Table 2.

Overall and RER Subgroup Univariate Cox Regression Analysis for Major Cardiac-Related Events^*

Parameter/Statistic	Overall (n = 1,728)	RER <1.00 (n = 319)	RER 1.00–1.04 (n = 218)	RER 1.05–1.09 (n = 256)	RER ≥1.10 (n = 935)
VE/Vco2 slope
Chi square	244.3	31.3	21.6	25.3	162.3
p Value	<0.001	<0.001	<0.001	<0.001	<0.001
HR (95% CI)	1.065 (1.056–1.074)	1.060 (1.038–1.082)	1.049 (1.027–1.071)	1.054 (1.032–1.077)	1.076 (1.063–1.088)
Peak Vo2
Chi square	116.9	13.5	16.6	16.0	71.6
p Value	<0.001	<0.001	<0.001	<0.001	<0.001
HR (95% CI)	0.844 (0.820–0.868)	0.882 (0.826–0.941)	0.837 (0.771–0.908)	0.841 (0.779–0.912)	0.829 (0.796–0.863)
LVEF
Chi square	98.7	28.3	16.6	2.0	54.1
p Value	<0.001	<0.001	<0.001	0.163	<0.001
HR (95% CI)	0.934 (0.921–0.947)	0.921 (0.892–0.951)	0.920 (0.882–0.959)	–	0.929 (0.911–0.948)
Age
Chi square	0.38	0.13	0.57	1.48	0.32
p Value	0.539	0.716	0.449	0.223	0.571
HR (95% CI)	–	–	–	–	–

^*p < 0.05 considered significant. Major event = death, left ventricular assist device implantation, or heart transplantation.

CI = confidence interval; HR = hazard ratio; other abbreviations as in Table 1.