Catheter ablation reduces mortality in patients with heart failure and AF
Landmark results from the CASTLE-AF trial has demonstrated that catheter ablation significantly improves outcomes in patients with heart failure and atrial fibrillation (AF), reducing the risk of all-cause mortality and hospitalizations for worsening heart failure by more than one-third compared with conventional treatment.
The results, presented at a late-breaking clinical trial session at the European Society of Cardiology (ESC) Congress 2017, offer the first comparative analysis of strategies for management of AF in heart failure patients using hard endpoints and have the potential to change current practice. “More than 30 percent of patients with heart failure also suffer or will suffer from AF. AF in heart failure therefore presents a major dilemma, while guidelines provide no specific recommendations on how to treat these patients,” said lead investigator Professor Nassir Marrouche of the Comprehensive Arrhythmia Research and Management (CARMA) Centre in Salt Lake City, UT, US.
This dilemma led to the design of the prospective, randomized, controlled CASTLE-AF trial. CASTLE-AF included 397 patients from 31 centres across the world who had symptomatic paroxysmal or persistent AF and heart failure with a left ventricular ejection fraction of ≤35 percent. Patients were randomized to receive radiofrequency catheter ablation or conventional treatment (rate or rhythm control) based on recommendations from the American College of Cardiology/American Heart Association and European Society of Cardiology 2006 guidelines for treatment of AF in heart failure patients.
“After 5 years of follow-up, catheter ablation led to a 38 percent relative risk reduction in the primary composite endpoint of all-cause mortality and hospitalizations for worsening heart failure vs conventional treatment [p=0.007],” reported Marrouche.
Secondary endpoints were also significantly improved in patients who received catheter ablation vs conventional treatment. The risk of all-cause mortality was reduced by 47 percent with catheter ablation vs convention treatment (13.4 vs 25 percent; p=0.011), while the risk of hospitalizations for worsening heart failure was reduced by 44 percent (20.7 vs 35.9 percent; p=0.004). “Moreover, there was a 51 percent reduction in the risk of cardiovascular mortality [p=0.008] and a 28 percent reduction in the risk of cardiovascular hospitalization [p=0.041] with catheter ablation vs conventional treatment,” said Marrouche.
In patients receiving ablation, the effect on mortality reduction could be seen at 3 years, while the reduction on hospitalizations for heart failure could be seen at 6 months. “We think this is attributed to cutting the AF burden by almost half, without using antiarrhythmic drugs,” Marrouche commented.
Discussing these results, Dr Carina Blomstrom-Lundqvist of Uppsala University in Uppsala, Sweden, noted the relevance of the study to clinical practice. “It’s time to offer AF ablation procedures at an early stage in patients with chronic heart failure and AF,” she said. “However, careful patient selection will be important when considering ablation in patients with chronic heart failure and AF, as the positive outcomes in CASTLE-AF may reflect a bias towards recruiting healthier patients who are better able to tolerate the ablation procedure. It also remains unclear whether ablation should be used to treat asymptomatic AF patients or whether the outcomes would differ between ischaemic and nonischaemic heart failure patients.”
“Patient selection should reflect the populations included in the trial,” Blomstrom-Lundqvist concluded.