[Type B natriuretic peptide in the diagnosis of heart failure with preserved systolic function]. / Peptídeo natriurético tipo B no diagnóstico de insuficiência cardíaca com função sistólica preservada.

BACKGROUND: Heart failure (HF) with preserved left ventricular systolic function (LVSF) is observed in up to 50% patients with HF. There is no consensus on non-invasive diagnosis of this entity. OBJECTIVE: Evaluation of B-type natriuretic peptide (BNP) in the diagnosis of HF with preserved left ventricular systolic function. DESIGN: Prospective study. PATIENTS: One hundred and seventy-six consecutive patients with suspected HF were evaluated. Patients were classified as having HF with preserved LVSF, if they had symptoms and signs of HF, an ejection fraction greater than 40% and an abnormal Doppler pattern of the mitral inflow or atrial fibrilation and no other causes for the symptoms. All patients had a 12-lead EKG, chest roentgenogram, simple spirometry, M-mode and 2D echocardiogram with pulsed Doppler study of transmitral inflow and determination of plasma BNP levels. RESULTS: Of the 176 patients, 65 had ejection fraction greater than 40%. Of these patients 46 were classified as having HF with preserved LVSF and 19 as not having HF. Patients with HF and preserved LVSF were older, had a higher systolic blood pressure (SBP), less pathologic Q waves on ECG and higher left ventricular ejection fraction and plasma BNP than patients without HF. Multivariate analysis revealed that BNP and SBP were independently associated with the diagnosis of HF. The accuracy of BNP in the diagnosis of HF with preserved LVSF evaluated by the area under the receiver operating characteristic curve was 0.94. CONCLUSION: These results suggest that the measurement of BNP levels can help clinicians in the diagnosis of HF with preserved LVSF. Whether BNP levels might be used in clinical practice as a test for the diagnosis of HF with preserved LVSF is a question that merits further studies.

Prognosis in patients with heart failure and preserved left ventricular systolic function.

BACKGROUND: It is recognized that heart failure patients with preserved left ventricular systolic function have better prognosis; nevertheless, there are some studies with conflicting results. Also, there is a paucity of data concerning the prognostic factors in this group of patients. OBJECTIVES: To determine possible variables with prognostic relevance in heart failure patients with preserved left ventricular systolic function (ejection fraction > 40%). METHODS: 157 consecutive ambulatory patients with heart failure were assessed; those patients with ejection fraction > 40% were included in the study (n = 46). All patients were evaluated by clinical interview and physical examination, ECG, echocardiogram (M-mode, 2D and pulsed Doppler of mitral flow), biochemical study and determination of type B natriuretic peptide (BNP). The patients were grouped according to the rhythm presented on ECG: Group I--patients with atrial fibrillation; Group II--patients in sinus rhythm Group II was further subdivided in two groups according to the presence or absence of restrictive left ventricular filling pattern. All patients had a clinical follow-up, with recording of events (death or hospitalization from cardiac cause). The mean follow-up time was 682.2 +/- 55 days. RESULTS: The mean age of the patients was 70.4 +/- 1.2 years; 54.3% were women; mean ejection fraction was 49.6 +/- 1%; mean BNP levels were 202.9 +/- 41.3 pg/ml. Mortality was 19.6% and the combined event death or hospitalization from cardiac cause) occurred in 26.1% of the patients. Among the clinical, demographic, biochemical, echocardiographic and neurohumoral parameters, only BNP levels had prognostic significance in the whole population. In Group II patients, BNP levels, heart rate and restrictive left ventricular filling pattern were identified as having prognostic significance. Kaplan-Meyer curve analysis showed that both BNP and restrictive left ventricular filling pattern seemed to be important prognostic markers. CONCLUSIONS: This preliminary study suggests thar neurohumoral activity (determined by plasma BNP levels) and a restrictive ventricular filling pattern may be important factors in prognostic stratification of heart failure patients with preserved left ventricular systolic function.

Predictors of prognosis in patients with stable mild to moderate heart failure.

BACKGROUND: A number of prognostic indexes have been developed to predict the outcome of patients with severe heart failure (HF). In patients with mild to moderate HF, however, there is no consensus regarding the usefulness of such indexes. The goal of this study is to determine the prognostic value of selected clinical variables in the latter group of patients. METHODS AND RESULTS: We prospectively evaluated the prognostic value of the functional capacity evaluation, the ventricular function, biochemical metabolic indicators, and brain natriuretic peptide (BNP) levels in 139 consecutive patients with mild to moderate HF. A clinical and echocardiographic examination (M-mode, 2D and pulsed Doppler of the mitral inflow); a 6-minute walk test; and a determination of serum sodium, uric acid, and BNP levels were performed. Death by any cause was predefined as the study end-point. Variables found to be related with survival in a univariate Cox regression analysis were NYHA class; ischemic origin for HF; left ventricular ejection fraction; deceleration time of the E wave; and 6-minute walk distance, serum sodium, uric acid, and BNP levels. In a multivariate analysis, ischemic origin of HF, 6-minute walk distance, deceleration time of the E wave, and BNP levels were found to be independent prognostic factors. The clustering of the independent prognostic factors was associated with the worse prognosis. CONCLUSIONS: These results suggest that the noninvasive evaluation used in this study and in our population of patients with mild to moderate HF allows the identification of individuals with the worst prognosis. The selected variables might prove to be very helpful in stratifying HF patients and identifying those that might benefit the most from a HF management program.