Ventilatory Equivalent Slope: A Strong Survival Predictor for Heart Transplant Candidates after Adjusting Gender Difference

在考量性別因素之後，呼吸效能對於等待心臟移植病患的預後有良好預測力

魏崢(Jeng Wei) ； 郭俐纓(Li-Ying Kuo) ； 鄭斐馨(Fei-Hsin Cheng) ； 陳瑞君(Jui-Chun Chen) ； 許青翎(Ching-Ling Hsu) ； 陳柏言(Bo-Yan Chen) ； 林郁珊(Yu-Shan Lin) ； 蔡蕙羽(Hui-Yu Tsai) ； 黃心怡(Hsin-Yi Huang)

《物理治療》 41卷4期 (2016/12) Pp. 271-279

https://doi.org/10.6215/FJPT.PTS1446092018

摘要

Background: Heart Failure Survival Score (HFSS), peak exercise oxygen consumption (VO_2), and ventilatory equivalent (ventilation/CO_2 Production, VE/VCO_2) slope have been suggested to predict survival in ambulatory patients with heart failure (HF) and are used for selection for heart transplantation (HTx). However most study populations were predominantly male. It is unclear if the prognostic powers are similar between genders. Methods: From 2004 to 2011 there were thirty-nine (20.0%) female HF patients referred for pre-HTx evaluation with complete exercise pulmonary function test (EPFT), and the data were collected retrospectively. Seventy-seven (39.5%) male patients matched in age and peak VO_2 were selected to compare gender differences. Both peak VO_2 and VE/ VCO_2 slope were obtained from the results of EPFT. Seven HFSS parameters were obtained from chart review. The outcomes were death, mechanical devices implantation, or HTx. The VE/VCO_2 slope lower than the medium value was defined as low risk, and that greater than the medium value was defined as high risk. Subjects were divided into high-, medium-, and low-risk strata for HFSS based on previous cutoff points of 8.10 and 7.19 and VO_2 based on cutoff points of 14 ml/kg/min. Survival curves were generated separately for each of the two VE/VCO_2 slope strata, three peak VO_2 strata, and three HFSS risk strata using the Kaplan-Meier (KM) method. To further identify gender difference survival curve was generated by adjusting gender. Results: The mean peak VO_2, VE/VCO_2 slope, and HFSS were 14.5 ± 4.9 ml/kg/min, 38.2 ± 10.9 and 7.1 ± 0.7, respectively. Considering gender difference, VE/ VCO_2 slope was a powerful predictor (p = 0.043). Survival curves for different strata based on peak VO_2 and HFSS were not significantly different (p ＞ 0.05) in both gender groups. Conclusion: Impairment in exercise ventilation holds clinical prognostic impact after adjusting gender factor in HF patients.

關鍵字

Heart transplantation ； Peak oxygen consumption ； Heart failure survival score ； Ventilatory equivalent ； Prediction

並列摘要

背景：心衰竭存活分數、最大攝氧量、及呼吸效能用於預測心衰竭病患的存活率。然而，大多研究以男性為主，對於女性是否有相同的預測力目前仍未知。方法：選取自2004至2011年間，轉介做換心評估並完成運動肺功能檢查的患者，共39名女性(20.0%)，並選取了77名(39.5%)年齡及最大攝氧量相符的男性病患，比較各指標在性別間的預測力，病患追蹤的終點定義為死亡、侵入性輔助器置入、或是換心。3個指標的分組方式分別為：(1)呼吸效能低於中位數列入低危險組，其餘列入高危險組；(2)心衰竭存活分數小於等於7.19，介於7.20至8.09，大於8.10分別為高、中、低危險；(3)最大攝氧量大於14ml/kg/min，介於10到14ml/kg/min，小於等於10ml/kg/min分別為低、中、高危險。利用存活分析男女分開分別畫出3項指標各組的生存曲線，統計顯著訂於p值小於0.05。結果：以呼吸效能分組在不同性別的預測力有顯著不同(p=0.043)，以最大攝氧量及心衰竭存活分數分組男女間皆沒有顯著差異。結論：運動中呼吸效能的損傷對於女性心衰竭族群是較佳的預測因子。

並列關鍵字

心臟移植 ； 最大攝氧量 ； 心衰竭存活分數 ； 呼吸效能 ； 預測因子