Reduced exercise capacity in patients with systemic sclerosis is associated with lower peak tissue oxygen extraction: a cardiovascular magnetic resonance-augmented cardiopulmonary exercise study

Table 5 Peak exercise CPET and CMR metrics

	SSc	SSc-PAH	NC-PAH	Healthy Controls	p value
iVO₂* (ml/min/kg)	14.2 (7.6–26.2)^†	9.2 (5.2–15.7)^†‡	10.8 (6.6–19.9) ^†	20.1 (12.8–28.7)	< 0.001
Cardiac index (L/min/m²)	5.5 ± 1.2^§	4.2 ± 1.0^†‡	4.3 ± 1.1^†	5.6 ± 0.8	< 0.001
avO₂* (mlO₂/100 ml)	10.3 (4.6–11.8) ^†	7.7 (6.1–12.9)^†	10.9 (6.9–17.5)	15.0 (7.1–18.7)	0.003
SV index (ml/m²)	44.8 ± 10.2	41.6 ± 8.2	37.0 ± 9.7^†	47.1 ± 10.2	0.034
HR (bpm)	124.0 ± 16.5	102.7 ± 14.0^†‡§	118.4 ± 22.4	122.1 ± 18.8	0.009
LVEF (%)	72 ± 12	76 ± 8	78 ± 10	77 ± 7	0.24
RVEF* (%)	71 (43–84) ^§	66 (42–79) ^†	59 (24–81) ^†	74 (62–89)	0.003

iVO₂ oxygen consumption indexed to weight, avO₂ tissue oxygen extraction, HR heart rate, LVEF left ventricular ejection fraction, RVEF right ventricular ejection fraction. Normally distributed data displayed as mean ± SD. *Denotes non-normally distributed data shown as median (range). ^†Significant difference between controls and indicated patient groups. ^‡Significant difference between SSc and SSc-PAH groups. §significant difference between NC-PAH and the indicated SSc groups

ISSN: 1532-429X