Abstract

Aims

The European cardiac resynchronization therapy (CRT) survey is a joint initiative taken by the Heart Failure Association and the European Heart Rhythm Association of the European Society of Cardiology with the primary objective of describing current European practice associated with CRT implantations. The results demonstrated that a substantial number of implantations took place in patients without conventional guideline indications. We investigated whether the volume of implants per centre was a determinant of the propensity to use devices for ‘off-label’ indications.

Methods and results

One hundred and forty-one centres from 13 European countries contributed data from consecutive patients successfully implanted with a CRT-P or CRT-D device between November 2008 and June 2009. Centres were categorized into low volume (LVol; ≤120 implantations/year) and high volume (HVol; >120 implantations/year) based on median implantable cardioverter-defibrilator implantation the previous year. No differences were noted with regard to sex, age, or peri-procedural and device-related complications. High-volume centres implanted CRT devices in significantly more patients with mild symptoms and a narrow QRS width. The procedure and fluoroscopy times were substantially longer at LVol centres and devices were more frequently implanted by surgeons and interventional cardiologists. Patients stayed longer in hospital in LVol centres with a median of 4 (2–9) vs. 2 (2–6) days.

Conclusions

High-volume centres explore newer indications in their CRT practice and implant devices more frequently in patients with mild symptoms and narrow QRS durations. Electrophysiologists dominate implantation practice at HVol centres and duration of hospitalization is substantially shorter at these centres.

Introduction and background

3The 2007 ESC/EHRA Guidelines for Cardiac Pacing,1 the 2008 ESC Heart Failure Guidelines2 and the 2008 ACC/AHA/HRS Guidelines for Device Therapy3 provide a class I recommendation with level of evidence A for cardiac resynchronization therapy (CRT) treatment with or without an implantable cardioverter-defibrilator (ICD) in order to improve survival and reduce morbidity in patients with symptomatic heart failure [New York Heart Association (NYHA) III and IV] despite adequate medical treatment, a QRS duration ≥120 ms and an ejection fraction (EF) ≤ 35%. More recently, the ESC Committee for Practice Guidelines published a focused update on the use of devices in heart failure and even present specific recommendations for patients with mild symptoms and atrial fibrillation.4

Guidelines provide limited guidance on which patients should have CRT-P or CRT-D, reflecting the lack of prospective randomized clinical trials (RCTs) designed to compare the efficacy of the two types of devices.5–7 The implantation rate of CRT-P or CRT-D in Western Europe was estimated to be 100/million inhabitants in 2008. Twenty-five per cent of these devices were CRT alone (CRT-P) and 75% were devices included an ICD (CRT-D). There was a significant increase in implantation rates from 2004 to 2008, especially regarding the CRT-D implantation rates.8 The first publication from the European CRT survey demonstrated considerable ‘off-label’ use of CRT devices in patients with NYHA functional class I or II, narrow QRS, atrial fibrillation, and previous device implantation.9 Although not off-label, the evidence used to support guidelines often excludes patients over the age of 75.

The European CRT survey was initiated by the Heart Failure Association (HFA) and the European Heart Rhythm Association (EHRA) of the ESC with the objective of describing current European practice and routines associated with CRT-P/CRT-D implantations based on a sample of patients enrolled in 13 countries. The data collected following implantation provided information including clinical characteristics, diagnostic criteria, implantation routines and techniques, adverse events, in hospital course, discharge status, and assessment of adherence to recommendations.9

These analyses focus on the difference in practice between high and low volume (LVol) centres participating in the CRT survey specifically with regard to adherence to guideline recommendations, off-label use of CRT devices, clinical routines, techniques, and in-hospital course. One would expect that high-volume (HVol) centres with more experience would be more likely to explore broader indications.

Methods

Design

The rationale and design of the CRT survey has been published previously.10 All centres implanting CRT devices (CRT-D/ CRT-P) in the chosen countries were invited to participate. Centres were asked to enrol consecutive patients with successful implantation of any CRT device between 1 November 2008 and 30 June 2009.

Data collection

Data were collected using an electronic case report form (eCRF). Its contents have been previously described.10 The eCRF was developed by the Scientific Committee (Appendix 1) to capture demographic and clinical characteristics, selection criteria assessed prior to implantation, implantation procedures and techniques, device programming and optimization, adverse events, duration of hospital stay, and pharmacological therapy at discharge. Two national coordinators, one each from the fields of heart failure and electrophysiology, were selected and given the responsibility of facilitating recruitment in their respective countries (Appendix 1). All participating centres were initially asked to complete a one-time site questionnaire describing the type and size of the centre, reference area population, facilities, and annual numbers of invasive procedures and implantations performed.

A central database was created at the data management centre, Institut für Herzinfarktforschung Ludwigshafen an der Universität Heidelberg, Germany, which also maintained and interrogated the database and performed analyses. A web site www.crt-survey.org supported by the ESC web department provided all the relevant documents and permitted online data entry.

Participating countries and centres

One hundred and forty-one centres participated in the survey from the following countries: Austria, Belgium, France, Germany, Ireland, Israel, Italy, the Netherlands, Norway, Spain, Sweden, Switzerland, and UK. Germany and Sweden have ongoing device registries which include CRTs and capture most of the information contained in the CRT survey eCRF. With permission from both of the Steering Committees (Appendix 2), CRT data collected consecutively in these two registries during the time frame were merged into the CRT survey database.

Centre size allocation and distribution

Information on centre size was collected from the initial site questionnaire where all invited centres were asked to provide number of inhabitants of reference area, annual pacemaker, and ICD implantations. ICD implantation rate the previous year was chosen as the basis for assignment of centre volume category as it showed to be most appropriate. A median of 120 ICDs were implanted at the participating centres. Centres implanting ≤120 ICDs per year were therefore regarded as LVol and centres implanting >120 ICDs per year were regarded as HVol centres. A total of 1200 CRT devices were implanted at HVol centres and 1192 CRT devices at LVol centres. Forty-two (29.8%) centres were classified as HVol and 94 (66.7%) as LVol centres with the average CRT implantation rate of 28.6 and 12.7, respectively. Complete centre volume information was not available in 5 (3.5%) of the participating centres. Germany, the Netherlands, and UK had the highest percentage of HVol centres while Belgium, Switzerland, Austria, Sweden, and Italy the highest percentage of LVol centres. Data are shown in Figure 1.

Figure 1

Ratio high- vs. low-volume centres per country.

Figure 1

Ratio high- vs. low-volume centres per country.

Statistical methodology

Absolute numbers and percentages are shown for categorical variables to describe the patient population, and means with standard deviations for continuous variables. Binary variables (yes/no response variables) were compared between subgroups by the Pearson chi-square test and continuous variables (numeric values) by the Mann–Whitney–Wilcoxon test. Odds ratios and confidence intervals were calculated where appropriate. Descriptive statistics were calculated for the available cases. A significance level of 0.05 was assumed for the statistical tests and all P values are results of two-tailed tests. All statistical analyses were performed using SAS© statistical software, version 9.1 (Cary, NC, USA).

Results

Patient selection

No difference was noted with regard to the sex, age, or proportion of elderly patients receiving CRT devices between LVol and HVol centres. No difference was observed regarding the distribution of patients based on previous revascularization and history of ablation while HVol centres had higher proportion of patients with previous device (pacemaker/ICD) implantation. Patients were equally distributed with regard to sinus rhythm (72.4 vs. 73.7%, P= 0.49), atrial fibrillation (23.3 vs. 22.4% , P = 0.60), QRS morphology (LBBB 67.7 vs. 66.7%, P = 0.62, RBBB 6.1 vs. 7.1%, P = 0.33) and left ventricular ejection fractions (LVEF) below 25% (39.0 vs. 36.7%, P = 0.25). Most patients were admitted for elective device implantation with similar distribution in both groups. Although the differences are modest, HVol centres significantly more often treated patients in NYHA functional class II, narrow QRS complexes (<120 ms) and patients with ischaemic aetiology for left ventricular (LV) dysfunction. Intraventricular dyssynchrony was assessed less frequently at HVol centres. Patients treated at LVol centres had more frequently been hospitalized for worsening heart failure during the previous year (62.1 vs. 48.7%, P < 0.0001). Data are shown in Table 1.

Table 1

Centre volume-related pre-implantation evaluation (n= 2392)

 Total HVola LVola P value OR (95% CI) 
Patients (n, %) 2392 1200 (50.2) 1192 (49.8)   
Age (years) 70 (62–76) 70 (62–76) 70 (63–73) 0.45  
Females 568 (23.7) 291 (24.4) 277 (23.2) 0.33 1.10 (0.91–1.33) 
Age ≥75 739 (30.9) 359 (29.9) 380 (31.9) 0.50 0.94 (0.79–1.12) 
Elective admission for CRT implantation 1936 (80.9) 940 (78.3) 996 (83.5) 0.08 0.83 (0.67–1.02) 
HF aetiology 
 Ischaemic 1121 (51.2) 576 (55.0) 545 (46.7) <0.01 1.35 (1.12–1.57) 
 Non-ischaemic 874 (39.9) 378 (36.1) 496 (43.3) <0.01 0.75 (0.63–0.89) 
 Other 196 (8.9) 93 (8.9) 103 (8.9) 0.94 0.99 (0.74–1.33) 
Selected past history (n= 2148)b 
 HF hospital during last year 1194 (55.6) 557 (49.7) 637 (53.4) <0.0001 0.60 (0.51–0.72) 
 Previous CABG 472 (22.0) 235 (21.1) 237 (19.8) 0.28 0.89 (0.73–1.10) 
 Previous PCI 563 (26.2) 279 (24.9) 284 (27.5 0.15 0.87 (0.72–1.05) 
 History of ablation 100 (4.7) 51 (4.6) 49 (4.7) 0.88 0.97 (0.65–1.45) 
 Prior device (PPM, ICD) (n= 2370)b 692 (29.2) 371 (31.7) 321 (26.7) <0.05 1.26 (1.06–1.51) 
Functional class (n= 2224)b 
 NYHA I 31 (1.4) 18 (1.6) 13 (1.1) 0.38 1.38 (0.67–2.82) 
 NYHA II 437 (19.6) 234 (21.2) 203 (18.1) <0.05 1.27 (1.03–1.57) 
 NYHA III 1564 (70.3) 761 (69.0) 803 (71.6) 0.13 0.87 (0.72–1.04) 
 NYHA IV 192 (8.6) 90 (8.2) 102 (9.1) 0.32 0.86 (0.64–1.16) 
ECG (n= 2347)b 
 Sinus rhythm 1709 (72.8) 838 (92.4) 871 (73.2) 0.49 0.94 (0–78–1.13) 
 Atrial fibrillation 544 (23.2) 270 (23.3) 274 (22.8) 0.60 1.05 (0.87–1.28) 
 Other 94 (4.0) 49 (4.2) 45 (3.8) 0.66 1.10 (0.72–1.66) 
QRS complex (n= 2347)b,c 
 Normal 288 (12.3) 170 (14.7) 118 (9.8) <0.001 1.58 (1.23–2.03) 
 LBBB 1597 (68.0) 775 (65.6) 822 (68.7) 0.62 1.04 (0.88–1.24) 
 RBBB 154 (6.6) 70 (6.1) 84 (7.0) 0.33 0.85 (0.61–1.18) 
 Paced rhythm 430 (18.3) 207 (17.9) 223 (18.6) 0.62 0.95 (0.77–1.17) 
QRS duration in ms (n= 1958)b 157 ± 31.4 157 ± 33.6 157 ± 28.8 0.99  
 QRS <120 163 (8.3) 108 (10.8) 55 (5.7) <0.001 1.98 (1.41–2.78) 
 QRS 120–150 675 (34.5) 328 (32.8) 347 (36.3) 0.08 0.85 (0.71–1.03) 
 QRS >150 1120 (57.2) 565 (56.4) 555 (57.9) 0.68 0.94 (0.79–1.13) 
Mean LV ejection fraction (n= 1656)b 
 <25% 621 (37.5) 312 (39.0) 309 (36.2) 0.50 1.08 (0.87–1.35) 
 25–35% 757 (45.7) 349 (43.6) 408 (47.2) 0.15 0.86 (0.69–1.06) 
 >35% 278 (16.8) 140 (17.5) 138 (16.2) 0.30 1.17 (0.87–1.55) 
Mitral regurgitation (n= 1453)b 
 None/trivial 1232 (84.8) 555 (82.2) 677 (87.0) 0.31 0.89 (0.71–1.09) 
 Mild 171 (11.8) 92 (13.6) 79 (10.1) 0.06 1.36 (0.99–1.87) 
 Moderate/severe 50 (3.4) 28 (4.2) 22 (2.8) 0.11 1.63 (0.90–2.95) 
Intraventricular dyssynchrony not assessed (n= 1465)b 676 (46.1) 383 (56.6) 293 (37.2) <0.0001 2.17 (1.76–2.68) 
 Total HVola LVola P value OR (95% CI) 
Patients (n, %) 2392 1200 (50.2) 1192 (49.8)   
Age (years) 70 (62–76) 70 (62–76) 70 (63–73) 0.45  
Females 568 (23.7) 291 (24.4) 277 (23.2) 0.33 1.10 (0.91–1.33) 
Age ≥75 739 (30.9) 359 (29.9) 380 (31.9) 0.50 0.94 (0.79–1.12) 
Elective admission for CRT implantation 1936 (80.9) 940 (78.3) 996 (83.5) 0.08 0.83 (0.67–1.02) 
HF aetiology 
 Ischaemic 1121 (51.2) 576 (55.0) 545 (46.7) <0.01 1.35 (1.12–1.57) 
 Non-ischaemic 874 (39.9) 378 (36.1) 496 (43.3) <0.01 0.75 (0.63–0.89) 
 Other 196 (8.9) 93 (8.9) 103 (8.9) 0.94 0.99 (0.74–1.33) 
Selected past history (n= 2148)b 
 HF hospital during last year 1194 (55.6) 557 (49.7) 637 (53.4) <0.0001 0.60 (0.51–0.72) 
 Previous CABG 472 (22.0) 235 (21.1) 237 (19.8) 0.28 0.89 (0.73–1.10) 
 Previous PCI 563 (26.2) 279 (24.9) 284 (27.5 0.15 0.87 (0.72–1.05) 
 History of ablation 100 (4.7) 51 (4.6) 49 (4.7) 0.88 0.97 (0.65–1.45) 
 Prior device (PPM, ICD) (n= 2370)b 692 (29.2) 371 (31.7) 321 (26.7) <0.05 1.26 (1.06–1.51) 
Functional class (n= 2224)b 
 NYHA I 31 (1.4) 18 (1.6) 13 (1.1) 0.38 1.38 (0.67–2.82) 
 NYHA II 437 (19.6) 234 (21.2) 203 (18.1) <0.05 1.27 (1.03–1.57) 
 NYHA III 1564 (70.3) 761 (69.0) 803 (71.6) 0.13 0.87 (0.72–1.04) 
 NYHA IV 192 (8.6) 90 (8.2) 102 (9.1) 0.32 0.86 (0.64–1.16) 
ECG (n= 2347)b 
 Sinus rhythm 1709 (72.8) 838 (92.4) 871 (73.2) 0.49 0.94 (0–78–1.13) 
 Atrial fibrillation 544 (23.2) 270 (23.3) 274 (22.8) 0.60 1.05 (0.87–1.28) 
 Other 94 (4.0) 49 (4.2) 45 (3.8) 0.66 1.10 (0.72–1.66) 
QRS complex (n= 2347)b,c 
 Normal 288 (12.3) 170 (14.7) 118 (9.8) <0.001 1.58 (1.23–2.03) 
 LBBB 1597 (68.0) 775 (65.6) 822 (68.7) 0.62 1.04 (0.88–1.24) 
 RBBB 154 (6.6) 70 (6.1) 84 (7.0) 0.33 0.85 (0.61–1.18) 
 Paced rhythm 430 (18.3) 207 (17.9) 223 (18.6) 0.62 0.95 (0.77–1.17) 
QRS duration in ms (n= 1958)b 157 ± 31.4 157 ± 33.6 157 ± 28.8 0.99  
 QRS <120 163 (8.3) 108 (10.8) 55 (5.7) <0.001 1.98 (1.41–2.78) 
 QRS 120–150 675 (34.5) 328 (32.8) 347 (36.3) 0.08 0.85 (0.71–1.03) 
 QRS >150 1120 (57.2) 565 (56.4) 555 (57.9) 0.68 0.94 (0.79–1.13) 
Mean LV ejection fraction (n= 1656)b 
 <25% 621 (37.5) 312 (39.0) 309 (36.2) 0.50 1.08 (0.87–1.35) 
 25–35% 757 (45.7) 349 (43.6) 408 (47.2) 0.15 0.86 (0.69–1.06) 
 >35% 278 (16.8) 140 (17.5) 138 (16.2) 0.30 1.17 (0.87–1.55) 
Mitral regurgitation (n= 1453)b 
 None/trivial 1232 (84.8) 555 (82.2) 677 (87.0) 0.31 0.89 (0.71–1.09) 
 Mild 171 (11.8) 92 (13.6) 79 (10.1) 0.06 1.36 (0.99–1.87) 
 Moderate/severe 50 (3.4) 28 (4.2) 22 (2.8) 0.11 1.63 (0.90–2.95) 
Intraventricular dyssynchrony not assessed (n= 1465)b 676 (46.1) 383 (56.6) 293 (37.2) <0.0001 2.17 (1.76–2.68) 

aCentre volume based on the previous year ICD implantation rate. High-volume centres with ICD implantation rate >120/year and low-volume centres with <120 ICDs/year.

bn are given because of variability in sample size.

cOverlapping registration between variables.

Procedural details

Cardiac resynchronization therapy-D's were implanted more frequently than CRT-Ps (72.5 vs. 27.5%) in the total survey population. The distribution of CRT-D and CRT-P implantations was similar between HVol and LVol centres. Cardiac resynchronization therapy programming for device optimization [both atrioventricular (AV) and interventricular (VV) delay] was reported with equal frequency while VV delay optimization was performed more frequently at Hvol centres. Patients treated at HVol centres more frequently received right ventricular (RV) leads at the apical position (85.2 vs. 62.1%, P < 0.0001) and LV leads at the posterolateral position (47.9 vs. 42.0%, P < 0.01). Surgeons (14.9 vs. 8%) and interventional cardiologists (17.9 vs. 10.5%) were more frequently involved in the implantation of devices in LVol centres. Procedures were more often performed in the operation room (29.4 vs. 12.2%) in these centres with more frequent usage of general anaesthesia and significantly longer duration of procedure and fluoroscopy time. Data are shown in Table 2.

Table 2

Centre volume-related procedural details and hospital durations (n= 2392)

 Total HVola LVola P value OR (95% CI) 
Patients (n, %) 2392 1200 (50.2) 1192 (49.2)   
Device type 
 CRT-D 1734 (72.5) 858 (73.9) 876 (71.2) 0.12 0.87 (0.72–1.04) 
 CRT-P 657 (27.5) 303 (26.1) 354 (28.8) 0.12 1.16 (0.96–1.39) 
CRT implantation based on (n= 2103) 
 QRS duration 1098 (52.2) 490 (49.8) 608 (54.3) <0.05 0.81 (0.68–0.97) 
 Mechanical dyssynchrony 208 (9.9) 100 (10.2) 108 (9.6) 0.62 1.08 (0.81–1.44) 
 Both 797 (37.9) 393 (40.0) 400 (35.7) <0.001 1.41 (1.17–1.71) 
Operator (n= 2135)b 
 Electrophysiologist 1620 (75.9) 862 (78.3) 758 (73.3) <0.01 1.14 (0.92–1.41) 
 HF physician 85 (4.0) 72 (6.5) 13 (1.3) <0.0001 7.99 (3.96–16.1) 
 Invasive cardiologist 299 (14.0) 116 (10.5) 183 (17.7) <0.0001 0.67 (0.51–0.88) 
 Surgeon 238 (11.1) 88 (8.0) 150 (14.5) <0.0001 0.08 (0.05–0.14) 
 Other 41 (1.9) 34 (3.1) 7 (0.7) <0.0001 34.3 (4.69–251) 
Location of procedure and sedation (n= 2135) 
 EP/cath lab 1647 (77.1) 968 (87.8) 679 (65.7) <0.0001 3.07 (2.41–3.92) 
 Operation room 459 (21.5) 134 (12.2) 325 (31.5) <0.0001 0.38 (0.30–0.48) 
 Other 29 (1.4) 29 (2.8) <0.0001 0.23 (0.16–0.33) 
 Sedation with general anaesthesia 264 (12.3) 90 (7.9) 174 (17.6) <0.0001  
RV lead position (n= 2067) 
 Basal 201 (9.7) 56 (5.4) 139 (14.0) <0.0001 0.35 (0.25–0.48) 
 Middle 351 (17.0) 99 (9.5) 237 (23.9) <0.0001 0.33 (0.26–0.43) 
 Apical 1515 (73.3) 890 (85.2) 616 (62.1) <0.0001 3.50 (2.83–4.34) 
LV lead position (n= 2051) 
 Anterior 18 (0.9) 9 (0.9) 9 (0.9) 0.91 0.95 (0.37–2.40) 
 Antero-lateral 196 (9.6) 80 (7.7) 113 (11.5) <0.01 0.64 (0.48–0.87) 
 Lateral 888 (43.3) 437 (42.1) 435 (44.2) 0.35 0.92 (0.77–1.10) 
 Posterolateral 921 (44.9) 497 (47.9) 413 (42.0) <0.01 1.27 (1.07–1.52) 
 Middle cardiac vein 28 (1.4) 14 (1.4) 14 (1.4) 0.89 0.95 (0.45–2.00) 
Duration of procedure (min) 100 (68–140) 90 (55–130) 110 (77–145) <0.0001  
Flouroscopy time (min) 17 (10–28) 15 (9–24) 20 (11–32) <0.0001 0.45 (0.29–0.68) 
CRT programming (n= 1935) 
 To optimize AV interval 344 (17.8) 165 (16.6) 177 (19.4) 0.11 0.83 (0.65–1.04) 
 To optimize VV interval 415 (21.4) 231 (23.2) 177 (19.4) <0.05 1.26 (1.01–1.57) 
 Both 1176 (60.8) 598 (60.2) 557 (61.1) 0.98 0.96 (0.80–1.15) 
Hospital durations (days) 
 Admission procedure 1 (0–3) 1 (0–2) 1 (0–3) 0.27  
 Admission discharge 3 (2–8) 2 (2–6) 4 (2–9) <0.0001  
 Procedure discharge 2 (1–4) 1 (1–3) 2 (1–4) <0.0001  
Device follow-up at the implant centre 1835 (92.4) 860 (93.1) 975 (90.2) 0.45 1.14 (0.80–1.63) 
 Total HVola LVola P value OR (95% CI) 
Patients (n, %) 2392 1200 (50.2) 1192 (49.2)   
Device type 
 CRT-D 1734 (72.5) 858 (73.9) 876 (71.2) 0.12 0.87 (0.72–1.04) 
 CRT-P 657 (27.5) 303 (26.1) 354 (28.8) 0.12 1.16 (0.96–1.39) 
CRT implantation based on (n= 2103) 
 QRS duration 1098 (52.2) 490 (49.8) 608 (54.3) <0.05 0.81 (0.68–0.97) 
 Mechanical dyssynchrony 208 (9.9) 100 (10.2) 108 (9.6) 0.62 1.08 (0.81–1.44) 
 Both 797 (37.9) 393 (40.0) 400 (35.7) <0.001 1.41 (1.17–1.71) 
Operator (n= 2135)b 
 Electrophysiologist 1620 (75.9) 862 (78.3) 758 (73.3) <0.01 1.14 (0.92–1.41) 
 HF physician 85 (4.0) 72 (6.5) 13 (1.3) <0.0001 7.99 (3.96–16.1) 
 Invasive cardiologist 299 (14.0) 116 (10.5) 183 (17.7) <0.0001 0.67 (0.51–0.88) 
 Surgeon 238 (11.1) 88 (8.0) 150 (14.5) <0.0001 0.08 (0.05–0.14) 
 Other 41 (1.9) 34 (3.1) 7 (0.7) <0.0001 34.3 (4.69–251) 
Location of procedure and sedation (n= 2135) 
 EP/cath lab 1647 (77.1) 968 (87.8) 679 (65.7) <0.0001 3.07 (2.41–3.92) 
 Operation room 459 (21.5) 134 (12.2) 325 (31.5) <0.0001 0.38 (0.30–0.48) 
 Other 29 (1.4) 29 (2.8) <0.0001 0.23 (0.16–0.33) 
 Sedation with general anaesthesia 264 (12.3) 90 (7.9) 174 (17.6) <0.0001  
RV lead position (n= 2067) 
 Basal 201 (9.7) 56 (5.4) 139 (14.0) <0.0001 0.35 (0.25–0.48) 
 Middle 351 (17.0) 99 (9.5) 237 (23.9) <0.0001 0.33 (0.26–0.43) 
 Apical 1515 (73.3) 890 (85.2) 616 (62.1) <0.0001 3.50 (2.83–4.34) 
LV lead position (n= 2051) 
 Anterior 18 (0.9) 9 (0.9) 9 (0.9) 0.91 0.95 (0.37–2.40) 
 Antero-lateral 196 (9.6) 80 (7.7) 113 (11.5) <0.01 0.64 (0.48–0.87) 
 Lateral 888 (43.3) 437 (42.1) 435 (44.2) 0.35 0.92 (0.77–1.10) 
 Posterolateral 921 (44.9) 497 (47.9) 413 (42.0) <0.01 1.27 (1.07–1.52) 
 Middle cardiac vein 28 (1.4) 14 (1.4) 14 (1.4) 0.89 0.95 (0.45–2.00) 
Duration of procedure (min) 100 (68–140) 90 (55–130) 110 (77–145) <0.0001  
Flouroscopy time (min) 17 (10–28) 15 (9–24) 20 (11–32) <0.0001 0.45 (0.29–0.68) 
CRT programming (n= 1935) 
 To optimize AV interval 344 (17.8) 165 (16.6) 177 (19.4) 0.11 0.83 (0.65–1.04) 
 To optimize VV interval 415 (21.4) 231 (23.2) 177 (19.4) <0.05 1.26 (1.01–1.57) 
 Both 1176 (60.8) 598 (60.2) 557 (61.1) 0.98 0.96 (0.80–1.15) 
Hospital durations (days) 
 Admission procedure 1 (0–3) 1 (0–2) 1 (0–3) 0.27  
 Admission discharge 3 (2–8) 2 (2–6) 4 (2–9) <0.0001  
 Procedure discharge 2 (1–4) 1 (1–3) 2 (1–4) <0.0001  
Device follow-up at the implant centre 1835 (92.4) 860 (93.1) 975 (90.2) 0.45 1.14 (0.80–1.63) 

RV, right ventricular; LV, left ventricular; AV, atrioventricular; VV, interventricular.

aCentre volume based on the previous year ICD implantation rate. High-volume centres with ICD implantation rate >120/year and low-volume centres with <120 ICDs/year.

bSome procedures involving more than a single operator.

Hospital durations and follow-up plans

Both admission to discharge and procedure to discharge times were substantially longer at LVol centres. Median (with range) admission to discharge time at LVol centres was 4 (2–9) vs. 2 (2–6) days at HVol centres. Most patients were followed up as outpatients at the implanting centre irrespective of centre volume. Data are reported in Table 2.

Peri-procedural and device-related complications

Serious peri-procedural and device-related complication rates and complications requiring intervention were rare and similar between HVol and LVol centres although pocket haematoma was reported more often at LVol centres. Data are reported in Table 3 and Figures 2 and 3.

Table 3

Centre volume-related peri-procedural and device-related complications (n= 2133)

 Total HVola LVola P value OR (95% CI) 
Patients (n, %) 2133 1104 (51.8) 1029 (48.2)   
Peri-procederal complications 219 (10.3) 105 (9.5) 114 (11.1) 0.32 0.86 (0.64–1.17) 
Bleeding 19 (0.9) 6 (0.5) 13 (1.3) 0.07 0.41 (0.16–1.10) 
 Requiring intervention 4 (0.2) 2 (0.2) 2 (0.2) 0.92 0.90 (0.13–6.43) 
Pocket haematoma 72 (3.4) 23 (2.1) 43 (4.2) <0.01 0.47 (0.28–0.79) 
 Requiring intervention 15 (0.7) 7 (0.6) 8 (0.8) 0.65 0.79 (0.29–2.19) 
Pneumothorax 19 (0.9) 7 (0.6) 12 (1.2) 0.17 1.52 (0.21–1.34) 
 Requiring intervention 9 (0.4) 3 (0.3) 6 (0.6) 0.25 0.45 (0.11–1.81) 
Pericardial tamponade 7 (0.9) 3 (0.3) 4 (0.4) 0.61 0.68 (0.15–3.04) 
 Requiring intervention 5 (0.2) 3 (0.3) 2 (0.2) 0.74 1.36 (0.23–8.15) 
Coronary sinus dissection 31 (1.5) 21 (1.9) 10 (0.9) 0.09 1.92 (0.90–4.09) 
 Requiring intervention 1 (0.1) 1 (0.1) 0.29 1.08 (0.60–1.94) 
Phrenic nerve pacing 46 (2.2) 25 (2.3) 21 (2.0) 0.80 0.77 (0.26–2.31) 
 Requiring intervention 13 (0.6) 6 (0.5) 7 (0.7) 0.65 1.33 (0.79–2.25) 
Lead dislocation 59 (2.8) 35 (3.2) 24 (2.3) 0.29 1.28 (0.69–2.40) 
 Requiring intervention 41 (1.9) 24 (2.2) 17 (1.6) 0.43  
Device-related complications (n= 1907) 72 (3.8) 32 (3.4) 40 (4.1) 0.52 0.85 (0.53–1.38) 
 Lead displacement 31 (1.6) 16 (1.7) 15 (1.6) 0.88 1.06 (0.52–2.15) 
 Lead malfunction 7 (0.4) 2 (0.2) 5 (0.5) 0.25 0.40 (0.08–2.04) 
 Phrenic nerve stimulation 28 (1.5) 14 (1.5) 14 (1.5) 0.98 0.99 (0.47–2.09) 
 Other serious events 9 (0.5) 2 (0.2) 7 (0.7) 0.41 0.49 (0.09–2.71) 
 Total HVola LVola P value OR (95% CI) 
Patients (n, %) 2133 1104 (51.8) 1029 (48.2)   
Peri-procederal complications 219 (10.3) 105 (9.5) 114 (11.1) 0.32 0.86 (0.64–1.17) 
Bleeding 19 (0.9) 6 (0.5) 13 (1.3) 0.07 0.41 (0.16–1.10) 
 Requiring intervention 4 (0.2) 2 (0.2) 2 (0.2) 0.92 0.90 (0.13–6.43) 
Pocket haematoma 72 (3.4) 23 (2.1) 43 (4.2) <0.01 0.47 (0.28–0.79) 
 Requiring intervention 15 (0.7) 7 (0.6) 8 (0.8) 0.65 0.79 (0.29–2.19) 
Pneumothorax 19 (0.9) 7 (0.6) 12 (1.2) 0.17 1.52 (0.21–1.34) 
 Requiring intervention 9 (0.4) 3 (0.3) 6 (0.6) 0.25 0.45 (0.11–1.81) 
Pericardial tamponade 7 (0.9) 3 (0.3) 4 (0.4) 0.61 0.68 (0.15–3.04) 
 Requiring intervention 5 (0.2) 3 (0.3) 2 (0.2) 0.74 1.36 (0.23–8.15) 
Coronary sinus dissection 31 (1.5) 21 (1.9) 10 (0.9) 0.09 1.92 (0.90–4.09) 
 Requiring intervention 1 (0.1) 1 (0.1) 0.29 1.08 (0.60–1.94) 
Phrenic nerve pacing 46 (2.2) 25 (2.3) 21 (2.0) 0.80 0.77 (0.26–2.31) 
 Requiring intervention 13 (0.6) 6 (0.5) 7 (0.7) 0.65 1.33 (0.79–2.25) 
Lead dislocation 59 (2.8) 35 (3.2) 24 (2.3) 0.29 1.28 (0.69–2.40) 
 Requiring intervention 41 (1.9) 24 (2.2) 17 (1.6) 0.43  
Device-related complications (n= 1907) 72 (3.8) 32 (3.4) 40 (4.1) 0.52 0.85 (0.53–1.38) 
 Lead displacement 31 (1.6) 16 (1.7) 15 (1.6) 0.88 1.06 (0.52–2.15) 
 Lead malfunction 7 (0.4) 2 (0.2) 5 (0.5) 0.25 0.40 (0.08–2.04) 
 Phrenic nerve stimulation 28 (1.5) 14 (1.5) 14 (1.5) 0.98 0.99 (0.47–2.09) 
 Other serious events 9 (0.5) 2 (0.2) 7 (0.7) 0.41 0.49 (0.09–2.71) 

aCentre volume based on the previous year ICD implantation rate. High-volume centres with ICD implantation rate >120/year and low-volume centres with <120 ICDs/year.

Figure 2

Peri-procedural complications.

Figure 2

Peri-procedural complications.

Figure 3

Hospital durations with range.

Figure 3

Hospital durations with range.

Discussion

This survey describes current European practice regarding CRT implantations in a relatively broad sampling of 141 centres from 13 countries. Previous publication from this survey demonstrated CRT implantations in patients not fulfilling current recommendations of available guidelines. Specifically, 21% of the devices were implanted in patients in NYHA class I or II, 23% of patients had atrial fibrillation and 9% had QRS duration below 120 ms. Although not ‘off-label’, 31% of patients who received CRT were >75 years of age.9 High-volume centres implanted significantly more patients in NYHA functional class II and patients with narrow complexes while no difference was noted with regard to patients with atrial fibrillation, RBBB or paced rhythm. Absence of assessment for intraventricular dyssynchrony was observed more at HVol centres which might suggest great dependence on electrical dyssynchrony based on QRS width.

Local reimbursement policies, the existence of national guidelines, and high number of conventional ICD implantations are identified as important factors for national practice variations while GDP or health-care spending appears to have a minor role.11 However, basing national practice on the number ICD implantations should be approached cautiously as a recent study from the USA has showed non-evidence-based practice.12

The data from RCTs on CRT are based on selected patients with strict inclusion criteria. Patient characteristics that are frequently encountered in clinical practice, such as important co-morbidities, are often exclusion criteria. The trial evidence for efficacy in elderly patients, patients with atrial fibrillation, patients with mild symptoms, or narrow QRS complex is limited. It is also recognized that several patients with an approved indication for a device therapy do not receive one. In contrast, there are patients assigned to device therapy in the absence of an indication according to applicable guidelines.13 Recent publications suggest that patients with higher LVEF, mild symptoms, atrial fibrillation, or narrower QRS durations with evidence of mechanical intraventricular dyssynchrony may benefit from the implantation of a CRT device.14–20 Some of these patient categories, specifically mild symptoms, and atrial fibrillation, have been addressed in the recent ESC Guidelines on use of devices in heart failure.4

There is substantial variation across Europe with regard to adoption of the recommendations by guidelines.11 Specifically, practice varies widely with regard to decisions concerning device type (CRT-P/CRT-D)21 due to lack of evidence to assist the clinicians in making decisions regarding device type. Comparison based on centre volume and experience in this survey provides important information regarding existing variations in practice.

The advantages of randomized controlled trials are they are designed and powered to evaluate new intervention in a blinded, controlled fashion. The disadvantages are that they select patients according to strict inclusion criteria and exclude elderly patients and patients with important comorbidities. The advantages of surveys are that they capture data from a much heterogeneous population and should reflect actual clinical practice. The disadvantages are potential selection bias, incomplete data collection, and may underestimate adverse experience.

Study limitations

Surveys are an important source of information on how messages obtained in RCTs are adopted in clinical practice and answer different questions.22,23 However, surveys have their own limitations which need to be acknowledged and considered during interpretation of the findings. Differences in practice between countries can skew the results.21 Centre participation was voluntary and the 141 centres recruited represent ∼18% of all potential implantation centres in the 13 participating countries. There was variation in distribution of HVol and LVol centres by participating countries. Although the importance of consecutive inclusion was emphasized, we cannot confirm that all patients were included consecutively. The accuracy of the data has not been audited and there is a potential for investigator selection bias. Importantly, only successful implantations were entered into the database which would lead to selection bias of patients and represent a potential source of under-reporting of adverse experience in connection with implantation. There is a considerable variation in the sample size for some of the eCRF variables due to unavailable information, incomplete data entry, and incomplete overlap between the variables collected in the two device registries and this survey.

Follow-up of patients 9–15 months after inclusion was completed in December 2010. Death and hospitalization are among the necessary parameters registered.

Conclusions

High-volume centres with more experience are exploring newer indications in their CRT practice and more frequently implant devices in patients with mild symptoms and narrow QRS durations. No difference was noted with regard to distribution of gender, age, proportion of elderly, patients with sinus rhythm, atrial fibrillation, QRS morphology, mean LVEF, device type (CRT-D vs. CRT-P), and peri-procedural and device-related complications. Electrophysiologists dominate implantation practice at Hvol centres and duration of hospitalization is substantially shorter at these centres.

Conflict of interest: Nigussie Bogale: none to declare.

Silvia Priori: is a member of the speaker's bureau for Medtronic and Boston Scientific.

Anselm Gitt: none to declare.

Marco Alings: participate in advisory boards for Bayer, Boehringer Ingelheim, MSD and Sanofiaventis (none of them pose a conflict for the CRT survey) and did receive non-personal grants from Boston-Scientific, Medtronic and St. Jude Medical.

Cecilia Linde: consultant to Medtronic, member of advisory board for St. Jude and has received a research grant from Medtronic.

Kenneth Dickstein: has received speaker's honoraria from Medtronic and Biotronik.

Funding

This work was supported by unrestricted grants from Stavanger University Hospital, EUCOMED (Biotronik, Boston Scientific, Medtronic, Sorin and St. Jude Medical), Roche Diagnostics Ltd, HFA, and EHRA.

Acknowledgements

We thank Stavanger University Hospital, EUCOMED, Roche Diagnostics Ltd., HFA and EHRA for financial support. We are grateful to Tessa Baak for her expert assistance in assuring adequate patient recruitment and follow-up and to Tobias Limbourg for excellent statistical support.

Appendix 1

Members of the European CRT Survey Scientific Committee and National Coordinators

Scientific CommitteeNational Coordinators

  • Kenneth Dickstein (HFA Coordinator)

  • Silvia Priori (EHRA Coordinator)

  • Angelo Auricchio

  • Nigussie Bogale

  • Josep Brugada

  • John GF Cleland

  • Geneviève Derumeaux

  • Anselm Gitt

  • Daniel Gras

  • Michel Komajda

  • Cecilia Linde

  • John Morgan

  • Dirk J van Veldhuisen

(HF=heart failure; EP=electrophysiology)

  • Austria: Friedrich Fruhwald HF, Bernhard Strohmer EP

  • Belgium: Marc Goethals HF, Johan Vijgen EP

  • France: Jean Noel Trochu HF, Daniel Gras EP

  • Germany: Michael Kindermann HF, Christoph Stellbrink EP

  • Ireland: Ken McDonnald HF, David Keane EP

  • Israel: Tuvia Ben Gal HF, Michael Glikson EP

  • Italy: Marco Metra HF, Maurizio Gasparini EP

  • Netherlands: Alexander Maass HF, Luc Jordaens EP, Marco Alings EP

  • Norway: Alf Inge Larsen HF, Svein Færestrand EP

  • Spain: Juan Delgado HF, Lluis Mont EP

  • Sweden: Hans Persson HF, Fredrik Gadler EP

  • Switzerland: Hans Peter Brunner-La Rocca HF, Stefan Osswald EP

  • UK: Ian Squire HF, John Morgan EP

Appendix 2

Steering Committee members of the Swedish Device registry and the German device registry

Sweden Germany

  • Johan Brant

  • Fredrik Gadler

  • Cecilia Linde

  • Dietrich Andresen

  • Christian Butter

  • Bernd Gonska

  • Werner Jung

  • Karl-Heinz Kuck

  • Jochen Senges

  • Christoph Stellbrink

Appendix 3

List of contributing centres

Austria: Belgium: France: Germany: Ireland: Israel: Italy: The Netherlands: Norway: Spain: Sweden: Switzerland: UK:

  • A. ö. Landeskrankenhaus - Universitätsklinikum Graz

  • Landeskrankenhaus-Innsbruck-Universitätskliniken

  • Krankenhaus der Elisabethinen Linz

  • Landesklinikum Thermenregion Mödling

  • Landeskrankenhaus Salzburg

  • Landesklinikum St. Pölten

  • Krankenhaus Hietzing mit Neurologischem Zentrum am Rosenhügel

  • Wilhelminenspital der Stadt Wien

  • A. ö. Krankenhaus Wiener Neustadt

  • Kaiser Franz Josef Spital

  • Clinique St Jean

  • Cliniques Universitaires Ucl

  • UZ Gent

  • Virga Jesse Ziekenhuis

  • Hôpital du Bocage

  • Chu

  • Nouvelles Cliniques Nantaises

  • Hôpital Louis Pradel

  • Hôpital Princesse Grace

  • Stadtisches Klinikum Dessau

  • Städt. Klinikum Brandenburg GmbH

  • Krankenhaus Reinbek

  • Universitätsklinikum Aachen - UKA-

  • Klinik Rotes Kreuz

  • Saarland-Heilstätten GmbH Kliniken Völklingen

  • Universitätskliniken des Saarlandes

  • Kreiskliniken Altotting-Burghausen

  • Klinikum St. Marien Amberg

  • Hufeland Krankenhaus GmbH

  • Städt. Klinikum Frankfurt

  • Städt. Klinikum München Klinik Bogenhausen

  • Krankenhaus St. Franziskus Mönchengladbach

  • St. Josefs-Krankenhaus Potsdam

  • Klinikum Lippe-Detmold

  • Städt. Kliniken Bielelfed - Klinikum Mitte

  • Krankenhaus München - Neuperlach (Kardiologie)

  • Klinikum der Universität München-Großhadern

  • Universitätsklinikum Heidelberg

  • Universitätsklinikum Münster (Kardiologie)

  • Klinikum Coburg

  • Herzzentrum Ludwigshafen

  • Herzzentrum Brandenburg

  • Allgemeines Krankenhaus Celle

  • Klinikum Ernst von Bergmann Potsdam

  • Herzzentrum Coswig

  • Mater Misercordea University Hospital

  • South Infirmary Victoria University Hospital

  • St Vincent's University Hospital

  • Sheba Medical Center

  • Barzilai Medical Center

  • Wolfson Medical Center

  • Kaplan Medical Center

  • Rabin Medical Center

  • Haemek Medical Center

  • Ospedale Moriggia-Pelascini

  • Osped. Fatebenefratelli Sgc

  • Osp. S. Giovanni di Dio Fatebenefratelli

  • P.O. Frosinone Ceccano

  • Osped. S.Maria Misericordia-Perugia

  • Presidio Ospedaliero di Rivoli

  • Ospedale S.Andrea

  • P.O. Genova-Ponente P.A. Micone

  • A.O. Osped. S.Gerardo Monza

  • Policlinico Di Monza - Monza

  • IRCCS Instituto Clinico Humanitas Rozzano

  • IRLCS Multimedica

  • A.O.Osp.Treviglio Caravaggio Trev - Treviglio

  • A.O. Desenzano Del Garda

  • Spedali Civili Di Brescia

  • Fond.ne Poliambulanza Ist. Osp.

  • A.O. Maggiore Della Carita’ Novara

  • Pres.Osped. Di Montebelluna

  • Az.Osped.S.Maria Miseric Udine

  • Presidio Osp. Di Camposampiero

  • Presidio Ospedaliero Di Cittadella

  • Azienda Ospedaliera Di Padova

  • Presidio Ospedaliero Di Vicenza

  • Osp.Civile Destra Secchia

  • Osp.Le S.M. Annunziata Bagno A Rip - Bagno A Ripoli

  • Stabilimento Di Cisanello

  • Istituto Fisiologia Clinica

  • Pia Fondazione (Tricase) - Tricase

  • Ospedale S.Maria Di Loreto Mare

  • Az.Osped.S.Giovanni Di Dio

  • Clinica Sant'Anna

  • Ospedale "Umberto I"

  • Clinica Mediterranea

  • Academisch Medisch Centrum

  • Amphia Ziekenhuis

  • Catharina Ziekenhuis

  • Isala Klinieken Zwolle

  • Medisch Centrum Alkmaar

  • Medisch Spectrum Twente

  • Erasmus MC

  • Kennemer Gasthuis

  • University Medical Center Groningen

  • Ålesund Hospital

  • Haukeland University Hospital

  • Kristiansand Hospital

  • Oslo University Hospital, Rikshospitalet

  • Oslo University Hospital, Ullevål

  • Stavanger University Hospital

  • St. Olavs Hospital

  • Hosp. De Cruces

  • Hospital Gregorio Maranon - Madrid

  • Hosp. Virgen de la Victoria

  • Hospital Universitario De Tenerife

  • Hospital Dr. Peset - Valencia

  • Centro Medico Salus Baleares S.l. - Benidorm - Alicante

  • Hospital Clinico Y Provincial - Barcelona

  • Hospital Sta. Creu Y St. Pau - Barcelona

  • Hospital General U. De Alicante - Alicante

  • Danderyds Sjukhus AB

  • Länssjukhuset, Kalmar

  • Karolinska Universitetssjukhuset, Solna

  • Akademiska sjukhuset

  • Blekingesjukhuset

  • Centrallasarettet Västerås

  • Falu lasarett

  • Hudiksvalls sjukhus

  • Kärnsjukhuset Skövde

  • Lässjukhuset Gävle

  • Länssjukhuset Kalmar

  • Norrlands Universitetssjukhus

  • Sahlgrenska Universitetssjukhuset

  • St Görans sjukhus

  • Sundsvalls sjukhus

  • Universitetssjukhuset Örebro

  • Universitetssjukhuset Lund

  • Varbergs sjukhus

  • Cardiocentro Ticino

  • HCF Hopital Cantonal Fribourg

  • Hopitaux Universitaires de Geneve - Geneve 14

  • Universitatsspital Basel

  • Southampton General Hospital

  • Kings College Hospital

  • Queen Elizabeth Hospital

  • Leeds General Infirmary

  • Hull Royal Infirmary

  • Papworth Hospital

  • University Hospital of Wales

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Author notes

Members of the Scientific Committee, National Coordinators and members of the Swedish and Germany device regitry steering commitee members are listed in appendix 1 and 2.