Cor Allaart appointed as Professor of Cardiology

Cardiologist Cor Allaart has been appointed Professor of Cardiology, with a focus on Electrophysiology at Radboud university medical center / Radboud University. He improves care for people with cardiac arrhythmias by preventing sudden cardiac death and enhancing imaging techniques around heart muscle tissue ablation. He is committed to providing meaningful care.

People with heart failure due to reduced pumping function of the heart are at higher risk of sudden death caused by a cardiac arrhythmia (ventricular fibrillation). Traditionally, these patients often receive a preventive ICD: a small device implanted under the skin that detects and terminates arrhythmias with an electric shock. Cor Allaart explains: ‘We implant ICDs based on studies that are 25 years old, while medications for these patients have improved so much that an ICD may no longer benefit all of them. Yet the device carries risks and can cause harm.’

Scarring

Allaart chaired the committee that revised the Dutch guideline two years ago to better select patients who truly benefit from ICD implantation. Since then, the number of ICD implantations has decreased. This Dutch guideline currently differs from the European one. A key difference is that Dutch doctors not only measure the heart’s pumping function but also use MRI scans to check for scarring in the heart. If no scars are found, no ICD is implanted.

A major study has just begun, led by UMC Groningen and Radboudumc, to determine whether patients with heart scarring do benefit from an ICD. In the study, half of the patients receive an ICD and the other half do not. All Dutch hospitals that implant ICDs are participating—26 centers in total. The study will take seven years. ‘Based on this study, I expect the international guideline will also change’, says Allaart.

Treatment threshold

MRI scans are also a key tool in Allaart’s second research area: determining whether ablation is useful for another arrhythmia—atrial fibrillation. This condition mainly affects people over 65. Due to aging and Western lifestyle factors, the number of people with atrial fibrillation is increasing. In a normal heartbeat, electrical impulses originate only from the sinus node. In atrial fibrillation, impulses arise from multiple locations in the heart, causing an irregular heartbeat.

During ablation for atrial fibrillation, a small piece of heart tissue is destroyed via a catheter to stop it from sending faulty electrical signals. This is usually done by freezing or heating the tissue. Although this technique helps many patients, a significant portion experiences little to no benefit.

‘It would be great if we could better predict who will benefit from ablation’, Allaart says. ‘That’s why we use MRI scans before ablation to assess how diseased the atrium is. A follow-up scan shows the result. If the heart muscle is already very diseased, ablation has little effect. And if symptoms return after ablation, should you do another one? We don’t yet know where the treatment threshold lies. I want to better determine when treatment is no longer meaningful or beneficial to quality of life.’

Effect on heart muscle

Allaart also sees a need for more research into a new form of ablation: pulsed field ablation (PFA). In this technique, a doctor delivers a short, high-voltage electric shock to a piece of cardiac tissue, causing it to die. ‘Doctors worldwide are successfully using this technique, but we don’t yet fully understand its effect on heart muscle tissue, especially in the long term. It works very differently from ablation with heat or cold’, Allaart explains. He plans to conduct further research on this.

To further develop the field of electrophysiology at Radboudumc, Allaart believes a strong alliance with MUMC+ is essential. ‘Thanks to this collaboration, we can leverage each other’s expertise and gain access to data from large patient groups for further scientific research.’

Career

Allaart studied Medicine at VU Amsterdam. In 1995, he earned his PhD there with a dissertation titled: Interaction between coronary perfusion and myocardial mechanical properties. He then specialized in cardiology at VUMC and Medical Center Alkmaar. Since 2003, he has worked as a cardiologist at VUMC, where he was appointed professor in 2021. His appointment as professor at Radboudumc began on October 1, 2025, and will continue until his retirement.

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