Cardiac imaging helps predict success, failure of AFib procedure

In recent research, Johns Hopkins University researchers demonstrated success in utilizing cardiac imaging to predict the effectiveness of using catheter ablation to treat atrial fibrillation (AFib).

A relatively high recurrence rate is associated with catheter ablation, noted authors of the study, published online Jan. 17 in the Journal of the American College of Cardiology: Cardiovascular Imaging. An inability to properly select qualified patients from a diverse patient population with varying degrees of left atrial (LA) was a primary cause of recurrence.

Additionally, an estimated 20 to 30 percent of ablation procedures performed each year fail to prevent irregular heart rhythms, prompting cardiologists to search for biological or anatomical markers to help identify patients best qualified for the procedure.

In this study, researchers used data from 208 AFib patients from Johns Hopkins Hospital who underwent ablation between June 2010 and December 2015.

Patients averaged 59 years old, 29 percent of whom were women. Before ablation, each subject received a cardiac magnetic resonance (CMR) or cardiac CT scan and were monitored for an average of 20 months to determine the recurrence of AFib, which recurred in 101 patients.

The images from a subgroup of 208 people were then analyzed between 107 of those with successful ablations, compared to the 101 with failed ablations. Team members looked for such things as the size of the left atria, percentage of blood pushed out of the left atrium and the strain on the left atrium during cardiac contraction.

To determine the level of dyssynchrony (difference in timing between left and right ventricles) in the left atrium, researchers used cardiac images to divide the atrium into 12 segments and calculate relaxation time in each segment. After separating the most and least dyssynchronous, researchers found patients with recurrent AFib had, on average, more preoperative dyssnchrony throughout the left atrium than those who had successful ablations.

In the second half of the research, 103 patient scans were separated into two groups: one less than or another greater than 2.86 percent atrial dyssynchrony. These groups were later compared to their actual outcome after ablation, with the former hypothesized to be better suited for ablation procedure.

Analysts found the model had a 76 percent sensitivity to correctly identify those who were unlikely to have successful ablations and 81 percent specificity to correctly identify those who would most likely have successful ablations.

"We believe we are developing a tool that can help with personalized decision-making to help refine patient selection and thus reduce the failure rate by saving candidates with low potential benefit from futile procedures and complications," said corresponding author Hiroshi Ashikaga, MD, PhD, an assistant professor of medicine at Johns Hopkins University School of Medicine in a university press release.