Device implantation: the human factor

Device therapy was introduced 50 years ago as single-chamber antibradycardia pacing. It underwent an ongoing development with increasing complexity due to dual-chamber devices, implantable cardioverter-defibrillators (ICDs) and, nowadays, triple-chamber cardiac resynchronization therapy (CRT). Devices prolong life, improve quality of life, and improve haemodynamics resulting in better exercise tolerance. In parallel, patients treated with rhythm control devices have become older and often are severely ill, including those with advanced heart failure. Additionally, many patients have a variety of co-morbidities. More than 200 000 patients in Europe receive a rhythm control device every year. 1 The implantation procedure is the primary and crucial step of successful device therapy. The first goal is the patient's safety without implant complications. The second goal is the quality of therapy, by achieving reliable long-term function of the device, which is determined by several factors such as venous access, lead position, and pacing and sensing thresholds. It is a common sense, supported by studies, to expect, that experienced operators have less complications than trainees. 2 However, reliable data on the magnitude of this difference are lacking. We therefore congratulate Pakarinen et al.3 who undertook the effort to analyse the complication rates of implantation procedures performed by trainees and compared these with those observed for cardiologists with an experience of 5–10 years. Although the results were somewhat disappointing, the authors had the faith to publish them. What did they find? During a 1-year period, 567 primary device implantations have been performed at a single centre, including 12.3% ICDs and 3.7% CRT devices. A total of 78 complications occurred in 69 patients, resulting in a complication rate of 12.2%. These data are in accordance with previous studies which reported the complication rates between 10.1 and 13.9% at 3 months. 4 , 5 In contrast, another study from a high-volume centre reported a lower complication rate of 3.0% within the first 3 months. 2 In the Danish pacemaker registry, a complication rate of 5.0% within the first 4 months has been reported. 6 This may be due to the fact that in Denmark pacemaker implantations are mainly performed at high-volume centres by experienced operators, 89% of whom have done more than 100 implantations. All ICD and CRT systems in the study by Pakarinen et al . have been implanted by four cardiologists with a mean implantation rate of 59 per year. Twelve trainees implanted 242 pacemakers under supervision, with a mean implantation rate of 20 devices per year. The overall complication rate of the procedures performed by trainees was more than double of that for cardiologists (17.4 vs. 7.7%; P = 0.001). The difference in the complication rates between both groups was even more striking for specific complications; the incidence of lead dislodgement, haematoma or bleeding, and pneumothorax was 6.6 vs. 1.5%, 5.0 vs. 1.8% (with 79% of patients using antiplatelet drugs or anticoagulation), and 3.7 vs. 0.6%, respectively; all the differences were statistically significant. In addition, experienced cardiologists did not have higher complication rates with more complex ICD and CRT systems compared with pacemakers (9.9 vs. 7.7%, P = n.s.). Thus, operator's inexperience was associated with up to 4-fold increased risk of complications. These data represent the start of a typical learning curve. All complications together caused 504 additional days of hospital stay. So, what do we learn from this study? Pacemaker implantation is a mandatory part of cardiology training in Finland, as it is in Germany and probably in many European countries. But the number of required implants is low and differs, for example, in Germany from federal state to federal state, due to federal regulations. These implantations are frequently performed at the end of the day, when the other interventions are done. Thus, many trainees are not happy to perform these implantations. The data presented by Pakarinen et al . should be a good reason to discuss whether it is really useful to include all trainees in device implantation training. It may be better to limit implantation training to the few trainees who are interested in device therapy. They will probably reach the end of the learning curve and will become experienced operators in the future. To achieve this purpose, structured training programmes are needed. The European Heart Rhythm Association made an important step into the right direction, with the recent publication of a ‘Core curriculum for the heart rhythm specialist’ to endorse a structured training, not only for device implantation. 7 In this curriculum, a 2-year structured teaching programme, including 50 pacemakers, 30 ICDs, and 20 CRT devices, is proposed. Hopefully, this will have a positive impact on training programmes in different European countries. One final aspect of the data presented deserves further attention: although subclavian vein puncture is a well-known cause of an increased complication rate compared with cephalic vein cut down, it is frequently used in device implantation. 4 In the study by Pakarinen et al ., axillary puncture was the most frequently used access. The rate of subclavian puncture varied between 0.0 and 15.6% depending on the type and position of lead. Nevertheless, the incidence of pneumothorax during the procedures performed by trainees was similar with attempted subclavian and axillary vein puncture. Experienced cardiologists caused no pneumothorax with axillary vein puncture, making this access an attractive alternative. In conclusion, trainees involved in rhythm control device implantation have a 4-fold higher complication rate compared with experienced operators, leading to considerable prolongation of hospital stay and increased costs. This makes a short-term training for all cardiologist applicants debateable. It may be better to train a few, but to train them well! Conflict of interest: none declared.