Abstract 17874: Comparison of the Seattle Heart Failure Model (SHFM) and Cardiopulmonary Exercise Testing (CPET) for Predicting Mortality of Patients With Ischemic Heart Failure
Background: Despite many therapeutic advances, prognosis of patients with heart failure remains poor. Assessment of prognosis and risk stratification remains a major diagnostic challenge. Cardiopulmonary exercise testing provides important prognostic information by peak O2 uptake (peak VO2), O2 pulse (O2P), O2 uptake efficiency slope (OUES) and VE/VCO2-slope (VE/VCO2). The Seattle heart failure model is based on clinical data (age, gender, NYHA class, body weight, LVEF, blood pressure, etiology of heart failure, ECG, medication, laboratory findings and resynchronization therapy) to calculate the estimated annual mortality. A comparison of the prognostic value of CPET and SHFM has not been performed so far.
Patients and methods: 119 patients (age 59±12 years, 13% female) with ischemic heart failure (LVEF 40±11 %, NYHA 2.3 ± 0.7; NT-proBNP 1061 ± 1151 pg/ml) were analyzed for death during a median follow-up of 3 years. CPET with analysis of peak VO2, O2Pmax, OUES and VE/VCO2 was performed in all patients at inclusion into the study. SHFM was calculated for every patient.
Results: During follow up, 10 patients died (8.4%). Non-survivors had significantly worse initial CPET results (peak VO2: 14±2 vs. 18±5 ml/min/kg, VE/VCO2 slope: 40±9 vs. 35 ±12, O2Pmax: 10±4 vs. 14±5, p<0.05) and a significantly higher SHFM score (16.4 vs. 6.1% predicted 1-year mortality, p<0.01). Receiver-operating-curve analysis of sensitivity and specificity for SHFM and CPET revealed the largest area-under-the-curve value for SHFM (0.74), followed by VE/VCO2-slope (0.66), whereas other CPET parameters had substantially lower values (OUES: 0.29, O2Pmax: 0.28, peak VO2: 0.25). Kaplan-Meier-analysis using cut-off points of SHFM and VE/VCO2-slope with highest sensitivity and specifity (SHFM: 21.5%; VE/VCO2: 39.5) resulted in significant discrimination of survivors and non-survivors in log-rank test by both parameters. In multivariate analysis, only SHFM persisted as independent predictor of mortality in these patients (p = 0.001, exponent beta 1.096, 95% CI 1.039 – 1.155). Summary These data indicate superior prognostic power of SHFM compared to CPET in patients with ischemic heart failure.
- © 2010 by American Heart Association, Inc.