From the Departments of Radiology and Nuclear Medicine.
Epidemiology.
Invest Radiol. 2018 Oct;53(10):616-622. doi: 10.1097/RLI.0000000000000479.
Recently, safety guidelines for the use of intravascular iodinated contrast material have been updated, and the recommended threshold for giving prophylaxis to prevent contrast-induced nephropathy (CIN) has been reduced to estimated glomerular filtration rate (eGFR) less than 30 mL/min/1.73 m. Data on this population in the context of CIN, especially evidence for efficacy of the recommendation of prophylactic intravenous hydration, are lacking. The aim of the current study was to test implicit assumptions underlying the guideline update: (1) patients with eGFR <30 mL/min/1.73 m, as opposed to former high-risk patients with eGFR ≥30 mL/min/1.73 m, are at high risk of CIN and other unfavorable outcomes after intravascular iodinated contrast material administration; (2) prophylactic intravenous hydration mitigates this risk; and (3) the risk of administering prophylactic intravenous hydration does not outweigh the positive preventive effect.
Retrospectively, data were collected from all patients with eGFR <30 mL/min/1.73 m referred for an elective procedure with intravascular iodinated contrast material administration and excluded from the AMACING trial (A MAastricht Contrast-Induced Nephropathy Guideline trial). We compared these patients with those prospectively included in the AMACING trial (with eGFR 30-59 mL/min/1.73 m and risk factors). Main outcomes were CIN (defined as an increase in serum creatinine by more than 25% or 44 μmol/L within 2-6 days postcontrast exposure), dialysis and mortality within 35 days postcontrast exposure, and complications of prophylactic intravenous hydration.
A total of 28,803 patients referred for an elective procedure with intravascular iodinated contrast administration were prospectively screened for inclusion in the AMACING trial. One hundred fifty-seven (0.5%) patients had eGFR <30 mL/min/1.73 m, and 155 received intravascular iodinated contrast material. Standard prophylaxis was given to 119/155 of these patients. Data on 2- to 6-day serum creatinine, 35-day dialysis 35-day mortality, and complications of prophylactic intravenous hydration were available for 59/119 (50%), 118/119 (99%), 119/119 (100%), and 119/119 (100%) standard prophylaxis patients, respectively. Incidences in eGFR <30 mL/min/1.73 m versus AMACING patients are as follows: CIN 13.6% versus 2.7% (P = 0.0019); 35-day dialysis 0.9% versus 0.0% (P = 0.2646); 35-day mortality 9.2% versus 0.0% (P < 0.0001); complications of prophylactic intravenous hydration 5.9% versus 5.5% (P = 0.8529).
Postcontrast incidences of CIN and mortality at 35 days are significantly higher in the population with eGFR <30 mL/min/1.73 m than in the former high-risk population with eGFR 30 to 59 mL/min/1.73 m, even after prophylactic intravenous hydration. The risk of complications of prophylactic intravenous hydration is similar and substantial in both populations. Obtaining evidence from a randomized trial that efficacy of prophylactic intravenous hydration outweighs the risk of complications is important but may not be feasible.
最近，血管内碘造影剂使用的安全指南已经更新，预防对比剂肾病（CIN）的推荐阈值已经降低到估计肾小球滤过率（eGFR）<30ml/min/1.73m。关于这一人群在 CIN 方面的数据，特别是预防静脉水化推荐的疗效证据，尚缺乏。本研究的目的是检验指南更新背后的隐含假设：（1）eGFR<30ml/min/1.73m 的患者，与以前 eGFR≥30ml/min/1.73m 的高危患者相比，在接受血管内碘造影剂后发生 CIN 和其他不良结局的风险较高；（2）预防性静脉水化可以减轻这种风险；（3）预防性静脉水化的风险不会超过积极预防的效果。
回顾性地，从所有 eGFR<30ml/min/1.73m 的患者中收集数据，这些患者因接受血管内碘造影剂而接受择期手术，并被排除在 AMACING 试验（A MAastricht Contrast-Induced Nephropathy Guideline trial）之外。我们将这些患者与前瞻性纳入 AMACING 试验的患者（eGFR 30-59ml/min/1.73m 且有危险因素）进行比较。主要结局是 CIN（定义为在造影后 2-6 天内血清肌酐升高超过 25%或 44μmol/L）、造影后 35 天内的透析和死亡率以及预防性静脉水化的并发症。
共有 28803 例接受血管内碘造影剂的择期手术患者被前瞻性筛选纳入 AMACING 试验。157 例（0.5%）患者 eGFR<30ml/min/1.73m，其中 155 例接受了血管内碘造影剂。119/155 例（77%）标准预防患者接受了标准预防。有 59/119（50%）、118/119（99%）、119/119（100%）和 119/119（100%）标准预防患者的 2-6 天血清肌酐、35 天透析、35 天死亡率和预防性静脉水化并发症数据。eGFR<30ml/min/1.73m 与 AMACING 患者的发生率如下：CIN 13.6%与 2.7%（P=0.0019）；35 天透析 0.9%与 0.0%（P=0.2646）；35 天死亡率 9.2%与 0.0%（P<0.0001）；预防性静脉水化并发症 5.9%与 5.5%（P=0.8529）。
eGFR<30ml/min/1.73m 患者的造影后 CIN 和 35 天死亡率发生率明显高于以前 eGFR 30-59ml/min/1.73m 的高危人群，即使给予了预防性静脉水化。预防性静脉水化并发症的风险在这两个人群中相似且相当大。从随机试验中获得预防静脉水化的疗效超过并发症风险的证据很重要，但可能不可行。
