AVNRT was the only substrate treated in all participating centers. The slight increase in the absolute number of procedures (3768; 243 more than in the previous year) was not reflected in the relative percentage, which slightly decreased again (20% of all ablations). The mean number of procedures was 36.9 ± 24.5 (range, 2-130) and the success rate was 99%. In addition, 47% of centers reported a 100% success rate.

The 4-mm radiofrequency ablation catheter tip was once again the most commonly used catheter (94%). Although the application of other catheters and energy sources was low, cryoablation use increased this year, to second place (2.5%), largely due to a center that performed 73% of its procedures with this energy source. Other catheters were rare. Notably, the use is consistently increasing of navigation systems to avoid fluoroscopy (25% of procedures vs 10.9% in 2018) and 82.1% of these procedures were entirely performed without fluoroscopy.

In total, 26 severe complications were reported (0.7%): 12 AVBs (1 transient), 11 vascular complications, 1 heart failure event, and 1 embolic phenomenon.

CTI ablation, with 3925 procedures (21%), was once again the second most commonly targeted substrate after AF, ahead of AVNRT. It was treated in 100 centers, with a mean of 39.2 (range, 4-117) procedures per center and a mean success rate of 96%. Conventional irrigated tip catheters remained the most frequently used catheters (1842 procedures; 46.9%), although irrigated catheters with contact forcesensing technology have tripled since 2018 (932; 23.7%). The use of 8-mm catheters was stable (973; 24.8%). Navigation system use slightly increased, with 1272 procedures (32.4%), as did zero-fluoroscopy interventions, with 678 (17.2%). A total of 30 major nonfatal complications (0.8%) were reported: 23 vascular complications (0.6%), 3 pericardial effusions, 1 AVB, 1 embolism, and 1 myocardial infarction.

Accessory pathways remain the fourth most targeted substrate. There was a slight decrease in the absolute number of procedures in 2019 (124 fewer): 2024 procedures for a total of 1904 accessory pathways, treated in 101 centers (3 more than in the previous year). An average of 20.1 ± 15.5 (range, 1-65) procedures was performed per center. A success rate of 89% was obtained, with 31 centers reporting 100% success.

The left ventricular free wall was once again the most frequent location (51.7%), with a 94% success rate, followed by inferoseptal (28.1%), with a 98% success rate. Para-Hisian/anteroseptal and right ventricular free wall had identical frequencies (10%) and similar success rates (84% and 85%, respectively).

Epicardial access was used for 31 accessory pathway procedures while the retroaortic approach was still the most commonly used approach for the ablation of left-sided pathways (66%).

The ablation rates of bidirectional conduction and exclusively antegrade conduction were similar (41.4% and 39.5%). Most of these ablations (54%) were performed with 4-mm ablation catheters. The use of irrigated catheters continued to increase (33.5%), although only 7.1% had contact forcesensing technology. Cryoablation was used in 4.9%, whereas the use of 8-mm catheters was limited (just 14 procedures).

There was major growth in the use of navigation systems in 2019, with an increase from 21.5% in 2018 to 44.5% in 2019. However, in contrast to the situation for AVNRT treatment, zero-fluoroscopy treatment of patients did not exceed 23% (10.2% of all accessory pathway ablations).

Complications markedly fell in 2019 (to half that of 2018). In total, 18 major complications were reported (0.9%): 8 vascular, 5 AVBs (1 transient), 2 pericardial effusions, 1 acute myocardial infarction, 1 embolism, and 1 transient bradycardia and hypotension.

The number of procedures targeting this substrate remained stable, with 811 ablations (4%) performed in 89 centers and a 93% success rate. Three minor complications were reported (0.3%), all vascular. Most of the procedures were performed with conventional 4-mm catheters (465; 57.3%), with the following distribution of the remainder: 209 conventional irrigated catheters (25.7%), 165 8-mm catheters (20.3%), and 17 irrigated contact forcesensing catheters (2.1%).

In total, 574 procedures (3%) were performed in 87 centers, with a success rate of 85%, similar to that of 2018. This ablation target was located in the right atrium in 370 procedures (with a 90.5% success rate) and in the left atrium in 204 (a 74.1% success rate). Six complications were reported (1%), including 2 vascular complications (0.3%), 2 pericardial effusions (0.3%), and 1 transient phrenic nerve palsy. The use of irrigated tip catheters fell to 197 procedures (34.3%) and there was a marked increase in the use of catheters with contact forcesensing technology (218; 37.9%). Navigation system use clearly increased to 367 procedures (63.9%); 78 of these (13.5% of the total) were entirely performed without fluoroscopy.

MAT (which includes atypical atrial flutter) is one of the least treated ablation targets, with a total of 678 procedures (4%) in 75 centers. Of the 475 cases reporting this etiology, most (244; 51.3%) occurred after a previous AF ablation, 96 (20.2%) in congenital heart disease, and 79 (16.6%) after atriotomy; the remainder had various causes. It has the lowest success rate of all procedures—74.4%—and navigation system use is slowly increasing and now represents 81.7% of procedures. Just 35 procedures (5.1%) were performed without fluoroscopy. Irrigated tip catheters with contact forcesensing technology (67.4%) were much more frequently used than conventional irrigated tip catheters (14.3%); the other types were rarely used. A total of 22 nonfatal complications (3.2%) were reported, including 10 femoral vascular complications, 6 pericardial effusions, and 2 AVBs.

AF was consolidated as the most often treated ablation target, with 5164 procedures in 4771 patients (26% of all ablations). This ablation target was treated by 7 new centers, giving a total of 84. The average number of procedures per center exceeded 50 ablations for the first time (mean, 61.5; range, 1-230), with a success rate of 92.3%. Nineteen centers performed more than 100 procedures (22.6%), with 2 performing more than 200 per year. According to the available data (4604 ablations), the distribution by type was 2886 paroxysmal AF procedures (62.7%), 1486 persistent AF procedures (32.3%), and 232 long-standing persistent AF procedures (5%).

Electrical isolation of the pulmonary veins was once again the most common procedure (91%). In addition, there were 37 reductions of the antral electrogram, 50 complex unfractionated electrogram ablations, and 116 superior vena cava isolations. Left atrial lines were placed in 193 procedures. Other targets included 24 magnetic resonance-guided scar ablations in 2 centers and 22 rotor ablations in 2 others. Also reported were ablation of the ganglion plexus and of extrapulmonary foci and a left atrial posterior box isolation.

The most commonly used technique for AF ablation was still point-by-point radiofrequency ablation, with 2925 procedures (57%); there was no increase in cryoablation, but it was consolidated as an alternative (2144; 42%). The use of other techniques was rare, such as the multielectrode pulmonary vein ablation catheter (PVAC) and laser ablation.

Irrigated catheters with contact forcesensing technology predominate (84.8% of point-by-point ablations). The use of steerable sheaths moderately increased to 1510 procedures (29.2% of the total, limited to 40 centers). Intracardiac echocardiography was still rarely used (445 procedures; 8.6%) and applied in just 15 centers. Three-dimensional navigation was used for 2938 procedures, and 5 centers reported zero-fluoroscopy procedures (115).

The number of complications was stable (178; 3.4%). Two were fatal (an atrioesophageal fistula and an atrial appendage perforation). The distribution of the remainder was as follows: 63 vascular complications (1.2%), 44 pericardial effusions (0.8%), 34 phrenic nerve palsies (0.6%), 14 embolisms (0.2%), 6 infarctions (0.1%), 3 perforations (0.06%, 1 requiring surgery), and 14 miscellaneous complications (eg, pericarditis, transient neurological symptoms, pulmonary embolism).

In total, 807 IVT ablation procedures (4%) were performed in 762 patients in 88 centers (4 more than in 2018). The mean number of procedures per center was 9.2 ± 8 (range, 1-46).

The following procedure locations were reported: 354 tachycardias of the right ventricular outflow tract, 155 of the left ventricular outflow tract, 71 aortic root tachycardias, 40 fascicular tachycardias, 36 epicardial tachycardias, 3 pulmonary artery tachycardias, and 63 tachycardias distributed in different locations, including 13 in the papillary muscles, 4 in the summit of the left ventricle, and 6 para-Hisian.

The overall success rate was 81.4%. The highest success rates were seen for the pulmonary artery (100%), aortic cusps (94%), and right ventricular outflow tract (91%). Left ventricular outflow tract and fascicular tachycardias had slightly lower success rates (83% and 82.5%, respectively), with even lower rates for the mixed group (76%). The worst results were seen for epicardial/coronary sinus procedures (53%).

Irrigated catheters with contact forcesensing technology predominated (62%), which, in conjunction with conventional irrigated catheters, were used in 85.4% of procedures. Almost all of the other procedures were performed with 4-mm catheters.

In 2019, the use of navigation systems reached 78%, with fluoroscopy-free procedures uncommon (7%).

Complications markedly increased (5%; 40 cases), mainly vascular complications and pericardial effusions: 13 vascular complications, 21 effusions/tamponades, 1 pericarditis, 4 AVBs, and 1 unspecified complication.

This substrate was targeted by the highest number of new centers (17 more than in 2018). However, the absolute number of procedures stabilized (532 ablations in 497 patients). A mean of 8.3 ± 7.4 (range, 1-43) procedures was performed per center.

The overall success rate has continued its progressive increase, reaching 85%, which is the highest rate in registry history. The approach in 70% of the procedures was ablation of the arrhythmogenic substrate.

An endocardial approach once again predominated (82.6%), both retroaortic and transseptal (302 vs 282 procedures). The use of the combined approach continues to increase, reaching a new peak this year (17.4%, much higher than the 11.2% of 2018). This tendency was not followed by the exclusively epicardial approach, which was stable but uncommon (2.4%).

The use of navigation systems predominates (91.2%, a large increase vs the 84% of 2018), although only 2 procedures were fluoroscopy-free. Steerable sheaths were common (44.2%) and practically all procedures were performed with irrigated tip catheters (96.7%), most with contact force sensing technology (76.5%)

There was a slight increase in complications (40; 7.5%): 20 vascular complications (3.8%), 1 AVB (0.2%), 8 pericardial effusions (1.5%), 7 heart failure events (1.3%), 1 AMI, 1 colonic perforation during the epicardial approach, 1 subsequent amputation of a lower limb due to critical ischemia, and 1 postprocedural arrhythmic storm. In addition, 1 death (0.2%) was reported, caused by cardiogenic shock several days after the intervention.

In total, 266 ablation procedures were performed in 247 patients in 51 centers (12 hospitals more than in 2018). Regardless, it continues to be the least addressed ablation target in both absolute numbers (1.5% of procedures) and the number of centers (only half of registry laboratories), with an average of 5.2 ± 5.5 (range, 1-30) procedures.

With an 80% success rate, the following ablation targets were reported: 155 in nonischemic dilated cardiomyopathy (77% successful), 40 in arrhythmogenic cardiomyopathy (90% successful), 26 in congenital heart diseases (100% successful), 9 in hypertrophic cardiomyopathy (78% successful), 9 bundle branch ventricular tachycardias (89% successful), and 24 miscellaneous cases (92% successful), including 7 in valvular heart disease, 5 in myocarditis, 2 in Chagas disease, and 1 in incessant ventricular fibrillation.

The endocardial approach continues to predominate, with a slight preference for the retroaortic over the transseptal (36% vs 29%). However, exclusively epicardial approaches doubled vs 2018 (10.5%) and there was another increase in the combined approach (27.4%). The vast majority of catheters were irrigated tip catheters (95%), typically with contact forcesensing technology (73%).

As for other VTs, navigation systems are invaluable and their use has increased vs previous years (90.6% vs 81.4% in 2018). Fluoroscopy-free procedures continue to be rare (8 procedures).

There were 15 complications (5.6%): 4 vascular (1.5%), 3 effusions/tamponades (1.1%), 2 AVBs (0.7%), 1 embolic phenomenon (0.3%), 1 AMI (0.3%), 3 heart failure events (1.1%), and 1 myocardial laceration. In addition, there was 1 death due to cardiogenic shock, which occurred several hours after incessant ventricular fibrillation ablation, and 1 death in a patient with previous cardiogenic shock receiving mechanical circulatory support and with arrhythmic storm.

Nonfluoroscopic navigation was used in 8336 procedures (44.9%). Such systems were most commonly used for VTs (90.9%) and MATs (81.7%). For the last few years, the registry has collected data on zero-fluoroscopy procedures. As in previous years, the number of zero-fluoroscopy procedures in 2019 doubled that of 2018, reaching 1967 procedures (11% of the total). For the first time, the ablation target most commonly treated without fluoroscopy was AVNRT (768 procedures, 20.4% of all AVNRT ablations), followed by CTI (678 procedures, 17.3% of all CTI procedures).

The number of centers and procedures in pediatric patients fell in 2019. In total, 286 ablation procedures (1.5%) were performed in 39 centers (7 fewer than in 2018).

The most frequently treated substrate was once again the accessory pathways (figure 9) (58% of all pediatric ablations and 8.2% of all accessory pathway ablations) but in a lower proportion than in 2018 (70.5% and 11.6%, respectively).

Figure 9.

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; FAT, focal atrial tachycardia; IVT, idiopathic ventricular tachycardia; MAT, macroreentrant atrial tachycardia.

(0.08MB).

The other reported ablations in pediatric patients were 72 AVNRTs, 1 MAT, 12 FATs, and 5 IVTs. Overall, they represented 8.2% of accessory pathways, 1.9% of AVNRTs, 0.1% of atypical flutters, 2.1% of FATs, and 0.6% of IVTs. No CTI ablations were reported in 2019.