Maximum oxygen uptake at peak exercise in elderly patients with coronary artery disease and preserved left ventricular function: the role of inflammation on top of tissue Doppler-derived systolic and diastolic function.

BACKGROUND

Several studies have shown that longitudinal systolic function and left ventricular filling pressures, as assessed with tissue Doppler imaging, predict exercise capacity.

AIM

The aim of this study was to evaluate whether natriuretic peptides and inflammatory parameters can independently predict maximum oxygen uptake at peak exercise (VO2max) on top of tissue Doppler imaging-derived markers.

METHODS

We evaluated 142 patients (age 70 +/- 6 years, 77% men) with known or suspected coronary artery disease and a preserved left ventricular ejection fraction (> or = 50%). All patients underwent bicycle spiroergometry, and N-terminal pro-B-type natriuretic peptide levels were determined. Cytokines (IL-6 and soluble tumor necrosis factor receptors 1 and 2) and high-sensitivity C-reactive protein were measured as inflammatory markers. Tissue Doppler imaging was applied to evaluate peak long axis systolic velocities (Sm) and early mitral annulus velocities (E'). Ratio of early transmitral flow (E) to E' was assessed as marker of left ventricular filling. Analysis of variance, comparing VO2max quartiles, was used to determine univariate predictors and linear regression to determine multivariate VO2max predictors.

RESULTS

Average VO2max was 18.5 +/- 5.7 mL/kg per minute (range 6-36.6). Compared with the highest quartile, patients with low VO2max were more frequently women (P < .0001). N-terminal pro-B-type natriuretic peptide and cytokine levels were significantly higher in the lower VO2max categories. Longitudinal myocardial velocities increased, and E/E' decreased along with increasing VO2max. In multivariate linear regression analysis, VO2max was independently predicted by sex, glucose, Sm, E/E', and cytokine levels.

CONCLUSION

Maximum oxygen uptake at peak exercise in patients with known or suspected coronary artery disease and preserved systolic function was independently predicted by inflammatory makers on top of tissue Doppler-derived systolic and diastolic function.