International Circulation: Do you end up with patients with hypotension at all?
　　Dr Weil: Yes. You should check for this and it is important to do follow-ups on every patient. We had one patient who dropped from 170mmHg to 110mmHg systolic and she contacted us saying she didn’t feel well. We have a bail out system where if the pressure goes below 130 or 120mmHg then reduce medication. We don’t do it in advance; usually the patient should stick with their medication throughout.
　　International Circulation: Now as this procedure gets more practiced， we would expect that it would become more widely used both in essential hypertension and people with renal disease and low eGFRs. Can we expect to see an expansion of the types of patients who receive this treatment?
　　Dr Weil: I am pretty sure. Roland Schmieder has presented a case here and we are doing a pilot study together where we treat patients on dialysis but this has only been done in clinical studies thus far. We have to wait on the results from that. The same applies to some clinical trials underway in heart failure which is very interesting because heart failure is associated with an increased sympathetic drive. So if we use beta-blockers in these patients then maybe it will be helpful. There is a pilot study going on in Australia and there will probably be a randomized clinical trial on the horizon.
　　International Circulation: What about expansion to patients as a replacement for medical treatment?
　　Dr Weil: It is down the road but it is a question that I am asked very frequently. We have to do the clinical trials for that. In my experience， the higher the blood pressure is initially， the better the drop. If you have patients starting with lower blood pressures the drop is not as much but that is based on experience only. Maybe in the future， we will be able to treat some patients with this method. There is the potential to be able to prevent hypertension as we have patients with prehypertension. The disadvantage of this method at the moment is that we really don’t have a good read-out. We don’t know which patients will respond and those that won’t. It would be wonderful to have a score or a parameter we can measure before the procedure starts to say there is a good probability of achieving a targeted blood pressure drop. In the study we had one in six non-responders. It really depends how you define a responder. A responder is defined in the SYMPLICITY Study as a drop of more than 10mmHg but this is arbitrary in a way. In drug studies， 4mmHg is quite a lot.
　　《国际循环》：您有没有碰到术后出现低血压的患者？
　　Weil博士：我们应当观察患者有没有低血压，对每一位患者都进行这样的随访是重要的。我有一位患者的收缩压从170 mm Hg降到了110 mm Hg，她联系我们，说她感觉不大好。我们有一个安全系统，如果患者的收缩压降到130或120 mm Hg以下的话，就减少药物用量。我们事先并不会规定减少药物用量，患者通常会持续一定的药物治疗。
　　《国际循环》：现在肾交感神经射频消融术被越来越多地用于临床实践。我们期望这一操作越来越广泛地被应用于原发性高血压患者、肾脏疾病患者和低eGFR患者。未来接受这一治疗的患者群会不会扩大？
　　Weil博士：我非常确信患者群会扩大。Roland Schmieder教授在会议上介绍了一个病例，我们正在合作开展一项先导性研究，对接受透析的患者实施肾交感神经射频消融术，不过目前还只是处于临床研究阶段。我们还在等结果出来。同样，针对心衰患者的一些临床试验也在进行当中，这非常有意思，因为心衰与交感神经张力增加相关。因此，如果我们在这些患者使用β受体阻滞剂的话，可能会对患者有帮助。目前，有一项在澳大利亚开展的先导性研究，可能还要开展一项随机临床试验。
　　《国际循环》：肾交感神经射频消融术能否替代药物治疗？
　　Weil博士：我们正在朝那个方向努力，这是一个我经常思考的问题。我们需要就此开展临床试验。按照我的经验，如果患者初始的血压水平越高，肾交感神经射频消融术后的血压下降就越明显。如果患者初始的血压不是那么高的话，术后的血压下降就不那么明显，不过这只是基于经验。也许在未来，我们能够用肾交感神经射频消融术来治疗一些高血压患者。对于高血压前期的患者来说，肾交感神经射频消融术还有潜力预防高血压的发生。目前，肾交感神经射频消融术的缺点在于没有一个非常好的读出机制（read-out）。我们不知道哪个患者接受手术的反应会好，哪些患者反应会不好。如果能够有术前评分或参数来进行评价，提示我们患者有很大的可能性达到目标的血压下降那就太理想了。在研究中，我们发现6例患者中有一例是无反应者。这确实取决于你如何定义反应者。SYMPLICITY研究中对反应者的定义为血压下降10 mm Hg以上，但是此种做法有一定的主观性。在药物研究中，血压下降4 mm Hg就已经很多了。