Dahle Dag Olav, Eide Ivar Anders, Åsberg Anders, Leivestad Torbjørn, Holdaas Hallvard, Jenssen Trond Geir, Fagerland Morten W, Pihlstrøm Hege, Mjøen Geir, Hartmann Anders
1 Department of Transplant Medicine, Oslo University Hospital, Oslo, Norway. 2 Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Norway. 3 Norwegian Renal Registry, Oslo University Hospital, Oslo, Norway. 4 Metabolic and Renal Research Group, UiT The Arctic University of Norway, Tromsø, Norway. 5 Oslo Centre for Biostatistics and Epidemiology Research Support Services, Oslo University Hospital, Oslo, Norway. 6 Department of Nephrology, Oslo University Hospital, Oslo, Norway. 7 Insitiute of Clinical Medicine, Medical Faculty, University of Oslo, Oslo, Norway.
Transplantation. 2015 Aug;99(8):1730-7. doi: 10.1097/TP.0000000000000660.
The association between aortic stiffness and all-cause mortality in kidney transplant recipients (KTRs) is uncertain, and aortic stiffness has not yet been incorporated into risk prediction tools.
During 2007 to 2012, we measured carotid-femoral pulse wave velocity (PWV; SphygmoCor apparatus) 8 weeks after transplantation. The association between PWV and mortality was assessed in a Cox regression analysis adjusting for seven risk factors from a previously validated model. Internal validation was performed by bootstrap resampling, and discrimination and overfitting evaluated by Harrell's C and the calibration slope.
Of 1497 KTRs, 1040 (69%) had a valid PWV measurement. During a median follow-up of 4.2 years, 82 patients died. The association between PWV and mortality showed a ceiling effect, and PWV was truncated at 12 m/sec. Each 1 m/sec increase in PWV, up to 12 m/sec, was associated with mortality, hazard ratio (HR) 1.36 (95% CI, 1.14-1.62; P = 0.001). An interquartile range increase (3.8 m/sec) tripled the hazard of mortality, HR, 3.21 (95% CI, 1.63-6.31), similar to the effect of being approximately 20 years older (interquartile range increase (21.6 years); HR, 3.06 [95% CI, 1.87-5.29]). The PWV improved model discrimination with an increase in Harrell's C from 0.76 to 0.78; C difference, 0.024 (95% CI, 0.005-0.043; P = 0.01). Overfitting was moderate with a calibration slope of 0.89, and the final model was adjusted accordingly. A spreadsheet version is presented to estimate expected 5-year survival.
The PWV is a strong risk factor for mortality in KTRs.
肾移植受者（KTRs）的主动脉僵硬度与全因死亡率之间的关联尚不确定，且主动脉僵硬度尚未纳入风险预测工具中。
在2007年至2012年期间，我们在移植后8周测量了颈股脉搏波速度（PWV；SphygmoCor设备）。在对先前验证模型中的七个风险因素进行调整的Cox回归分析中评估PWV与死亡率之间的关联。通过自抽样进行内部验证，并通过Harrell's C和校准斜率评估辨别力和过度拟合情况。
在1497名KTRs中，1040名（69%）有有效的PWV测量值。在中位随访4.2年期间，82名患者死亡。PWV与死亡率之间的关联显示出上限效应，且PWV截断值为12米/秒。PWV每增加1米/秒（直至12米/秒），与死亡率相关，风险比（HR）为1.36（95%置信区间，1.14 - 1.62；P = 0.001）。四分位数间距增加（3.8米/秒）使死亡风险增加两倍，HR为3.21（95%置信区间，1.63 - 6.31），类似于年龄增加约20岁的影响（四分位数间距增加（21.6岁）；HR，3.06 [95%置信区间，1.87 - 5.29]）。PWV改善了模型辨别力，Harrell's C从0.76增加到0.78；C差异为0.024（95%置信区间，0.005 - 0.043；P = 0.01）。过度拟合程度适中，校准斜率为0.89，最终模型据此进行了调整。提供了一个电子表格版本以估计预期的5年生存率。
PWV是KTRs死亡的一个强有力的风险因素。
