以住院期六分鐘行走測試預測心臟手術患者心血管死亡研究

Abstract

研究背景 心臟手術後的高死亡率與不良的功能能力相關，而六分鐘行走測驗可用以評估功能能力。目前探討六分鐘行走距離與心臟手術後死亡關係的文獻仍然不足。 材料與方法 研究設計為單一中心回溯世代研究，對象為2011及2012年於台大醫院接受冠狀動脈繞道且/或心瓣膜手術者。六分鐘行走距離做為自變數放入Cox proportional hazards model進行存活分析。結果定義為至2013年12月31日之心血管致因死亡，經由連結衛生福利部統計處健康資料加值應用協作中心取得資料。 結果 共383位患者(平均年齡60.5±11.3歲，女性占28.5%)住院中接受六分鐘行走測驗(平均301.3±97.1公尺)，在追蹤中位數24個月後(四分位距12個月)，有14位發生心血管致因死亡。六分鐘行走距離以連續變數放入模型中，每增加100公尺風險比為0.27 (95%信賴區間為0.10-0.69，p=0.007)。相較於行走距離<200公尺組，患者行走距離≥200公尺且<300公尺組風險比0.22 (95%信賴區間0.05-0.91)，≥300公尺組風險比0.09 (95%信賴區間0.01-0.59)。次分組分析則顯示六分鐘行走測試距離只在左心室射出率較低組(<60%)中為顯著的預後因子，於左心室射出率較高組則無統計顯著。

結論 六分鐘行走測試對於心臟手術後患者具有預後的預測價值，可辨認出需密切追蹤的高風險族群，鼓勵其參與術後的心臟復健計畫。

Background High mortality after cardiac surgery was related to poor functional capacity which can be evaluated by six-minute walking test (6MWT). Scanty literature was about the relationship between 6MWT distance and the mortality after heart surgery. Material and methods We conducted a retrospective cohort from National Taiwan University Hospital who received CABG and/or valve surgery in 2011 and 2012. We put 6MWT distance as the independent variable into Cox proportional hazards model for survival analysis. Outcome is cardiovascular mortality till 2013/12/31 via linking data to the Collaboration Center of Information Application (CCHIA). Results A total of 383 patients (mean age 60.5±11.3 years old, 28.5% female) undertook 6MWT (301.3±97.1m) during post-surgical hospitalization, and 14 died of cardiovascular causes during a follow-up of median 24 months (interquartile range, IQR=12 months). When 6MWT distance was put as continuous variable, the hazard radio (HR) was 0.27 (95% Confidence interval, CI: 0.10-0.69, p=0.007) with 100m increment. While compared with <200m group, HR of ≥200m and <300m group was 0.22 (95% CI: 0.05-0.91), and HR of ≥300m group was 0.09 (95% CI: 0.01-0.59). Subgroup analysis showed that 6MWT distance was a significant factor of predicting cardiovascular mortality in the lower LVEF group (<60%), but not in the higher LVEF group. Conclusion Our findings demonstrated the prognostic value of 6MWT in post cardiac surgery patients, implying to identify the vulnerable patients who may need more intensive follow-up and active participation in cardiac rehabilitation.