Prognostic impact of peakVO2-changes in stable CHF on chronic beta-blocker treatment

Abstract

Background Peak oxygen uptake (pVO2) is used for risk stratification in chronic heart failure (CHF), but little is known about the prognostic impact of pVO2-changes in patients on chronic beta-blocker (BBL) therapy. We therefore prospectively evaluated individual pVO2-changes at a 6-month interval in patients all receiving BBL. Methods 194 patients with stable CHF on stable medication were included (V1) and underwent clinical evaluation and exercise testing. Testing was repeated (V2) at 5.7 ± 1.5 months after V1 and patients were followed > 12 months after V2. Death or hospitalisation due to cardiac reasons was the predefined EP (EPP, end-point positive; n = 62; EPN, end-point negative; n = 113). Results Initial characteristics did not differ between EPP and EPN. Multivariate cox regression analysis revealed that change of pVO2 (EPP: − 0.6 ± 2.6 ml/kg min; EPN: + 2.5 ± 3.3 ml/kg min; p < 0.001) was independent to pVO2, LVEF, NTproBNP and NYHA at V2 for prediction of the combined end-point during follow-up. An increase of pVO2 by 10% was identified as an adequate cut-off value for risk stratification and ROC-analysis showed the significant incremental prognostic value of the determination of pVO2 changes in combination with pVO2. Conclusions Serial measurements of pVO2 yield additional information for risk stratification in clinically homogenous CHF patients receiving BBL. This is the first study demonstrating this fact within a narrow predefined interval with all patients on BBL.