Tsuneoka H; Koike A; Nagayama O; Sakurada K; Kato J; Sato A; Yamashita T;
Aonuma K.

International Heart Journal. 53(2):102-7, 2012.

Parameters obtained from cardiopulmonary exercise testing (CPX) are
recognized for their high prognostic value in predicting future cardiac
events in cardiac patients. Our group compared the prognostic value of CPX
parameters between patients with sinus rhythm (SR) and patients with
atrial fibrillation (AF).Peak O2 uptake (VO2), the ratio of the increase
in VO2 to the increase in work rate (DELTAVO2/DELTAWR), and the slope of
the increase in ventilation to the increase in CO2 output (VE-VCO2 slope)
were obtained from CPX in 72 AF patients and 478 SR patients. The
prognostic values of these indices were compared between the two
groups.Six cardiac deaths and 25 cardiac events were observed in the AF
group and 9 cardiac deaths and 96 cardiac events were observed in the SR
group, over a prospective follow-up period of 1,192 days. The percentages
of cardiac deaths and cardiac events were higher in the AF group than in
the SR group. In a multivariate Cox proportional hazards analysis, peak
VO2 was identified as a sole significant predictor of cardiac death and
cardiac events in SR patients and VE-VCO2 slope was identified as a sole
significant predictor of cardiac death and cardiac events in AF
patients.
Our results suggest that the VE-VCO2 slope is strongly predictive
of future cardiac events in patients with AF and that peak VO2 is strongly
predictive of future cardiac events in SR patients.