Quantitative variables are presented as mean (standard deviation). Differences between quantitative variables were assessed using the Student t test for dependent or independent samples, as appropriate. Differences between qualitative variables were analyzed using the chi-squared test and the Fisher exact test. A P value of <.05 was used as a cutoff for statistical significance. The statistical analysis was performed using an SPSS 15.0 database.

As in previous registries, epidemiologic characteristics were only available for data collected prospectively. This year, 8 centers used this method (as in 2011), with a total of 1885 ablation procedures.

The mean age of the patients was 44 (15) years. The youngest were those undergoing AP ablation (38 [11] years) and the oldest were those undergoing AVN ablation (75 [8] years). AVNRT ablation was predominantly performed in women (79%), whereas AF (77%) and VT (72%) ablation (whether associated with structural heart disease or not) were predominantly performed in men. These data are virtually identical to those reported in previous registries.

Similarly, 40% of patients had a history of structural heart disease, whereas left ventricular dysfunction was generally limited to patients undergoing AVN and VT ablation associated with heart disease. The same distribution was observed in patients with automatic implantable cardioverter defibrillators.

Tables 1 and 2 show the technical and human resources available in the laboratories participating in the registry, as well as their activities.

A total of 54 centers (73%) had at least 1 laboratory exclusively dedicated to electrophysiology and 10 centers (13.5%) had 2. As in previous years, the laboratory was available for a mean 3.7 (1.4) days/week (median, 4). Only 3 of the 15 private centers had a room exclusively dedicated to electrophysiology.

External electrical cardioversion was performed in 46 laboratories (62% of the total laboratories) and internal cardioversion in 23%. Compared with 2011, there was an increase in the number of centers with facilities for cardiac pacing device implantation: most laboratories (81%) were equipped for this procedure, mainly defibrillators. In 70.3% of laboratories, both defibrillators and pacemakers were implanted; defibrillators alone were implanted in 6.8% and pacemakers alone in 4.1%.

Digital polygraphy was available in all centers; 82.4% had digital radiology, and 55.4% had portable fluoroscopy. A nonfluoroscopic navigation system was available in 81.1% of the centers: 20 centers had 2, and 1 center had 3. Although there were few differences compared with previous registries, nonfluoroscopic navigation systems were more widespread among public-sector centers (89.8% vs 53.3% in private centers).

The number of remote navigation systems slightly increased compared with previous years. Four centers had a magnetic navigation system and 2 had a robotic navigation system. There was also a slight increase in the number of centers offering intracardiac echocardiography (26 centers). Echocardiographic ablation continued to be available in just 1 center, whereas a significantly greater number of centers offered cryoablation (34 centers; 45.9%).

The number of healthcare staff in electrophysiology laboratories remained largely unchanged. Some 73% of centers had more than 1 full-time physician, 40% had more than 2, and just 1 health center had 5 full-time staff physicians. Some 83% of laboratories had at least 2 full-time registered nurses. In total, 25 centers had fellowship students, with a mean of 1.76 per center (1 hospital had 8).

In total, 74 centers submitted data in 2012, constituting the highest level of participation since the registry began (Figs. 1 and 2). Some 11 042 ablations were reported, representing a mean of 149 (103) procedures/center (median, 128 [range, 6-457]). Just 5 private centers performed more than 50 ablations/year; 2 of these carried out more than 200/year. Five public centers performed more than 300 ablations; 3 of these performed more than 400.

Figure 1.

Data analyzed.

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Figure 2.

Number of electrophysiology laboratories in the Spanish Catheter Ablation Registry by number of ablation procedures performed during 2012.

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The overall success rate was 94.9% (8283/8725), excluding AF and VT-AMI substrate ablation. There was a total of 210 (1.9%) reported complications (vascular complications, atrioventricular block, stroke, effusion/tamponade, myocardial infarction, heart failure, and death) during the ablation procedures (including AF and VT-AMI). Five deaths were reported (0.04%): 2 patients with CTI ablation (one in a patient with advanced heart failure who developed acute pulmonary edema 48 h after the procedure, and another in a patient who had a massive stroke after withdrawal of anticoagulation prior to pacemaker implantation). Two deaths occurred in patients with VT-AMI ablation (due to electric storm or refractory shock in both cases) and another occurred in a patient with AF ablation secondary to perforation of the coronary sinus. Iatrogenic atrioventicular block occurred in 22 patients (0.19%) who required permanent pacemaker implantation: 10 occurred during AVNRT ablation, 4 during AP ablation, 1 during FAT ablation, 1 during CTI ablation, 1 during AT ablation, 1 during VT-NAMI ablation, and 4 during VT- AMI ablation. Figures 3 and 4 show the overall results in terms of success and complication rates compared with those of previous years. Percentage success rates for the different substrates remained stable, except for IVT ablation, for which they decreased from 84% to 79%, and for FAT ablation, for which they increased from 80% to 85%. The incidence of complications remained stable for all substrates except AVN (for which they increased from 0.3% to 1.1%), FAT (from 1.4% to 2.1%) and AF (from 3.7% to 4.6%). The most frequently treated substrate was AVNRT, followed by CTI and AP (Fig. 5). The number of ablation procedures increased for all substrates except VT-AMI, for which there was a 3% decrease compared with 2011. However, there was a very significant increase in AF, AP, FAT, AVN, and IVT ablation (there was a 30% increase in IVT ablation compared with 2011). The number of AF ablation procedures increased by 21% compared with 2011, accounting for 17% of all procedures (was the fourth substrate in order of frequency). The least treated substrate continued to be VT-NAMI, although the number of procedures increased considerably in the last 2 years.

Figure 3.

Change in percentage success rates for catheter ablation since 2006 by substrate treated. AP, accessory pathways; AT: atrial tachycardia; AVN, atrioventricular node; AVNRT, atrioventricular nodal reentrant tachycardia; CTI, cavotricuspid isthmus; IVT, idiopathic ventricular tachycardia.

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Figure 4.

Percentage of complications in catheter ablation since 2003 by substrate treated. AF, atrial fibrillation; AP, accessory pathways; AVN, atrioventricular node; AVNRT, atrioventricular nodal reentrant tachycardia; CTI, cavotricuspid isthmus; FAT, focal atrial tachycardia; VT, ventricular tachycardia.

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Figure 5.

Relative frequency of different conditions treated by catheter ablation in Spain during 2012. The percentage change for each substrate compared with the 2011 registry is shown. AF, atrial fibrillation; AP, accessory pathways; AVN, atrioventricular node; AVNRT, atrioventricular nodal reentrant tachycardia; CTI, cavotricuspid isthmus; FAT, focal atrial tachycardia; IVT, idiopathic ventricular tachycardia; MAT, macroreentrant atrial tachycardia/atypical atrial flutter; VT-AMI, ventricular tachycardia associated with acute postinfarction myocardial scarring; VT-HD, ventricular tachycardia associated with heart disease.

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Changes in the relative frequency of the substrates treated since 2002 are shown in Figure 6. In the last decade, AVNRT and AP ablation decreased, whereas AF ablation increased.

Figure 6.

Change in the relative frequency of different substrates since 2002. AF, atrial fibrillation; AP, accessory pathways; AT, atrial tachycardia; AVN, atrioventricular node; AVNRT, atrioventricular nodal reentrant tachycardia; CTI, cavotricuspid isthmus; VT, ventricular tachycardia.

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In 2012, AVNRT and AP were the only substrates treated in all centers, followed by CTI (98.6%) and AVN (89.2%) (Fig. 7). The substrate treated in the fewest centers continued to be VT-NAMI (50%). The number of centers performing AF ablation rose from 44 to 50, accounting for 67.6% of all centers and 71.6% public-sector centers.

Figure 7.

Number of electrophysiology laboratories participating in the Spanish catheter ablation registry that treat each of the substrates. AF, atrial fibrillation; AP, accessory pathways; AVN, atrioventricular node; AVNRT, atrioventricular nodal reentrant tachycardia; CTI, cavotricuspid isthmus; FAT, focal atrial tachycardia; IVT, idiopathic ventricular tachycardia; MAT, macroreentrant atrial tachycardia; VT-AMI, ventricular tachycardia associated with acute postinfarction myocardial scarring; VT-NAMI, ventricular tachycardia not associated with acute postinfarction myocardial scarring.

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The following sections analyze the data for each arrhythmia.

This was the most frequently treated substrate and ablation was performed in all centers. A total of 2842 ablation procedures were performed (25.7% of all procedures). The average number of procedures per center was 38 (24) (range, 1-105). The success rate was 98.2% (2792/2842) and 49 centers (66%) achieved 100% success rates. Complications occurred in 17 patients (0.6%): 10 patients (0.35%) had an atrioventricular block requiring permanent pacemakers, 6 patients developed vascular access complications, and 1 patient developed a pulmonary thromboembolism.

The most commonly used ablation catheter was the conventional 4-mm-tip radiofrequency catheter. An 8-mm-tip catheter was used in 20 patients, irrigated-tip catheter in 26, and cryoablation catheter in 65.

The second most frequent procedure was CTI ablation. A total of 2485 ablation procedures were performed (mean 34 [24]) and were successful in 2400 patients (96.6%). This substrate was treated in 73 of the 74 centers (98.6%) and 37 centers reported 100% success rates. Major complications occurred in 25 patients (1%): 17 patients developed vascular complications; 1 patient had an atrioventricular block requiring a permanent pacemaker, 2 patients had strokes, 1 patient developed pericardial effusion (without associated tamponade), 1 patient developed heart failure, 1 patient had a pulmonary thromboembolism, and 2 died. One of the 2 patients who died had decompensated heart failure; a few hours after ablation, the patient went into cardiogenic shock and died. The other death occurred in a patient who had a massive stroke after withdrawal of anticoagulation prior to pacemaker implantation.

The use of a 4-mm-tip ablation catheter was rare (5.6%) in this substrate. Irrigated-tip catheters were used in 1357 procedures, 8-mm-tip catheters in 965, and cryoablation catheters in 40.

This was the third most frequently treated substrate and was performed all centers. A total of 1999 AP ablation procedures were performed, with a mean of 27 (20) procedures per center (range, 1-97). There were 1816 successful procedures (90.8%) and only 4 of the 57 centers that performed more than 10 AP ablations reported 100% success rates. Major complications occurred in 28 patients (1.4%): 15 patients had vascular complications, 4 had an atrioventricular block requiring permanent pacemakers, 3 had strokes, 2 developed pericardial effusion, and 4 had myocardial infarctions.

Nonconventional ablation catheters were used in 328 patients (16.4%): irrigated-tip-catheters were used in 235 procedures, cryoablation catheters in 91, and 8-mm-tip catheters in 10.

The AP location was reported in all patients. As in previous registries, the most frequent locations continued to be the left ventricular free wall (51.2%) and inferior paraseptal pathways (25.3%). The locations least often treated continued to be the peri-Hisian or superior paraseptal pathways (8.3%). Procedural success depended on the AP location: 95% (972/1024) success was reported in the left free wall, 91.6% (286/312) in the right free wall, 86.4% (437/506) in the inferior paraseptal pathway, and 77% (127/165) in the peri-Hisian/superior paraseptal pathways.

This was the first year in which the register collected data on the type of conduction in the AP. In total, 58 centers submitted data: there was bidirectional conduction in 878 AP, exclusively anterograde conduction in 126, and exclusively retrograde conduction in 567.

In total, 459 procedures were performed and success was achieved in 97.4% of the procedures. Complications occurred in 5 patients (1.1%): 3 patients presented vascular access complications; and 2, heart failure.

Nonconventional catheters were used in 98 cases: 8-mm-tip catheters were used in 38 procedures; and irrigated-tip catheters in 60.

A total of 333 FAT ablation procedures were performed, with a success rate of 85.3% (284/333) and a mean of 6.2 (5.9) procedures per center. This substrate was treated in the right atrium in 61 centers, but in the left atrium in only 36. In total, 72 centers reported the origin of FAT and the procedural success rate was similar in both atria: 83% (195/235) for ablations in the right atrium vs 82.2% (74/90) for those in the left atrium. This was in contrast to previous years in which a higher success rate was reported for procedures in the right atrium.

Complications occurred in 7 patients(2.1%): 1 patient had an atrioventricular block requiring a permanent pacemaker, 2 developed vascular complications; and 4 had pericardial effusions.

As in 2011, the upward trend continued in the use of special catheters (156 in 2012 vs 119 in 2011): irrigated-tip catheters were used in 127 cases; cryoablation catheters in 23; and 8-mm-tip catheters in 6.

This substrate was treated in 44 centers (59.5%), with a total of 227 procedures (mean, 5 [range, 1-15] procedures per center). The procedure was successful in 170 cases (74.8%). Complications occurred in 5 patients (2.2%): 1 patient developed femoral vascular complications, 2 had cardiac tamponade, 1 had acute pulmonary edema, and 1 had an atrioventricular block.

The origin of MAT was reported for all procedures: there were 109 cases of right origin; and 118, left origin; success rates were 81% and 68.3%, respectively. Catheters other than the conventional 4-mm tip were used in 87.6% of the procedures; an irrigated tip was used in most cases (90.4%) and an 8-mm tip in the remainder (9.6%).

In total, 1852 AF ablation procedures (range, 2-123) were performed in 50 (67.6%) of the participating centers. This represents a 21% increase compared with the previous registry, with a mean of 37 procedures per center. Ten laboratories performed less than 10 procedures and 19 laboratories less than 25. Eleven centers performed more than 50 procedures, and only 4 of these performed more than 100. Some 61.5% of the procedures (1139) were for paroxysmal AF and 37.5% (695) for persistent AF. Five centers reported 18 procedures for permanent AF. Of the procedures for persistent AF, 85 were for long-standing AF.

The treatment technique used was indicated in 1791 procedures (96.7%): ostial electrical disconnection was performed in 16.6% of patients, circumferential isolation with disconnection in 80.6%, and circumferential isolation with discharge reduction in the remaining 2.3%. In 37 procedures, the substrate was treated in the right atrium.

Almost all centers (76.8%) used irrigated-tip ablation catheters. There was a clear increase in the use of cryoenergy balloon ablation (350 procedures; 19%). An 8-mm-tip ablation catheter was used in only 4 procedures. Steerable sheaths were used in only 4 centers in 150 procedures (8% of all procedures).

Complications occurred in 87 patients (4.6%): significant pericardial effusion/cardiac tamponade in 42 patients, vascular access in 28, stroke in 7, phrenic nerve palsy in 7, and pulmonary vein stenosis in 2. One death (0.5%) occurred in the setting of tamponade secondary to perforation of the coronary sinus.

A total of 349 IVT ablation procedures were reported in 62 centers (mean, 4.7 [range 1-28] ablations per center). Success was achieved in 276 procedures (79%), with 12 complications (3.4%): 7 cases of tamponade, 3 vascular complications, 1 atrioventricular block, and 1 myocardial infarction in the setting of a circumflex coronary artery dissection that required stenting.

The type of VT treated was reported in 303 procedures: 201 occurred in the right ventricular outflow tract and 62 in the left ventricular outflow tract; 40 were fascicular, and 46 were reported as “other location”. The success rates for these procedures were 79.1%, 83%, 85%, and 76%, respectively. The focal origin of the VT was the aortic root in 16 patients, pulmonary artery in 9, and in the interior of a coronary vein in 1. A 4-mm-tip ablation catheter was used 46.5% of patients, irrigated-tip catheter in 51.5%, and 8-mm-tip catheter in the remaining 2%.

A total of 53 (71.6%) centers performed 323 VT-AMI ablation procedures (6 [range, 1-27] ablations per center). The complications reported (n=23; 7.1%) were vascular access (5); cardiac tamponade in 8 patients, stroke in 2, heart failure in 2, and complete atrioventricular block in 4. Two patients (0.6%) died due to electrical storm, shock, and electromechanical dissociation.

The type of ablation performed was reported in 98.4% of procedures: 75 used a “conventional” approach and 243 used a substrate approach. Irrigated-tip ablation catheters were used for these types of ablation in most procedures. Steerable sheaths were used in 61 procedures. The success rate was 82% with the conventional approach and 85.1% with the substrate approach. Compared with 2011, there was a significant increase in the number of epicardial procedures: 13.6% (44 procedures in 16 centers).

A total of 168 ablation procedures were performed for this substrate in 37 laboratories (50%).

The types of VT were arrhythmogenic cardiomyopathy in 38 patients, branch-branch in 11, nonischemic dilated cardiomyopathy in 61, nonsustained VT in 25, and “other” in 31. The success rates were 86.8%, 100%, 68.8%, 94.2%, and 67.7%, respectively. Four procedures were epicardial; 2 of these with acute success.

Complications occurred in 4 patients, all of which were related to vascular access.

Irrigated-tip ablation catheters were used in 97% of the procedures and 4-mm-tip catheters in the remainder.