November 06, 2013 | As more and more people live longer, more patients are likely to suffer from heart failure. With MediGuide Technology, physicians can navigate devices through a diseased heart by means of magnetic tracking. Continuous fluoroscopy of the patient is no longer necessary. So, considerable radiation is saved – without compromising on the outcome.
Text: Hildegard Kaulen
Photos: Andréas Lang
The Heart Center at Leipzig University is no ordinary hospital. It was the first privately financed and operated university heart center in Germany. It proves that economical operation, highly innovative medical science, and premium performance are not incompatible with another. This is also the maxim of Professor Gerhard Hindricks, MD, Head of the Department of Rhythmology. He relies on high-end innovations, as he feels the competitive pressure on hospitals and the increasing disease burden of the aging population. Take heart failure, for example: According to the German Federal Statistical Office, heart failure was responsible for 380,100 hospitalizations in 2011, and was therefore the most frequent cause for hospital admission in Germany. As there is a clear correlation between increasing age and incidence of heart failure, the number of cases will dramatically increase in the coming decades throughout the world.
Technology to Cope with an Increasing Disease Burden
What can be done about the increasing incidence of heart failure and what is the contribution MediGuideTM Technology can make? According to Hindricks, cardiac resynchronization therapy, CRT for short, presents a possible and clinically established solution in selected patients. Here, both ventricles of a heart that is not beating synchronously are equipped with one electrode each and stimulated simultaneously. “CRT is the most important treatment innovation for heart failure of the past 10 years,” the electrophysiologist explains. “If the electrodes of the biventricular pacemaker are optimally placed, cardiac health and pumping function improve almost without any side effect –for many years. So, mortality decreases and the quality of life increases again.” MediGuide Technology helps to implant electrodes precisely and with considerably less radiation than previously used. So, CRT implantation can be safer and more reliable. With a world facing a growing disease burden, this is significant.
Significantly Less Radiation during CRT Implantation
Implantation of CRT devices involves a comparatively high radiation exposure caused by the challenging implantation of the left ventricular (LV) electrode. The necessary equipment such as sheaths, guide wires, and the electrodes themselves are navigated during fluoroscopy. This is not necessary with MediGuide Technology. Here, the position of the device is determined by magnetic tracking and projected in real-time to pre-recorded cine loops. Respiratory and cardiac movements are compensated by means of special algorithms and a reference sensor at the patient’s sternum. Therefore, the navigation is stable over time, making it more like 4D catheter tracking. At best, with MediGuide Technology, fluoroscopy is only needed at the beginning and at the end of a procedure. This saves a lot of radiation. The interventionalist also benefits since he or she stands near the left shoulder of the patient during the CRT implantation and probes the coronary sinus by means of left anterior oblique projections. In this position, the interventionalist is exposed to considerable scattered radiation.
Measurable Results of MediGuide Technology
The Heart Center in Leipzig was the first hospital in the world to use MediGuide Technology for CRT implantations. So far, Hindricks and his colleagues have completed fifty such interventions. Radiation exposure could be reduced significantly. The average fluoroscopy period for LV electrode positioning was less than three minutes and the entire implantation was less than six minutes, without any increase in the rate of complications. Hindricks is already thinking ahead to interventions performed without a lead apron. “In electrophysiological laboratories of the future, it will only be necessary to use fluoroscopy at the beginning and at the end of a procedure, and no investigator would need to wear a lead apron,” he says.
Further Potential Applications for CRT Treatment
What is so special about MediGuide Technology? It is not a new mapping system but a cardiovascular CRT treatment platform. It can be used whenever a device must be positioned under fluoroscopic control for diagnostic or therapeutic purposes. According to Hindricks, interventional electrophysiology is just the beginning, the first of many possible applications. The MediGuide Technology system can also be used for catheter ablations in all cases of supraventricular and ventricular tachycardia. Further applications are also imaginable, such as the deposition of stem cells in a heart damaged by myocardial infarction. Additionally, Hindricks sees an increased care demand with respect to CRT implantation. Although Germany has a volume of 202 implantations per million inhabitants and ranks number two in the European care statistics, the majority of eligible patients are not yet treated correspondingly. Among other reasons for this undersupply, Hindricks mentions the lack of a proper screening program for the identification of patients who will benefit from the CRT treatment. In many countries, the technique is not covered by insurers or electrophysiological centers and there is subsequently a lack of trained physicians.
Translating Technology into Clinical Practice
Will the interventionalists readily adjust to the MediGuide Technology? “The system offers one of the shortest learning curves you can imagine,” Hindricks says. “We had colleagues who were familiar with it in just 10 minutes time, which was not only due to the fact that they were excellent electrophysiologists. Due to the projection of the catheter onto a conventional fluoroscopy image, we stay within an environment that is well known to most users. They obtain additional imaging quality, but basically no new views. This helps them get accustomed to the MediGuide Technology system. “The simpler and safer it is to navigate the device through the heart, the greater the benefit for patients with heart failure.”
Hildegard Kaulen, PhD, is a molecular biologist. Following positions at Rockefeller University in New York and Harvard Medical School in Boston, she has worked as a freelance scientific journalist for notable daily newspapers and scientific magazines since the mid-nineties.