Practice Update - ESC Congress 2017

Catheter Ablation Improves Outcomes in Patients

With Heart Failure and Atrial Fibrillation –

CASTLE-AF Trial

Dr. Nassir F. Marrouche

Catheter ablation may improve

outcomes for patients with left

ventricular dysfunction and atrial

fibrillation. Patients who received

catheter ablation of atrial

fibrillation had lower mortality and

less hospitalization for worsening

heart failure than those receiving

conventional drug treatment.

his outcome of Catheter Ablation vs Standard conven-

tional Treatment in patients with LV dysfunction and AF

(CASTLE-AF) was reported at the 2017 European Society

of Cardiology (ESC) Congress, from August 26–30.

“Themedical community continues to debate the ideal treatment for

atrial fibrillation in patients with left ventricular dysfunction because

clinical studies that support one definitive treatment are lacking.

Common therapies for atrial fibrillation include medication that reg-

ulates or slows the heart rate,” said Nassir F. Marrouche, MD, of the

Comprehensive Arrhythmia Research and Management (CARMA)

Centre, University of Utah Health, Salt Lake City

Dr. Marrouche and Johannes Brachmann, MD, of the Klinikum

Coburg, Germany, jointly conducted a clinical trial to examine the

effect of catheter ablation on all-causemortality and hospitalization

rates in patients with atrial fibrillation and left ventricular dysfunc-

tion, vs state-of-the art conventional treatment recommended

by the American Heart Association and European Society of

Cardiology.

CASTLE-AF is the first randomized clinical trial comparing catheter

ablation to current first-line antiarrhythmic drug therapy for patients

with coexisting heart failure (HF) and atrial fibrillation evaluating the

primary outcome of mortality and hospitalization for worsening

heart failure. After screeningmore than 3000 patients, CASTLE-AF

included 397 patients with symptomatic paroxysmal or persistent

atrial fibrillation and heart failure with ejection fraction <35%.

All patients were supplied with an implantable cardioverter defi-

brillator with home monitoring capability to enable continuous

surveillance of atrial fibrillation. Patients were recruited frommore

than 30 clinical centers fromNorth America, Europe, and Australia.

Patients were randomized to radiofrequency catheter ablation

or conventional drug treatment (rhythm control or rate control)

for atrial fibrillation. The primary endpoint was the composite of

all-cause mortality and unplanned hospitalization for worsening

heart failure.

During a median follow-up of 37.8 months, the rate of the primary

endpoint was significantly lower in the ablation group (28.5%)

vs the control group (44.6%; hazard ratio 0.62; 95% confidence

interval 0.43–0.87; P = .007).

The secondary endpoints of all-cause mortality and heart failure

hospitalization were also significantly lower with catheter ablation

than with conventional treatment. Rates of all-causemortality were

13.4% with catheter ablation vs 25% with conventional treatment

(hazard ratio 0.53; 95% confidence interval 0.32–0.86; P = .011).

Rates of heart failure hospitalization were 20.7% with catheter

ablation vs 35.9% with conventional treatment (0.56; 95% confi-

dence interval 0.37–0.83; P = .004).

Dr. Marrouche noted that compared to those receiving conven-

tional treatment, patients receiving catheter ablation were 38%

less likely to experience the primary endpoint, 47% less likely to

die, and 44% less likely to be hospitalized with worsening heart

failure. “A significant number of patients undergoing ablation were

still in normal rhythm at the end of the study,” he said.

Dr. Marrouche added that the study also carried limitations, namely

that all patients had a previous implantable cardioverter defibrilla-

tor implanted, which may have affected mortality in both groups.

He said, “Nevertheless, this clinical trial sheds light on the impor-

tance of restoring and maintaining regular heart rhythm with

ablation.”

“The findings of CASTLE-AF will help not only save the lives of

many patients suffering from heart failure and atrial fibrillation but

will also exert a major impact on the cost of treating these patients

by keeping them out of hospital,” he said.

According to

stopafib.org

, a patient-driven information site about

atrial fibrillation, catheter ablation has evolved over time. “The

most frequent catheter ablation done today is the radiofrequency

catheter ablation. It is typically some variation of pulmonary vein

isolation (PVI). The goal of the procedure is to eliminate the irreg-

ular heartbeat that research has shown typically originates from

the four pulmonary veins and is most successful with paroxysmal

atrial fibrillation.”

PracticeUpdate Editorial Team

PRACTICEUPDATE CONFERENCE SERIES • ESC Congress 2017