International Circulation:  We would like to hear your opinion about patient selection and indications for renal angiography and stenting.
国际循环：您能给我们谈谈肾血管造影和支架植入术患者选择和适应症的意见吗？

Prof. John H. Rundback:  We can start by talking about the crossroads of renal intervention.  I was just speaking today about the guidelines and recommendations for whom renal intervention， angiography， and intervention is appropriate.  Broadly speaking， the guidelines indicate that intervention is warranted in 3 groups of patients， those with hypertension， with renal artery stenosis， with renal insufficiency， and those patients who have cardiac disturbance syndrome most predominantly described as patients with recurrent episodes of congestive heart failure (CHF) due to right ventricular dysfunction or diastolic dysfunction.  If you look at that more critically you start realize the types of hypertensive populations you want to treat who have renal artery stenosis would be those patients who have hemodynamically significant renal artery stenosis， as well as a clinical syndrome， which includes refractory， accelerated， or malignant hypertension.  Hemodynamic significance is at the crux of this.  There was a rather elegant article by DeBrun in the Journal of American Cardiology last year trying to define this age-old debate of what is hemodynamic significance.  That is， what percentage of renal artery stenosis reduces perfusion to the glomeruli to the point where a patient is unable to have adequate filtration and the juxta-glomerular apparatus is stimulated?  Data in dog models seems to suggest that once you get below a perfusion pressure of 80mmHg， at that JJ apparatus there is stimulation of renin-angiotensin.  Understandably that is actually quite a bit more complex and has to do with stretch receptors and sense differences between systemic and renal blood pressure.  Hemodynamic significance has been studied by DeBrun， and their elegant articles describes that in patients who had renal stents placed， they did graded inflation of ballons in the renal artery， measuring the trans-stenotic radius during the course of the process， and measure stimulated renin.  They found that， in essence， a 20mmHg trans-stenotic gradient seems to correlate with a release of renin and hypertension.  This is interesting because I published guidelines back in ’02 or ’03 and we chose 20mmHg as a sort of stab into the dark and seems as though we got it right.  You have to have hemodynamic significance， a real stenosis， refractory associations who are on multiple medications， and persistent elevations in blood pressure， systolic more than 160 mmHg and diastolic more than 90 mmHg.  I like to think of this as more of a failed medical therapy report， which actually should be studied more， accelerated those patients who were on prior control and now have rapid and unexplained deteriorations in blood pressure control or patients who have end-organ damage.  It could be retinopathy， proteinurea， or could be CHF. 
In terms of renal function， those patients who have progressive declines in renal function， asymmetry in kidney size， and significant stenosis generally warrant consideration for intervention， bearing in mind that there is a less likely to have a rewarding benefit in terms of improved renal function than you are for stabilization of renal function.  If you look at the data for patients who have renal artery stenosis， whether unilateral bilateral， 75-80% of patients will have beneficial decline， stabilization， or improvement in renal function.  Improvement being the minority， seen in just 5-20% of cases， stabilization being more in order.  Interestingly， the challenge with some of the randomized clinical trials is what I’ve just talked about. 
Clearly there have been benefits in terms of stabilization of renal function， which has been sustained after two years.  Also， in several performance goal types of trials， including objective performance criteria (OPC) out to two years， such as we have seen in the ASPIRE II and the RENAISANCE trials.  We have seen sustained benefit in terms reductions in serum creatinine.  Again， in the optimal patients， which are those with the most rapid decline in renal function prior to intervention， those patients have some sort of acute episode of either superimposed embolization with atherosclerotic nephropathy， superimposed on an ischemia nephropathy and/or plaque destabilization with a sudden worsening of stenosis， or something along these lines. 
Finally， you have the patients who have cardiac disturbance syndrome or patients who have recurrent CHF/pulmonary edema due to diastolic dysfunction， presumably stiff ventricles under the effect of endothelian and angiotensin II.  That being said， this is obviously much more complex in that we realize， interestingly， if we look at cohorts of patients who have renal artery stenosis and coronary artery disease who have non-reconstructable coronary artery disease and contractile angina but undergo renal intervention， they have the same rate of benefit in terms of resolution and reduction of their anginal episodes after renal intervention as would those patients who have coronary intervention.  There is a very nice article by Simonitti， published last year， which investigated the preservation of left ventricular function.  There is a more recent article this year as well that clearly show that patients with CHF who undergo intervention have fewer subsequent interventions for CHF， fewer admissions for CHF， and a reduced severity of American Heart Association classification.  That is a good indication for renal intervention. 
Prof. John H. Rundback:  我们先从肾介入开始说起。今天我介绍了指南和对哪些患者可进行肾介入，血管造影和介入的推荐意见。一般来说，指南建议介入用于3类患者，即高血压，肾动脉狭窄和肾功能不全的患者，以及有心脏紊乱综合征的患者，主要是指由于右心室功能不全和舒张功能障碍导致的充血性心力衰竭再发患者。对于肾动脉狭窄患者，主要是治疗有血液动力学显着性肾动脉狭窄和临床症状，包括难治性，急进性或恶性高血压患者。血流动力学有很重要的意义。去年DeBrun在美国心脏病杂志发表了一篇很好的文章，试图确定这个年龄血流动力学的意义。也就是说，肾动脉狭窄达到什么样的程度可降低肾小球灌注，使患者滤过不足，进而激活肾小球旁器。犬模型的研究资料提示，一旦灌注压降低到80 mmHg以下，肾素血管紧张素系统即可激活。但实际情况要复杂得多，而且与全身和肾血流压力间肺牵张感受器和感受差异有关。DeBrun对血流动力学的意义进行了很好的研究，在该研究中对患者放置肾支架，进而测量该过程中的跨狭窄半径，并检测肾素的释放。他们发现，20 mmHg跨狭窄梯度似乎与肾素释放和高血压有关。这很有趣，因为早在02或03公布的指南，我们就正确选择了20 mmHg作为这样一个梯度。必须有血流动力学意义，真正的狭窄，多药治疗的难治性患者，持续血压升高，即收缩压升高超过160 mmHg，舒张压超过90 mmHg。对于这些药物治疗失败的病例，实际上需要进行更多的研究。而对于那些开始控制较好，但随后血压发生快速和不可解释的恶化或终末器官损害的患者，可能是视网膜病变，蛋白尿，或充血性心力衰竭。
关于肾功能逐步下降，肾大小不对称，并有明显狭窄的患者，一般需要考虑进行介入，要记住改善肾功能并不比稳定肾功能获得的获益多。如果分析一下肾动脉狭窄患者的资料，无论是单侧还是双侧，75%-80％患者肾功能获益会有下降，稳定，或改善。而改善的患者占少数，仅仅发生于5%~20％的患者。有趣的是，一些随机临床试验的挑战则是我刚才讲的这些内容。
显然，稳定肾功能对患者有益，这种获益可持续近两年。此外，进行的几个试验，包括OPC，正如我们在ASPIRE II和RENAISANCE试验中所观察到那样。我们已经观察到血清肌酐下降的可使患者持续获益。同样，最佳的患者是介入前肾功能下降最快的患者，这些患者有急性栓塞重叠动脉粥样硬化性肾病，缺血性肾病和/或斑块不稳重叠狭窄突然恶化，或这样的一些情况。
最后<