BAFS: Ablation complications down, but patients outcomes are similar
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| Schematic of the heart showing the minimally invasive approaches to allow access to the surface of the heart (the blue and red areas) during hybrid EP procedure. Source: UCLA |
To understand the trends of AF ablation, Roger A. Winkle, MD, and colleagues evaluated the trends of catheter ablation between 2003 and 2010. During this time period, 1,125 patients underwent 1,504 ablations at a single center. Researchers evaluated changes in patient characteristics, procedural variables, complications and procedural outcomes, including AF-free rates post-ablation.
Winkle, an electrophysiologist at Sequoia Hospital in Redwood City, Calif., told Cardiovascular Business that during the eight-year period patients got progressively older, had higher CHADS2 scores and had greater instances of coronary artery disease, persistent AF and hypertension.
While Winkle said that there was little change in the patient mix, there was a decrease in the number of patients with paroxysmal AF and long-standing persistent AF. However, the number of patients with persistent AF rose during the study period.
“The most important finding of the study was that we got better at performing catheter ablations,” Winkle offered. The researchers reported fluoroscopy times halved from nearly four hours to two hours, Winkle noted. Total complication rates improved as well, from 9 percent in 2003 vs. 1.5 percent in 2010. Major and minor complication rates also decreased.
Winkle said operator experience and implementing enhanced safety features during the procedure explained why fluoro times and complication rates decreased. Using an RF needle for transseptal puncture, increasing the power of the ablation to destroy tissue faster and using an irrigated tip were safety features integrated into the procedure over the study period, which contributed to the decreased complication rates.
Winkle said that decreasing the procedural complication rates was no easy feat. In fact, Winkle estimated that it took nearly six years and between 600 and 800 cases to “knock down” the complication rate.
“We got better and faster at performing these procedures; however, we still found that we are not curing that many more patients compared to years ago,” he said.
While Winkle offered that for paroxysmal AF patients, AF-free rates improved over time, improvement “hit a ceiling” within the past couple of years. For persistent AF, AF-free rates also plateaued in recent years. The researchers found that long-standing persistent AF patients did not see significant outcome improvements after an initial ablation procedure over time.
“There was no trend for improved final outcomes (including repeat ablation) over time for paroxysmal, persistent or long-standing AF,” Winkle and colleagues found.
“What we need to do better is drive patients to think about undergoing an ablation procedure sooner rather than later,” Winkle said. “If a patient has been in AF for six months or a year and they reach the point where they may need treatment, this is when they should begin to consider an ablation.
“Most are looking at cryoablation techniques or administering adenosine; however, these decisions are only making small dents,” Winkle said. “We have yet to figure out how to make these things work for 95 percent of the people with a first ablation.
“This is the frustrating part. How can we get these numbers higher? I don’t think anyone has the right answer right now,” Winkle said.
Winkle and colleagues at Sequoia are also studying what happens when drugs fail in these AF patients. “Every time a patients fails a drug, the cure rate from ablation decreases,” Winkle said, because by then the disease has progressed.
Attempting to convince patients to undergo ablation earlier in the course of the disease may be the solution, Winkle concluded. However, he noted that understanding AF initiation and maintenance remains understudied.