RESUMO
Brain natriuretic peptide [BNP] represents a new biochemical marker for left ventricular systolic dysfunction [LVSD], especially the amino terminal fragment of its prohormone; NT-proBNP. In this study, plasma levels of NT-proBNP, as well as its second messenger cyclic guanosine monophosphate [cGMP], were evaluated for their diagnostic and prognostic potential and their impact on treatment strategies in patients with congestive heart failure [CHF]. Patients and Eighty patients with CHF [Class II-III] were included in the study in addition to ten healthy subjects [control group]. Ten of the patients were treated with standard therapy [ST] of digoxin and furosemide. Other patients were receiving one or more of the following treatments in addition to the ST; angiotensin-converting enzyme inhibitor [captopril], aldosterone antagonist [spironolactone] and vasodilator [isosorbide dinitrate]. Plasma level of NT-proBNP showed a highly significant increase in all CHF patients with LVSD, compared to normal controls. Poor prognosis was obtained in patients treated with ST alone assuming insufficient effect of ST to improve cardiac remodeling. Treatment with either captopril or spironolactone, together with ST, were nearly equally effective in ameliorating LVSD, as reflected by the significant decrease in NT-proBNP, compared to ST alone. The combination of captopril with spironolactone and/or isosorbide dinitrate exhibited a more powerful effect in lowering NT-proBNP, indicating relief of the ventricular overload in CHF patients. The vasodilator isosorbide dinitrate was one of the most promising drugs in improving cardiac function and reducing NT-proBNP and hence improving prognosis. Cyclic GMP showed no correlation with plasma NT-proBNP, although it was significantly increased in patients treated with isosorbide dinitrate in combination with captopril and spironolactone, compared to ST group. Moreover, plasma NT-proBNP showed no correlation with the ejection fraction, the measurable value of echocardiography. These results suggest the use of NT-proBNP as a prognostic marker in development of strategies of therapy for CHF. However, the link between neurohormonal activation and homodynamic approaches requires further investigations