Pulmonary vein isolation for paroxysmal atrial fibrillation using high-power short duration radiofrequency or second-generation cryoballoon ablation

Funding Acknowledgements

Type of funding sources: None.

Background

Differences in the left atrial (LA) tissue loss can occur following different pulmonary vein isolation (PVI) techniques.

Purpose

Our prospective study compared the biomarker, the LA mechanical, and the electrophysiological findings as indicators of LA myocardial damage after a high-power short duration  (HPSD) with contact force radiofrequency catheter and second-generation cryoballoon (CB2) ablation of paroxysmal atrial fibrillation (AF).

Methods :We enrolled 40 patients with paroxysmal AF [16 (40%) women, mean age = 55.9 ± 12.4 years] who underwent HPSD (n = 21) or CB2 (n = 19). Biomarker levels (hs-cTnT, CK-MB, hs-CRP, LDH) and the transport function of the LA by transthoracic echocardiography (TTE) were compared pre and post procedurally. High-density mapping (HDM) was performed in sinus rhythm using a multielectrode diagnostic catheter in each group to define isolated left atrial low voltage area (LVA; <0.2mV in bipolar voltage mapping).  LA CT-angiography and HDM merge was used to calculate the post-PVI LVA and the LVA/LA surface ratio.

Results

Postablation hs-cTnT and hs-CRP levels were comparable in the ablation groups (HPSD: 1249 ± 469 and 9.53 ± 10.30 vs. CB2: 995 ± 280 and 12.36 ± 5.76, p = 0.065 and p = 0.732), while CK-MB and LDH levels were significantly higher following CB2 ablation (HPSD: 6.61 ± 2.62 and 349.9 ± 65.6 vs. CB2: 26.01 ± 6.88 and 451.6 ± 91.3, p < 0.001 and p < 0.001). The transport function of the LA did not change significantly by TTE after the procedure. Fractional Area Change at baseline and 3 months was 33.9 ± 13.8 and 33.5 ± 10.7  p = 0.9 in the HPSD group while 38.1 ± 8.6 and 35.3 ± 12.2 p = 0.9 in the CB2 group.  LA Ejection Fraction measured in the two groups (before and 3-month post-procedure): HPSD: 51.2 ± 20.5% and 49.5 ± 14.7%, p = 0.9, CB2: 49.7 ± 15.5% and 50.7 ± 13.3%, p = 0.8). Ablation time was comparable in the two groups (HPSD: 1676 ± 570 sec, CB2: 1495 ± 494 sec, p = 0.279), while fluoroscopy time and radiation exposure were significantly higher in the CB2 group (HPSD: 5.62 ± 4.31 min and 232 ± 406 cGycm2, CB2: 13.65 ± 5.18 min and 1819 ± 1669 cGycm2, p <0.001 and p <0.001). The LVA/LA surface ratio were: HPSD group: 8.37 ± 6.42% and CB2 group: 13.58 ± 8.92% (p = 0.007). At 12-month follow-up, the success rate, defined as freedom from AF/atrial tachycardia without antiarrhythmic drug was 80.1% (HPSD) and 84.2% (CB2) respectively.

Conclusions

The LA scar tissue was significantly higher following CB2 ablation, but did not affect medium-term efficacy. However, tissue loss did not reduce the transport function of the LA.

High-power short-duration radiofrequency ablation for atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Introduction

In recent times, high-power short-duration (HPSD) radiofrequency ablation (RFA) has emerged as an alternative strategy for pulmonary vein isolation (PVI) in atrial fibrillation (AF).

Purpose

We aimed to compare HPSD approach and conventional, ablation-index (AI) guided PVI using contact force sensing ablation catheters in respect of efficacy, safety, procedural characteristics, and outcome.

Methods

A total of 184 consecutive AF patients with first PVI were enrolled (age: 60 ± 11 years, paroxysmal: 56.5%, persistent: 43.5%) between November 2016 and December 2019. An ablation protocol of 50W energy with 15-20 g contact force was used for a duration of 8-12 sec based on the loss of capture concept in the HPSD group (n = 91) meanwhile, PVI was achieved according to the conventional power settings (posterior wall 25W, AI: 400, anterior wall 35W, AI: 550 ) in the control group (n = 93). During 1-year follow-up, documented AF for more than 30 seconds was considered as recurrence.

Results

Radiofrequency time and procedural time were significantly shorter using HPSD ablation (26.0 ± 12.7 min vs. 42.9 ± 12.6 min, p < 0.001, and 91 ± 30.1 min vs. 105.3 ± 28 min, p < 0.001). The HPSD strategy significantly lowered fluoroscopy time and radiation dose (5.47 ± 4.07 min vs. 8.15 ± 10.04 min, p = 0.019, and 430.2 ± 534.06 cGycm2 vs. 604.2 ± 633.9 cGycm2, p = 0.046). The HPSD group showed significantly less arrhythmia recurrence during 1-year follow-up with 76.9% of patients free from AF compared to 66.7% in the control group (p = 0.037). No pericardial tamponade, periprocedural thromboembolic complication, or atrio-oesophageal fistula occurred in the HPSD group. We observed 2 pericardial tamponade and 1 periprocedural stroke in the control group.

Conclusions

HPSD RFA for AF was demonstrated to be safe, and lead to significantly improved 1-year outcome in our mixed patient population. HPSD protocol significantly shortened procedural and radiofrequency time with decreased fluoroscopy time and radiation exposure.

472 Epidemiology and temporal trends of cardiac device related infective endocarditis

Background

Infective endocarditis (IE) is a rare, but life-threatening complication of cardiac device implantation. Despite recent preventive strategies, and advances in antimicrobial and surgical treatment, morbidity and mortality rates are still high.

Aims

The objective of our study was to assess the epidemiological characteristics, temporal tends and mortality rate of cardiac device related IE (CDRIE) in our high-volume, tertiary referral center.

Methods

retrospective data collection was performed from January 1, 2006 to December 31, 2016. Thirty-day, 6-month and 1-year mortality was estimated, which were compared to left-sided native valve endocarditis (LSNIE). Patients administered between 2006 and 2010 and between 2011 and 2016 were compared to assess temporal trends.

Results

465 cases of IE were administered, out of whom 54 patients had CDRIE (39 males [72%], mean age: 55.8 ±19 yrs; 4 VVI, 7 VDD, 7 VVI-ICD, 20 DDD, 5 DDD-ICD and 11 CRT devices; median time since first implantation: 1558 days [IQR: 470 days – 8.6 yrs]). The infection was caused by streptococci in 3 cases (5.5%), Staphylococci were the most prevalent infective agents (70%), S. aureus (SA) in 28 cases (52%, out of whom 10 were MRSA), coagulase negative Staphylococcus in 10 cases (18.5%), blood culture negative cases in 8 patients (15%), and in 5 cases other pathogens were responsible. 266 patients had LSNIE (201 males [75%], mean age: 54.4 ± 15.6 yrs). There was no difference between the two groups in age or in portion of males. Mortality rates were the same in CDRIE group compared to LSNIE group (30-day: 13% vs 13%, 6-month: 20% vs 25%, 1-year: 26% vs 29% and long-term: 44% vs 44%, ns resp.) Patients who died in the CDRIE group (n = 25) were older (64 yrs [IQR:59-71 yrs] vs 52 yrs [IQR: 27-69 yrs], p = 0.02), male sex was less common (52% vs 79%, p = 0.03), had lower ejection fraction (39.6 ±16.6% vs 54.6 ±14.5%, p < 0.001), had worse renal function (GFR: 46.3 ± 15.3 vs 60.2 ± 23.5 ml/min/1.73m2, p = 0.04), shorter time since first device implantation (2.1 yrs [IQR: 1.1-4.8 yrs] vs 6.7 yrs [4.1-12.9 yrs], p = 0.006), and CRT device implantation were more prevalent (32% vs 10%, p < 0.05).

Patients admitted before 2011 (n = 22) did not differ from patients admitted after 2011 (n = 32) in terms of age, male gender, concomitant valve infection, pocket infection, or embolic event. The 30-day (0% vs 6%) and the 1-year mortality (18% vs 31%) were the same before and after 2011, but the 6-month mortality was better before 2011 (4.5% vs 31%, p = 0.01). CRT device implantation was more prevalent over time (5% vs 31%, p = 0.01), and SA infection became more frequent (36% vs 63%, p = 0.05)

Conclusions

During the last decade patients with CDRIE had a same survival as patients with LSNIE, every fourth patient died one year after the diagnosis. Almost three-quarter of the infections were caused by Staphylococci, and the portion of S. aureus infection increased over time.