Clinical Study Results

Multicenter, joint, randomized,
open label study in Japan

Purpose

To evaluate the safety and efficacy of the SATAKE･HotBalloon® system (SATAKE･HotBalloon® catheter, TRESWALTZ® and SATAKE･HotBalloon® generator) among subjects who were adult patients diagnosed with paroxysmal atrial fibrillation (PAF) who had been verified to be refractory or intolerant (cannot be used due to safety issue) to at least one Class I, II, III or IV antiarrhythmic drug.

Scope, design and methodology of the study

This trial was conducted at 17 Japanese centers as a prospective, randomized, controlled, multicenter pivotal clinical trial. Subjects with symptomatic PAF who were introduced for ablation were randomly assigned to the radiofrequency (RF) ablation group (investigational device group) or the test antiarrhythmic drug (drug therapy group) at a 2:1 ratio. In terms of verification of atrial fibrillation recurrence, for the subjects in the investigational device group, the first 12 weeks were considered as a blanking period, and for the subjects in the drug therapy group, the first 4 weeks after start of dosing were considered as a blanking period for drug titration period. After the blanking period, the subjects were evaluated regularly for 36 weeks to verify the recurrence of atrial fibrillation. Recurrence was verified by means of a weekly mobile ECG, as well as a 12-lead ECG and 24-hour Holter monitor in the 12th week and 36th week after the blanking period. If there was recurrence in the drug therapy group or dosing needed to be discontinued for reasons such as adverse effects to the antiarrhythmic drug, if the subject desired it, RF ablation using the investigational device could be used as a crossover case. Ablation could be used in a single PV ostium or antrum for a maximum of three repetitions.

Results

  1. 1) Efficacy endpoints
    1. (1) Acute success rate in the investigational device group
      All PVs (RSPV, RIPV, LSPV and LIPV) were isolated in 93.0% of the subjects. The rate of isolated PVs among ablated PVs was 98.0%. Successful isolation was defined as “the achievement of an electrogram amplitude of 0.1 mV or dissociation of PV potentials from left atrial potentials.”
    2. (2) Chronic success rate
      The chronic success rate, which is the primary endpoint, was 59% in the investigational device group and 4.7% in the drug therapy group (p<0.0001).
  2. 2) Safety endpoints
    1. (1) Major complications in the investigational device group and crossover group
      Major complications became evident in 12.0% (12/100 cases) of the investigational device group and 8.8% (3/34 cases) of the crossover group. The breakdown was 2 cases of cerebral infarction, 1 case of complete atrioventricular block, 1 case of sick sinus syndrome, 1 case of vascular pseudoaneurysm, 5 cases of phrenic nerve paralysis, and 7 cases of PV stenosis.
    2. (2) Adverse events during the trial
      Serious adverse events occurred in 6% (6/100 cases) of the investigational device group and 11.8% (4/34 cases) of the crossover group. The breakdown was 2 cases of cerebral infarction, 1 case of complete atrioventricular block, 1 case of cardiac failure acute, 1 case of Prinzmetal’s angina, 2 cases of sick sinus syndrome, 1 case of vascular pseudoaneurysm, 1 case of loss of consciousness, 1 case of bradycardia, 1 case of bladder cancer (*1), 1 case of colon cancer, 1 case of gastric cancer, 1 case of pneumonia (*2), 1 case of bronchitis (*1), and 1 case of anxiety disorder (*2). (*1 and *2 respectively refer to the same case.)

Bibliography