Seeking to improve proper selection guidelines for catheter ablation (CA) candidates, researchers assessed the potential of using speckle tracking echocardiography (STE) for detailed examinations of left atrium (LA) function to predict CA outcomes in patients with non-valvular atrial fibrillation (AF) and no structural heart disease. According to lead author Ewa Pilichowska-Paszkiet, MD, PhD, and colleagues, longitudinal LA strain (LAS) analysis appears to be highly relevant in selecting CA candidates from patients with AF.
Specifically, two parameters that reflect LA compliance and diastolic function, left atrial reservoir strain (LASr) and left atrial conduit strain (LAScd), were observed to be strong and independent predictors of CA outcome in patients with AF, according to the study’s report in Medicine. The findings suggest that “detailed echocardiographic assessment of LA function prior to CA for AF may play a major role in selecting patients for this procedure,” added Dr. Pilichowska-Paszkiet. The investigators also observed that structural fibrotic changes in the LA can be witnessed at the very early stages of AF.
The study enrolled 82 patients with non-valvular paroxysmal AF scheduled for CA and assessed them with transthoracic and transesophageal echocardiography. Peak LAS and LA strain rate (LASR) during the reservoir, conduit, and contraction phases were evaluated with STE before the CA operation. The secondary outcome was the accuracy of CA efficacy predications in patients with normal baseline echocardiography parameters. All participants had normal left ventricular systolic and diastolic function and 65% had standard LA dimensions.
Complete freedom from any AF recurrence was achieved by 44 (54%) patients. Global LASr was identified as a predictor of CA efficacy in multivariable analysis (odds ratio [OR], 1.35; 95% confidence interval [CI], 1.17–1.55; P <0.0001). The researchers estimated that the opportunity of CA success was 135 times higher for each 1% increase in global LASr. Receiver operating characteristic (ROC) analysis identified global LASr, as well as left LAScd, as the most powerful predictors, with an area under the curve in the whole study group of 0.896 and 0.860, respectively, and 0.922 and 0.938, in patients with not enlarged LA, respectively.
The study was limited by the relatively small sample size and short follow-up duration. Additionally, the report noted that silent episodes of AF may have been missed because no long-term continuous electrocardiogram monitoring was used.
The study’s authors concluded that LASr has high value as predictor of AF recurrence after CA and that, out of the many function parameters, LA reservoir and conduit strain are strong and independent predictors of CA outcome.