Table 3.

Cox Proportional Hazards Models for CPX Variables According to Time Past Baseline Assessment

	Hazard Ratio (95% CI) Continuous	p-value	Hazard Ratio (95% CI) Dichotomous^*	p-value	Hazard Ratio (95% CI) Continuous	p-value	Hazard Ratio (95% CI) Dichotomous^*	p-value
VE/VCO₂ slope
	All Cardiac Events				Cardiac Mortality
Overall (263 events; 199 deaths)	1.06 (1.05–1.07)	<0.001	4.1 (3.2–5.3)	<0.001	1.05 (1.04–1.06)	<0.001	3.5 (2.7–4.7)	<0.001
6 months post CPX (187 events; 164 deaths)	1.05 (1.04–1.06)	<0.001	3.3 (2.5–4.4)	<0.001	1.05 (1.04–1.06)	<0.001	3.2 (2.3–4.4)	<0.001
12 months post CPX (136 events; 124 deaths)	1.06 (1.04–1.07)	<0.001	3.4 (2.4–4.8)	<0.001	1.05 (1.04–1.07)	<0.001	3.3 (2.3–4.7)	<0.001
18 months post CPX (95 events; 89 deaths)	1.06 (1.04–1.07)	<0.001	3.4 (2.3–5.1)	<0.001	1.06 (1.04–1.07)	<0.001	3.5 (2.3–5.3)	<0.001
24 months post CPX (67 events; 64 deaths)	1.05 (1.04–1.07)	<0.001	3.4 (2.1–5.5)	<0.001	1.05 (1.04–1.07)	<0.001	3.5 (2.2–5.8)	<0.001
30 months post CPX (47 events; 45 deaths)	1.05 (1.02–1.07)	<0.001	2.6 (1.5–4.7)	0.001	1.05 (1.02–1.07)	<0.001	2.9 (1.6–5.2)	<0.001
36 months post CPX (32 events; 31 deaths)	1.05 (1.02–1.08)	0.001	2.4 (1.2–4.8)	0.01	1.05 (1.02–1.08)	0.001	2.5 (1.2–5.1)	0.01
42 months post CPX (19 events; 19 deaths)	1.05 (1.00–1.09)	0.05	2.2 (0.90–5.6)	0.08	1.05 (1.00–1.09)	0.05	2.2 (0.90–5.6)	0.08
Peak VO₂
	All Cardiac Events				Cardiac Mortality
Overall (263 events; 199 deaths)	0.88 (0.86–0.91)	<0.001	3.2 (2.4–4.2)	<0.001	0.91 (0.88–0.93)	<0.001	2.3 (1.6–3.2)	<0.001
6 months post CPX (187 events; 164 deaths)	0.90 (0.88–0.93)	<0.001	2.6 (1.8–3.7)	<0.001	0.91 (0.89–0.94)	<0.001	2.2 (1.5–3.3)	<0.001
12 months post CPX (136 events; 124 deaths)	0.91 (0.88–0.94)	<0.001	2.0 (1.3–3.2)	0.002	0.92 (0.88–0.95)	<0.001	1.8 (1.1–3.0)	0.02
18 months post CPX (95 events; 89 deaths)	0.92 (0.89–0.96)	<0.001	1.7 (0.95–3.1)	0.07	0.93 (0.89–0.96)	<0.001	1.7 (0.93–3.2)	0.08
24 months post CPX (67 events; 64 deaths)	0.96 (0.91–1.00)	0.03	1.1 (0.45–2.5)	0.82	0.95 (0.91–1.00)	0.03	1.2 (0.5–2.7)	0.73
30 months post CPX (47 events; 45 deaths)	0.96 (0.91–1.01)	0.10	1.3 (0.53–3.4)	0.53	0.96 (0.91–1.01)	0.10	1.4 (0.56–3.6)	0.47
36 months post CPX (32 events; 31 deaths)	0.97 (0.92–1.03)	0.34	1.6 (0.57–4.7)	0.36	0.98 (0.92–1.04)	0.44	1.7 (0.59–4.9)	0.32
42 months post CPX (19 events; 19 deaths)	0.95 (0.88–1.03)	0.26	2.2 (0.63–7.5)	0.22	0.95 (0.88–1.03)	0.26	2.2 (0.63–7.5)	0.22

Thresholds: VE/VCO₂ slope </≥36, Peak VO₂ </≥10 ml• kg⁻¹•min⁻¹