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. 2017 Mar 1;11(3):135–145. doi: 10.1177/1753465816684424

Table 4.

Correlations of cardiopulmonary exercise testing parameters to cardiac output in patients with idiopathic pulmonary arterial hypertension.

Variables All
(n = 83)
 Men
(n = 30)
 Women
(n = 53)
r p value r p value r p value
Exercise capacity parameters
 Peak workload, Watts 0.238 0.032 0.312 0.094 0.121 0.391
Metabolic parameters
 Peak VO2, ml/min/kg 0.433 <0.001 0.612 <0.001 0.209 0.137
 AT, ml/min/kg 0.318 0.004 0.474 0.008 0.126 0.373
Ventilatory parameters
 Peak VE, l/min 0.287 0.059 0.037 0.847 0.482 0.050
 Peak VCO2, ml/min 0.444 <0.001 0.432 0.017 0.447 0.001
 OUES, l/min/log 0.372 0.001 0.448 0.013 0.280 0.051
 OUEP, ml/l 0.170 0.128 0.213 0.258 0.110 0.480
 VE/VCO2 slope −0.188 0.045 −0.278 0.137 −0.122 0.388
Cardiovascular parameters
 Peak O2 pulse, ml/beat 0.379 <0.001 0.341 0.065 0.393 0.001
 Peak HR, beats/min −0.076 0.500 0.141 0.457 −0.021 0.881
Gas exchange parameters
 Peak RER −0.055 0.634 −0.046 0.820 −0.078 0.588
 Peak PETCO2, mmHg 0.199 0.033 0.441 0.015 0.020 0.890
 PETCO2 at AT, mmHg 0.196 0.037 0.391 0.032 0.061 0.666

Data are Spearman’s rank correlation coefficient or Pearson.

AT, anaerobic threshold; OUEP, oxygen uptake efficiency plateau; OUES, oxygen uptake efficiency slope; PETCO2, end-tidal partial pressure of CO2; VCO2, carbon dioxide output; VE, minute ventilation; VO2, maximum oxygen consumption; HR, heart rate; RER, carbon dioxide elimination/oxygen consumption.