A pacemaker the size of a vitamin
Emory University researchers have created an unprecedentedly small Micra TPS heart rate driver and successfully conducted a clinical study of the device.
Unlike traditional pacemakers, Micra TPS (Micra Transcatheter Pacing System), whose size is comparable to the size of a multivitamin tablet, does not require the use of wires that stretch inside blood vessels in order to connect the device to the heart. These wires are often the cause of serious complications, such as infection and venous damage.
In addition to the absence of wires, the advantage of Micra TPS, whose size is about 10 times smaller than the size of traditional heart rate drivers, is the minimally invasive procedure for its introduction. The device is delivered to the heart cavity using a catheter inserted through the femoral vein. There it attaches to the endocardium – the inner shell of the heart muscle, registers cardiac arrhythmias and, with the help of special electrodes, sends electrical impulses normalizing it to the myocardium.
A total of 795 patients participated in an international prospective multicenter non-randomized clinical trial, the purpose of which was to assess the safety and functionality of Micra TPS in real clinical practice conditions.
According to the data presented by the researchers, the Micra TPS 792 heart rate driver was successfully implanted in 792 out of 795 (99.6%) participants in 96 clinics. 87% of the specialists who took part in the work had no previous experience in introducing Micra TPS.
The authors believe that the value of this study lies not only in the fact that patients from all corners of the globe took part in it, but also in the fact that the operators who performed the procedure had a different amount of experience with the new technology.
They also note that a pleasant surprise for them was the low level of complications, especially the lower frequency of development of exudative pericarditis, compared with the results of a preliminary clinical study of the device. Serious complications, such as effusion into the heart cavity, perforation of the heart wall, displacement of the device and sepsis, developed only in 1.5% of patients within the first 30 days after implantation. For comparison, during the preliminary study, this indicator was 2.89%, and for the implantation procedure of traditional heart rate drivers, the average incidence of acute complications is 4-5%.
Associate Professor Michael El-Chami from Emory University, who together with his colleagues conducted the first Micra TPS implantations in 2014, notes that the results of this study describe exclusively short-term results of using a new heart rate driver. Intermediate and long-term results, which are extremely important for clinicians, will be presented later. In total, 1830 patients are planned to be included in the ongoing clinical trial.
Article by Paul R. Roberts et al. A Leadless Pacemaker in the Real-World Setting: The Micra Transcatheter Pacing System Post-Approval Registry is published in the journal Heart Rhythm.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Emory University: World's smallest, leadless pacemaker yields positive results in Emory-led study.
23.05.2017