1Universitätsklinikum Schleswig-Holstein Klinik für Rhythmologie Lübeck, Deutschland; 2Jichi Medical University Data Science Center Tochigi, Japan; 3LANS Cardio Hamburg Kardiologie Hamburg, Deutschland
Background:
Formation of linear lesions is a possible ablation strategy in patients with isolated pulmonary veins (PV) during re-do procedures in patients with atrial fibrillation or during ablation of non-PV dependent left atrial tachyarrhythmias (LAT). However, it is unclear which patient characteristics or procedural variables predict the durable blockage of an anterior linear lesions (ALL).
Aim:
We aimed to find potential predictors for durable ALL block.
Methods:
A total of 261 consecutive patients with symptomatic LAT undergoing their first ALL ablation utilizing ablation index (AI) or contact force (CF) guided radio frequency ablation (ablation strategy including creation of an ALL) were enrolled in an observational, single-center prospective registry between May 2015 and August 2020. Target AI value for the AL was 550, while target CF was 10-40 g.
Procedures and follow- ups (FU) were performed as per institutional standard. In case of LAT recurrence, a repeat ablation procedure was offered to patients if indicated.
Thereby, ALL was checked for persistent block via standard pacing maneuvers during the re-do procedure.
Results:
Eighty four percent of patients underwent FU. 158 (72.15 %) patients presented with a LAT recurrence during a median FU of 27.67 ± 16.90 months. 91 (57,60%) patients received a repeat procedure (Index AL guidance: 74 AI, 17 CF).
Chronic block of ALL was assessed in 41 of 91 (54.95 %) patients undergoing a repeat procedure.
At univariate analysis, the following predictors for persistent blocks of ALL were found: Age (OR 1.05; 95% CI, 1.00-1.11; p= 0.044), EHRA classification (OR 2.25; 95% CI, 1.04-4.85; p= 0.039), AI (OR 0.88; 95% CI, 0.77-0.99; p= 0.039) and CF (OR 0.95; 95% CI, 0.89-0.99; p= 0.049). (Figure 1, figure 2) At multivariate analysis of the procedural parameter, no predictor of persistent block remained significant.
In our study population subgroup (ALL and re procedure) the age was 69.29 ± 9.31 years, EHRA was 2.57 ± 0.58, CF per application was 29.36 ± 7.97 g and AI was 513.52 ± 40.51. (Table 1, table 2)
Conclusion:
Higher age and higher EHRA classification as well as lower AI and lower CF were identified as predictors of chronic ALL block at univariate analysis. No predictor of persistent block remained significant at multivariate analysis.
Figure 1: ROC curve – Age
Figure 2: ROC curve - EHRA
Table 1: Baseline characteristics of patients with ALL undergoing re procedure
|
Variable |
|
|
Male gender, n (%) |
49 (54%) |
|
Age (years) |
69.29 ± 9.31 |
|
BMI (kg/m2) |
28.5 ± 4.98 |
|
EHRA |
2.57 ± 0.58 |
|
CHA2DS2-VASc Score |
3.12 ± 1.68 |
|
HAS-BLED Score |
1.74 ± 0.92 |
|
Ischemic heart diasease, n (%) |
23 (25%) |
|
Left ventricular ejection fraction (%) |
51.41 ± 9.34 |
|
Left atrial volume - |
147.14 ± 42.01 |
|
Serum creatinin (µmol/L) |
94.09 ± 28.21 |
|
GFR (ml/min/1.73 m²) |
67.07 ± 16.29 |
Table 2: Procedural variables of patients with ALL undergoing re procedure
|
Variable |
|
|
|
MV ± SD |
|
RF time per line (s) |
361,82 ± 137.83 |
|
RF applications per line, n |
16.63 ± 5.52 |
|
Lengh (mm) |
60.86 ± 10.37 |
|
Duration per RF application (s) |
21.92 ± 6.47 |
|
CF (g) |
29.36 ± 7.97 |
|
Max. temperature (°C) |
26.56 ± 2.94 |
|
Max. power (W) |
35.38 ± 5.69 |
|
Base impedance (ohm) |
133.26 ± 114.27 |
|
Impedancedrop (%) |
9.20 ± 2.58 |
|
FTI (g s) |
569.14 ± 168.68 |
|
AI |
513.52 ± 40.51 |
|
Bidirektional block, n (%) |
85 (93%) |