Patients
This study protocol consisted of two parts: the first study measured
average LA WT (mm) in each anatomical segment for PVI by intra-cardiac
echocardiography (ICE) and calculated optimal AI for creating 1-mm
transmural lesion (AI/mm). The second study was a prospective randomized
study to compare the procedure characteristics of PVI between a
force-time integral protocol and a tailored-AI protocol, following the
first study (Figure 1).
From May 2018 to September 2019, 100 paroxysmal AF patients undergoing
PVI in Fujita Health University were eligible. The review board of
Fujita Health University School of Medicine approved the protocol and
all patients gave written informed consent. Baseline demographics and
clinical information were obtained, and laboratory examinations were
performed before the PVI. Left-atrial diameter (LAD), left-ventricular
systolic/diastolic dimensions, and left-ventricular ejection fraction
(LVEF) were assessed by transthoracic echocardiography. A 3-dimensional
image of the LA/PV geometry was reconstructed by cardiac computed
tomography (CT) imaging.
All patients received oral anticoagulation therapy with vitamin K
antagonist (VKA) or non-vitamin K antagonist oral anticoagulant (NOAC)
for ≥4 weeks prior to the catheter ablation. In patients taking VKA, an
international normalized ratio was controlled between 2.0 and 3.0. VKA
and NOAC were used without interruption during the procedure.
Transesophageal echocardiography was performed one day before catheter
ablation to detect LA thrombus.
Exclusion criteria were as follows: patients aged under 18 years old,
previous ablation procedure for AF, prior prosthetic mitral valve
replacement, severe structural cardiac abnormality (e.g., congenital
heart disease), severe left ventricular systolic dysfunction
(LVEF<35%), severe renal dysfunction (creatinine clearance
<15 ml/min)/hemodialysis, LA thrombus detected by TEE, and
pregnancy.
All anti-arrhythmic drugs were stopped 5 days prior to the procedure. No
patient was being treated with amiodarone.