Joost Beusekamp succesfully defended his thesis on electrolyte disturbances in heart failure

On 2 February Joost Beusekamp successfully defended his thesis “Electrolyte disturbances in heart failure, focus on sodium and potassium”. His defense took place at the Academy building of the University of Groningen and, because COVID-restricted were partially lifted, people were finally able to physically attend the ceremony. Joost was flanked by his para-nimfs dr. J.B. van Praagh and drs. B.A. de Cort. He was opposed by internationally renowned academics which resulted in a great debate about the importance of electrolyte observation, physiology and treatment in patients with heart failure.

Supervisors: Prof. dr. Peter van der Meer, Prof. dr. Adriaan Voors, Dr. Jasper Tromp

Opponents:  Prof. dr. Maarten van den Berg, Prof. dr. Stefan Bakker, Prof. dr. Brunner-La-Rocca, Prof. dr. Carolyn Lam, Prof. dr. Isabel van Gelder, Dr. Kevin Damman,

His thesis includes papers published in the European journal of Heart failure and the Journal of American College of Cardiology (Heart Failure). Joost is now working full-time as a medical resident in the cardiology department of the University Medical Center of Groningen.

A short summary of the thesis

Heart failure (HF) is defined as a condition in which the oxygen requirements of the metabolizing tissues outreach the heart’s delivering capacity. Multiple successful therapies have been developed over the years to reduce morbidity and mortality in heart failure, however up-titrating these therapies to therapeutic dosages posed some challenges. The most common of which were hypotension and renal dysfunction, leading to suboptimal therapeutic dosing of heart failure therapies and side effects. Mainly in ACE-inhibitors and Mineralocorticoid Receptor Antagonists (MRA) hyperkalemia as a side effect is seen as a major concern. Potassium ions are a crucial cation in humans, playing a role in the electrophysiology of the neuromuscular cells and the human heart. Patients with hyper- and hypokalemia are prone to life-threatening complications and surveying the kidney function with electrolytes is common/good medical practice. Joost proves in his thesis that slight disturbances in electrolyte function should not lead to different medical treatment for heart failure and that stopping ACE-inhibitors and MRA’s lead to worse outcome in the long-term.

Furthermore, he studied the effects of empafliglozin in acute decompensated heart failure. His research showed that empafliglozin increased cumulative urninary volume and a net negative fluid balance in a subset of patients. Continuing, empafliglozin did not alter sodium and potassium excretion despite an initial dip in eGFR. Lastly, he showed that empafliglozin leads to lower rates of death and rehospitalization in heart failure.

His thesis is a very novel piece on renal physiology of sodium and potassium and the efficacy of empafliglozin.