Determinants of Peak Oxygen Uptake at Each Stage of Renal Dysfunction in Patients with Heart Disease

Asami Ogura; Kazuhiro P Izawa; Shinji Sato; Hideto Tawa; Fumie Kureha; Masaaki Wada; Masashi Kanai; Ikko Kubo; Ryohei Yoshikawa; Yuichi Matsuda

doi:10.31083/j.rcm2306191

Determinants of Peak Oxygen Uptake at Each Stage of Renal Dysfunction in Patients with Heart Disease

Rev Cardiovasc Med. 2022 May 27;23(6):191. doi: 10.31083/j.rcm2306191. eCollection 2022 Jun.

Authors

Asami Ogura^{1

2

3}, Kazuhiro P Izawa^{2

3}, Shinji Sato⁴, Hideto Tawa⁵, Fumie Kureha⁵, Masaaki Wada¹, Masashi Kanai^{2

3}, Ikko Kubo^{2

3}, Ryohei Yoshikawa⁵, Yuichi Matsuda⁵

Affiliations

¹ Department of Rehabilitation, Sanda City Hospital, 669-1321 Hyogo, Japan.
² Department of Public Health, Graduate School of Health Sciences, Kobe University, 654-0142 Hyogo, Japan.
³ Cardiovascular Stroke Renal Project (CRP), 654-0142 Hyogo, Japan.
⁴ Department of Sport and Medical Science, Faculty of Medical Technology, Teikyo University, 192-0395 Tokyo, Japan.
⁵ Department of Cardiology, Sanda City Hospital, 669-1321 Hyogo, Japan.

Abstract

Background: Identifying the causes of low peak oxygen uptake (peak V̇ $O_{2}$ ) in heart disease patients with renal dysfunction is necessary for prognostic improvement strategies. The purpose of this study was to verify the determinants of peak V̇ $O_{2}$ for each stage of renal function in heart disease patients, focusing on end-tidal oxygen partial pressure ( ${PETO}_{2}$ ).

Methods: Two hundred fifty heart disease patients who underwent cardiopulmonary exercise testing (CPET) in our institution were consecutively enrolled. Patients were divided into three groups by their estimated glomerular filtration rate (eGFR): $<$ 45, 45-59 and $\geq$ 60 mL/min/1.73 $m^{2}$ . Patient characteristics and CPET parameters including $Δ$ ₂ (rest-anaerobic threshold) were compared between the groups. The relationship between $Δ$ PETO ${PETO}_{2}$ and peak V̇ $O_{2}$ was also investigated for each group.

Results: In total, 201 patients were analyzed. $Δ$ ${PETO}_{2}$ decreased with the deterioration of renal function (eGFR $<$ 45, 0.1 mmHg vs. eGFR 45-59, 2.4 mmHg vs. eGFR $\geq$ 60, 5.2 mmHg, p $<$ 0.001). In the eGFR $<$ 45 group, left ventricular ejection fraction (LVEF) and hemoglobin (Hb) were significantly associated with peak V̇ $O_{2}$ $β$ = 0.518, p $<$ 0.001 and $β$ = 0.567, p $<$ 0.001, respectively), whereas $Δ$ ${PETO}_{2}$ was not. In the eGFR 45-59 group, age, Hb, and $Δ$ ${PETO}_{2}$ showed a significant association with peak V̇ $O_{2}$ ( $β$ = -0.354, p = 0.006; $β$ = 0.258, p = 0.007; $β$ = 0.501, p $<$ 0.001; respectively). In the univariate analysis, eGFR 45-59 group showed the highest coefficient of determination of $Δ$ ${PETO}_{2}$ to peak V̇ $O_{2}$ ( $R^{2}$ = 0.247, p $<$ 0.001).

Conclusions: The determinants of peak V̇ $O_{2}$ in heart disease patients depended on the stage of renal function. The determinants of peak V̇ $O_{2}$ in patients with eGFR $<$ 45 were LVEF and Hb, while $Δ$ ${PETO}_{2}$ was the strongest predictor of peak V̇ $O_{2}$ in patients with eGFR 45-59.

Keywords: end-tidal oxygen partial pressure; heart disease; peak oxygen uptake; renal dysfunction.