Wednesday, April 09, 2014

IS RADIOFREQUENCY ABLATION SAFE? WHAT ARE THE NUMBERS LIKE?

Radiofrequency ablation for cardiac arrhythmias have been with us for the last 15-30 years. It was Dr Scheinmen ( UCSF ) in 1981 who first used catheter based electrical ( at that time it was DC current ) to ablate SVT from W-P-W syndrome. It was Dr James Cox 1987 who first showed that interruption of intra-atrial pathways could treat atrial fibrillation. He was doing it with cardiac surgery. This is the Cox Maze procedure. Then in 1998, Dr Michelle Haissaguerre of Bordeaoux who applied the same technique to ablate atrial fibrillation. Dr Michelle discovered that often the foci triggering atrial fibrillation originated from around and from the inside of pulmonary veins.. He mapped out these foci in his patients and proceeded to isolate the foci, thereby doing a non-invasive interventional maze. His initial success rate was about 60-70 %.
Since then, the technique has taken of and RF ablation for atrial and ventricular arrhythmias is an acceptable way to treat arrhythmias.

                   Common foci for atrial fibrillation
After 15-30 years down this path, how are we doing?

               The catheter for RF ablation
Well, in the March 31st online edition of the Journal of the American Medical Association, Dr Michael Curley of the Medical College of Wisconsin in Milwaukee, reviewed the data from the American National In-patient Registry ( NIS registry ). From 1998 - 2009, the registry recorded 115,955 procedures of RF ablation. The mean age was 60 years. The indications were the usual, atrial arrhythmias ( SVT, A flutter and A Fib ). There were also some done for ventricular arrhythmias. The in hospital mortality was about 0.6% and the complication rate was about 15.2%. The complications varied from complete heart block requiring pace maker implantation ( 12.9 % ) to pericardial tamponade ( 0.2 % ).
In 2012, Dr Abhishek Deshmukh of the University of Arkansas, Little Rock, presented a review of the European Registry for RF ablation fro Atrial Fibrillation, at the 2012 ESC. The cohort from that registry was 1,400 patients with atrial fibrillation. They had a in-patient mortality of 0.07% and a complication rate of 7.7%.
I think the mortality is quite acceptable, but I do hope that the complication rate can be lower.
Afterall, the European Registry, showed that procedural success rate was 73.7% and 88% were in sinus rhythm at 1 year. In Dr Haissaguerre's own registry, most patients had recurrence 2-3 years down the road and needed a repeat ablation. Then on followup for a year ( European registry ) there were 30% readmission for cardiac events, 21% were arrhythmia related. Many still required  anticoagulation, and there were 4 deaths ( 0.3 % ) some of which were from stroke.

Putting all these together, would you subject an asymptomatic atrial arrhythmia to RF ablation, without a good trial of medical therapy?

2 comments:

dHarjma said...

Id only refer afib ablation in those who are quite symptomatic and failed one anti arrhythmic, kinda youngish and dont have too large an atria. Touch up repeat ablayions might be necessary. Afib ablation success are soooo operator dependent I would be very careful as to who I refer to too

hmatter said...

You are perfectly right, Dr Harjma. The patient must earn the right for Atrial Fibrillation.
I am afraid that some of my colleagues are using ablation as primary therapy for A.Fib. What is worse, they are also the operator.