Pulmonary Vein Isolation in Typical Atrial Flutter and Heart Failure

• Pulmonary vein isolation plus cavo-tricuspid isthmus ablation (Procedure): For those who are randomized to CTI+CPVI Arm, additional CPVI should be performed after finishing CTI ablation. CPVI could be performed using open-irrigated contact-force catheter, cryoballoon catheter or pulse-field ablation catheter. The endpoint is defined as both entrance and exit block in the pulmonary veins.
• Cavo-tricuspid isthmus ablation (Procedure): In periprocedural period, all antiarrhythmic drugs were discontinued for at least 5 half-lives and amiodarone for 2 months before the procedure. An electrophysiological study was performed after overnight fasting and mild sedated state with administration of intravenous midazolam and fentanyl. CTI ablation should be performed under the CARTO or Ensite electroanatomic mapping system using an open-irrigated contact-force ablation catheter. Radiofrequency should be delivered at 30-50 W with a contact-force between 5-30 g in a point-by-point fashion until the CTI line is completed. Touch-up radiofrequency should be performed as needed. The endpoint of ablation is termination of AFL, if present, and the demonstration of bidirectional block across the CTI by using differential pacing.

Primary outcomes

• Composite endpoint of worsening heart failure requiring unplanned hospitalizations or urgent visits, and cardiovascular death [From randomization until completion of the planned follow-up, assessed up to 48 months]

Secondary outcomes

• Time to cardiovascular death [From randomization until completion of the planned follow-up, assessed up to 48 months]
• Time to hospitalization or urgent visits for heart failure [From randomization until completion of the planned follow-up, assessed up to 48 months]
• Time to hospitalization for heart failure [From randomization until completion of the planned follow-up, assessed up to 48 months]
• Time to urgent visits for heart failure [From randomization until completion of the planned follow-up, assessed up to 48 months]
• Time to all-cause death [From randomization until completion of the planned follow-up, assessed up to 48 months]
• Time to atrial fibrillation recurrence [From randomization until completion of the planned follow-up, assessed up to 48 months]
• Time to change of diuretics [From randomization until completion of the planned follow-up, assessed up to 48 months]
• Change in quality of life - Kansas City Cardiomyopathy Questionnaire score (KCCQ-23) at one-year [One-year]: KCCQ is a 23-item, self-administered instrument that quantifies physical function, symptoms (frequency, severity and recent change), social function, self-efficacy and knowledge, and quality of life. The KCCQ Total Symptom Score incorporates the symptom domains into a single score. Scores are transformed to a range of 0-100, in which higher scores reflect better health status.
• Change in 6-minute walk test at one-year [One-year]
• Change in N-terminal pro-B type natriuretic peptide (NT-proBNP) at one-year [One-year]
• Change in New York Heart Association (NYHA) class at one-year [One-year]: NYHA class is a widely used system for assessing the functional status and severity of heart failure symptoms in patients, with NYHA class IV being the worst.

Sex: All, ages: 18 Years to 80 Years

Inclusion Criteria:

* Aged 18 to 80 years
* Typical AFL referring for ablation
* No prior history of AF
* Fulfilling the criteria for HF: New York Heart Association (NYHA) function class II or greater; and N-terminal pro-brain natriuretic peptide (NT-pro-BNP) >125 pg/ml in sinus rhythm or >365 pg/ml in AFL
* Optimized guideline-directed medical therapy for HF for at least one month
* A minimum of anticoagulation for three weeks
* Sign informed consent

Exclusion Criteria:

* Any AF episodes documented during 48-hour Holter monitoring
* Presence of left atrial thrombus
* HF due to infiltrative cardiomyopathy, constrictive pericarditis, active myocarditis, cardiac tamponade, or uncorrected primary valvular disease
* Acute coronary syndrome, cardiac surgery, angioplasty, or cerebrovascular accident within three months prior to enrollment
* Previous cardiac transplantation, complex congenital heart disease, rheumatic heart disease
* Untreated hypothyroidism or hyperthyroidism
* Dialysis-dependent terminal renal failure
* Life expectancy <12 months due to non-cardiovascular causes.
* Any conditions that, in the opinion of the investigator, may render the patient unable to complete the study
* Female under pregnancy or breast-feeding
* Involved in other studies