Day 2 at Boston AF symposium: Morning notes
January 13, 2012
Guest post by Dr. John Mandrola
Dr. Frank Marchlinski moderated the first sessions: The global topic involved pulmonary vein reconnections.
This is the bane of AF ablation. Our inability to broach the 80% success rates has most to do with the fact that PVs don’t stay isolated. Everyone wants to enhance the durability of PV isolation.
Nassir Marrouche spoke about what ablation lesions look like on MRI. His group has made their name with MRI imaging. They assess MRIs immediately after AF ablation. He shows beautiful pictures of scars on MRI that correlate with good lines of isolation. Good scars = Good isolation. He gave us some sobering data on cryo-balloon lesions: 3 month scans showed that cryo lesions were not impressive on the right sided veins. On long-term predictability of lesions at 2 years–lesions that were good at 3 months mostly stayed good at 2 years.
He also made note that not every atrial ablation target is the same: MRI scans show that fibrosis makes it tough to make good lesions. (A common theme.)
This data is impressive. Being able to look at the actual lesions offers us a great chance to learn. The problem of course with MRI is that most centers can’t reproduce highly technical scans–at least at this level of technology.
Dr Stanley Nattel spoke about using medicines (adenosine primarily) to help unmask PV reconnections. He presented elegant physiologic research that showed adenosine may unmask veins that later regain electrical connection. Compared to isoproterenol (adrenaline-like), adenosine did better at predicting veins that had dormant conduction.
Dr Nattel’s talks make you really enjoy science. He’s an excellent speaker. Basically, he showed HOW adenosine might work to predict dormant conduction in veins.
Dr Hans Kottkamp (Zurich) addressed the clinical role of adenosine, waiting time, early monitoring, AF meds, and even steroids after PV isolation. He mentioned the same Japanese study that Dr Prystowsky did yesterday. In these quite patient investigators experience, 90-minute waits after isolation was the best predictor of reconnection, as some veins recurred even after 60 minutes. Dr Kottkamp then showed some of his own data–showing that acute reconnection of PVs might predict a slight increase in AF recurrences. (Better to isolate them well initially, again.)
On the clinical use of Adenosine: Unfortunately, dormant PV connections that are unmasked by adenosine have little specificity for predicting late recurrences. Early monitoring as a predictor of success: Patients who have no early recurrences do very well, while early recurrences strongly predict later episodes of AF. But not all early recurrences mean failure. Steroids: There was one study in JACC (2010 56; 1463-72) which suggested that pre-procedure steroids might mitigate early recurrences. (Not convincing.) AF drugs after ablation: The use of meds after ablation suppresses short-term recurrences but did not change the long-term success rate. “Upstream” therapies: Nada here that was useful.
His recommendations: Wait longer. Do early monitoring and Adenosine is interesting, but its specific role is unknown.
Dr Frank Marchlinski spoke on techniques to improve catheter contact during ablation: He gave a number of tips and tricks for ablation. His group uses JET ventilation during ablation. The idea is that high-frequency but lower volume breaths helped provide better catheter stability. They have also shown that these techniques may improve ablation success in the long-term. Though most centers can’t easily do JET ventilation (it’s complicated and dependent on expertise from anesthesia), the global idea is that getting good catheter stability helps make more durable lesions.
Dr Vivek Reddy talked about the durability of PV isolation. His message was that it’s all about good lesions. He emphasized getting good catheter stability, paying attention to good catheter contact, making circumferential burns and don’t jump around. He echoed what others have said. He also advocated pacing from the line to make sure the (ablated) area does not support capture.
His recent data (AHA) shows encouraging results: when they incorporated all these techniques, durable PV isolation [PVI] improved. On a Cryo question from the audience he answered that isolation with cryo still has the problem with durability of isolation.
These were helpful talks. They all speak to the idea of making high quality burns on the first attempt. Not just to get PVI, we can always get PVI, but to get the best possible PVI.
It’s funny; I’ve been coming to Boston AF since AF began and this is the same message every year.
Dr. Mandrola is a cardiac electrophysiologist who blogs at Dr. John M