April 27, 2007 — Berlin-based BIOTRONIK announced today that is launching a worldwide long-term clinical study to investigate the effectiveness of ablation therapy in patients suffering from atrial fibrillation and congestive heart failure. The CASTLE-AF Study (Catheter Ablation versus Conventional Treatment in Patients with Left Ventricular Dysfunction and Atrial Fibrillation) will compare the clinical effect of ablation therapy to the conventional therapy for atrial fibrillation regarding the treated patient's life expectancy and hospitalization.
Atrial fibrillation is often triggered by proarrhythmic areas around the pulmonary veins. Pulmonary vein ablation, the isolation of these proarrhythmic areas, presents an alternative method of treatment. This ablation therapy is currently the only curative therapeutical approach, which can continuously sustain the natural sinus rhythm in the heart and thus significantly improves the cardiac capacity.
The company states that it has been proven that patients suffering from congestive heart failure — whose cardiac output is already reduced — profit from an improved pumping capacity of the heart through a sustained sinus rhythm. However, for this patient group there is no data available on the long-term clinical effects of the ablation therapy regarding life expectancy (respectively mortality) or a decrease in hospitalization (morbidity).
The CASTLE-AF Study compares the effectiveness of ablation therapy to conventional
therapy in patients with atrial fibrillation, congestive heart failure and indications for the implantation of a cardiac defibrillator. For the first time the focus is placed on the criteria mortality and morbidity. This randomized clinical study will be carried out with 400 patients in approximately 60 medical centers in the U.S., Germany, Belgium, the Netherlands, Great Britain, Switzerland, the Czech Republic and Hungary.
Alongside the crucial mortality and morbidity rate, the occurrence of atrial fibrillation during the study as well as the number of possible strokes will among others also be researched.
"The results of this until now unique study may potentially have great influence on future guidelines for the therapy of patients suffering from atrial fibrillation and congestive heart failure,” said Jochen Proff, project leader of the CASTLE-AF Study. “The results will give the medical community more certitude about whether the ablation therapy should be used on such high risk patients."
In order to increase informational value of the CASTLE-AF Study, only patients will be considered who have also received a BIOTRONIK dual chamber ICD with the Home Monitoring function in addition to as well as ablation therapy.
BIOTRONIK developed the Home Monitoring system over six years ago, with the
intention of enabling remote monitoring of patients after the implantation of a pacemaker or ICD independent of time and place. Since then this combination of medical and cellular phone technology has improved the standard of care for heart patients. The physician can call up important information on his patients at any time and is automatically and immediately alarmed in the case of a noticeable rhythm disturbance.
The combination of ablation therapy and Home Monitoring improves the situation for the patient and physician alike, the company says. Through the constant monitoring and checking of the heart rhythm the attending physician can recognize at an early stage, whether atrial fibrillation, particularly non-symptomatic, reoccurs. As a result the early re-intervention increases the chance of permanent elimination of atrial fibrillation.
In addition, information from Home Monitoring enables physicians to make a better decision, whether the rhythm or rate controlling drugs may be discontinued, so to spare the patient the sometimes serious side effects of the medication.
The coordinating investigators of the CASTLE-AF study are Dr. Nassir F. Marrouche from the University of Utah Health Science Center, and Professor Dr. Johannes Brachmann from Klinikum Coburg, Germany,
For more information visit www.biotronik.com.
January 22, 2026 
