk for MACE compared to control [odds ratio (OR): 0.838; 95% confidence interval (CI): 0.73–0.96]. Conclusion Our results support the idea that telemedicine can achieve better control of BP and TCVR.

Does Information on Systolic and Diastolic Function Improve Prediction of a Cardiovascular Event by Left Ventricular Hypertrophy in Arterial Hypertension

Left ventricular (LV) mass (LVM) is the most important information requested in hypertensive patients referred for echocardiography. However, LV function also predicts cardiovascular (CV) risk independent of LVM. There is no evidence that addition of LV function significantly improves model prediction of CV risk compared with LVM alone. Thus, composite fatal and nonfatal CV or cerebrovascular events were evaluated in 5380 hypertensive outpatients (2336 women, 298 diabetics, and 1315 obese subjects) without prevalent CV disease (follow-up: 3.5±2.8 years). We compared 5 risk models using Cox regression and adjusting for age and sex: (1) LV mass normalized for height in meters2.7 (LVMi); (2) LVMi, concentric LV geometry, by relative wall thickness (>0.43), ejection fraction, and transmitral diastolic pattern (by thirtiles of mitral deceleration index); (3) LVMi, LV geometry, midwall shortening, and mitral deceleration index thirtiles; (4) as No. 2 with the addition of left atrial dilatation (>23 mm); and (5) as No. 3 with the addition of left atrial dilatation. Individual hazard functions were compared using receiving operating characteristic curves and z statistics. Areas under the curves increased from 0.60 in the model with the sole LVMi to 0.62 in the others (all P values for differences were not significant). The additional information on systolic and diastolic function decreased the contribution (Wald statistics) of LVMi in the Cox model without improving the model ability to predict CV risk. We conclude that risk models with inclusion of information on LV geometry and systolic and diastolic function, in addition to LVMi, do not improve the prediction of CV events but rather redistribute the impact of individual predictors within the risk variance.

AKT Participates in Endothelial Dysfunction in Hypertension

Background—In hypertension, reduced nitric oxide production and blunted endothelial vasorelaxation are observed. It was recently reported that AKT phosphorylates and activates endothelial nitric oxide synthase and that impaired kinase activity may be involved in endothelial dysfunction. Methods and Results—To identify the physiological role of the kinase in normotensive Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR), we used adenoviral vectors to transfer the human AKT1 gene selectively to the common carotid endothelium. In vitro, endothelial vasorelaxations to acetylcholine, isoproterenol, and insulin were blunted in control carotids from SHR compared with WKY rats, and human AKT1 overexpression corrected these responses. Similarly, blood flow assessed in vivo by Doppler ultrasound was reduced in SHR compared with WKY carotids and normalized after AKT1 gene transfer. In primary cultured endothelial cells, we evaluated AKT phosphorylation, activity, and compartmentalization and observed a mislocalization of the kinase in SHR. Conclusions—We conclude that AKT participates in the settings of endothelial dysfunction in SHR rats by impaired membrane localization. Our data suggest that AKT is involved in endothelium dysfunction in hypertension.

Effects of valsartan on left ventricular diastolic function in patients with mild or moderate essential hypertension: comparison with enalapril.

OBJECTIVE This study compares the effects of an AT1 angiotensin II receptor antagonist (valsartan) with those of an ACE inhibitor (enalapril) on left ventricular (LV) diastolic function in patients with mild or moderate essential hypertension and no evidence of LV hypertrophy at echocardiography. METHODS A total of 24 patients (16 men, mean age 47 +/- 8 years) underwent radionuclide ambulatory monitoring (Vest) of LV function at rest and during upright bicycle exercise testing before and after two 4-week treatment periods with valsartan (80-160 mg/day orally) and enalapril (20-40 mg/day orally) according to a double-blind, crossover randomization scheme. RESULTS In the overall population no differences between the two treatments were found in LV peak filling rate (PFR) either at rest or at peak exercise. In a subgroup analysis it was found that baseline PFR was normal (= 2.5 EDV/sec) in 12 patients (subgroup A) and impaired (< 2.5 EDV/sec) in the remaining 12 (subgroup B). In both subgroups, valsartan and enalapril induced a significant and comparable reduction of systolic and diastolic blood pressure. In subgroup A, valsartan and enalapril did not induce significant changes in PFR. In subgroup B, valsartan increased PFR both at rest (from 2.0 +/- 0.3 to 2.4 +/- 0.3 EDV/sec, P < 0.01) and at peak exercise (from 4.1 +/- 1.1 to 4.4 +/- 1.0 EDV/s, P < 0.05), whereas enalapril did not change PFR either at rest (2.0 +/- 0.4 EDV/s, P < 0.01 versus valsartan) or at peak exercise (3.7 +/- 1.1 EDV/sec, P < 0.05 versus valsartan). CONCLUSIONS Valsartan-induced renin-angiotensin system blockade is able to improve LV filling in patients with mild or moderate essential hypertension and impaired diastolic function. These findings support the hypothesis of a contribution of the renin-angiotensin system in the control of LV diastolic function in these patients.

The Glu27 allele of the β2 adrenergic receptor increases the risk of cardiac hypertrophy in hypertension

Objective Cardiac and vascular remodeling occur in response to hypertension. Genetic background appears to modify the development of target organ damage (TOD). We evaluated the impact on hypertension-associated TOD of a highly polymorphic gene with elevated significance for the regulation of the cardiovascular system, the β2AR gene. Methods We recruited 775 hypertensives (mean ± SE: age 53.5 ± 0.5, from 20 to 84 years; female 32.7%; systolic (SBP)/diastolic (DBP) blood pressure: 159 ± 1.2/101 ± 0.6 mmHg) referred to the departmental outpatient clinic and screened them for the Arg16Gly, Gln27Glu, and Ile164Thr variants of β2AR gene. We performed association analyses on clinical, anamnesis, anthropometrical and biochemical parameters as well as cardiac and vascular ultrasound. Results We found that the three polymorphisms did not affect blood pressure levels. Cardiac TOD appeared to be related to the Glu27 variant. In fact, the Glu27 allele associates with a 1.4-fold higher risk of developing cardiac hypertrophy, and directly correlated with larger systolic and diastolic left ventricle internal diameters. Vascular TOD was not affected by the three polymorphisms. Ancillary to our finding we observed that the Glu27 variant is associated with a higher incidence of dyslipidemia. Conclusions Our data indicate that β2AR gene polymorphisms participate in the determination of cardiac TOD associated with hypertension.

β2‐Adrenergic receptor polymorphisms and treatment‐induced regression of left ventricular hypertrophy in hypertension

Although blood pressure is considered the major determinant of left ventricular hypertrophy in hypertension, genetic variability is increasingly being considered among the factors influencing this complication. β2‐Adrenergic receptors (β2ARs) are up‐regulated in hypertension and largely polymorphic within the human population. Recently, we have shown that the Glu27 β2AR variant is strongly associated with cardiac hypertrophy in hypertension. The objective of this study is to verify whether this polymorphism also affects hypertrophy regression in response to antihypertensive therapy.

Distinct Vasodilation, without Reflex Neurohormonal Activation, Induced by Barnidipine in Hypertensive Patients

Barnidipine is a new 1,4-dihydropyridine calcium antagonist with a strong and long-lasting vasodilatory effect. In order to assess the haemodynamic profile of the antihypertensive effect of barnidipine, a randomized, double-blind study of barnidipine vs nitrendipine was performed in 24 patients with mild to moderate essential hypertension. Following an initial 4-week placebo period, patients whose sitting diastolic blood pressure (SiDBP) was between 95 and 114 mm Hg, and whose sitting systolic blood pressure was between 150 and 219 mm Hg, were randomized (2:1 ratio) to receive either barnidipine (10 mg) or nitrendipine (10 mg) once daily, for a 6-week double-blind period. Subsequently, patients with an SiDBP of less than 90 mm Hg continued for a second 6-week period with the same monotherapy, while patients with an SiDBP of 90 mm Hg or above received double the dose of antihypertensive treatment for the next 6 weeks. Two-dimensional M- and B-mode echocardiography with Doppler flowmetry was performed at the end of both the placebo and active treatment phases. Barnidipine and nitrendipine reduced blood pressure by the same degree (barnidipine: from 165 +/- 2/100 +/- 1 to 145 +/- 2/89 +/- 1 mm Hg, p < 0.01; nitrendipine: from 163 +/- 3/100 +/- 2 to 143 +/- 7/90 +/- 3 mm Hg, p < 0.01) as a result of peripheral vasodilation. This was not accompanied by reflex neurohormonal activation. Moreover, only in the group receiving barnidipine was a significant decrease in plasma noradrenaline observed, both when the patients were in the supine position (from 298 +/- 27 to 214 +/- 21 pg/ml, p < 0.05) and when they were upright (from 472 +/- 37 to 348 +/- 38 pg/ml, p < 0.05).

Rilmenidine in patients with left ventricular hypertrophy : Beyond the reduction of left ventricular mass

It is generally accepted that the development of left ventricular hypertrophy (LVH) represents a multifactorial phenomenon that also involves neurohormonal mechanisms. This finding may account for the ability of angiotensin-converting enzyme inhibitors to induce faster and more complete reversal of LVH than that observed with other antihypertensive treatments. The sympathetic system is also involved in the genesis of hypertension-induced LVH. We assessed the effects of satisfactory long-term treatment with rilmenidine, a new oxazoline with a potent antihypertensive action, on cardiovascular structural abnormalities and cardiac endocrine function in hypertensive patients with left ventricular hypertrophy. Eleven patients underwent M-mode and two-dimensional Doppler echocardiography, peripheral pulsed Doppler flowmetry, determination of plasma atrial natriuretic factor [(ANF) pg/ml] and renin activity, and 24-h urine electrolyte excretion under control conditions, after 4 weeks of blood pressure normalization, after 1 year of satisfactory antihypertensive treatment and, finally, 4 weeks after therapy withdrawal. I.VH (g/m2 body surface area) was reversed after 1-year treatment (from 152 +/- 5 to 131 +/- 4, p < 0.05). One-year treatment induced an improvement in brachial artery compliance (cm4/dyne.10(7)) (from 0.92 +/- 0.06 to 1.16 +/- 0.08, p < 0.05) that persisted after withdrawal of treatment (1.17 +/- 0.06, p < 0.05). Plasma renin activity and urinary electrolyte excretion did not change throughout the study, whereas ANF remained unchanged after blood pressure normalization (48.4 +/- 6.2 versus 44.7 +/- 2.9, NS), fell after reversal of LVH (28.6 +/- 3.4, p < 0.05), and remained significantly lower than under control conditions after therapy withdrawal (27.5 +/- 2.9, p < 0.05). These results demonstrate that a satisfactory long-term antihypertensive treatment with rilmenidine is able to reverse cardiovascular structural changes and to restore cardiac endocrine function.

Site of myocardial ischemia as a determinant of postexercise blood pressure and heart rate response in coronary artery disease

Forty patients with coronary artery disease and 15 normal subjects (group C) were studied to assess the influence of the site of stress-induced myocardial ischemia on cardiovascular response after exercise. Patients were divided in 2 groups according to myocardial thallium-201 scintigraphy: those with an anteroseptal reversible perfusion defect (group A; n = 24), and those with an inferoposterior reversible perfusion defect (group I; n = 16). All patients underwent serial bicycle exercise stress tests. The first 2 stress tests were interrupted when 0.1 mV of ST-segment depression was achieved (2,000 to 2,500 kg-m); a third test was stopped before the onset of ischemia (1,500 kg-m). Normal subjects performed stress tests at comparable work loads. At ischemic threshold, there was no difference in ejection fraction between groups A (65.5%) and I (67.3%). Mean values and recovery ratios of heart rate and systolic blood pressure were significantly higher in group A than in C and I during the recovery period of the 2,000 to 2,500 kg-m stress test. In contrast, no significant difference was observed among the groups in the 1,500 kg-m stress test, and between groups I and C in any stress test. The data show that in patients with the same degree of stress-induced impairment of ventricular function, the anterior site of ischemia leads to persistently higher values of heart rate and blood pressure after exercise, which are likely due to an enhanced adrenergic discharge.