Biomedical subjects

Roberto Pontremoli

Publications and source records attributed to Roberto Pontremoli.

23 records · Page 2Linked to original sources

PubMed2002

Pulse pressure and subclinical cardiovascular damage in primary hypertension.

BACKGROUND: High pulse pressure (PP) values have recently been implicated in the development and progression of large vessel atherosclerosis, small vessel disease, and in the occurrence of cardiovascular events. The aim of the present study is to investigate the relationship between PP and subclinical cardiovascular damage in a cohort of unselected middle-aged patients (204 male, 129 female) with untreated primary hypertension. METHODS: PP was calculated as the difference between systolic (SBP) and diastolic blood pressure (DBP). Left ventricular mass index (LVMI) was assessed by M-B mode echocardiography (LVH=LVMI>51 g/m(2.7)), and carotid intima-media thickness (IMT) by high-resolution US scan. Albuminuria was measured as the albumin to creatinine ratio (ACR) in three non-consecutive first morning urine samples. RESULTS: PP was positively correlated to gender (P<0.05), duration of disease (P<0.001), age (P<0.0001), LDL cholesterol (P=0.007), and to early signs of target organ damage (TOD), namely LVMI (P<0.0001), IMT (P<0.0001), and ACR (P=0.036). Patients in the upper quartile of PP showed higher LVMI (P<0.001), thicker carotid walls (P<0.001), as well as higher ACR (P<0.04). Multiple linear regression analysis showed that PP and ACR independently influence LVMI (F=26.476, r(2)=0.29, P<0.0001) and IMT (F=17.813, r(2)=0.26, P<0.0001). Patients with LVH, increased carotid IMT and microalbuminuria showed higher PP values as compared with those with lesser degrees of target organ involvement (F=4.97, P<0.003 inter-group comparison). Moreover, the risk of having the simultaneous occurrence of various signs of TOD increases significantly with each SD increase in PP or SBP, but is not influenced by DBP. CONCLUSIONS: PP is an independent marker of preclinical cardiovascular damage in relatively young patients with primary hypertension and, therefore, can be useful for identifying those at higher risk of cardiovascular events.

Adult↗

PubMed2002

Microalbuminuria identifies overall cardiovascular risk in essential hypertension: an artificial neural network-based approach.

BACKGROUND: Ultrasound (US) examination of heart and carotid arteries provides an accurate assessment of target organ damage (TOD) and may influence the stratification of the absolute cardiovascular risk profile. Microalbuminuria has recently proved to be a useful cost-effective marker of increased cardiovascular risk but is still too often neglected in clinical practice. OBJECTIVE: To evaluate how well artificial neural networks (ANNs) predict cardiovascular risk stratification by means of routine data and urinary albumin excretion, as compared to prediction by the clinical work-up suggested by the International Society of Hypertension (ISH), with and without ultrasound-determined TOD. METHODS: A group of 346 never previously treated essential hypertensives (212 men, 134 women, mean age 47 +/- 9 years) was studied. Risk was stratified according to the criteria suggested by the 1999 WHO/ISH guidelines; first, by routine procedures alone, and subsequently by reassessment, using data on cardiac and vascular structures obtained by US evaluation. The ANN was trained and tested to predict the overall cardiovascular risk on the basis of routine clinical data and urinary albumin excretion (UAE). The impact of these three approaches on the determination of cardiovascular risk profile was evaluated. RESULTS: According to the first classification, 5.5% (n = 19) of patients were considered at low risk, 47.3% (n = 164) at medium, 26.7% (n = 92) at high and 20.6% (n = 71) at very high risk. A marked change in risk stratification, namely an increase in the prevalence of high- and very-high-risk patients (2.3% low, 29.8% medium, 42.8% high and 25.2% very high risk; chi(2) 15.201, P < 0.0001), was obtained when US examination of TOD was taken into consideration. On the basis of routine clinical data and UAE, the artificial neural network successfully predicted overall cardiovascular risk and allocated patients in different classes as accurately as the US-based evaluation. CONCLUSIONS: The use of US techniques allows a more precise stratification of absolute cardiovascular risk in hypertensive patients as compared to routine clinical data. An ANN can accurately identify the patients' risk status by using low-cost routine data and UAE. These results further emphasize the value of UAE in the stratification of cardiovascular risk.

Adult↗

PubMed2002

Microalbuminuria, cardiovascular, and renal risk in primary hypertension.

Microalbuminuria is defined as abnormal urinary excretion of albumin between 30 and 300 mg/d. It can be measured accurately by several widely available and sensitive methods. This abnormality can be found in 8 to 15% of nondiabetic patients with primary hypertension, although its prevalence varies greatly in the literature, likely due to differences in the methods used to detect it and to the criteria applied in the selection of patients. The pathogenetic mechanisms leading to the development of microalbuminuria are still not completely known. BP load and increased systemic vascular permeability, possibly due to early endothelial damage, seem to play a major role. Increased urinary albumin excretion has been associated with several unfavorable metabolic and nonmetabolic risk factors and subclinical hypertensive organ damage. In fact, a higher prevalence of concentric left ventricular hypertrophy and subclinical impairment of left ventricular performance, as well as the presence of carotid atherosclerosis, have been reported in patients with microalbuminuria. These associations might per se justify a greater incidence of cardiovascular events. Long-term longitudinal studies have recently confirmed the unfavorable prognostic significance of microalbuminuria in hypertensive patients. It has also been hypothesized that microalbuminuria might be a forerunner of overt renal damage in primary hypertension. Clinical studies, however, have shown conflicting results, and this hypothesis has to be considered tempting but speculative at present. In conclusion, microalbuminuria is a specific, integrated marker of cardiovascular risk and target organ damage in primary hypertension and one that is suitable for identifying patients at higher global risk. A wider use of this test in the diagnostic work-up of hypertensive patients is recommended.

Albuminuria↗

PubMed2002

Changes in renal resistive index and urinary albumin excretion in hypertensive patients under long-term treatment with lisinopril or nifedipine GITS.

INTRODUCTION: Increased renal vascular resistance and microalbuminuria are associated with hypertensive target organ damage and may be predictors of hypertensive nephrosclerosis. AIM: We investigated changes in renal resistive index (RI) and urinary albumin excretion (UAE) in a group of patients with primary hypertension before and during long-term antihypertensive treatment. METHODS: Thirty-two patients were randomized to receive antihypertensive treatment with either a calcium channel blocker (nifedipine GITS, up to 90 mg/day, n = 16) or an ACE inhibitor (lisinopril, up to 20 mg/day, n = 16), alone or in association with a diuretic (chlortalidone, 25 mg/day). Blood pressure, renal resistive index (by US Doppler) and UAE (mean of three nonconsecutive timed urinary collections, microg/min) were evaluated at baseline and over the course of 24 months of treatment. RESULTS: Both regimens effectively lowered blood pressure (mean blood pressure from 123 +/- 1.8 at baseline to 103 +/- 1.5 mm Hg at 24 months in the lisinopril group and from 122 +/- 1.9 at baseline to 104 +/- 0.8 at 24 months in the nifedipine group, p < 0.001 for both groups). Overall, blood pressure decrease was associated with a reduction in UAE and no change in RI throughout the study. However, despite similar blood pressure reduction, the two regimens showed different specific effects. Lisinopril was associated with a significant decrease in both UAE (33.8 +/- 16.2 at baseline and 9.1 +/- 2.1 at 24 months, p < 0.01) and renal RI (0.61 +/- 0.02 at baseline and 0.56 +/- 0.04 at 24 months, p < 0.05) while nifedipine GITS did not significantly influence UAE (35.7 +/- 12.2 at baseline and 31.2 +/- 12.1 at 24 months, n.s.) or RI (0.61 +/- 0.01 at baseline and 0.59 +/- 0.02 at 24 months, n.s.). CONCLUSION: Effective blood pressure control over a long period of time reduces the severity of organ damage, namely UAE while maintaining renovascular resistance in patients with essential hypertension. Different classes of antihypertensive agents might convey additional specific renal protection beyond blood pressure control. These data could be useful in devising individualized therapeutic strategies in hypertensive patients at increased renal risk.

Adult↗

PubMedDate not supplied

Microalbuminuria and subclinical cerebrovascular damage in essential hypertension.

BACKGROUND: Microalbuminuria is a marker of hypertensive and atherosclerotic organ damage in essential hypertension and has powerful prognostic value for cerebral and cardiovascular morbidity and mortality. An association between carotid artery intima-media thickness (IMT) and increased urinary albumin excretion (UAE) has been reported in patients with essential hypertension, suggesting a link between microalbuminuria and atherosclerotic stroke mechanism(s). METHODS: We investigated the relationships between UAE, carotid artery changes, and asymptomatic cerebrovascular damage in two groups of untreated essential hypertensive patients, with (n=11) and without (n=11) microalbuminuria. The study groups, selected among participants in a large epidemiological trial, were carefully matched for several potential confounding variables such as sex, age, duration of hypertension, and body mass index. None had neurological abnormalities. Albuminuria was measured as albumin excretion rate (UAE) on three overnight collections; microalbuminuria was defined as between 20-200 microg/min. Carotid IMT was assessed by high resolution US scan, cerebral lacunar lesions by magnetic resonance imaging (MRI), and left ventricular mass index (LVMI) by M-B mode echocardiography. Office and 24-h ambulatory blood pressures (ABP, Takeda 2420) were also recorded. RESULTS: There were no differences between the two groups in office and ABP, lipid profile and smoking habits. Microalbuminuric patients had a higher prevalence of cerebral ischemic lacunae (82 vs 27%; P=0.03, OR=12, confidence interval - CI 1.6-91.1), and higher carotid IMT (0.94+/-0.05 vs 0.75+/-0.06 mm; P=0.03) than normoalbuminuric patients. No differences were found in LVMI and in the prevalence of Left Ventricular hypertrophy. Patients with ischemic lacunae showed a higher prevalence of microalbuminuria (75 vs 22%; P=0.03, OR=12, CI 1.0-13.5) and higher UAE (58.7+/-21.8 vs 9.4+/-3.7 mg/mmol, P=0.01) than to patients with normal MRI. CONCLUSIONS: Microalbuminuria is an early marker of preclinical brain damage in essential hypertension and may therefore be useful for identifying patients at higher risk of cerebral and cardiovascular events, for whom preventive therapeutic measures are advisable.

Aged↗