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Stefano Nistri

Publications and source records attributed to Stefano Nistri.

9 recordsLinked to original sources
PubMed2006

Hypertrophic cardiomyopathy is predominantly a disease of left ventricular outflow tract obstruction.

BACKGROUND: Nonobstructive hypertrophic cardiomyopathy (HCM) has been regarded as the predominant hemodynamic form of the disease on the basis of assessment of outflow gradient under resting conditions. We sought to prospectively define the prevalence, clinical profile, and significance of left ventricular (LV) outflow tract obstruction under resting conditions and with physiological exercise in a large HCM cohort. METHODS AND RESULTS: We prospectively analyzed 320 consecutive HCM patients (age, 47+/-17 years), measuring LV outflow gradient at rest, with Valsalva maneuver, and with exercise echocardiography. LV outflow obstruction was present at rest and/or with exercise in 225 patients (70%); 119 had rest gradients > or = 50 mm Hg and were not exercised. Of the other 201 patients with gradients < 50 mm Hg at rest (average, 4+/-9 mm Hg), 106 developed mechanical obstruction to LV outflow resulting from mitral valve-septal contact after exercise (80+/-43 mm Hg), including 76 with marked gradients > or = 50 mm Hg and 46 with heart failure symptoms. The remaining 95 patients (30%) had no or small gradients (< 30 mm Hg) both at rest and with exercise. Valsalva maneuver underestimated the presence and magnitude of exercise-induced obstruction. CONCLUSIONS: Among those patients who come to clinical evaluation, HCM is a predominantly obstructive disease in which LV outflow gradients, frequently associated with heart failure symptoms and often identified only with exercise, are evident in most patients (ie, 70%). Identification of LV outflow obstruction with exercise echocardiography may broaden management options in HCM by identifying symptomatic patients not otherwise regarded as potential candidates for septal reduction therapy. Assessment of subaortic gradients with exercise should be a routine component of the evaluation of HCM patients without outflow obstruction under resting conditions.

Adult↗
PubMed2006

Prognostic significance of left atrial size in patients with hypertrophic cardiomyopathy (from the Italian Registry for Hypertrophic Cardiomyopathy).

This study assessed left atrial (LA) dimension as a potential predictor of outcome in hypertrophic cardiomyopathy (HC). From the Italian Registry for Hypertrophic Cardiomyopathy, 1,491 patients (mean age 47 +/- 17 years; 61% men; 19% obstructive), followed for 9.4 +/- 7.4 years after the initial echocardiographic evaluation, constituted the study group. The mean LA transverse dimension was 43 +/- 9 mm and was larger in patients with severe symptoms (48 +/- 9 mm for New York Heart Association classes III and IV vs 42 +/- 9 mm for classes I and II, p <0.001), atrial fibrillation (47 +/- 9 vs 42 +/- 8 mm in sinus rhythm, p <0.001), and left ventricular outflow obstruction (46 +/- 9 mm for >or=30 mm Hg at rest vs 42 +/- 9 mm for <30 mm Hg at rest, p <0.001). On univariate analysis, each 5-mm increase in LA size was associated with a hazard ratio (HR) of 1.2 for all-cause mortality (p <0.0001). On multivariate analysis, a LA dimension >48 mm (the 75th percentile) had a HR of 1.9 for all-cause mortality (p = 0.008), 2.0 for cardiovascular death (p = 0.014), and 3.1 for death related to heart failure (p = 0.008) but was unassociated with sudden death (p = 0.81). Similar results were obtained after the exclusion of patients with atrial fibrillation (HR 1.7, p = 0.008) or outflow obstruction (HR 1.8, p = 0.003). The predictive power of LA dimension >48 mm was also validated in an independent HC cohort from the United States, with similar HRs (1.8 for all-cause mortality, p = 0.019). In conclusion, in a large cohort of patients with HC from a nationwide registry, a marked increase in LA dimension were predictive of long-term outcome, independent of co-existent atrial fibrillation or outflow obstruction. LA dimension is a novel and independent marker of prognosis in HC, particularly relevant to the identification of patients at risk for death related to heart failure.

Adult↗
PubMed2006

Midventricular obstruction and clinical decision-making in obstructive hypertrophic cardiomyopathy.

The presence of intraventricular obstruction is a powerful predictor of outcome in patients with hypertrophic cardiomyopathy (HCM) and, when associated with severe, drug-refractory symptoms, should be managed aggressively. Resting left ventricular outflow obstruction is found in approximately 20% of the patients, classically occurs at the subaortic level, and is associated with mitral valve systolic anterior motion (SAM). In a minority of patients, however, the impedance to flow occurs at midventricular level, unrelated to SAM. Symptomatic midventricular obstruction represents a clinical challenge, and its treatment is not standardized. In these patients, both surgical myectomy and alcohol septal ablation (ASA) are technically feasible. A rational approach to the management of these patients depends on accurate characterization of the pathophysiology, coupled with comparison of the results of different management strategies. To illustrate these points, the details of a patient who first underwent percutaneous ASA and subsequently required redo surgical treatment are described here, with special emphasis on the implications to the management of midventricular obstruction, as well as to the more global issue of obstructive HCM.

Adult↗
PubMed2006

Aortic dilatation in patients with bicuspid aortic valve.

The association of a bicuspid aortic valve (BAV) with abnormalities of the proximal thoracic aorta, including dilatation, aneurysm and dissection, has been previously described, leading to the hypothesis of a common underlying developmental defect involving the aortic valve and the aortic wall. Consequently, any patient with BAV should receive a careful assessment not only of the valve function, but also of the aortic root and the ascending aorta. Dilatation of the proximal thoracic aorta is a common finding in patients with BAV and is believed to be related to aortic rupture and dissection. Because progressive dilatation can occur, careful long-term surveillance of the aortic dimensions is required. Prophylactic surgical repair of the dilated aorta should be recommended more aggressively for patients with BAV than for those with a tricuspid aortic valve. However, the optimal timing of aortic surgery in BAV patients remains uncertain because of the limited data available on the natural history of asymptomatic aortic dilatation.

Aorta, Thoracic↗
PubMed2006

A molecular screening strategy based on beta-myosin heavy chain, cardiac myosin binding protein C and troponin T genes in Italian patients with hypertrophic cardiomyopathy.

BACKGROUND: Mutations causing hypertrophic cardiomyopathy (HCM) have been described in nine different genes of the sarcomere. Three genes account for most known mutations: beta-myosin heavy chain (MYH7), cardiac myosin binding protein C (MYBPC3) and cardiac troponin T (TNNT2). Their prevalence in Italian HCM patients is unknown. Thus, we prospectively assessed a molecular screening strategy of these three genes in a consecutive population with HCM from two Italian centres. METHODS: Comprehensive screening of MYBPC3, MYH7 and TNNT2 was performed in 88 unrelated HCM patients by denaturing high-performance liquid chromatography and automatic sequencing. RESULTS: We identified 32 mutations in 50 patients (57%); 16 were novel. The prevalence rates for MYBPC3, MYH7 and TNNT2 were 32%, 17% and 2%, respectively. MYBPC3 mutations were 18, including two frameshift, five splice-site and two nonsense. All were 'private' except insC1065 and R502Q, present in three and two patients, respectively. Moreover, E258K was found in 14% of patients, suggesting a founder effect. MYH7 mutations were 12, all missense; seven were novel. In TNNT2, only two mutations were found. In addition, five patients had a complex genotype [i.e. carried a double MYBPC3 mutation (n = 2), or were double heterozygous for mutations in MYBPC3 and MYH7 (n = 3)]. CONCLUSIONS: The first comprehensive evaluation of MYBPC3, MYH7 and TNNT2 in an Italian HCM population allowed a genetic diagnosis in 57% of the patients. These data support a combined analysis of the three major sarcomeric genes as a rational and cost-effective initial approach to the molecular screening of HCM.

Cardiomyopathy, Hypertrophic↗
PubMed2005

Frequency of bicuspid aortic valve in young male conscripts by echocardiogram.

The database of echocardiographic examinations performed during the military screening of 20,946 young men in northeastern Italy was systematically reviewed to assess the frequency, hemodynamic characteristics, and aortic sizes of subjects with bicuspid aortic valves (BAVs). One hundred sixty-seven patients with BAVs were identified (0.8%), of whom 80 (48%) were diagnosed de novo during military screening. Aortic insufficiency was the predominant hemodynamic lesion in 110 subjects (66%), mild in 90, and moderate to severe in 20. Patients with BAVs displayed larger aortic sizes than controls at each aortic level, and the degree of dilation was related to the presence but not the severity of aortic insufficiency.

Adolescent↗
PubMed2005

The Italian Registry for hypertrophic cardiomyopathy: a nationwide survey.

BACKGROUND: National registries are advocated as instrumental to the solution of rarity-related problems for patients with hypertrophic cardiomyopathy (HCM), including limited access to advanced treatment options. Thus, an Italian Registry for HCM was created to assess the clinical profile and the level of care nationwide of patients with HCM. METHODS: Cardiology centers over the national territory were recruited to provide clinical data of all patients with HCM ever seen at each institution. The enrollment period was from May 2000 to May 2002. RESULTS: The registry enrolled 1677 patients from 40 institutions. Most (69%) were followed at referral centers, whereas 31% were from community centers with intermediate-low patient flow. Patients diagnosed after routine medical examinations or familial screenings were 39%. Most patients were male (62%), in their fourth to sixth decade of life, and in New York Heart Association class I to II (89%); 24% had resting left ventricular obstruction and 18% had atrial fibrillation. During a 9.7-year average follow-up, cardiovascular mortality was 1%/y, mostly because of heart failure, with no significant change over the last 3 decades; sudden death was less common (0.4%/y). Only 4% of patients received a defibrillator; 14% of the 401 patients with LV outflow obstruction underwent invasive relief of obstruction; and <1% were offered genetic analyses or counseling. CONCLUSIONS: The Italian Registry represents the first comprehensive attempt to evaluate the clinical impact and management of HCM at a national level. Findings underscore the role of screening strategies for an early diagnosis and suggest limited use of the advanced therapeutic options for HCM.

Adult↗
PubMed2002

Bicuspid aortic valve: abnormal aortic elastic properties.

BACKGROUND AND AIMS OF THE STUDY: Bicuspid aortic valve (BAV) is frequently associated with clinically relevant abnormalities of the aorta, suggesting the existence of a common underlying developmental defect involving the aortic valve and wall of the ascending aorta. The study aim was to evaluate noninvasively the elastic properties of the aortic root in young males with BAV, to discover whether structural abnormalities of the aorta might be manifested by impairment in elasticity. METHODS: Forty-nine young male subjects with isolated BAV were consecutively detected during preenrollment military screening, and studied using transthoracic echocardiography. Data were compared with those obtained in 45 normal subjects, matched for gender and age. RESULTS: Patients and controls were comparable for body size, and systolic and diastolic blood pressures. BAVs were normally functioning in 18 patients (37%), and mildly regurgitant in 31 (63%). Measurements made by two-dimensional echocardiography showed that BAV patients had significantly larger aortic root dimensions at the annulus (2.4+/-0.2 versus 2.2+/-0.2 cm, p <0.001), at the sinus of Valsalva (3.3+/-0.4 versus 2.6+/-0.3 cm, p <0.001), at the sinotubular junction (2.9+/-0.3 versus 2.5+/-0.2 cm, p <0.001), and at the proximal ascending aorta (2.8+/-0.3 versus 2.5+/-0.2 cm, p <0.001). Measurements made using M-mode echocardiography at 3 cm from the annulus, showed the difference between systolic and diastolic diameters of the aortic root to be significantly smaller in patients than in controls (2.1+/-1.2 versus 3.0+/-1.1 mm, respectively, p <0.001). In patients and in controls, both aortic distensibility (2.7+/-1.5 versus 4.8+/-2.2 x 10(-6) cm2 dyne(-1), respectively, p <0.001) and aortic stiffness index (10.2+/-5.3 versus 5.03+/-1.97, respectively, p <0.001) were significantly different. CONCLUSION: Young male subjects with BAV and no or mild aortic regurgitation display large aortic size and abnormal elastic properties of the ascending aorta compared with controls. These findings confirm the notion that, in these patients, aortic root dilatation is a morphological correlate of intrinsic structural aortic abnormality.

Adult↗