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Biomedical subjects

Stefano Perlini

Publications and source records attributed to Stefano Perlini.

14 recordsLinked to original sources

Adenosine A1 receptor expression during the transition from compensated pressure overload hypertrophy to heart failure.

OBJECTIVES: Myocardial adenosine is increased in pressure-overload hypertrophy (POH) and exerts important cardioprotective effects that delay transition to left ventricular failure. Adenosine-mediated signaling is attenuated in POH, but whether this depends on receptor or postreceptor defects is unknown. We therefore examined left ventricular adenosine A1-receptor gene and protein expression in experimental POH. METHODS: Six week-old Sprague-Dawley rats were subjected to abdominal aortic banding (group B) or sham operation (group S). Echocardiography and left ventricular catheterization were performed 10 weeks later under ketamine anesthesia. Left ventricular and lung weight indices were obtained postmortem. A1-Receptor mRNA and protein expression were measured in samples from left ventricular, right ventricular and aortic arch tissue. Group B rats were subgrouped as having compensated or decompensated hypertrophy according to the absence or presence of lung congestion (lung weight index below or above mean +/- 2SD compared with group S rats). RESULTS: Both mRNA and protein A1-receptor expression were significantly increased in compensated group B versus group S rats (by, respectively, 37 and 77%; both P < 0.01). This was not observed in decompensated group B rats. No consistent gene or receptor expression changes were observed in right ventricular or aortic tissues. CONCLUSIONS: In compensated POH, increased interstitial adenosine concentrations are accompanied by increased expression of the specific receptor mediating the major cardioprotective effects of this autacoid. Such overexpression is no longer detectable once the transition from POH to left ventricular failure has occurred. These observations may have pathophysiological and, in perspective, therapeutic relevance to the course of hypertensive heart disease.

Animals↗

Survival benefits of different antiadrenergic interventions in pressure overload left ventricular hypertrophy/failure.

We observed previously that in rats with aortic banding (Bd), development of left ventricular (LV) hypertrophy is opposed by beta-blockade, whereas interventions interfering with alpha-adrenoceptor function also inhibit interstitial fibrosis. To assess whether these differential structural effects do translate into different effects on LV function and on heart failure mortality, Bd or sham Bd 8-week-old rats were randomized to vehicle treatment (Vh), chemical sympathectomy ([Sx] 6-hydroxydopamine, 150 mg/kg IP twice a week), beta-adrenoceptor blockade (propranolol [Pro], 40 mg/kg per day PO), or alpha-adrenoceptor blockade (doxazosin [Dox], 5 mg/kg per day PO). After monitoring survival for 10 weeks, the survivors were anesthetized to undergo echocardiography and intraarterial blood pressure measurement. Bd-Vh rats showed increased LV and lung weights, as well as LV dilation, depressed endocardial and midwall fractional shortening and a restrictive transmitral diastolic flow velocity pattern. Compared with Bd-Vh rats, all of the actively treated Bd rats showed less LV hypertrophy, LV dilation, and lung congestion but no less depression of midwall fractional shortening. In contrast, Sx and Dox but not Pro treatment were also associated with lesser degrees of diastolic dysfunction and, even more importantly, with a striking increase in survival (sham banded rats, 100%; Bd-Vh, 40%; Bd-Pro, 51%; Bd-Sx, 83%; and Bd-Dox, 82%). Although Pro, Sx, and Dox provide similar midterm protection from development of LV hypertrophy and dysfunction and from circulatory congestion, only Sx and Dox favorably affected mortality. These findings indicate that in the aortic banding rat model, alpha-adrenoceptors are importantly involved in the pathogenesis of cardiovascular deterioration and disease progression.

Adrenergic alpha-Antagonists↗

Circulating amyloidogenic free light chains and serum N-terminal natriuretic peptide type B decrease simultaneously in association with improvement of survival in AL.

N-terminal natriuretic peptide type B (NT-proBNP) is a marker of cardiac dysfunction in light chain amyloidosis (AL) and a powerful prognostic determinant. Serum NT-proBNP and circulating free light chains (FLCs) were measured at enrollment and after 3 cycles of chemotherapy in 51 patients with cardiac AL. In patients (n = 22, 43%) in whom FLCs decreased by more than 50% (hematologic response), NT-proBNP concentration decreased by a median of 48%, whereas in the remaining patients it increased by 47% (P = .01). The reduction of NT-proBNP was greater in patients (n = 9) in whom amyloidogenic FLCs disappeared at immunofixation (median 53%), than in the remaining responding patients (median 31%, P = .04). Left ventricular wall thickness decreased by at least 2 mm in 3 of 20 patients in whom NT-proBNP improved. Fifteen patients died. Thirteen of them, in whom NT-proBNP and FLCs did not improve, died after a median of 1.8 months. The decrease of FLCs translates into a simultaneous decrease of NT-proBNP and improved survival. Patients in whom chemotherapy fails to induce such a decrease are at risk of early death. Cardiac function in AL can rapidly improve due to a reduction of the circulating amyloidogenic precursor, despite the amount of cardiac amyloid deposits remaining apparently unaltered, as measured by echocardiography.

Adult↗

Unusual manifestations of disseminated neoplasia at presentation: right-sided heart failure due to a massive cardiac metastasis and autoimmune thrombocytopenia in pleomorphic rhabdomyosarcoma of the adult.

Although it is recognized that aggressive soft tissue sarcomas may give rise to cardiac metastases, these manifestations are usually late and clinically silent, being the prevailing finding in exceptional cases. This report describes the occurrence of a massive cardiac metastasis at diagnosis of leg rhabdomyosarcoma in a middle-age adult. This manifestation was the cause of rapidly progressive congestive heart failure and, together with the unusual occurrence of autoimmune thrombocytopenia, led to difficult patient care with a significantly negative influence on the outcome.

Adult↗

Sympathectomy or doxazosin, but not propranolol, blunt myocardial interstitial fibrosis in pressure-overload hypertrophy.

The adaptive changes that develop in the pressure-overloaded left ventricular (LV) myocardium include cardiomyocyte hypertrophy and interstitial fibrosis. Although the former is known to depend to a sizeable extent on sympathetic (over)activity, little information exists whether the same applies to the latter, ie, whether excess catecholamine exposure contributes to the imbalance between collagen deposition by fibroblasts and degradation by matrix metalloproteases (MMPs), eventually leading to LV collagen accumulation. Sprague-Dawley rats were subjected to abdominal aortic banding (B) or sham operation (S) and treated with beta-blockade (Bb, oral propranolol, 40 mg/kg per day), chemical sympathectomy (Sx, 6-hydroxydopamine, 150 mg/kg intraperitoneal twice per week) or vehicle (Vh). Ten weeks later, systolic blood pressure, LV weight, collagen abundance (computer-aided histology), zymographic matrix metalloproteinase (MMP)-2 activity and its specific tissue inhibitor concentration (TIMP-2) were measured. Both sympathectomy and beta-blockade failed to attenuate the banding-induced blood pressure elevation but significantly attenuated the attendant LV hypertrophy. As expected, pressure-overload hypertrophy was associated with interstitial fibrosis (collagen: 4.37+/-1.23% BVh versus 1.23+/-0.44% SVh, P<0.05), which was abolished by sympathectomy (2.55+/-1.31%, P=not significant versus SSx) but left unchanged by beta-blockade (4.11+/-1.23%, P<0.05 versus both SBb and BSx). beta-blockade, but not sympathectomy, was also associated with an increased TIMP-2/MMP-2 ratio (P<0.05), indicating reduced interstitial collagenolytic activity. In separate groups of banded and sham-operated rats, treatment with the alpha-receptor blocker doxazosin (10 mg/kg per day) displayed similar antifibrotic and biochemical effects as sympathectomy. Thus in the course of experimental pressure overload, the sympathetic nervous system plays a major pro-fibrotic role, which is mediated via alpha-adrenergic but not beta-adrenergic receptors.

Adrenergic alpha-Antagonists↗

Peripheral blood progenitor cell mobilization and collection in 42 patients with primary systemic amyloidosis.

BACKGROUND: High-dose chemotherapy followed by an inoculum of autologous peripheral blood progenitor cells (PBPCs) can improve survival in patients affected with primary systemic amyloidosis (AL). It has been documented, however, that the morbidity and mortality of PBPC mobilization and collection in this setting are higher than in patients with other diseases. To minimize the mobilization and collection-related risks, we developed a multidisciplinary approach involving different specialists to manage AL patients with predominant heart and renal involvement. STUDY DESIGN AND METHODS: We report our experience in 42 patients (23 men, 19 women; median age, 51.2 years; range, 28-68 years) with AL who underwent PBPC mobilization and collection. Twenty of the 42 patients (47.6%) had cardiac involvement and 35 of 42 (83.3%) renal involvement. Thirty-three patients (78.5%) were mobilized with granulocyte-colony-stimulating factor (G-CSF) alone (10 microg/kg) and 9 (21.4%) with cyclophosphamide (CTX) (3 g/m(2)) plus G-CSF (10 microg/kg). RESULTS: The median number of collections per patient after either G-CSF or CTX plus G-CSF was 1.8 (range, 1-3). The median number of CD34+ cells collected in patients mobilized with G-CSF alone was 8.2 x 10(6) per kg (range, 1.35 x 10(6)-21.3 x 10(6)/kg) and in patients mobilized with CTX plus G-CSF it was 8.9 x 10(6) per kg (range, 5.5 x 10(6)-14.9 x 10(6)/kg). Forty of the 42 (95.2%) patients produced the minimum required CD34+ cell target dose (4 x 10(6)/kg). The overall rate of morbidity during the collections was 50 percent (21/42 patients): 18 patients (42.8%) had asymptomatic hypotension, 1 (2.4%) had symptomatic hypotension with nausea and vomiting, and 2 (4.7%) experienced a life-threatening hypotensive episode. There were no procedure-related deaths. CONCLUSION: Our multidisciplinary approach was effective in limiting the serious side effects related to PBPC mobilization and collection in AL patients.

Adult↗

Cost-effectiveness in Italy of preventive treatment with ramipril in patients at high risk of cardiovascular events.

OBJECTIVES: A cost-effectiveness analysis was conducted in Italy of preventive treatment with ramipril (an angiotensin converting enzyme [ACE] inhibitor) compared to no treatment in patients at high risk of cardiovascular death. The analysis was based on data extracted from the HOPE trial. METHODS: The current life table method was used in order to model a lifetime time horizon for outcomes and costs. The cohorts used were 1000 subjects on ramipril, and 1000 subjects on placebo enrolled in the HOPE trial. Kaplan-Meier curves at 5 years of the clinical study were fitted using an exponential model over a lifetime horizon, the outcome variables being myocardial infarction, stroke, revascularization and death. Total direct medical costs have been considered from a third-party payer's perspective--the Italian National Health Service. Resources involved in each event/activity were estimated using the modified Delphi technique with a panel of six clinicians. Types of resources reported included drug therapies, laboratory and imaging tests, physician visits, outpatient and inpatient rehabilitation, as well as medical and surgical hospital admissions. The incremental cost per life year gained was the main measure of the analysis. RESULTS: ICER (incremental cost-effectiveness ratio) decreases with the length of the treatment period. After the first year the ICER is 55,062 euros and subsequently decreases to about 12,770 euros at 5 years, 5945 euros at 10 years and 3726 euros at 20 years. The two ways sensitivity analysis showed that at 5 years ICERs range from a saving of 4059 euros to a cost of 22,929 euros (at 20 years they are 1814 euros and 4434 euros), mainly depending on the cost of drug and cost of events. Previous analyses in other countries based on the HOPE study obtained ICER values which are comparable with our results, when taking into account the different cost structure of the health care systems. CONCLUSIONS: On the basis of these results, the use of ramipril is likely to represent an efficient use of public health expenditure in the Italian healthcare system.

Angiotensin-Converting Enzyme Inhibitors↗

The combination of thalidomide and intermediate-dose dexamethasone is an effective but toxic treatment for patients with primary amyloidosis (AL).

Based on the efficacy of thalidomide in multiple myeloma and on its synergy with dexamethasone on myeloma plasma cells, we evaluated the combination of thalidomide (100 mg/d, with 100-mg increments every 2 weeks, up to 400 mg) and dexamethasone (20 mg on days 1-4) every 21 days in 31 patients with primary amyloidosis (AL) whose disease was refractory to or had relapsed after first-line therapy. Eleven (35%) patients tolerated the 400 mg/d thalidomide dose. Overall, 15 (48%) patients achieved hematologic response, with 6 (19%) complete remissions and 8 (26%) organ responses. Median time to response was 3.6 months (range, 2.5-8.0 months). Treatment-related toxicity was frequent (65%), and symptomatic bradycardia was a common (26%) adverse reaction. The combination of thalidomide and dexamethasone is rapidly effective and may represent a valuable second-line treatment for AL.

Adult↗

Serum N-terminal pro-brain natriuretic peptide is a sensitive marker of myocardial dysfunction in AL amyloidosis.

BACKGROUND: Brain natriuretic peptide (BNP) is a marker of ventricular dysfunction and can be used to assess prognosis in heart failure and after myocardial infarction. Heart involvement is the most important prognostic factor and causes death in almost all patients with light-chain amyloidosis (AL). We investigated the prognostic value of NT-proBNP and its utility in monitoring amyloid heart dysfunction. METHODS AND RESULTS: NT-proBNP was quantified at diagnosis in 152 consecutive patients seen at the coordinating center of the Italian Amyloidosis Study Group (Pavia) from 1999 throughout 2001. Heart involvement was estimated on the basis of clinical signs, electrocardiography, and echocardiography. NT-proBNP concentrations differed in patients with (n=90, 59%) and without (n=62, 41%) heart involvement (median: 507.8 pmol/L versus 22.1 pmol/L, P=10(-7)). The best cutoff for heart involvement was at 152 pmol/L (sensitivity: 93.33%, specificity: 90.16%, accuracy: 92.05%) and distinguished two groups with different survival (P<0.001). The Cox multivariate model including NT-proBNP was better than models including echocardiographic and clinical signs of heart involvement. NT-proBNP appeared to be more sensitive than conventional echocardiographic parameters in detecting clinical improvement or worsening of amyloid cardiomyopathy during follow-up. CONCLUSIONS: NT-proBNP appeared to be the most sensitive index of myocardial dysfunction and the most powerful prognostic determinant in AL amyloidosis. It adds prognostic information for newly diagnosed patients and can be useful in designing therapeutic strategies and monitoring response. NT-proBNP is a sensitive marker of heart toxicity caused by amyloidogenic light chains.

Adult↗

Adenosine A1 and A2A receptor cross-talk during ageing in the rat myocardium.

Adenosine (Ado), a naturally occurring autacoid, exerts cardioprotective effects against myocardial ischemia and reperfusion injury, through activation of its receptors type 1 (A1) and 2A (A2A). Since ageing involves a complex change in these effects, we evaluated A1 and A2A gene expression in left (LV) and right ventricle (RV) from 2-, 5-, 12-, and 21-month-old Sprague-Dawley rats. LV end-diastolic (EDD) and end-systolic (ESD) internal dimensions (mm) and LV fractional shortening (FS, %) were measured by M-mode echocardiography. Senescence was associated with a reduction in FS (42+/-1, 38+/-2, 39+/-2 and 35+/-2, in 2-, 5-, 12- and 21-month-old rats; p<0.02) and increases in EDD (7.5+/-0.2, 8.1+/-0.2, 8.5+/-0.2 and 8.8+/-0.2; p<0.001) and ESD (4.2+/-0.1, 4.4+/-0.2, 4.7+/-0.2 and 5.1+/-0.2; p=0.002). Ado A1 mRNA levels were highest in 12 and 21-month-old animals in both ventricles (LV: p<0.001; RV: p=0.001). By contrast, Ado A2A gene expression was lower in the aged LV (p<0.001), but higher in the aged RV (p<0.001). These modifications of Ado receptor gene expression and especially the increase in A1 receptor mRNA may partially explain the stronger antiadrenergic effects of Ado in the senescent heart.

Aging↗

Preservation of the baroreceptor heart rate reflex by chemical sympathectomy in experimental heart failure.

BACKGROUND: The mechanisms underlying impaired baroreflex sensitivity in congestive heart failure (CHF) are incompletely understood. The purpose of the present study was to test the hypothesis that this alteration depends on the marked degree of sympathetic overactivity known to characterize the CHF syndrome. METHODS AND RESULTS: Eight-week-old rats were subjected to induction of postmyocardial infarction CHF obtained by coronary ligation (Lig), chronic chemical sympathectomy by 6-hydroxydopamine (Sx), both interventions (Sx-Lig), or neither intervention (Veh-Sham, sham surgery, and vehicle administration). Four weeks after infarction, in conscious state, baroreflex sensitivity was assessed from the bradycardic responses to graded phenylephrine-induced elevations in blood pressure (BP). Left ventricular (LV) diameter was assessed by echocardiography, and plasma catecholamines were assayed to estimate sympathetic activity. Lungs were eventually excised and weighed (LW). CHF was associated with the following: (1) no changes in BP and heart rate; (2) sympathetic overactivity (norepinephrine, 320.2+/-53.8 pg/mL for Veh-Lig versus 173.4+/-20.5 pg/mL for Veh-Sham, P<0.01), prevented by Sx (181.2+/-35.5 pg/mL for Sx-Lig versus 159.8+/-33.1 pg/mL for Sx-Sham, P=NS); (3) LV enlargement (10.3+/-0.7 mm for Veh-Lig versus 6.8+/-0.6 mm for Veh-Sham, P<0.01), irrespective of Sx (9.7+/-0.7 mm for Sx-Lig versus 6.6+/-0.5 mm for Sx-Sham, P<0.01); (4) pulmonary congestion (LW, 7.55+/-0.40 mg per gram of body weight for Veh-Lig versus 5.21+/-0.44 mg per gram of body weight for Veh-Sham, P<0.01), marginally attenuated by Sx (6.54+/-0.28 mg per gram of body weight for Sx-Lig versus 4.98+/-0.22 mg per gram of body weight for Sx-Sham, P<0.05); (5) reduction in baroreflex sensitivity (0.443+/-0.032 ms/mm Hg for Veh-Lig versus 0.860+/-0.420 ms/mm Hg for Veh-Sham, P<0.01), entirely prevented by Sx (1.217+/-0.058 ms/mm Hg for Sx-Lig versus 1.345+/-0.093 ms/mm Hg for Sx-Sham, P=NS). CONCLUSIONS: In early post-MI CHF, sympathectomy only partially attenuated LV dysfunction and entirely prevented baroreflex sensitivity impairment that arises from enhanced sympathetic activity.

Adrenergic beta-Antagonists↗