"Nearly half of our patients with heart failure also experience atrial fibrillation," says Professor Burkert Pieske, principal investigator and director of the Department of Internal Medicine and Cardiology at the Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, and director of the Department of Internal Medicine - Cardiology at the German Heart Center Berlin. Around 2.5 million people in Germany suffer from heart failure, and more than one million of these also experience concomitant atrial fibrillation. At first, atrial fibrillation usually occurs intermittently; some people feel it while others do not. In any case, the condition should be recognized and treated as it increases the risk of stroke and may become permanent.
"Previously, it was thought that atrial fibrillation could trigger heart failure, a condition known as tachycardiomyopathy, which was considered rather rare," Pieske said. "Today, however, we know that the reverse can also occur, namely that heart failure triggers the atrial fibrillation. The ensuing, often rapid and irregular heartbeat in turn worsens the heart failure - a vicious circle sets in."
To counteract this dangerous combination of heart failure and atrial fibrillation, DZHK scientists are investigating in the CABA-HFPEF-DZHK27 trial whether the treatment of atrial fibrillation by so-called catheter ablation helps heart failure patients and has a positive effect on their state of health and prognosis.
Better quality of life and fewer hospitalizations
In general, there are two ways to treat atrial fibrillation: Either drug treatment or catheter ablation. In the latter case, an ablation catheter is used to electrically isolate the heart tissue responsible for disrupting the rhythm.
Smaller observational studies have already shown that catheter ablation achieves better results in heart failure patients with atrial fibrillation than drug treatment: the quality of life improves, clinical performance increases and patients need to be hospitalized less often.
CABA-HFPEF-DZHK27 is now the first large, multicenter study to investigate this relationship. Across Europe, 60 centers are participating, and 1,550 patients with predefined inclusion and exclusion criteria are expected to participate. The study is expected to continue for five years.
Focus on heart failure with preserved pump function
In the study, the research team is focusing on heart failure patients with preserved or only mildly reduced ejection fraction (Heart Failure with Preseverd Ejection Fraction, HFpEF, and Heart Failure with Mildly Reduced Ejection Fraction, HFmrEF). "In this form of heart failure, cardiac strength is largely preserved, but the heart muscle is stiffened so that the heart chambers cannot fill sufficiently with blood," says Dr. Abdul Shokor Parwani, co-principal investigator and head of Electrophysiology at the Department of Internal Medicine and Cardiology at Charité Campus Virchow-Klinikum.
Heart failure with preserved ejection fraction accounts for half of all heart failure cases, but there are currently few therapies that improve the condition and survival of these patients. "The goal of our study is to determine whether catheter ablation of atrial fibrillation is superior to current standard drug treatment in this patient population," Parwani said.
Patients are randomly assigned to one of two study arms. In one group, physicians perform catheter ablation, while the other group receives the current standard drug treatment. So-called antiarrhythmics - drugs used to treat cardiac arrhythmias - will only be used if beta blockers or other heart rate-lowering drugs are not sufficient. Antiarrhythmics have many side effects: For example, they can lead to hyperthyroidism, corneal plaques or pulmonary fibrosis, or even trigger cardiac arrhythmias themselves.
"Catheter ablation has come a long way in the last decade. In the hands of experienced physicians, it is a relatively quick procedure that is minimally stressful for patients and results in atrial fibrillation disappearing altogether in most cases," Pieske said. Normal heart function is not affected during this procedure.
Therefore, the scientists hope that the results of their study will also improve the therapy and prognosis of HFpEF patients.
Study title: CABA-HFPEF-DZHK27 (CAtheter-Based Ablation of atrial fibrillation vs. conventional treatment in patients with Heart Failure with Preserved Ejection Fraction).
Contact: Christine Vollgraf, Press and Public Relations, German Center for Cardiovascular Research (DZHK), Tel: 030 3465 529 02, presse(at)dzhk.de.
Principal investigators: Prof. Dr. med. Burkert Pieske, Charité - Universitätsmedizin Berlin, Department of Internal Medicine and Cardiology - Campus Virchow Klinikum, German Heart Center Berlin, Department of Internal Medicine - Cardiology, burkert.pieske(at)charite.de
Abdul Shokor Parwani, MD, Charité - Universitätsmedizin Berlin, Department of Internal Medicine and Cardiology - Campus Virchow Klinikum, abdul.parwani(at)charite.de
