Clinical and prognostic value of Duke's Activity Status Index along with plasma B-type natriuretic peptide levels in chronic heart failure secondary to ischemic or idiopathic dilated cardiomyopathy.

The Duke Activity Status Index (DASI) provides an accurate estimate of functional capacity in patients with chronic heart failure (HF). The aim of this study was to evaluate the prognostic value of the DASI against well-established prognostic factors in 130 consecutive patients hospitalized for worsening HF symptoms (mean age 64 +/- 12 years, mean left ventricular ejection fraction 26 +/- 7%), followed for 9 months for major cardiovascular events, defined as death or hospitalization for HF decompensation. During follow-up, 77 of 130 patients (59%) experienced major cardiovascular events after a median time of 60 days (range 5 to 220). Patients with eventful courses were in higher New York Heart Association functional classes (p = 0.001) and had shorter 6-minute walking distances (p = 0.041), lower ejection fractions (p <0.001), higher plasma B-type natriuretic peptide (BNP) levels at hospital admission and discharge (both p <0.001), and lower DASI scores (16 +/- 12 vs 25 +/- 17, p = 0.003). In multivariate Cox regression analysis including all these variables, only BNP level at discharge (p = 0.006) and DASI score (p = 0.047) were independently associated with event-free survival. A BNP cutoff of 697 pg/ml predicted future events with 59% sensitivity and 86% specificity, while a DASI score cutoff of 8 had 76% sensitivity and 25% specificity. The combination of the 2 cutoffs predicted events with 33% sensitivity and 95% specificity. Event-free survival was significantly lower in patients with the 2 markers positive (BNP >697 pg/ml and DASI score <8) compared with those with with 2 markers negative (63 +/- 27 vs 183 +/- 15 days, log-rank p <0.0001). In conclusion, functional status assessment by the DASI bears prognostic value, and its combination with plasma BNP may provide quite specific risk stratification in patients with chronic HF.