Clinical benefits after physical training in patients with HF are associated with blunting of adrenergic overactivity and of natriuretic peptide overexpression.

Increased chemosensitivity has been observed in HF (heart failure) and, in order to clarify its pathophysiological and clinical relevance, the aim of the present study was to investigate its impact on neurohormonal balance, breathing pattern, response to exercise and arrhythmic profile. A total of 60 patients with chronic HF [age, 66+/-1 years; LVEF (left ventricular ejection fraction), 31+/-1%; values are means+/-S.E.M.] underwent assessment of HVR (hypoxic ventilatory response) and HCVR (hypercapnic ventilatory response), neurohormonal evaluation, cardiopulmonary test, 24-h ECG monitoring, and assessment of CSR (Cheyne-Stokes respiration) by diurnal and nocturnal polygraphy. A total of 60% of patients had enhanced chemosensitivity. Those with enhanced chemosensitivity to both hypoxia and hypercapnia (i.e. HVR and HCVR), compared with those with normal chemosensitivity, had significantly (all P<0.01) higher noradrenaline (norepinephrine) and BNP (B-type natriuretic peptide) levels, higher prevalence of daytime and night-time CSR, worse NYHA (New York Heart Association) class and ventilatory efficiency [higher VE (minute ventilation)/VCO(2) (carbon dioxide output) slope], and a higher incidence of chronic atrial fibrillation and paroxysmal non-sustained ventricular tachycardia, but no difference in left ventricular volumes or LVEF. A direct correlation was found between HVR or HCVR and noradrenaline (R=0.40 and R=0.37 respectively; P<0.01), BNP (R=0.40, P<0.01), N-terminal pro-BNP (R=0.37 and R=0.41 respectively, P<0.01), apnoea/hypopnoea index (R=0.57 and R=0.59 respectively, P<0.001) and VE/VCO(2) slope (R=0.42 and R=0.50 respectively, P<0.001). Finally, by multivariate analysis, HCVR was shown to be an independent predictor of both daytime and night-time CSR. In conclusion, increased chemosensitivity to hypoxia and hypercapnia, particularly when combined, is associated with neurohormonal impairment, worse ventilatory efficiency, CSR and a higher incidence of arrhythmias, and probably plays a central pathophysiological role in patients with HF.

In systolic HF patients, CAs occurred throughout a 24-h period and were associated with a neurohormonal activation, ventricular arrhythmic burden, and worse prognosis.

Background:We compared the diagnostic accuracy of brain natriuretic peptide (BNP) and amino-terminal proBNP (NT-proBNP) for diagnosis of preclinical and mild heart failure (HF).

Over the last 5 years, several immunoassay methods for the measurement of B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) became commercially available. Recent studies have confirmed the clinical usefulness of measurements of these cardiac natriuretic peptides for the prognostic stratification of patients with congestive heart failure, for the detection of left ventricular systolic and/or diastolic dysfunction, and for the differential diagnosis of dyspnea (1-4 ). However, to answer the most urgent requests of current clinical practice and to allow widespread use of BNP and NT-proBNP assays, some key issues had to be solved, such as increasing the sensitivity, precision, and experimental practicability (5 ). The aim of the present study was to evaluate and compare the analytical and clinical performance of five commercial natriuretic peptide immunoassays.Throughout this report, the values in healthy individuals and patients are reported as the range, median, and 25th and 75th percentiles. We enrolled 172 healthy adults (89 women and 83 men; age range, 16 -73 years; median age, 49.0 years; 25th percentile, 38 years; 75th percentile, 58 years). All participants were nonobese (body mass index, 19.4 -27.6 kg/m 2 , 24 kg/m 2 , 22.8 kg/m 2 , and 25.6 kg/m 2 ), normotensive (diastolic blood pressure, 60 -85 mmHg, 70 mmHg, 70 mmHg, and 80 mmHg; systolic blood pressure, 90 -140 mmHg, 120 mmHg, 102.5 mmHg, and 124.5 mmHg), and free from acute or chronic diseases. All participants had main plasma indices (including creatinine, urea nitrogen, glucose, uric acid, albumin, enzymes, electrolytes, and hemoglobin) within the appropriate reference intervals, and normal erythrocyte and leukocyte counts and urine analyses. All were asymptomatic and underwent a complete examination by a cardiologist, including a visit, standard 12-lead electrocardiogram, Doppler echocardiographic examination, and a bicycle stress test (when older than 50 years), which excluded silent heart disease.We also prospectively evaluated 279 consecutive patients with heart failure (211 men and 68 women; age, 20 -89 years, 66.0 years, 57.3 years, and 73 years). Cardiac morphology and function were assessed by two-dimensional echocardiography, or cardiac catheterization when needed. Idiopathic dilated cardiomyopathy was diagnosed in 136 patients (48.7%), whereas the other 143 patients suffered from secondary cardiomyopathy. Of these, 126 (45.1%) had ischemic cardiomyopathy. The inclusion criterion was a depressed (Ͻ50%) left ventricular ejection fraction [mean (SD), 31.8 (9.4)%; range, 10 -48%]. Heart failure severity was evaluated clinically according to the New York Heart Association (NYHA) classification: 32 patients were in functional NYHA class I, 133 were in class II, 81 were in class III, and 33 were in class IV, respectively. Patients were treated with a multidrug treatment (78% of patients treated with frusemide, 94% with angiotensin-converting enzyme inhibitor, 70% with carvedilol, and 58% with spironolactone), which was not stoppe...