Table 2

Changes in gas exchange parameters, biventricular function and haemodynamics from rest to peak exercise before and after sildenafil administration

Controls (n=7)CTEPH (n=14)
Pre-sildenafilPost-sildenafilp ValuePre-sildenafilPost-sildenafilp Value
Heart rate, bpm
 Rest61±378±40.00279±3*82±30.152
 Peak exercise147±4†153±7†0.186122±5†*118±5†*0.038
LVEF, %
 Rest60.7±2.165.6±2.60.07261.0±2.563.5±2.20.004
 Peak exercise69.6±1.6†73.0±1.7†0.04464.1±3.667.4±3.2†0.006
RVEF, %
 Rest59.1±2.362.5±3.30.26836.2±1.8*40.1±1.9*<0.001
 Peak exercise73.2±1.9†75.3±3.2†0.43634.8±2.2*40.0±3.0*0.002
SVi, mL/m2
 Rest53±550±50.37035±2*37±2*0.036
 Peak exercise59±657±60.46234±3*39±3*0.009
CI, L/min m2
 Rest3.1±0.33.7±0.20.0192.7±0.22.9±0.2*0.006
 Peak exercise8.7±1.1†8.8±1.2†0.6924.1±0.3†*4.5±0.2†*0.021
mSAP, mm Hg
 Rest101±591±50.05894±483±30.001
 Peak exercise125±3†118±4†0.062117±6†105±5†0.001
mPAP, mm Hg
 Rest11±18±10.01245±3*38±2*<0.001
 Peak exercise24±3†19±1†0.02664±3.0†*54±3.0†*<0.001
RA pressure, mm Hg
 Rest8±26±20.044
 Peak exercise19±3†14±4†0.017
tPVR dyne/s/cm5
 Rest154±2397±110.012727±53*553±41*<0.001
 Peak exercise126±2295±110.105688±63*527±53*<0.001
tSVR, dyne/s/cm5
 Rest1483±2171072±1080.0121565±1541227±104<0.001
 Peak exercise661±86†639±114†0.6411271±136†*1031±109†*0.001
tPVR/tSVR ratio
 Rest0.11±0.010.09±0.010.0940.48±0.03*0.47±0.03*0.130
 Peak exercise0.20±0.02†0.16±0.01†0.0370.59±0.04†*0.53±0.03†*0.019
PaO2, mm Hg
 Rest102±785±60.07871±6*56±3*0.001
 Peak exercise90±695±70.29465±6*56±3*0.037
PaCO2, mm Hg
 Rest36±237±10.54133±133±1*0.529
 Peak exercise37±133±2†0.05329±1†*31±1†0.020
ScvO2,%
 Rest73±274±10.66965±2*62±2*0.057
 Peak exercise43±6†41±5†0.20138±3†41±3†0.083
C(a-cv)O2, mL O2/100 mL
 Rest4.8±0.44.4±0.20.1696.3±0.4*6.0±0.3*0.434
 Peak exercise10.8±1.0†11.3±0.9†0.30311.3±0.6†10.2±0.6†0.003
  • p Values from repeated measures ANOVA for difference between pre-sildenafil and post-sildenafil, and for rest vs peak exercise; †p<0.05 for difference vs rest; *p<0.05 for difference vs healthy control subjects by unpaired two-sample t test.

  • ANOVA, analysis of variance; C(a-cv)O2, arterial-central venous oxygen content difference; CI, cardiac index; CTEPH, chronic thromboembolic pulmonary hypertension; mPAP, mean pulmonary arterial pressure; mSAP, mean systemic arterial pressure; PaCO2, arterial carbon dioxide tension; PaO2, arterial oxygen tension; RA, right atrial pressure; ScvO2, central venous oxygen tension; SVi, indexed stroke volume; tPVR, total pulmonary vascular resistance; tSVR, total systemic vascular resistance.