In 2018, this target was once again the second most treated substrate. A total of 3525 AVNRT ablation procedures were performed (21% of the total) in 96 hospitals. There were 96 more procedures than in the previous year, which, in conjunction with a slight reduction in CTI ablation procedures, explains its elevation to second place.

The mean number of procedures was 31.3±12 (range, 1-145), with a success rate of 96%; 69% of centers reported a 100% success rate.

Eleven severe complications were reported (0.3%): 3 cases of atrioventricular block requiring a pacemaker, 6 vascular complications, 1 heart failure event, and 1 pulmonary thromboembolism.

The 4-mm radiofrequency ablation catheter tip is still the most frequently used catheter (96% of procedures). Although the use of other catheters and energy sources was low, the use of cryoablation increased this year, to second place (2.2%), followed by 8-mm catheters (1.1%); irrigated catheters occupied the final position with limited use (0.7%).

The use of navigation systems remained stable vs last year (10.9%), and most of these procedures were performed without fluoroscopy (10% of the total).

CTI ablation, with 3425 procedures (20.7%), was the third most commonly targeted substrate after AF and AVNRT. It was performed in 95 centers, with a mean of 34.2±27.5 (0-119) procedures per center. It was successfully completed in 94% of cases (60 centers [63%] reported a 100% success rate).

There were 38 major nonfatal complications (1.1%), including 18 vascular complications (3.4%), 9 atrioventricular blocks (0.3%), 6 embolisms (0.2%), 2 pericardial effusions, 2 myocardial infarctions, and 1 heart failure event.

Conventional irrigated tip catheters remain the most frequently used, with 1792 procedures (54.4%), although irrigated catheters with contact forcesensing technology doubled since 2017 (247; 7.5%). The use of 8-mm catheters continues to fall (952; 28.9%). Navigation system use remained relatively stable, with 1013 procedures (29.6%), as did zero-fluoroscopy interventions, with 495 (14.4%).

Accessory pathways remain the fourth most targeted substrate. The upward trend that was registered in 2017 continued, with a slight increase in the absolute number of procedures. Overall, 2148 procedures were performed in 98 centers, making it the substrate treated by the highest number of centers (7 more than in the previous year). A mean of 35.4±53.7 (1-90) procedures was performed. A success rate of 91% was obtained, with 30 centers reporting 100% success.

Bidirectional conduction remained the most frequent direction (40.8%), although the percentage of concealed pathways was very similar in 2018 (39.6%). Exclusively antegrade conduction pathways were the most infrequent (19.6%). Regarding their locations, left-sided accessory pathways continued to predominate (51.2%), followed by inferoseptal (27.1%), right ventricular free wall (11.9%), and para-Hisian (9.8%) pathways.

Navigation systems were used in 21.5% of procedures and 4.4% of the total was performed without fluoroscopy.

The retroaortic approach was still preferred (69%) for the ablation of left-sided pathways.

Procedural success rates by location were as follows: left ventricular free wall, 96%; right ventricular free wall, 88.6%; inferoseptal, 86.5%; and para-Hisian/anteroseptal, 74.1%.

Most ablations (61%) were performed with 4-mm ablation catheters. The use of irrigated catheters continued to increase (32.7%), although only 13% had contact forcesensing technology. Cryoablation was used in 4.6%, whereas the use of 8-mm catheters was limited (1.7%).

There were 35 major complications (1.6%): 16 vascular, 5 atrioventricular blocks (2 permanent), 4 acute myocardial infarctions, 3 pericardial effusions, 1 heart failure event, 1 mitral regurgitation, 1 traumatic lesion of the femoral nerve, and 3 embolic phenomena (1 systemic, 1 air embolism in the right coronary artery, and 1 deep venous thrombosis). In addition, 1 patient died of unspecified causes.

The number of these procedures remained stable, with 686 ablations performed in 86 centers. The success rate was 95%. Only 4 nonfatal complications were reported (0.7%), 1 vascular and 3 due to the onset of heart failure. One of the latter patients died 48hours after the ablation. Based on the available data, most of the procedures were performed with conventional 4-mm catheters (456; 66.5%). The distribution of the remainder was as follows: 160 conventional irrigated catheters (23.3%), 53 8-mm catheters (7.7%), and 11 irrigated contact forcesensing catheters (1.6%).

In total, 463 procedures (3%) were performed in 74 centers, with a success rate of 86%, as in 2017. This ablation target was located in the right atrium in 325 cases (with a 90.1% success rate) and in the left atrium in 138 (an 83.3% success rate). There were 8 complications (1.7%): 3 pericardial effusions (0.6%), 2 atrioventricular blocks (0.4%), 2 vascular complications (0.4%), and 1 phrenic nerve palsy (0.2%).

The use of irrigated tip catheters increased to 297 procedures (64.1%); a high number of catheters (141) had contact forcesensing technology.

A navigation system was used in 218 procedures (47.1%); 37 of these (8.0% of the total) were entirely performed without fluoroscopy.

Despite a slight increase in both the number of centers targeting this arrhythmia (6 more than in 2017, up to 64 hospitals) and the number of procedures (588 in 579 patients, an increase of almost 10% [mean, 5.9; range, 0-26]), MAT remained one of the least addressed ablation targets in Spain. Of the 365 cases with this etiology, most occurred after a previous AF ablation (156 cases, 42.7%), as well as 72 in congenital heart disease (19.7%), 55 after atriotomy (15.1%), and 82 others (22.5%).

This procedure had the lowest success rate of all procedures, just 70%. Despite this and the complexity of the substrate, a navigation system was used in only 69.2% of cases. Just 0.7% of the total was performed without fluoroscopy.

Irrigated tip catheters with contact forcesensing technology (58.3%) surpassed conventional irrigated tip catheters (37.2%); the other types are rarely used (0.4%).

There were 20 nonfatal complications (3.4%): 10 pericardial effusions, 5 femoral vascular complications, 2 embolisms, 1 atrioventricular block, 1 chordal rupture, and 1 phrenic paralysis.

Although only 3 new centers began to perform this procedure in 2018, making a total of 77 centers (75.5%), AF treatment overtook that of the other targets by some distance. It was thus consolidated as the most frequently treated substrate, with 4234 procedures in 3907 patients (26% of all ablations), 777 more procedures than in 2017.

The mean number of procedures per center was 42.3 (range, 0-198), with an acute success rate of 94.1%. Already, 33 centers perform more than 50 procedures per year (42.9% of the total); of these, 14 performed more than 100 procedures (18.2%). According to the available data (3747 ablations), the distribution by type was as follows: 2430 paroxysmal AF procedures (64.8%), 1158 persistent AF procedures (30.9%), and 159 long-standing (> 1 year) persistent AF procedures (4.2%).

Electrical isolation of the pulmonary veins was again the most common procedure (93%), with a success rate of 96.9%. In addition, there were 186 reductions of the antral electrogram (successful in 100%), 45 complex fractionated electrogram ablations (successful in 88.9%), and 136 superior vena cava isolations (successful in 74.3%). Left atrial lines were placed in 186 procedures, successfully in 82.2%. Other targets were reported in 66 procedures, such as 20 magnetic resonance-guided scar ablations in 2 centers and 15 rotor ablations in 2 others. Also noted were ablation of the ganglion plexus and of the pulmonary and extrapulmonary foci and a left atrial posterior box isolation.

Although the most commonly used technique for AF ablation is still point-by-point radiofrequency ablation, with 2323 procedures (55.7%), cryoablation continued to gain ground, reaching 1818 procedures (43.6%), 8% more than in 2017. There was limited use of other techniques such as the Multielectrode Pulmonary Vein Ablation Catheter (PVAC, Medtronic, Inc., Minneapolis, USA) (0.9%) and laser ablation (0.4%).

Irrigated catheters with contact forcesensing technology are more and more common and were used in 76.7% of point-by-point ablations in 2018.

The use of steerable sheaths was maintained this year (1025 cases), and they were deployed in 24.2% of all procedures in 33 centers. Intracardiac echocardiography is still rarely used, being applied in just 331 procedures (7.8%) and in only 14 centers.

Three-dimensional navigation was used for this ablation target in 2416 cases, exceeding the 2323 cases reported for point-by-point. This means that it was used in almost 100 cases of cryoablation/ablation with the multielectrode pulmonary vein ablation catheter (PVAC).

Several centers reported the use of “minimal fluoroscopy” and 3 procedures were even completely performed without fluoroscopy.

A total of 145 complications were recorded (3.4%), another slight decrease vs previous years: 3.9% in 2016 and 3.6% in 2017. Of these, 1 was fatal and was associated with ST-segment elevation of unspecified site. The distribution of the remainder was as follows: 49 vascular complications (1.2%), 33 pericardial effusions (0.8%), 27 phrenic nerve palsies (0.6%), 6 embolisms (0.1%), 5 infarctions (0.1%), 4 severe hypotensive events requiring catecholamines (0.1%), and 3 perforations (1 requiring surgery). No atrioesophageal fistulae were reported, although 1 center detected 12 esophageal erosions. Also reported were 1 hemoptysis and 1 aortic puncture.

In total, 729 procedures (4%) were performed in 688 patients in 84 centers (mean, 9.0±4.9 [0-30]). This ablation target experienced the greatest increase in the number of laboratories addressing it (12 more than in 2017).

Overall success was achieved in 85.8%. The following were reported: 354 tachycardias of the right ventricular outflow tract and 119 of the left ventricular outflow tract, 66 aortic root tachycardias, 40 fascicular tachycardias, 25 epicardial tachycardias, 1 pulmonary artery tachycardia, and 71 tachycardias distributed in different locations, including 15 in the papillary muscles, 5 in the summit of the left ventricle, and 4 para-Hisian. The most successfully ablated tachycardias were those of the right ventricular outflow tract and the pulmonary artery (95% and 100%, respectively). Success rates were higher for the aortic root and left ventricular outflow tract than for fascicular tachycardias (86.0%, 83.0%, and 82.5%, respectively). The most complex substrates remain those with an epicardial/coronary sinus location (68%).

Irrigated catheters were used in 85% of the reported cases (with contact forcesensing technology in 47%). A navigation system was used in 73.5% of cases and 7.7% of the procedures were fluoroscopy free.

There were 24 complications (3.3%): 19 effusions/tamponades, 2 vascular complications, 1 pericarditis, 1 atrioventricular block, and 1 patient who experienced left branch block that led to left ventricular dysfunction. One death was reported, but the cause was not stated.

The total number of VT-AMI ablation procedures was stable, with 505 procedures (3%) in 442 patients (mean, 6.5 [0-24]).

The type of ablation performed was reported for 84% of the procedures: 77 with a “standard” approach and 349 with a substrate approach. The overall success rate was 84.1% (the highest rate reported in the last 5 years).

An exclusively endocardial approach remains the most frequent (85.7%), although the number of combined approaches continues to increase, in line with the trend found in previous years (7.6% in 2016, 8.9% in 2017, and 11.2% this year). In contrast, use of the exclusively epicardial approach continued to be marginal, although it was slightly higher than the rate reported in 2017 (2.5% vs 1.2% in 2017). As for the endocardial approach, a balance between retroaortic (53%) and transseptal (47%) approaches was becoming established.

For this substrate, the application of all of the available technological support was evident, with a predominant use of navigation systems (84%). Although no procedure was performed without fluoroscopy, there was an apparent increase in the deployment of steerable sheaths (reaching 40% of cases) and the predominant use of irrigated tip catheters (93.2%), mainly with contact forcesensing technology (70%).

There were 33 complications (6.5%): 11 vascular complications (2.1%), 11 pericardial effusions (2.1%), 7 heart failure events (1.3%), 1 aortic puncture during the transseptal approach, without consequences, and 1 cardiac arrest requiring resuscitation. In addition, 2 deaths (0.4%) were reported: the first due to electromechanical dissociation after the end of the procedure; the other due to cardiac tamponade and refractory ventricular fibrillation.

A total of 226 VT-NAMI ablation procedures (1.4%) were performed in 39 laboratories (mean, 6.3 [0-32]). This year, there was a fall in both the number of procedures and the number of laboratories involved (23 fewer procedures and 9 fewer centers) and it was the ablation target addressed by the fewest centers. The type of ventricular tachycardia substrate was specified in 213 cases: 114 in nonischemic dilated cardiomyopathy (79% successful), 26 in arrhythmogenic cardiomyopathy (96% successful), 10 in hypertrophic cardiomyopathy (80% successful), 35 in congenital heart disease (83% successful), 16 bundle branch ventricular tachycardias (100% successful), and 15 miscellaneous cases (87% successful), including 3 after myocarditis, 1 in valvular heart disease, 1 in Chagas disease, and 1 in Brugada syndrome.

As for the approach used for these substrates, the number of exclusively epicardial approaches fell (11 procedures, which represents 4.9%), but there was a marked increase in the combined endocardial-epicardial approach (56 procedures, representing 24.8%). In addition, 81.4% of procedures were performed with navigation system support, although only 3 were fluoroscopy free.

The most commonly used catheter type continued to be the irrigated tip (98%), mainly with contact forcesensing technology (78%).

There were 12 complications (5.2%): 4 vascular complications (1.8%), 4 pericardial effusions/tamponades (1.8%), 1 heart failure event (0.4%), 1 atrioventricular block (0.4%), 1 peripheral embolism (0.4%), and 1 ventricular fibrillation (0.4%).

Nonfluoroscopic navigation systems were used in 5944 procedures (35.9%). Such systems were most commonly used for point-by-point pulmonary vein isolation.

For 2017 and 2018, the registry collected data on zero-fluoroscopy procedures. In 2018, the number more than doubled that of 2017, reaching 1068 (6.4% of the total). As in the previous registry, the ablation target most commonly treated without fluoroscopy was the CTI (495 procedures, 14.4% of all CTI ablations). At the other extreme, VT-AMI was not ablated at all without fluoroscopy.

The number of procedures in pediatric patients remained stable. In total, 353 ablation procedures (2.1% of the total) were performed in 46 centers (12 more than in 2017). In addition to the accessory pathways, which remained the most frequently treated substrate (representing 70.5% of all pediatric ablations and 11.6% of all accessory pathway ablations), 72 AVNRTs were ablated, as well as 9 FATs, 6 CTIs, 3 MATs, 13 IVTs, and 1 ventricular tachycardia associated with another (unspecified) heart disease (figure 8).

Figure 8.

Pediatric ablation procedures. The bar chart shows the proportion of pediatric procedures for each ablation target and the total number of procedures in the registry while the pie chart shows the proportion of each substrate ablated with respect to the total number of pediatric procedures. AP, accessory pathway; AVNRT, atrioventricular nodal reentrant tachycardia; CTI, cavotricuspid isthmus; FAT, focal atrial tachycardia; IVT, idiopathic ventricular tachycardia; MAT, macroreentrant atrial tachycardia; VT-NAMI, ventricular tachycardia not associated with acute myocardial infarction.

(0.11MB).