Moderated Poster Session IV: Exercise physiology

P160 Determinants and prognostic value of the VE/VCO2 slope as compared to neurohormonal activation in elderly patients with CAD and preserved LV function J H A J De Sutter, N Van De Veire, J Philippe, M De Buyzere Ghent University, Ghent, Belgium Topic: Biomarkers Background and study aims:The VE/CO2 slope is considered as a powerful predictor of cardiac events in patients with heart failure. In this study we evaluated the determinants and prognostic value of the VE/VCO2 slope in the ever increasing population of elderly patients with CAD and preserved LV function. We also compared the predictive value of the VE/CO2 slope with NTproBNP as marker of neurohormonal activation. Methods:We studied 89 patients 70 years or older (mean age 75 4 years, 85% men) with CAD and LVEF = 50% (mean LVEF 64 9 %). All patients underwent a maximal bicycle spiroergometry for the evaluation of VO2max and the VE/CO2 slope. Serum NT-proBNP, creatinine and high sensitivity CRP were determined. Echocardiography was performed to evaluate E/E as marker of LV filling pressures. Patients were followed for a median follow-up of 32months for the combined end-point of mortality, AMI, PCI, CABG or hospitalisation for heart failure. Results:Mean VO2max was 15,5 4,1 ml/kg/min andmean VE/CO2 slope was 32 6. Tertiles of VE/CO2 slope were associated with higher levels of NT-proBNP, hsCRP and E/E (all p-values < 0.05) but not with age, VO2max or creatinine levels. Patients with events during follow-up (n1⁄416) had higher values of VE/CO2 slope, NT-proBNP and creatinine but no differences were noted for age, VO2max, hsCRP and E/E . ROC analysis showed AUC values of 0,74 (95%CI 0,59-0,89, p<0.01) for NT-proBNP and 0,67 (95% CI 0,53-0,81, p<0.05) for VE/CO2 slope. In multivariate Cox regression analysis, VE/CO2 slope appeared as an independent predictor (p<0.05) for cardiac events. However, after introduction of NT-proBNP in the model, VE/CO2 did not remain as predictor, in contrast to NT-proBNP (p<0.01). Conclusions: In elderly patients with CAD and preserved LV function, increased levels of VE/ VCO2 slope are related to higher LV filling pressures as well as higher levels of parameters of neurohormonal and inflammatory activation. Although the VE/CO2 slope is a predictor of cardiac events, its predictive power is weaker as compared to NT-proBNP.