Author + information
- Received October 3, 2017
- Revision received January 5, 2018
- Accepted January 5, 2018
- Published online February 28, 2018.
- Lars Eckardt, MDa,∗ (, )
- Gerrit Frommeyer, MDa,
- Philipp Sommer, MDb,
- Daniel Steven, MDc,
- Thomas Deneke, MDd,
- Heidi L. Estner, MDe,
- Charalampos Kriatselis, MDf,
- Malte Kuniss, MDg,
- Sonia Busch, MDh,
- Roland R. Tilz, MDi,
- Hendrik Bonnemeier, MDj,
- Christian von Bary, MDk,
- Frederik Voss, MDl,
- Christian Meyer, MDm,
- Dierk Thomas, MDn,o and
- Hans-Ruprecht Neuberger, MDp
- aAbteilung für Rhythmologie, Department für Kardiologie und Angiologie, Universitätsklinikum Münster, Münster, Germany
- bAbteilung für Rhythmologie, Herzzentrum der Universität Leipzig, Leipzig, Germany
- cAbteilung für Elektrophysiologie, Herzzentrum der Uniklinik Köln, Köln, Germany
- dKlinik für Kardiologie, Herz- und Gefäß-Klinik GmbH, Bad Neustadt an der Saale, Germany
- eMedizinische Klinik und Poliklinik, Interventionelle Elektrophysiologie, Klinikum der Universität München, Campus Großhadern, München, Germany
- fKlinik für Innere Medizin – Kardiologie, Deutsches Herzzentrum Berlin, Berlin, Germany
- gAbteilung Kardiologie, Kerckhoff Klinik GmbH, Bad Nauheim, Germany
- hII Medizinische Klinik für Kardiologie, Pneumologie und Angiologie, Krankenhaus Coburg, Coburg, Germany
- iMedizinische Klinik II (Kardiologie, Angiologie, Intensivmedizin), Universitäres Herzzentrum Lübeck, Lübeck, Germany
- jKlinik für Innere Medizin III, Schwerpunkt Kardiologie und Angiologie, Universitätsklinikum Schleswig-Holstein, Campus Kiel, Kiel, Germany
- kMedizinische Klinik I, Rotkreuzklinikum München, LKH der TU München, München, Germany
- lInnere Medizin III, Krankenhaus der Barmherzigen Brüder Trier, Trier, Germany
- mKlinik für Kardiologie mit Schwerpunkt Elektrophysiologie, Universitäres Herzzentrum, Universitätsklinikum Hamburg-Eppendorf, DZHK Standort Hamburg/Lübeck/Kiel, Kiel, Germany
- nKlinik für Kardiologie, Universitätsklinik Heidelberg, Heidelberg, Germany
- oHCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Heidelberg, Germany
- pInnere Medizin, Kardiologie/Rhythmologie, Klinikum Traunstein, Traunstein, Germany
- ↵∗Address for correspondence:
Dr. Lars Eckardt, Abteilung für Rhythmologie, Universitätsklinikum Münster, Albert-Schweitzer Campus 1, 48149 Münster, Germany.
Objectives This study provides an update and comparison to a 2010 nationwide survey on cardiac electrophysiology (EP), types and numbers of interventional electrophysiological procedures, and training opportunities in 2015.
Background In 2010, German cardiology centers performing interventional EP were identified and contacted to provide a survey on cardiac EP.
Methods German cardiology centers performing interventional EP in 2015 were identified from quality reports and contacted to repeat the 2010 questionnaire.
Results A majority of 131 centers (57%) responded. EP (ablation procedures and device therapy) was mainly part of a cardiology department (89%) and only independent (with its own budget) in 11%. The proportion of female physicians in EP training increased from 26% in 2010 to 38% in 2015. In total, 49,356 catheter ablations (i.e., 81% of reported ablations in 2015) were performed by the responding centers, resulting in a 44% increase compared with 2010 (the median number increased from 180 to 297 per center). Atrial fibrillation (AF) was the most common arrhythmia interventionally treated (47%). At 66% of the centers, (at least) 2 physicians were present during most catheter ablations. A minimum of 50 (75) AF ablations were performed at 80% (70%) of the centers. Pulmonary vein isolation with radiofrequency point-by-point ablation (62%) and cryoablation (33%) were the preferred ablation strategies. About one-third of centers reported surgical AF ablations, with 11 centers (8%) performing stand-alone surgical AF ablations. Only one-third of the responding 131 centers fulfilled all requirements for training center accreditation.
Conclusions Comparing 2010 with 2015, an increasing number of EP centers and procedures in Germany are registered. In 2015, almost every second ablation was for therapy for AF. Thus, an increasing demand for catheter ablation is likely, but training opportunities are still limited, and most centers do not fulfil recommended requirements for ablation centers.
Over the past 2 decades, clinical electrophysiology (EP), including device therapy and catheter ablation of arrhythmias, has rapidly developed as a subspecialty in cardiology. Catheter ablation is first-line therapy for regular supraventricular tachycardias and at least second-line therapy for most symptomatic patients with atrial fibrillation (AF). It has been estimated that about 60,000 catheter ablation procedures are performed per year in Germany (1). The increasing number of procedures and quality issues require national and international standards as well as trained specialists in the field of cardiac EP. National and international cardiology societies have developed training programs for a “heart rhythm specialist,” and the Accreditation Committee of the European Heart Rhythm Association (EHRA), American societies (American College of Cardiology, American Heart Association, and Heart Rhythm Society), and the German Society of Cardiology (DGK) have recently published curricula for clinical electrophysiologists (2–4). These curricula recommend requirements for training centers and trainees.
In view of this background, we performed a survey on infrastructure, training conditions, and procedure numbers in Germany in 2010, which served as a reference for the present survey (5). The purpose of this study was to provide a 5-year follow-up of this nationwide survey on cardiac EP, including types and numbers of electrophysiological studies and ablations performed in 2015 in Germany.
German cardiology centers performing interventional EP were identified from (legally mandatory) quality reports of German hospitals (http://www.dimdi.de/static/de/klassi/ops/anwendung/zweck/qualitaetsberichte/index.htm). Hospitals reporting the following operation and procedure codes (OPS) were identified: 8-835.2 (radiofrequency ablation), 8-835.3 (irrigated radiofrequency ablation), 8-835.4 (ablation with other energy sources), 8-835.9 (mesh ablation), 8-835.a (cryoablation), and 8-835.8 (ablation with 3-dimensional mapping). The number of OPS is not necessarily identical to the number of ablation procedures performed, because more than 1 OPS (e.g., irrigated radiofrequency ablation plus ablation using 3-dimensional mapping) can be coded for a single ablation procedure. As previously (5), centers coding <30 ablation procedures were excluded from analysis. This cutoff was chosen because a small number of coded ablation procedures increased the likelihood that the procedure itself was performed at a different hospital or by an external electrophysiologist (e.g., employed at another hospital). The head of the cardiology department or of interventional EP was contacted by e-mail and/or phone to answer a questionnaire that had already been used in the previous survey (5). The following parameters were queried: type of hospital, staff numbers and functions in cardiology and EP, sex, infrastructure, number and types of electrophysiological procedures, techniques used, imaging modalities, presence of or distance to cardiac surgery (for a detailed description, see Neuberger et al. ).
In addition to previous data (5), information on methods for protection of esophageal lesions during ablation of AF was collected. Data were made anonymous and sent to a statistical center. Descriptive statistics were analyzed using SPSS version 24.0 (SPSS, Chicago, Illinois).
According to OPS data, 327 centers coded ablation procedures in 2015. Among them were 97 centers that coded <30 catheter ablation procedures. Of the remaining 230 centers (n = 189 in 2010), which coded ≥30 procedures, 131 (57%) responded. The completed questionnaires of these centers were used for analysis (Tables 1 to 4⇓⇓⇓⇓). Data came from 31 university hospitals (24%), 84 teaching hospitals (nonuniversity hospitals involved in training of medical students) (64%), 13 nonteaching hospitals (6.9%), and 3 private medical practices (1.6%) performing catheter ablations at a neighboring hospital.
The structure of interventional EP
EP (ablation procedures and device therapy) was mainly part of a cardiology department (n = 117 of 131 [89.3%]), and only 14 centers were independent (with their own budgets; 10.7%). Ninety-three centers (70%) were officially certified training centers for interventional EP according to the EP curriculum of the DGK. In 2015, overall, 109 centers were officially certified for EP by the DGK (DGK, personal communication); thus 85% of those participated in the survey. Interventional EP was the main area of expertise of the head of the cardiology department at 28 centers (12%). At least 1 catheter laboratory was almost exclusively (>90%) used for EP in 88 centers (67%), whereas at the remaining centers (n = 43 [33%]) the EP laboratory was used for non-EP procedures as well. At 18 centers (14%), at least 2 dedicated EP laboratories were available. An electroanatomical mapping system was present at 121 centers (92%) (CARTO, n = 82; NAVX, n = 77; Rhythmia, n = 2; CARTO and NAVX, n = 40).
Device implantation was at least partly performed in a catheter laboratory at 90 of the centers (69%), always at 61 (47%), most often (≥50%) at 12 (9%), and sometimes (<50%) at 17 (13%). At the remaining 41 centers (31%), device implantation was done in the operating room. Devices were implanted by cardiologists at 76 (69%), by surgeons at 20 (16%), and by both at 32 (24%) of the EP facilities.
Physicians involved in EP
Thirty-five of the 131 cardiology departments (27%) at which ≥30 catheter ablations were performed had >1 department head (e.g., head of interventional cardiology, head of EP) (Table 1). In total, 166 department heads (4 women [2%]), 988 consultants (Oberarzt; 204 women [21%]), and 2,801 physicians in training (1,371 women [49%]) were employed. At these centers, 1 (n = 28 [22%]), 2 (n = 49 [37%]), or more than 2 (n = 39 [30%]) electrophysiological consultants (Oberarzt) were employed. At 83 centers, electrophysiological consultants also performed coronary interventions (63%). No EP fellows in training were present at 41 of the centers (33%), 1 fellow at 28 (22%), 2 at 20 (16%), and 3 or more at 31 (29%) (Figure 1).
In total, 276 electrophysiological consultants (48 women [17%]) were accompanied by 291 training positions (112 women [38%]). The centers employed 403 physicians (73 women [18%]) able to perform catheter ablations as primary operators (only 1 per center at 8 centers [6%]). Of these, 163 (40%) were younger than 40 years, 166 (41%) between 40 and 50 years of age, and 74 (18%) older than 50 years; 32 (8%) worked part-time.
At 86 of the centers (66%), (at least) 2 physicians were present during the majority of catheter ablations. The median number of ablations per center was 297. At 15 of the centers (11%), <100 ablations were performed; at least 200 catheter ablations were performed at 79 centers (60%). At least 50  pulmonary vein isolations (PVIs) were performed at 105 (80%) [92 (70%)] of the centers; 18 centers (14%) performed <50 PVIs, and 8 centers (6%) did not ablate AF.
In total, 59,033 EP procedures, including 49,356 catheter ablations, were reported for 2015 (Table 2). Patient consent for interventional electrophysiological procedures was obtained before hospital admission always at 22 (17%), most often (>50%) at 44 (34%), often (<50%) at 31 (24%), and rarely (<10%) at 34 (26%) centers. In case of consent before admission, the electrophysiological study was performed on the day of admission.
Target arrhythmias (>1 type of arrhythmia could be ablated in a single case) were regular supraventricular tachycardia (n = 11,221 [22%]), atrial flutter (n = 9,749 [20%]), ventricular tachycardia (VT) (n = 5,621 [11%]), and AF (n = 23,441 [47%]) (Figure 2). Ablation of left-sided accessory pathways was reported by 126 centers (97%) (no accessory pathway ablation at 3 [2%], no data available for 2 [2%]) using either a transseptal (n = 83 [63%]) or a retrograde approach (n = 43 [34%]) as primary access. Left-sided VT ablation was reported by 111 centers (85%) (no VT ablation at 18 [15%], no data for 2 [2%]). Access to the left ventricle was primarily retrograde via the aorta at 51 (46%) and using a transseptal approach at 60 (54%) centers. Additionally, epicardial ablation was performed at 38 centers (34%) performing VT ablation (i.e., 29% of all EP centers).
In total, 123 of the responding 131 centers (94%) performed AF ablation procedures. As the method for AF ablation, the majority of centers (n = 89 [72%]) used point-by-point radiofrequency current, 50 (41%) used a cryoballoon (Arctic Front, Medtronic, Minneapolis, Minnesota), 21 (17%) a circular multielectrode ablation catheter (PVAC; Medtronic), and 7 (6%) other energy sources. In 2015, 9,644 cryoballoon ablation catheters were sold in Germany (Medtronic, personal communication). Therefore, the 7,781 cryoballoon ablations performed by the participating centers covered about 80% of the distributed balloons. PVI was the ablation strategy for paroxysmal AF at all centers. For persistent AF, PVI was first-line therapy at 102 centers (82%), whereas a minority performed PVI plus linear ablation (n = 11 [9%]) and/or PVI plus substrate modification (n = 10 [8%]). Imaging before AF ablation was routinely performed at 61 centers (50%) (magnetic resonance imaging at 16 [13%], computed tomography at 38 [30%], rotational angiography at 7 [6%]). During AF ablation, patients were under general anesthesia (tracheal intubation, n = 3 [2%]) or sedated with (n = 92 [75%]) or without (n = 28 [23%]) propofol. Consecutive left atrial arrhythmias following AF ablations were treated by catheter ablation at 106 of 123 centers (86%) performing AF ablation procedures.
The majority of centers (n = 96 [78%]) used strategies for protection of the esophagus. These included administration of H2-blockers post-ablation (n = 85 [69%]), use of esophageal temperature probes (n = 52 [42%]), and/or energy reduction at the posterior left atrial wall (n = 66 [54%]).
Fifty-five centers (45%) performing AF ablation had in-house cardiosurgical backup. For the other centers, the distance to the next hospital performing cardiac surgery ranged from 2 to 100 km (mean 27.6 ± 28.6 km). Surgical ablations were performed at 37 centers (28%) (surgical AF ablation, n = 37 [28%]; VT ablation, n = 6 [5%]). Eleven centers (8%) performed surgical AF ablations as stand-alone procedures.
Training center requirements
Table 4 lists the requirements for training center accreditation according to the EHRA and the DGK (2–4). Approximately two-thirds of the centers reported a number of procedures that fulfilled these criteria. However, all European requirements together were fulfilled only by one-third of the centers. Besides, more recently German national recommendations for AF ablation have been published (4), which include, for example, 75 AF ablations per year. This would have been fulfilled by only 70% of the centers performing AF ablation in 2015.
For the second time, this survey reports detailed data from the majority of German centers performing interventional EP. The present survey allows the opportunity to report trends in EP over a period of 5 years, as it compares survey data from 2010 and 2015. In total, almost identical to the previous survey (5) about two-thirds of the identified centers responded. They carried out 49,356 catheter ablations, which represent the majority (81%) of catheter ablations performed in Germany (60,933 diagnosis-related groups including a catheter ablation [F50A, F50B, F50C, and F50D]). Compared with 2010, we observed an almost 50% increase in the total number of ablations. Interventional EP was performed at a relatively large number of hospitals; more than 300 hospitals were identified.
For training in the subspecialty of EP, the DGK and the EHRA have published requirements for physicians in training and for training centers (not legally binding). It seems relevant to interpret our data with regard to these curricula (2,3). On the basis of EHRA recommendation, an electrophysiological training center should, for example, employ at least 2 fully trained heart rhythm specialists and needs to be integrated within a cardiosurgical unit (Table 4). According to our data, only 42% of the responding centers would have fulfilled this criterion. Besides, 31% of the centers performed <200 ablations a year, which is recommended by the EHRA and the DGK as a minimum number for a training center. In fact, only about one-third of the EP centers fulfilled all European training center requirements. Compared with 2010, these data illustrate an increase in electrophysiological training centers but also the continuous need for collaboration of EP centers to guarantee training standards and qualification. Being aware that the recommendations of the DGK advise the presence of 2 physicians during catheter ablation, it is remarkable that catheter ablations were performed always or in most cases by 2 physicians at only 21 (16%) and 65 (50%) centers, respectively. Furthermore, almost identical to 2010, about one-third of centers did not employ EP fellows. Thus, a realistic chance of training in interventional EP does not exist at a relevant proportion of the participating centers, even independent of curricular requirements.
Comparable with 2010, at the majority of centers, clinical EP was part of a cardiology department. Despite a high degree of subspecialization in cardiology and the increasing complexity of procedures (e.g., AF, VT, device therapy), only about 20% of EP centers were independent. Nevertheless, it is remarkable that this percentage doubled over the 5-year period (from 10% in 2010). It remains important that almost one-third of EP consultants also performed coronary interventions. This was 77% in 2010 and thereby illustrates growing independence of clinical EP in Germany.
The proportion of female physicians in EP training increased from 26% to 38%. The proportion of women among physicians able to perform catheter ablations as primary operator is at 17% still very low but has increased (from 10% in 2010). This proportion is still lower than the proportion of female cardiology consultants (21% in 2015 vs. 14% in 2010). Duration of training and radiation exposure during child-bearing age may have contributed to this observation. The option to work part-time in this field has only slightly changed between 2010 (2%) and 2015 (8%).
Of note, in 2015 almost every second catheter ablation (47% vs. 35% in 2010) was an ablation of AF (PVI). Thus, in the presence of an almost 50% increase in the total number of ablations, the proportion of ablation procedures has shifted over a relatively short period of time as well. In consequence, the relative number of SVT and atrial flutter ablations decreased from 32% and 25% in 2010 to 22% and 20% in 2015, respectively. As a likely result of the increasing numbers and experience, primarily transseptal approaches increased for both left-sided accessory pathways (from 56% to 66% in 2015) and left ventricular VT ablations (from 32% to 54% in 2015) at the responding centers. Growing experience likely further increases the safety of transseptal procedures (6). Point-by-point radiofrequency current was the method most commonly used for PVI (63%), with 33% cryoablations in 2015. A low prevalence of other less established technologies (e.g., PVAC  at 3.5%) was observed. Given the high prevalence of AF and its consequences, prospective AF ablation trials with mortality as an endpoint are still urgently needed. Positive results may further increase the already growing demand for the procedure. It is surprising that still a relevant proportion of 14% (25% in 2010) of centers performing PVI did not treat consecutive left atrial arrhythmias (8). Thus, there is still a mismatch between the need for interventional AF treatment and the availability of experienced EP specialists performing ablations for secondary “iatrogenic” atrial arrhythmias. This mismatch may further increase with growing use of the technically less demanding cryoballoon ablation. Of note, “single-shot devices” such as the PVAC catheter (9) but also the cryoballoon (10) have been reported to cause a smaller number of left atrial arrhythmias after PVI. With regard to persistent AF, it is remarkable that 82% of the responding centers performed (only) PVI during a first catheter ablation, which is in line with the STAR AF II trial (11), which was published in May 2015.
Almost 80% of AF ablation centers reported strategies to protect the esophagus, including the use of H2-blockers (12) (69%), energy reduction at the posterior wall (54%), and the use of esophageal temperature probes (45%). This illustrates the widespread fear and growing awareness of the dramatic and mostly lethal complication of an atrioesophageal fistula (13,14). No general and conclusive documentation of atrioesophageal fistula apart from case reports are available, however.
In the presence of the most recent European Society of Cardiology AF guidelines (15), which strengthen the role of surgical AF ablation, it is remarkable that only 28% of the responding centers, which included almost all large ablation centers in Germany covering 81% of all ablations, performed surgical AF ablations in 2015 (less than in 2010, at 34%). Stand-alone surgical AF ablations were performed at only 8% of the responding ablation centers. This questions the practicability of AF heart teams and surgical AF ablation suggested by the recent guidelines (16).
A comparison with the American College of Cardiology/American Heart Association/Heart Rhythm Society advanced training statement on clinical cardiac EP (17) to define potential differences between the United States and Europe reveals that requirements suggested for the United States are similar to those established in Europe and in Germany. Of note, the required numbers for ablation procedures for physicians are slightly larger in Europe.
Specific certifications for electrophysiologists may play an important role for outcome quality. Similar to the situation in the United States, specific certifications have therefore been established by the DGK as well as by the EHRA to ensure increasing quality in particular for AF ablation. In the recently published 2017 Heart Rhythm Society/EHRA/European Cardiac Arrhythmia Society/Asia Pacific Heart Rhythm Society/Sociedad Latinoamericana de Estimulación Cardiaca y Electrofisiologia expert consensus statement on catheter and surgical ablation of AF (18) training requirements for operators have been addressed. Although this consensus document concludes that exact procedure numbers are difficult to specify, minimum numbers have been suggested. These numbers are similar in the United States and in Europe, as the consensus document is a joint document from American and European societies. However, recommended numbers may still underestimate the experience required for a high degree of proficiency (18).
Comparable with 2010, not all EP centers responded, and possibly not all centers were identified. Nevertheless, the reported data cover the majority of EP centers and procedures performed in 2015 in Germany and give a unique opportunity to illustrate recent trends in EP over a period of 5 years. The numbers rely on self-reporting. Thus, the results may not exactly represent the exact number of procedures. Additionally, the responding two-thirds of the identified EP centers reported 81% of all DRG-coded catheter ablations. Thus, smaller centers are probably underrepresented, resulting in an overestimation of the median and mean number of procedures per center. Furthermore, as in the previous survey (5), we excluded centers coding <30 ablation procedures in 2015 to prevent an overestimation of sites at which catheter ablation is rarely performed. As a result, this survey may again even overestimate the number and percentage of possible training centers fulfilling curricular requirements, which, however, are not based on evidence-based information. In addition, the present survey only displays how many centers in Germany would have met the requirements for ablation centers but does not display the corresponding figures for single operators. The given data also provide an incomplete perspective because of a lack of outcome data and in particular of procedure-related complications. This is important because the safety of ablation therapy may depend on the volume of procedures performed at centers and by single operators (19). However, because this project was designed to assess nationwide structural conditions with specific regard to training in EP, these data cannot be provided.
The results of this survey indicate a continuous increase in specialization in cardiology and a large number of electrophysiological centers and procedures. In 2015, almost every second ablation performed in Germany was a PVI. At most, one-third of EP centers fulfilled suggested requirements for training centers. In addition, women remain clearly underrepresented among interventional electrophysiologists.
COMPETENCY IN MEDICAL KNOWLEDGE: The present study illustrates a clear trend toward increasing numbers of catheter ablations, with almost every second ablation for therapy of AF. Future studies and trends in cryoablation versus radiofrequency ablation for PVI will be of interest. The growing need for EP centers is in contrast to a limited number of training positions. In the presence of suggested training requirements for EP centers, the majority of centers performing catheter ablation did not fulfill suggested recommendations in 2015. Future studies should investigate possible changes and whether training requirements correlate with the safety, efficacy, and therefore quality of invasive EP.
The authors thank the nucleus of the working group AG1 Rhythmologie of the DGK (speakers: T. Deneke and C. Piorkowski) for collaboration.
The authors received an unrestricted travel grant from Johnson & Johnson Medical.
- Abbreviations and Acronyms
- atrial fibrillation
- German Society of Cardiology
- European Heart Rhythm Association
- operation and procedure code(s)
- pulmonary vein isolation
- ventricular tachycardia
- Received October 3, 2017.
- Revision received January 5, 2018.
- Accepted January 5, 2018.
- 2018 American College of Cardiology Foundation
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