探討亮點追蹤心臟超音波與水分過多在血液透析病人臨床預後的關聯性

Evaluation of Associations of Speckle-tracking Echocardiography and Overhydration with Clinical Outcomes in Maintenance Hemodialysis Patients

黃俊祺(Jiun-Chi Huang)

指導教授 ： 張哲銘

高雄醫學大學/醫學院/臨床醫學研究所博士班/博士(2020年)

摘要

在全世界，台灣的末期腎臟病之盛行率與發生率高居全球之冠。在台灣，有將近8萬個接受透析治療的病人，而其中超過90%是接受血液透析治療。特別的是，心血管疾病是這個族群病患死亡的最主要原因。造就如此高的心血管負荷之背後機轉，仍是相當地複雜並且尚未被完整的了解。傳統與非傳統的危險因子和心臟功能的異常，在預測不良臨床預後上有其重要的角色。其中，水分過多常見於接受血液透析治療的病人，並導致心臟負荷增加與心臟功能的受損。身體組成頻譜監測儀，為一非侵襲性用來測量個人水分含量狀態的工具。心臟超音波檢查在評估心臟的左心室功能有相當吃重的角色。和傳統的心臟超音波相比，二維亮點追蹤心臟超音波可以量化整個左心室心肌形變的程度，因此能更精準的反映左心室收縮與舒張的功能。透過亮點追蹤心臟超音波，左心室收縮期縱向形變能力(global left ventricular longitudinal systolic strain, GLS)是測量左心室收縮能力的新穎指標；早期二尖瓣血流速度與左心室舒張形變速率比值(ratio of early mitral inflow velocity to global diastolic strain rate, E/E’sr)是反映左心室舒張功能的新興指標。本博士論文研究假說為血液透析病人的水分過多，可能和受損的左心室收縮與舒張功能有所關聯；再者，水分過多、左心室收縮期縱向形變能力(GLS)與早期二尖瓣血流速度與左心室舒張形變速率比值(E/E’sr)，可能可以預測心血管事件與死亡的發生。因此，我們設計並執行了前瞻性的研究，來探討水分過多、左心室收縮期縱向形變能力(GLS)與早期二尖瓣血流速度與左心室舒張形變速率比值(E/E’sr)在預測血液透析病人臨床預後的角色。從我們的研究中，發現在校正左心室收縮與舒張功能後，水分過多仍可獨立的預測全原因死亡與心血管死亡。其次，我們更進一步的研究也發現左心室收縮期縱向形變能力(GLS)與早期二尖瓣血流速度與左心室舒張形變速率比值(E/E’sr)的異常，在血液透析病人能顯著地預測死亡與重大心血管事件的發生，而且在預測臨床不良預後上勝過在傳統心臟超音波測量之左心室收縮與舒張功能的參數。透過以上研究，我們得知水分過多、左心室收縮與舒張功能的新穎指標，包括：左心室收縮期縱向形變能力(GLS)與早期二尖瓣血流速度與左心室舒張形變速率比值(E/E’sr)，可以預測血液透析病人的死亡與心血管疾病的發生。未來針對這些因子的治療或改善預後方式的研究工作，仍需要再投注相當的心力進行。

關鍵字

血液透析 ； 水分過多 ； 亮點追蹤心臟超音波 ； 左心室收縮期縱向形變能力 ； 早期二尖瓣血流速度與左心室舒張形變速率比值 ； 臨床預後

並列摘要

Taiwan has the highest rate of prevalence and incidence of end-stage renal disease (ESRD) worldwide. Nearly 80,000 patients are dialysis-dependent in Taiwan, and more than 90% of them are undergoing maintenance hemodialysis (HD). In particular, cardiovascular disease (CVD) is the leading cause of death in this patient population. The mechanisms mediating such high cardiovascular (CV) burden remain not fully elucidated. Traditional, non-traditional, and functional abnormalities of the heart have their important roles in prognostic significance. Volume overload is not uncommom, leading to increased cardiac load and functional impairment of the heart. Body composition monitor (BCM) is a non-invasive tool to assess the individual’s hydration status. Echocardiography plays a key role in assessing left ventricular (LV) function. Specifically, two-dimensional (2D) speckle-tracking echocardiography (STE) can obtain the quantification of myocardial deformation and more precisely reflect systolic and diastolic performance of all myocardial segments. Global LV longitudinal systolic strain (GLS) and the ratio of early mitral inflow velocity to global diastolic strain rate (E/E’sr) are the novel indices of LV systolic and diastolic function using 2D-STE. We hypothesized that overhydration, assssed using BCM, might link with impaired GLS and E/E’sr, and these factors might predict CVD and mortality in HD patient. We conduct prospective studies to examine their roles in prognostic significance. Our studies showed that overhydration was independently associated with overall and CV deaths after adjusting for systolic and diastolic function of the LV. Furthermore, we found that worsening GLS and higher E/E’sr ratio significantly predict mortality and CVD, and outweigh the conventional indices of LV systolic and diastolic function in outcome prediction in patients undergoing HD. In conclusion, overhydration, worsening novel systolic and diastolic indices of LV, could predict unfavorable clinical and CV outcomes in maintenance HD patients. Further works and studies of therapeutic targeting these factors are warranted in patients with ESRD.

並列關鍵字

hemodialysis ； overhydration ； speckle-tracking echocardiography ； global longitudinal systolic strain ； ratio of early mitral inflow velocity to the global diastolic strain rate ； clinical outcomes

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