N-terminal proatrial natriuretic peptide and prognosis in patients with heart failure and preserved systolic function

Congestive heart failure and preserved left ventricular systolic function is a common clinical condition. Although the prognosis in this type of heart failure is better in comparison to systolic dysfunction, prognostic markers to evaluate long-term outcome are lacking. The atrial peptide, N-terminal proatrial natriuretic peptide (proANP), has been shown to predict survival in patients with systolic dysfunction. We intended to evaluate the predictive capability of N-terminal proANP in patients with preserved systolic function (ejection fraction [EF] > or = 0.40).

A clinical and echocardiographic examination was performed in 149 patients with idiopathic heart failure from a population-based cohort, and 84 patients were identified to have preserved systolic function, with an EF of 0.40 or greater. The patients were followed up during 7 years with regard to symptoms, treatment, hospitalization, and survival. The patients with normal EFs had greater plasma concentrations of N-terminal proANP compared with a control group, and N-terminal proANP level was an independent predictor of mortality (risk ratio, 2.44; 95% confidence interval, 1.28 to 4.67; P = .007). In addition, a high concentration of N-terminal proANP predicted an increased rate of hospitalization (50% for a level > 1,200 pmol/L versus 19% for a level < or = 1,200 pmol/L; P = .046) and a greater future dosage of diuretic (127+/-102 vs 51+/-39 mg; P = .007).

N-terminal proANP level was an independent marker of increased mortality and morbidity in patients with preserved systolic function, whereas EF was not usable in this regard. It is suggested that this peptide could be used to identify clinically relevant left ventricular dysfunction in patients with EFs within the normal range.