N-terminal protype-B natriuretic peptide and Doppler diastolic variables are incremental for risk stratification of patients with NYHA class I–II systolic heart failure - Dini, Frank Lloyd; Fontanive, Paolo; Buralli, Simona; Panicucci, Erica; Andreini, Diana; Conti, Umberto; De Tommasi, Salvatore Mario (International Journal of Cardiology, 2009)