Biomedical subjects

M L Muiesan

Publications and source records attributed to M L Muiesan.

At least 19 recordsLinked to original sources

PubMed2001

Cardiovascular status of carriers of the apolipoprotein A-I(Milano) mutant: the Limone sul Garda study.

BACKGROUND: Carriers of the apolipoprotein A-I(Milano) (apoA-I(M)) mutant present with very low plasma HDL cholesterol and moderate hypertriglyceridemia, apparently not leading to premature coronary heart disease. The objective of this study was to establish whether this high-risk lipid/lipoprotein profile is associated with structural changes in the carotid arteries and heart, indicative of preclinical atherosclerosis. METHODS AND RESULTS: Twenty-one A-I(M) carriers were compared with age- and sex-matched control subjects from the same kindred and with 2 series of matched subjects with primary hypoalphalipoproteinemia (HA). Structural changes in the carotid arteries were defined as the intima-media thickness (IMT) measured by B-mode ultrasound. HA subjects, both recruited among patients attending our Lipid Clinic and blood donors, showed significant thickening of the carotids (average IMT, 0.86+/-0.25 and 0.88+/-0.29 mm, respectively) compared with control subjects (average IMT, 0.64+/-0.12 mm); the apoA-I(M) carriers instead showed normal arterial thickness (average IMT, 0.63+/-0.10 mm). Moreover, a significantly higher prevalence of atherosclerotic plaques was found in patients and blood donors with HA (both 57%) compared with apoA-I(M) carriers (33%) and control subjects (21%). Echocardiographic findings and maximal treadmill ECG did not differ significantly between apoA-I(M) carriers and control subjects, apart from a slight increase in left ventricular end-diastolic dimension in the carriers. CONCLUSIONS: Despite severe HA, carriers of the apoA-I(M) mutant do not show structural changes in the arteries and heart, in contrast to HA subjects, who are characterized by a marked increase in carotid IMT and increased prevalence of atherosclerotic plaques.

Adult↗

PubMed2001

Structural alterations in subcutaneous small arteries of normotensive and hypertensive patients with non-insulin-dependent diabetes mellitus.

BACKGROUND: It is not presently known whether non-insulin-dependent diabetes mellitus (NIDDM) is associated with the presence of structural alterations in small arteries or whether the combination of hypertension and NIDDM may have an additive effect on endothelial dysfunction. Therefore, we investigated subcutaneous small arteries in 12 normotensive subjects (NT group), 18 patients with essential hypertension (EH group), 13 patients with NIDDM, and 11 patients with NIDDM and EH (NIDDM+EH group). METHODS AND RESULTS: Subcutaneous small arteries were evaluated by a micromyographic technique. The internal diameter, the media-to-lumen ratio, remodeling and growth indices, and the collagen-to-elastin ratio were calculated. Concentration-response curves to acetylcholine, bradykinin, the endothelium-independent vasodilator sodium nitroprusside, and endothelin-1 were performed. The media-to-lumen ratio was higher in the EH, NIDDM, and NIDDM+EH groups compared with the NT group. EH patients showed the presence of eutrophic remodeling, whereas NIDDM and NIDDM+EH patients showed 40% to 46% cell growth. The collagen-to-elastin ratio was significantly increased in the EH and NIDDM+EH groups compared with the NT group. The vasodilatation to acetylcholine and bradykinin was similarly reduced in EH, NIDDM, and NIDDM+EH groups compared with the NT group. The contractile responses to endothelin-1 were similarly reduced in EH, NIDDM, and NIDDM+EH patients. CONCLUSIONS: Our data suggest that the effects of NIDDM and EH on small artery morphology are quantitatively similar but qualitatively different and that the presence of hypertension in diabetic patients has little additive effect on small artery morphology and none on endothelial dysfunction.

Acetylcholine↗

PubMed2001

Midwall mechanics are improved after regression of hypertensive left ventricular hypertrophy and normalization of chamber geometry.

BACKGROUND: It is still unclear whether substantial regression of hypertensive left ventricular hypertrophy (LVH) and normalization of chamber geometry are associated with improved left ventricular (LV) myocardial function. METHODS AND RESULTS: Midwall mechanics were evaluated in 152 patients undergoing 1 year of effective antihypertensive treatment. Two-dimensionally directed M-mode echocardiography was performed as follows: (1) after a 4-week placebo "run-in" period, (2) after 1 year of treatment with 20 mg/d lisinopril (alone or associated with 12.5 to 25 mg/d hydrochlorothiazide), and (3) after a final 1-month placebo period to allow blood pressure (24-hour average ambulatory monitoring) to return to pretreatment levels. Treatment-induced reductions in blood pressure (from 149+/-16/95+/-11 to 131+/-12/83+/-10 mm Hg, P:<0.05) and circumferential end-systolic wall stress (from 84+/-22 to 72+/-19 g/cm(2), P:<0.05) were associated with a marked reduction in LV mass index (from 159+/-30 to 133+/-26 g/m(2), P:<0.05). LVH regression was accompanied by an increase in midwall fractional shortening (from 19.7+/-2.7% to 20.9+/-2.7%, P:<0.05) and by a decrease in relative wall thickness (from 48.2+/-7.7% to 44.1+/-6.7%, P:<0.05). The improvement in midwall function associated with afterload reduction and substantial LVH regression persisted after antihypertensive therapy withdrawal and restoration of the hypertensive state. Despite a significant increase in end-systolic wall stress, further LV chamber remodeling did not occur. The preservation of relative wall thickness was associated with a persistent improvement in midwall systolic function. CONCLUSIONS: Regression of concentric LVH is associated with an improvement of midwall systolic function, which is more dependent on the normalization of LV geometry than on the reduction in LV systolic stress.

Adult↗

PubMed2001

Flow-mediated dilatation of the brachial artery and left ventricular geometry in hypertensive patients.

OBJECTIVES: In arterial hypertension, the spectrum of geometric patterns in the left ventricle may parallel the structural alterations detected in the carotid arteries and in subcutaneous small arteries. It has been also reported that hypertensive left ventricular hypertrophy (LVH) may be associated with endothelial dysfunction, as evaluated by the response of coronary or forearm vasculature to acetylcholine infusion. The aim of this study was to evaluate the flow-mediated vasodilatation (FMD) of the brachial artery, non-invasive estimate of endothelium-dependent vasodilatation according to left ventricular geometric adaptations in hypertensive patients. METHODS AND RESULTS: In 16 normotensive (nine males, seven females, aged 40-68 years) and in 78 hypertensive subjects (50 males, 28 females, aged 42-67 years), we performed an echocardiographic study for the measurement of left ventricular mass index (LVMI) and relative wall thickness (RWT); we measured to a high resolution the brachial artery diameter at rest, during reactive hyperaemia (5 min of brachial artery occlusion) and after sublingual glyceril trinitrate (GTN); brachial artery flow velocity was measured by pulsed Doppler. Twenty-six hypertensive patients had a normal LVMI (LVMI < 51 g/ m2.7) and geometry (RWT < 0.44), five had concentric remodelling (RWT > or = 0.44), and concentric and eccentric LVH were observed in 19 and 28 patients, respectively. FMD was reduced in hypertensive patients as compared with normotensive subjects (P< 0.01). No correlation was found between FMD and LVMI (r= -0.078) or RWT (r = 0.049); in addition, no difference in FMD was found among the left ventricular geometric patterns in hypertensive patients. CONCLUSIONS: In hypertensives, the presence of endothelial dysfunction is not associated with the LVH or with different left ventricular geometric patterns, suggesting that different and independent mechanisms may be responsible for the presence of LVH and of endothelial dysfunction.

Adult↗

PubMed2001

The smoothness index, but not the trough-to-peak ratio predicts changes in carotid artery wall thickness during antihypertensive treatment.

BACKGROUND: It has recently been demonstrated that the smoothness index (SI) (the ratio between the average of the blood pressure changes computed for each hour of the recording and its standard deviation), a new and reproducible measure of the homogeneity of blood pressure reduction by antihypertensive treatment, has evident advantages over trough-to-peak ratio (T/P) in the prediction of the regression of left ventricular hypertrophy. Therefore we considered it to be worthwhile to compare the ability of SI and T/P to predict changes of the carotid artery intima-media thickness (IMT) during pharmacological treatment in patients with essential hypertension. METHODS: In 100 patients with essential hypertension, 24 h ambulatory blood pressure and carotid artery IMT were measured after 3 weeks of therapeutic wash-out and after 12 months of antihypertensive treatment (calcium antagonists, diuretics, angiotensin converting enzyme (ACE) inhibitors or beta-blockers). The homogeneity of the effect of treatment over blood pressure was evaluated by computing T/P and SI. RESULTS: Twenty-four hour blood pressure was significantly reduced by therapy, while, on average, a small but significant increase in indices of carotid artery wall thickness was observed. However, IMT was clearly reduced in patients with high SI. Statistically significant correlations were observed between changes in indices of carotid artery IMT during therapy and SI. No significant correlation was observed between indices of carotid artery morphology and T/P, basal 24 h blood pressure or changes in blood pressure during therapy. CONCLUSIONS: SI, but not T/P is the predictor of changes in carotid artery wall thickness. The information provided by SI is independent from basal blood pressure values. For carotid artery morphology, the smoothness of blood pressure reduction is even more important than its absolute change.

Adult↗

PubMed2001

Endothelial dysfunction in small resistance arteries of patients with non-insulin-dependent diabetes mellitus.

OBJECTIVE: Arterial hypertension is frequently associated with the presence of endothelial dysfunction in human subcutaneous small resistance arteries, as evaluated by responses to acetylcholine or bradykinin; however it is not known whether patients with diabetes mellitus show similar alterations. Therefore, we have investigated endothelial function in subcutaneous arteries of normotensive subjects (NT), of patients with essential hypertension (EH), of patients with non-insulin-dependent diabetes mellitus (NIDDM), as well as of patients with both essential hypertension and non-insulin-dependent diabetes mellitus (NIDDM+EH). PATIENTS AND METHODS: All subjects were submitted to a biopsy of the subcutaneous fat Small arteries were dissected and mounted on a micromyograph. The media to lumen ratio (M/L) was calculated. A concentration-response curve to acetylcholine, to bradykinin as well as to the endothelium-independent vasodilator sodium nitroprusside were performed. We also evaluated the contractile response to endothelin-1. Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) plasma levels were also measured. RESULTS: The vasodilatation to acetylcholine and bradykinin (but not to sodium nitroprusside) was significantly and similarly reduced in EH, in NIDDM, and in NIDDM+EH compared with NT. The contractile response to endothelin-1 was similarly reduced in EH, in NIDDM and in NIDDM+EH. Plasma ICAM-1 and VCAM-1 concentrations were higher in EH, NIDDM and NIDDM+EH than in NT. CONCLUSIONS: An evident endothelial dysfunction was detected in patients with NIDDM, and the simultaneous presence of EH did not seem to exert an additive effect. The contractile responses to endothelin-1 were reduced possibly as a consequence of ET(A) receptor down-regulation.

Arteries↗

PubMed2000

Time course of apoptosis in small resistance arteries of spontaneously hypertensive rats.

OBJECTIVE: The time course of programmed cell death (apoptosis) in the vasculature of spontaneously hypertensive rats (SHRs) is still unclear. Moreover, no data are presently available about the possible inter-relationships between apoptosis and vascular remodelling. The aim of this study was to investigate the mesenteric small resistance arteries and large arteries (aortas) of SHRs and normotensive Wistar-Kyoto (WKY) rats at different ages, before and after the development of overt hypertension. METHODS: Twenty-four SHRs (4, 8 or 12 weeks old) and 24 age-matched WKY rats were included in the study. Blood pressure was measured non-invasively. Rats were killed by decapitation and segments of aortas and small mesenteric arteries were dissected free from the surrounding tissue. Mesenteric arteries were mounted on a micromyograph and structural characteristics were measured (media thickness, media:lumen ratio, etc.). Apoptotic cells in the tunica media of large and small vessels were then stained using modified TdT-mediated dUTP Nick-End Labeling (TUNEL). RESULTS: At 4 weeks of age no difference in the blood pressure and percentage of apoptosis in mesenteric arteries between SHRs and WKY rats was detected; however, the media:lumen ratio of mesenteric small resistance arteries was significantly greater in SHRs. At 8 and 12 weeks of age systolic blood pressure, media:lumen ratio and apoptosis rate in mesenteric small arteries was significantly higher in SHRs. The rate of apoptosis in the aortas was similar in the two strains at all three ages. CONCLUSIONS: An increased prevalence of apoptosis was observed in mesenteric small arteries of 8- and 12-week-old SHRs. It is possible that apoptosis may exert a role in small resistance artery remodelling during the development and establishment of hypertension.

Aging↗

PubMed2000

Changes in midwall systolic performance and cardiac hypertrophy reduction in hypertensive patients.

OBJECTIVE: To investigate changes in left ventricular (LV) performance, as evaluated by measurement of midwall LV fractional shortening (FS), after reduction of cardiac hypertrophy. DESIGN AND METHODS: Echocardiographic evaluation of LV anatomy and function was performed by M-mode echocardiography at baseline, after long-term antihypertensive therapy, and after treatment withdrawal in 68 asymptomatic hypertensive patients (50 males, 18 females, age range 22-62 years). Patients were divided according to the presence of LV hypertrophy (LVH) at baseline (LV mass index, LVMI, > or = 51 g/m(2.7)). RESULTS: At baseline patients with concentric (relative wall thickness > 0.44) LV hypertrophy (n = 38) or remodelling (n = 7) had reduced midwall shortening with respect to patients with normal LV geometry (n = 4) or eccentric LVH (n = 19); no differences were observed for endocardial FS. After long-term treatment (average 15 months), in 11 patients LV mass remained within normal limits, in 45 patients LVH reduction was obtained, while in 12 patients LV mass remained persistently elevated. Midwall FS was significantly increased in patients with reduction of LVH both during treatment and after withdrawal of treatment, while it remained significantly lower in patients with persistently elevated LV mass. Changes in midwall fractional shortening were independently associated with modifications in relative wall thickness (P < 0.00001), with changes in end-diastolic dimensions (P < 0.0001) and those of LVMI (P< 0.02) as shown by multivariate analysis. CONCLUSION: LV midwall systolic performance significantly improved after reduction of LVH, even in the presence of high blood pressure values. Modifications in relative wall thickness are more independently associated with changes, in LV diastolic dimensions and mass, to midwall improvement

Adult↗

PubMed2000

Cellular hypertrophy in subcutaneous small arteries of patients with renovascular hypertension.

Structural alterations of small arteries in patients with essential hypertension are characterized by inward eutrophic remodeling. However, small arteries in patients with secondary hypertension, as well as in experimental models of hypertension with high circulating renin, are characterized by inward hypertrophic remodeling, which is characterized by smooth muscle cell hypertrophy in animal models. The aim of our study was to determine whether remodeling of subcutaneous small arteries in patients with secondary forms of hypertension is associated with smooth muscle cell hypertrophy and/or alterations in the elastic modulus of the vessel wall. Fifteen patients with renovascular hypertension, 9 with primary aldosteronism, and 13 with essential hypertension and 9 normotensive subjects were included in the study. A biopsy of subcutaneous fat was taken from all subjects. Small arteries were dissected, and morphology was determined on a micromyograph. Unbiased estimates of cell volume and number were made in fixed material. From the resting tension-internal circumference relation of the small arteries, the incremental elastic modulus was calculated and plotted as a function of wall stress. Blood pressure was greater in patients with essential hypertension, renovascular hypertension, or primary aldosteronism than in normotensive subjects, but no significant difference was observed among the 3 groups of hypertensive patients. The media/lumen ratio, the medial cross-sectional area, and the smooth muscle cell volume were significantly greater in patients with renovascular hypertension than in normotensive subjects and patients with essential hypertension. No difference in cell number or in the elastic properties was observed among the 4 groups of subjects. In conclusion, our data demonstrate for the first time that a pronounced activation of the renin-angiotensin-aldosterone system is associated with vascular smooth muscle cell hypertrophy in human hypertension in a manner similar to that found in animal models.

Arteries↗

PubMed2000

[The primary and secondary prevention of hypertensive cardiopathy].

Antihypertensive treatment is useful in reducing cardiovascular morbidity and mortality. The possibility of preventing cardiac events is mainly related to the effect of antihypertensive drugs on the occurrence of hypertensive heart disease, i.e. on the anatomic and functional abnormalities of the left ventricle that represent the direct consequence of blood pressure increase. Hypertensive heart disease is associated with the concomitant occurrence of structural and functional changes in large arteries and small resistance arteries. Left ventricular hypertrophy represents the sign of preclinical disease in hypertensive heart disease. The use of antihypertensive treatment may induce the regression of left ventricular hypertrophy and determine a significant improvement of functional and clinical consequences of cardiac hypertrophy, and more importantly the regression of left ventricular hypertrophy is associated with an improvement of cardiovascular prognosis in hypertensive patients. It remains to be established whether some antihypertensive drugs are more effective, or only faster, in determining left ventricular hypertrophy regression. Antihypertensive treatment is extremely useful not only in the primary prevention of cardiac events and hypertrophy, but also in the reduction of cardiac complications in patients already presenting with cardiac disease; in fact these patients are at higher cardiovascular risk and therefore the benefit from blood pressure reduction may be even more evident.

Antihypertensive Agents↗

PubMed1999

Reliability and limitations of echocardiographic measurement of left ventricular mass for risk stratification and follow-up in single patients: the RES trial. Working Group on Heart and Hypertension of the Italian Society of Hypertension. Reliability of M-mode Echocardiographic Studies.

OBJECTIVE: To investigate the clinical reliability of repeated measurements of left ventricular mass in a single patient. DESIGN: We used test-retest reliability analysis, within-class correlation and interval of agreement measures. METHODS: Two M-mode tracings (three consecutive cycles) were recorded in the same session and 3-10 days apart (5+/-2 days; mean +/- SD) in 261 participants (age 45+/-13 years, body mass index 24.7+/-3.6 kg/m2; 131 hypertensive and 130 normotensive; 50% of each group women) in 16 centres in Italy. The two tracings were read by two observers in each centre, after classification by a three-order quality score (1 = poor, 2 = sufficient, 3 = optimal). RESULTS: The average quality score was 2.11+/-0.71 (21% poor, 50% sufficient, 29% optimal). Left ventricular mass values ranged from 56 to 419 g (170+/-61 g). On the same day, within-observer 90% interval of agreement between tracing 1 and tracing 2 was -28 to +22 g (-17 to +11% of tracing 1). For day-to-day test-retest within-observer variability (average three cycles), the 90% interval of agreement was -30 to +35 g (-18 to +18%). This variability decreased to -13 to +12% at the 80% interval of agreement and -12 to +11% at the 75% interval of agreement. The 90% interval of agreement of test- retest between-observer variability was -26 to 30 g (-19 to +15%). A negligible regression toward the mean was identified. Categorical consistency of retest in the identification of hypertensive patients with left ventricular hypertrophy, classified in the first study, was 87% (k = 0.87). CONCLUSIONS: Measurement of left ventricular mass in single patients allows reliable risk stratification on the basis of the presence of left ventricular hypertrophy. The probability of a true change in left ventricular mass over time is maximized for a single-reader difference greater than 18% of the initial value, although differences of 10-13% might also have clinical relevance.

Adolescent↗

PubMed1999

Effect of treatment on flow-dependent vasodilation of the brachial artery in essential hypertension.

off aim of our study was to evaluate the effect of antihypertensive treatment on flow-mediated dilation (FMD)of a large artery, a noninvasive estimate of endothelial function, in hypertensive patients. In 78 consecutive hypertensive patients (40%men; age range, 42 to 67 years) we measured by a high-resolution ultrasound system the changes of brachial artery diameter during reactive hyperemia and after sublingual glyceryl trinitrate (400 microg); brachial artery flow velocity was measured by pulsed Doppler. The results of 2 studies are reported. In the first study, this procedure was repeated in 58 patients after 6 and 12 months of treatment with a combination of antihypertensive drugs; in a second study, the FMD was assessed in 20 patients after 2 months of monotherapy with either nifedipine or hydrochlorothiazide. In the first study, FMD was significantly increased after treatment compared with baseline (from 3.1+/-3% at baseline to 6.5+/-4.5% at 6 months and to 8.12+/-4. 6% at 12 months; P<0.001 by ANOVA), concomitant with blood pressure reduction (from 162+/-24/102+/-13 mm Hg to 141+/-12/89+/-6 mm Hg and to 141+/-9/89+/-6 mm Hg; P<0.001 by ANOVA); significant changes of endothelium-independent dilation were also observed, but only after 12 months of treatment (from 14.2+/-4.8 at baseline to 15.5+/-4.7 at 6 months and 16.8+/-5.9% at 12 months; P=0.03 by ANOVA). In the second study, FMD was significantly increased during nifedipine treatment as compared with baseline (from 5+/-6.18% at baseline to 9. 45+/-3.94%, P<0.001), while it did not change in patients receiving hydrochlorothiazide (from 5.15+/-5.28% at baseline to 4.69+/-4.34%, NS). No significant changes of endothelium-independent dilation were observed with both drugs (from 17.10+/-2.4% to 18.14+/-3.76% and from 18.73+/-4.07% to 17.46+/-4.27% during nifedipine and hydrochlorothiazide, respectively, NS). Thus, in essential hypertensive patients an improvement of the impaired FMD of the brachial artery, evaluated by noninvasive ultrasound, may be observed after long-term, effective blood pressure reduction, suggesting a beneficial effect of antihypertensive treatment on endothelial function. It seems that beyond blood pressure control, a calcium antagonist may be more effective than a diuretic in this respect.

Adult↗

PubMed1998

Relations between cardiac and vascular structure in patients with primary and secondary hypertension.

BACKGROUND: Data on cardiac and vascular structure in secondary hypertension are generally scarce, and no data on the interrelations between cardiac mass and structural characteristics of the vessel wall, both in large and in small resistance arteries, are presently available. OBJECTIVES: The aim of this study was to investigate the relation between structural changes in subcutaneous small arteries, left ventricular mass and wall thickness of the common carotid artery in patients with primary and secondary hypertension. METHODS: Seventy-four subjects were included in the study: 11 patients with pheochromocytoma, 14 with primary aldosteronism (PA), 19 with renovascular hypertension (RVH), 18 with essential hypertension (EH) and 12 normotensive (NT) control subjects. All subjects were submitted to a biopsy of subcutaneous fat. Morphologic characteristics of subcutaneous small resistance arteries (relaxed diameter <300 microm) were directly evaluated using a micromyographic technique. All subjects were submitted to calculation of left ventricular mass index (LVMI) and common carotid artery intima-media thickness (CCIMT), using ultrasound technique. RESULTS: The correlation coefficients between the media to lumen ratio in subcutaneous small arteries (M/L) and LVMI or between M/L and CCIMT were closer in RVH than in pheochromocytoma, EH or NT; in PA the correlation coefficients were slightly less close than those in RVH. An excess prevalence of carotid plaques in RVH was observed. CONCLUSIONS: A close relation between small resistance artery morphology and cardiac or carotid artery structure may be observed in those hypertensive patients in whom the renin-angiotensin-aldosterone system is activated. In constrast, in NT, EH and pheochromocytoma no significant correlation between M/L and LVMI or CCIMT was observed.

Arterioles↗

PubMed1998

Effects of hypotensive and non-hypotensive doses of manidipine on structure, responses to endothelin-1 and ICAM-1 production in mesenteric small resistance arteries of spontaneously hypertensive rats.

OBJECTIVE: We have evaluated the effects of a new calcium channel blocker, manidipine, given at both high, hypotensive and low, non-hypotensive doses, on vascular morphology, response to endothelin-1 and ICAM-1 production in mesenteric small resistance arteries of spontaneously hypertensive rats (SHR). METHODS: Ten SHR were treated with manidipine 3 mg/kg per day (high dose) and 10 with manidipine 0.3 mg/kg/per day (low dose). The drug was administered by gavage from the 4th to 12th weeks of age. Eighteen Wistar-Kyoto (WKY) rats and 18 SHR were kept untreated as controls. Rats were killed at 13 weeks. Mesenteric small arteries were dissected and mounted on a micromyograph for determination of indexes of vascular structure (media thickness, wall thickness, media/lumen ratio). RESULTS: Systolic blood pressure was significantly reduced by the high dose of the drug, while no effect was observed with low-dose manidipine. A reduction in the media/lumen ratio was observed only in SHR treated with high-dose manidipine. The response to endothelin-1 in untreated SHR was significantly lower in comparison with WKY; a significant reduction was observed in SHR treated with high-dose manidipine. ICAM-1 vascular concentrations were higher in untreated SHR than in WKY controls. Both high- and low-dose manidipine reduced ICAM-1 concentrations toward normalization. CONCLUSIONS: Manidipine at high, hypotensive, but not at low, non-hypotensive doses has been proven to reduce structural alterations in mesenteric small resistance arteries, and to normalize vascular responses to endothelin-1. In addition, manidipine, at both low and high doses, may reduce ICAM-1 vascular production, thus suggesting a possible anti-atherogenic effect.

Animals↗

PubMed1998

Reduction of cardiovascular structural changes by nifedipine GITS in essential hypertensive patients.

The aim of this study was to evaluate the effect of the calcium antagonist Nifedipine GITS in a double-blind, randomized comparison with the diuretic hydrochlorothiazide (HCTZ) on reduction of left ventricular (LV) mass and minimal vascular resistance in a group of essential hypertensives with left ventricular hypertrophy (LVH). The effects on blood pressure and on echocardiographic LV functional parameters were also analysed. After two months of randomized treatment with Nifedipine GITS or HCTZ, if diastolic blood pressure was > 90 mmHg, a combination of the two drugs was given and was continued for 24 weeks. M-mode, 2D-guided echocardiography was used to measure LV mass index (LVMI) according to the "Penn convention". Minimal vascular resistance was measured in the forearm, from arterial pressure and maximal blood flow, using a strain gauge plethysmography. All examinations were performed before and after 8 and 24 weeks of treatment. Changes in LVMI were analysed at 8 weeks and at 24 weeks in patients receiving monotherapy ("according to protocol" analysis), and also at the end of treatment in patients taking Nifedipine or HCTZ monotherapy or the combination of the two drugs ("intention to treat" analysis). Both Nifedipine and HCTZ significantly reduced systolic and diastolic blood pressure (p < 0.001), without any significant difference between the two drug treatments. Heart rate was not significantly modified by either treatment. A progressive decrease in LVMI was observed after 8 and 24 weeks of treatment with Nifedipine monotherapy (ANOVA, p = 0.03), while the decrease in LVMI during HCTZ treatment did not progress further at 24 weeks (ANOVA, p = 0.49). A significant reduction of minimal vascular resistance was observed in patients treated with Nifedipine GITS monotherapy (ANOVA, p = 0.001), but not in the HCTZ group (ANOVA, p = 0.06). Comparison of changes of forearm minimal vascular resistance, considering baseline values, could demonstrate a greater effect during Nifedipine monotherapy as compared to HCTZ monotherapy. In conclusion, in a group of hypertensive patients with LVH, treatment for 24 weeks with Nifedipine GITS alone or in combination with HCTZ induced a significant reduction in LVMI and of forearm vascular structural changes, as evaluated by minimal vascular resistance. The decrease of minimal vascular resistance was significantly greater in patients treated with Nifedipine monotherapy, as compared to those given HCTZ.

Adult↗

PubMed1998

Reproducibility and clinical value of nocturnal hypotension: prospective evidence from the SAMPLE study. Study on Ambulatory Monitoring of Pressure and Lisinopril Evaluation.

OBJECTIVE: To assess whether modifications in the nighttime blood pressure fall caused by antihypertensive treatment predict the regression of end-organ damage of hypertension. METHODS: The analysis was performed in patients with essential hypertension and echocardiographically detected left ventricular hypertrophy involved in the SAMPLE study. For each patient, ambulatory blood pressure monitoring and echocardiographic determination of left ventricular mass index were performed at the end of a 4-week wash-out pretreatment period, after 3 and 12 months of treatment with lisinopril or with lisinopril plus hydrochlorothiazide and after a final 4-week placebo period. For each ambulatory blood pressure monitoring the 24 h average, daytime average (0600-2400 h), night-time average (2400-0600 h) and day-night difference was computed. The percentages of dipper and non-dipper patients (i.e. the patients with night blood pressure falls greater and less than 10% of the daytime average, respectively) were also computed. RESULTS: The reproducibility of the day-night difference was low, both for comparison of the pretreatment and final placebo periods (n = 170) and for comparison of the third and the 12th month of treatment (n = 180). The reproducibility of the dipper-non-dipper dichotomy was also low, 35-40% of patients becoming non-dippers if they were dippers and vice versa, both with and without treatment The changes in left ventricular mass index after 12 months of treatment were significantly (P<0.01) related to the changes in 24 h, daytime and night-time blood pressure (r always > 0.33), but this was not the case for the treatment-induced modification of the day-night difference (r= -0.03 and -0.008 for systolic and diastolic blood pressures, respectively). CONCLUSIONS: Our results show that day-night blood pressure changes and the classification of patients into dippers and non-dippers are poorly reproducible over time. It also provides the first prospective evidence that treatment-induced changes in day-night blood pressure difference are not related to treatment-induced regression of left ventricular mass index, thus having a limited clinical significance.

Adult↗

PubMed1998

Various ways of calculating echocardiographic left ventricular mass and their relative prognostic values.

OBJECTIVE: To compare the calculations of left ventricular mass according to thick-wall [American Society of Echocardiography (ASE) and Penn convention] and thin-wall (Wikstrand formula) models. METHODS: We have reexamined the data from the cross-sectional study on the general population sample of Vobarno and from a prospective longitudinal study of hypertensive patients assessing the prognostic significance of changes in left ventricular mass during a follow-up period of 10 years on average (Brescia population). RESULTS: For the Vobarno and Brescia populations, we found a close relationship between values of left ventricular mass calculated by using a thin-wall ellipsoidal model (Wikstrand formula) and those calculated using a thick-wall model with Penn convention or ASE left ventricle measurements (r = 0.99, for both the Vobarno and Brescia populations). Highest values of Penn left ventricle mass were slightly underestimated by use of the thin-wall formula. The numbers of nonfatal cardiovascular events and the relative risks, evaluated by Cox proportional hazard models for 151 patients seen at follow-up did not differ for patients with persistence of left ventricular hypertrophy (LVH), those with regression of LVH, and those with normal left ventricle mass, both at baseline and at follow-up, when these different ways of measuring left ventricle mass and partition values for LVH were used. CONCLUSIONS: The calculation of left ventricle mass according to the ASE recommendations or to the Penn convention, both of which are based on the assumption that the left ventricle can be represented by a prolate ellipsoid with both the internal and external long axes twice the short axis, produces results similar to those obtained using an alternate formula for the calculation of left ventricle mass, considering wall thickness constant around the ellipsoidal cavity. The cardiovascular risk stratification, in relation both to baseline left ventricular mass and to its change during long-term antihypertensive treatment, does not differ significantly among the results of these three different calculations.

Antihypertensive Agents↗

PubMed1998

Power spectral analysis of the heart rate in hypertensive patients with and without left ventricular hypertrophy: the effect of a left ventricular mass reduction.

OBJECTIVE: The aim of this study was to evaluate the spectral analysis of the heart rate in normotensive subjects and in hypertensive patients with and without left ventricular hypertrophy (LVH), under basal conditions and after a reduction in left ventricular mass. SUBJECTS AND METHODS: In 12 normotensive subjects and 22 hypertensive patients (14 with and eight without LVH), we performed 24 h electrocardiogram Holter monitoring, ambulatory blood pressure monitoring and an echocardiographic study. Sequences of 512 R-R intervals, during daytime, afternoon and night-time periods, were taken for an evaluation of spectral analysis (Box-Jenkins method). We then calculated the absolute and percentage power spectral density of the peak centred at 0.10 Hz (low-frequency peak) and at 0.25 Hz (high-frequency peak). RESULTS: At baseline, a daytime to night-time decrease in the low-frequency peak was detected in normotensives (P < 0.01) and in hypertensives without LVH (P < 0.01), while no change was observed in hypertensives with LVH. The power spectral density low-frequency peak during the daytime and night-time was significantly greater in hypertensives with LVH than in those without LVH (P < 0.001) and in normotensive subjects (P < 0.001). Fourteen of these patients with LVH were given effective long-term antihypertensive treatment and were studied again 20 days after the treatment had been withdrawn, when blood pressure had increased to pretreatment values. In eight patients showing a reduction in LVH, we found a significant decrease in the power spectral density low-frequency peak and an increase in the high-frequency peak during daytime and night-time in respect to basal conditions, and circadian variations in the spectral indices of heart rate variability were restored. In contrast, in six patients without reversal of LVH, the power spectral density low-frequency peak did not change in respect to basal conditions and remained significantly higher in comparison with the patients with LVH regression. CONCLUSION: A reduction in LVH may be associated with restoration of daytime to night-time cardiac autonomic control, as evaluated by a power spectral analysis of the heart rate.

Adolescent↗