Dialysis Modality and Incident Atrial Fibrillation in Older Patients With ESRD Jingbo Niu, Maulin K. Shah, Jose J. Perez, Medha Airy, Sankar D. Navaneethan, Mintu P. Turakhia, Tara I. Chang and Wolfgang C. Winkelmayer 2019.04.03 Chih-Hsin, Yeh 今天要報的這篇主要是要了解在老年的ESRD病人身上 不同的透析方式 之後AF的發生率是否有所差異

Introduction Atrial fibrillation/flutter (AF) is the most common sustained arrhythmia in the general population and is particularly common in patients with end-stage renal disease (ESRD). More than 10% of prevalent US patients on hemodialysis (HD) therapy carry a confirmed diagnosis of AF, and the percentage increases steeply with age, reaching approximately one- quarter of patients older than 85 years. The cumulative incidence of newly diagnosed AF during the first year of dialysis therapy among older patients initiating HD is almost 15%. 首先introduction的部分 AF在ESRD患者是很常見的 美國有10％以上血液透析（HD）患者確診AF，並且隨著年齡的增長，百分比急劇增加，大約有四分之一的患者超過85歲。 開始透析的老年患者中，在透析治療的第一年中新診斷的AF的累積發生率將近15％。

Introduction Several risk factors for the development of AF have been identified, including sociodemographic characteristics and chronic conditions (eg, heart failure, diabetes, and hypertension), and it appears that most of these factors similarly increase AF risk in patients with kidney failure requiring maintenance dialysis. One potential AF risk factor unique to patients with kidney failure that has not been investigated sufficiently is the dialysis modality used for kidney replacement therapy. 已經有很多確定AF的危險因子，包括年齡較大，女性，白種人等和慢性病（如heart failure心衰竭，糖尿病和高血壓），這些因素對同樣需要維持性透析的腎衰竭患者也會增加AF風險。 目前腎衰竭病患特有的一種潛在的AF風險因素尚未得到充分研究，就是透析方式。

Introduction Patients undergoing HD are exposed to considerable cyclical changes in fluid and electrolyte status with accumulation of fluid and uremic toxins, including potentially pro-arrhythmogenic electrolytes during the intradialytic interval followed by rapid fluid removal and electrolyte shifts during the relatively short HD procedure. By contrast, PD confers more continuous removal of excess fluids and maintenance of electrolyte balance, thus exercising less strain on the heart while reducing the burden of other potential AF triggers. 接受HD的病人長期暴露於體內水份 電解質及血壓變化大，心輸出量升高，長期下來對心血管系統影響較大。 相比之下，PD可以更連續地去除多餘的液體並維持電解質平衡，從而減輕心臟的壓力，同時減少其他增加AF發生的潛在風險。

Objective However, little is known about whether the AF incidence differs between patients undergoing HD versus PD. We conducted this study to specifically challenge the null hypothesis of no difference in AF incidence between incident patients with ESRD using PD versus HD in a large ESRD registry. 接受血液透析和腹膜透析的患者的AF發病率是否不同尚不確定。 因此這篇研究就是想要看PD和HD的ESRD病人 AF的發生率是否有差異

Methods Study Design : Retrospective cohort study. Source Population : Using the US Renal Data System, we identified older patients (≥67 years) with Medicare Parts A and B who initiated dialysis therapy (1996-2011) without a diagnosis of AF during the prior 2 years. 這篇的Study Design : Retrospective cohort study. 資料是使用USRDS 美國腎臟登錄系統 納入大於67歲以上持續納保Medicare A B的病人 用開始透析那天當作index_date 在index_date前兩年內都沒有診斷AF 診斷碼使用427.3

Methods Exposure: Dialysis modality at incident end-stage renal disease (ESRD) and maintained for at least 90 days. We excluded patients who died on the index date or underwent preemptive kidney transplantation, discontinued dialysis therapy, recovered kidney function, or were lost to follow-up during the 90 days following the index date. Outcome: Patients were followed up for 36 months or less for a new diagnosis of AF. Exposure: 持續透析至少90天, 並排除在index_date之後死亡, 腎臟移植, 沒有持續透析, 腎功能恢復, 或是在index_date後的90天內lost follow up Outcome: follow 期間有新診斷AF

Methods Statistical Analysis Time-to-event analysis using multivariable Cox proportional hazards regression to estimate cause- specific HRs while censoring at modality switch, kidney transplantation, or death. Then we applied the Fine-Gray model to estimate the subdistribution HR. This model considered persons with competing events as being still in the risk set when defining the hazard of AF and is preferable in “predicting an individual’s risk.”

Results 這篇最後納入有27萬名病人, 其中25萬是HD的病人, 1萬7千是PD的病人, 年齡中位數大約在75歲左右 , 女性占51%左右 PD的病人年齡相較年輕, 男性比例較多 共病的比例也比較低, 他也有提到因為樣本數很大的關係 所以都有達顯著差異 Follow三年的期間 overall有六萬九千多個病人發生AF 在folloe 90天內發生AF的比例是有差異的 在91天到3年的期間則沒有顯著差異

Results 橫坐標是follow up的時間, 縱坐標是未校正的情況下, AF的累積發生率 在index_date後的前面幾個月，PD組的AF發生率較低，但這個差異在follow 36個月漸漸縮小

Results 透析方式 人年 發生AF個案數 和發生率 Hazard ratio是以HD當reference 在開始透析後90天內 PD發生AF的風險都比HD低 在follow 90天後到3年 兩種透析方式

Results

Results

Discussion Why the benefit of PD for AF risk is not sustained is unclear. Perhaps it is related to the complex pathophysiology of AF. Because patients with kidney failure have volume overload long term and neurohormonal alterations leading to cardiac structural abnormalities, modality differences for dialysis may not be enough to reduce the risk for AF. It has been shown that chronic inflammation and oxidative stress may be implicated in the pathophysiology of AF, both of which are present in patients with kidney failure on any dialysis modality. 在超過3個月的透析方式之間AF發病率沒有任何重大差異可能是出乎意料的。為什麼不能維持PD對AF風險的益處尚不清楚。也許它與復雜的病理生理學有關。由於腎衰竭患者長期容量超負荷，神經激素改變導致心臟結構異常，因此透析的方式差異可能不足以降低房顫的風險。已經表明，慢性炎症和氧化應激可能與AF的病理生理學有關，這兩者都存在於任何透析方式的腎衰竭患者中。

Discussion Limitations: Residual confounding from unobserved differences between exposure groups; ascertainment of AF from billing claims; study of first modality may not generalize to patients switching modalities; uncertain generalizability to younger patients.

Conclusion Although patients initiating dialysis therapy using peritoneal dialysis had a lower AF incidence during the first 90 days of ESRD, there was no major difference in AF incidence thereafter. The value of interventions to reduce the early excess AF risk in patients receiving hemodialysis may warrant further study. 儘管使用腹膜透析開始透析治療的患者在ESRD的前90天內AF發生率較低，但此後AF發生率沒有顯著差異。 降低接受血液透析的患者早期過度房顫風險的干預措施的價值可能需要進一步研究。