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

Figures & data

Table I. Patient profile, U22, and SF-36 in 105 ablated patients.

	All first-time ablations		Paroxysmal	Non-paroxysmal	p
n	105		52	52
Men (%)	74		67	81	0.2
Age (years)	58 (9)		56 (10)	60 (7)	0.03
CHADS2 score 0 (%)	49		48	50	> 0.5
Left atrial diameter (mm)	44 (7)		44 (6)	45 (8)	0.3
Structurally normal echo (%)	75		77	69	0.5
Procedure time (min)	208 (50)		214 (50)	202 (51)	0.2
Fluoroscopy time (min)	36 (13)		38 (13)	35 (13)	0.2
No AF in post-ablation Holter (%) ^a	62		44	78	0.001
Days to questionnaire follow-up ^b	304 (121)		272 (119)	335 (117)	0.007
U22 score q01baseline ^c	4.1 (2.6)	p < 0.0001	3.8 (2.4)	4.5 (2.8)	0.2
U22 score q01follow-up	6.1 (3.0)		5.7 (3.0)	6.7 (2.8)	0.07
U22 score q11baseline ^d	8.1 (1.9)	p < 0.0001	8.4 (1.7)	7.9 (2.1)	0.2
U22 score q11follow-up	4.9 (3.8)		5.3 (3.7)	4.3 (3.9)	0.2
U22 score Time-aspectbaseline ^e	6.6 (1.9)	p < 0.0001	6.6 (1.6)	6.5 (2.1)	> 0.5
U22 score Time-aspectfollow-up	4.0 (3.1)		4.5 (2.9)	3.4 (3.2)	0.08
U22 score q12baseline ^f	8.0 (1.8)	p < 0.0001	8.5 (1.4)	7.7 (2.1)	0.03
U22 score q12follow-up	5.0 (3.8)		5.5 (3.8)	4.4 (3.9)	0.2
SF-36 score PCSbaseline	39.8 (9.9)	p = 0.003	39.4 (10.1)	40.5 (9.6)	> 0.5
SF-36 score PCSfollow-up	43.9 (11.5)		43.1 (12.1)	45.1 (10.8)	0.4
SF-36 score MCSbaseline	41.7 (12.5)	p < 0.0001	40.8 (12.0)	42.4 (13.2)	0.5
SF-36 score MCSfollow-up	47.6 (10.9)		47.5 (10.5)	47.6 (11.5)	> 0.5
Days to review ^g	873 (490)		959 (570)	801 (378)	0.1
Reablated at review time (%)	43		50	35	0.16

^aFreedom from atrial fibrillation in a 7-day Holter recording at time of a clinical follow-up.

^bTime between ablation and answering the follow-up forms.

^cU22 score for well-being, 0–10 (miserable–very well).

^dU22 arrhythmia cause for impaired well-being, 0–10 (not at all–very much).

^eComputed from U22 q08 and q10, 0–10 (10 is most severe).

^fU22 discomfort during attack, 0–10 (not at all–very much).

^gTime between ablation and review of the patient record with respect to subsequent reablation.

Table II. Singular and repeated ablations.

	Singular procedure			First of repeated procedures			Last of repeated procedures
n	69			36			19
Men	48 (70%)			30 (83%)			14 (74%)
Age (years)	59 (9)			57 (8)			58 (9)
Days to questionnaire follow-up ^a	331 (121)			250 (103)			299 (91)
	Baseline	At follow-up	p	Baseline	At follow-up	p	Baseline	At follow-up	P
U22 q01 ^b	4.3 (2.8)	7.0 (2.8)	< 0.0001	3.8 (2.1)	4.4 (2.5)	0.1	4.1 (2.2)	6.5 (2.7)	0.0001
U22 q11 ^c	8.0 (2.1)	3.5 (3.8)	< 0.0001	8.4 (1.4)	7.4 (2.4)	0.02	8.0 (1.7)	3.1 (3.8)	0.0002
U22 Time-aspect ^d	6.3 (2.1)	2.7 (3.0)	< 0.0001	7.1 (1.4)	6.4 (1.6)	0.03	7.1 (1.1)	2.7 (2.8)	0.0001
U22 q12 ^e	7.8 (2.1)	3.6 (3.9)	< 0.0001	8.4 (1.2)	7.5 (2.1)	0.03	8.4 (1.2)	2.6 (3.1)	<0.0001
SF-36 PCS	39.9 (10.2)	45.6 (11.6)	< 0.0001	39.8 (9.4)	40.7 (10.8)	> 0.5	39.6 (11.8)	42.8 (13.7)	0.05
SF-36 MCS	41.9 (12.5)	48.6 (11.0)	< 0.0001	41.3 (12.7)	45.6 (10.6)	0.1	40.7 (13.7)	49.4 (10.2)	0.03

^aTime between ablation and answering the follow-up form.

^bU22 score for well-being, 0–10 (miserable–very well).

^cU22 arrhythmia cause for impaired well-being, 0–10 (not at all–very much).

^dComputed from U22 q08 and q10, 0–10 (10 is most severe).

^eU22 discomfort during attack, 0–10 (not at all–very much).

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.

Table III. Estimation of internal consistency of the U22 scores in 105 first-time procedures.

	Set of scores	Cronbach's alpha ^a
Baseline	q01, q11, q12, time-aspect	0.79
Follow-up	q01, q02, q11, q12, time-aspect	0.94
Individual patients' difference scorefollow-up – scorebaseline	q01, q11, q12, time-aspect	0.91

^aq11, q12, and the time-aspect were reverse-coded for the computation of Cronbach's alpha.