U22 protocol as measure of symptomatic improvement after catheter ablation of atrial fibrillation

Abstract

Introduction: Left atrial catheter ablation is useful as symptomatic treatment in selected patients with atrial fibrillation (AF). Evaluation requires measurement of arrhythmia-related symptoms. Many of the published protocols have drawbacks and have been used in AF only, with no possible comparison to other ablations that compete for the same resources. U22 is a published protocol that quantifies paroxysmal tachycardia symptoms through scales with 11 answer alternatives, translated into discrete numerical scales 0-10. It has been shown to reflect the clinical improvement after ablation of supraventricular tachycardia. Here we report the use of U22 in measuring improvement after catheter ablation for AF.

Material and methods: A total of 105 patients underwent first-time ablation for AF and answered U22 and SF-36 forms at baseline and follow-up 304 (SD 121) days after ablation. Independently, the patients underwent a clinical follow-up. All decisions regarding medication and reablation were taken without knowledge of the symptom scores. Results. The U22 scores for well-being, arrhythmia as cause for impaired well-being, derived time-aspect score for arrhythmia, and discomfort during attack detected relevant improvements of symptoms after the ablation. U22 showed larger improvement in patients undergoing only one procedure than in patients who later underwent repeated interventions, thus reflecting the independent clinical decision for reablation.

Conclusion: U22 quantifies the symptomatic improvement after AF ablation with adequate internal consistency and construct validity. U22 mirrors aspects of the arrhythmia symptomatology other than SF-36.

Figure 1.

Symptomatic improvement in 105 patients and freedom from subsequent reablation. Survival curves for freedom from reablation as a function of days after first-time ablation. The population was dichotomized into two subsets along the median of individual patients' differences in U22 scores, computed as (score_follow-up – score_baseline). The plot is shown for the U22 score q11 (effect of arrhythmia on the well-being), p < 0.0001 for the difference between the survival curves. A similar pattern was seen in the U22 scores q01, q12, and time-aspect of arrhythmia (p = 0.0006, p < 0.0001, and p < 0.0001, respectively).

Figure 2.

Differences in U22 scores in singular ablations compared to the first of multiple ablations. The differences for q01, q11, q12, and time-aspect in individual patients were computed as (score_follow-up – score_baseline). Singular ablations are represented by white boxes, the first of multiple ablations by grey boxes. The boxes are delimited by mean ± 1 SD. The central line depicts the mean, and the whiskers are placed at the extreme values. For all scores the singular ablations resulted in significantly larger improvements than the first of multiple ablations.