Prognostic value of oxygen consumption and ventilatory equivalent slope in female candidates referred for heart transplantation--experience of a single Asian center.
BACKGROUND
Ventilatory equivalent (ventilation/CO2 production, VE/VCO2) slope has been suggested to be a much more accurate predicator than peak oxygen consumption (VO2) during exercise for prognosis in patients with heart failure. However, patients tested were predominately male.


METHODS
To investigate whether peak VO2 and VE/VCO2 slope predict the prognosis of female patients with heart failure, we retrospectively collected data of 39 female candidates referred for heart transplantation (HTx) from 2004 to 2011. Both peak VO2 and VE/VCO2 slope were obtained from the results of an exercise pulmonary function test. The outcome was death or mechanical devices implantation or HTx. Logistic regression was used for data analysis.


RESULTS
Mean age and heart failure survival score were 55.8 ± 13.7 years and 7.3 ± 0.7, respectively. Each increment of VE/VCO2 slope decreased 2-year event-free rate (odds ratio [OR] = 0.88, 95% confidence interval [CI] = 0.79 to 0.98) in the female group. The predictions of VE/VCO2 slope for 1-year event-free survival did not reach statistical significance (OR = 0.92, 95% CI = 0.84 to 1.00). On the other hand, peak VO2 was not a strong predictor for 1- and 2-year event-free survival (OR = 1.22 and 1.16, 95% CI = 0.96 to 1.55 and 0.94 to 1.44, respectively).


CONCLUSIONS
Impairment in exercise ventilation holds a clinical and long-term prognostic impact in female patients with heart failure. The role of peak VO2 during exercise in prognostic prediction among the cohort should be further investigated.
Heart Center, Cheng Hsin General Hospital, Pei-Tou, Taipei, Taiwan.
H Y
HY
Huang
Heart Center, Cheng Hsin General Hospital, Pei-Tou, Taipei, Taiwan.
L Y
LY
Kuo
Heart Center, Cheng Hsin General Hospital, Pei-Tou, Taipei, Taiwan.
F H
FH
Cheng
Heart Center, Cheng Hsin General Hospital, Pei-Tou, Taipei, Taiwan.
J C
JC
Chen
Heart Center, Cheng Hsin General Hospital, Pei-Tou, Taipei, Taiwan.
C L
CL
Hsu
Heart Center, Cheng Hsin General Hospital, Pei-Tou, Taipei, Taiwan.
B Y
BY
Chen
Heart Center, Cheng Hsin General Hospital, Pei-Tou, Taipei, Taiwan.
Y S
YS
Lin
Heart Center, Cheng Hsin General Hospital, Pei-Tou, Taipei, Taiwan.
H Y
HY
Tsai
Heart Center, Cheng Hsin General Hospital, Pei-Tou, Taipei, Taiwan. Electronic address: chghjw@yahoo.com.tw.
J
J
Wei
D000328:Adult; D000368:Aged; D005260:Female; D016027:Heart Transplantation; D006801:Humans; D008875:Middle Aged; D010101:Oxygen Consumption; D011379:Prognosis; D012017:Referral and Consultation; D012129:Respiratory Function Tests