Acute and long-term success of left atrial anterior line and mitral isthmus line ablation in patients after mitral valve surgery

Background

Perimitral flutter and atrial fibrillation may occur in patients with prior surgical mitral valve (MV) repair or replacement and can be challenging for percutaneous catheter ablation.

Objective

This study sought to determine the feasibility, acute success and durability of catheter ablation of atrial fibrillation or atrial tachycardia by way of a mitral isthmus line (MIL) or an anterior line (AL).

Methods

A total of 81 patients (49 males, mean age 62±11 years) with prior MV replacement (n=30) or repair (n=51) underwent creation of a MIL (n=34) and/or an AL (n=72). Control group patients without prior surgery were matched 1:1 with the valve group (MIL, n=34; AL, n=72).

Results

Acute bidirectional block of the MIL was successfully achieved in 24/34 cases and of the AL in 64/72 patients with prior MV surgery. In the control group, acute bidirectional block was achieved in 31/34 MIL patients and 65/72 AL patients. In terms of durability, the MIL valve subgroup showed the poorest results (probability of long-term failure 2.224, as opposed to 0.605 in the MIL control subgroup; hazard ratio [HR]=0.27, 95% confidence interval [CI], 0.11–0.65; p=0.004). In the AL subgroups, long-term outcomes were similar (probability of failure in AL valve subgroup 0.844 vs. AL control subgroup 1.03; HR=1.22, 95% CI, 0.66–2.26; p=0.523).

Conclusions

Percutaneous creation of MIL and AL is feasible and safe in patients with prior MV replacement/repair. Because of poor long-term outcomes, MIL creation appears not advisable in patient with prior MV surgery.

Funding Acknowledgement

Type of funding sources: None.

Repeat procedures and reconnection rates after cryoballoon PVI with phrenic nerve injury

Funding Acknowledgements

Type of funding sources: None.

Aims

Cryoballoon (CB) based pulmonary vein isolation (PVI) is an effective treatment for atrial fibrillation (AF). The most frequent complication during CB-based PVI is right-sided phrenic nerve injury which is leading to premature abortion of the freeze cycle. Here we analysed repeat procedures and reconnection rates after CB-based PVI and phrenic nerve injury in a large-scale population. Due to the fact that the freezing process was prematurely interrupted the data may offer unique findings in optimizing the CB dosing protocols.

Methods and Results

In the YETI registry a total of 17356 patients underwent CB-based PVI in 33 centers and 731 (4.2%) patients experienced phrenic nerve injury. A total of 111 / 731 (15.2%) patients received a repeat procedure utilizing a 3D mapping system due to AF recurrence. In 94/111 (84.7%) of patients data on repeat procedures was available. During their initial PVI procedures, phrenic nerve injury occurred during treatment of RSPV (n=80), RIPV (n=13) and LSPV (n=1). A total of 89/94 (94.7%) target PVs have been isolated during the initial PVI (RSPV: 75/80, 94%; RIPV: 13/13; 100%; LSPV: 1/1; 100%). The mean freezing time was 127±46s and the mean minimal temperature was -49±7°C. During the repeat procedures 67 of initially 89 isolated PVs showed persistent isolation (75%, for RSPV: 55/75; 73%; RIPV: 11/13; 85%; LSPV: 1/1; 100%).

Conclusion

In patients initially treated by CB-based PVI with interruption of the freezing due to phrenic nerve injury, a high rate of durable isolated PVs has been detected at repeat procedures. Our data may help to identify the optimal dosing protocol in CB-based PVI procedures

Second and fourth generation Cryoballoon based left atrial appendage isolation for the treatment of persistent atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

Although pulmonary vein isolation (PVI) is an effective treatment strategy for patients with paroxysmal atrial fibrillation (AF), it is associated with limited success rates in patients with persistent AF (PersAF). In this context the left atrial appendage (LAA) was recently identified as a target of catheter ablation especially in PVI non-responders. Although effective, this strategy may cause electromechanical dissociation and was therefore assumed to be associated with an increased risk of thromboembolism despite oral anticoagulation (OAC). Since RF based LAAI showed increased rates of thromboembolism and stable LAAI is difficult to achieve in some cases, Cryoballoon-based LAAI might offer a valuable option to achieve safe and durable LAAI. Recently the fourth generation cryoballoon was introduced. Additionally, the 40% shorter tip potentially increases the safety profile as well as efficacy of CB-based LAAI.

Objective

To assess safety and efficacy on CB2 vs CB4 based LAAI.

Methods

Cryoballoon based PVI and LAAI was performed in 20 patients with PersAF and long-standing PersAF. The first 10 consecutive patients were treated by the second-generation cryoballoon (CB2) the last 10 patients were treated by the CB4. LAAI was performed by utilizing a bonus freeze protocol (freezing time 300 seconds + another 300 seconds after LAAI).

Results

Stable LAAI was achieved after a mean of 2.6+/- 1.7 cryoballoon applications with a mean minimal temperature of -52+/-6 °C. Unless one phrenic nerve palsy (5.6%) of the left phrenic nerve no further periprocedural complications occurred. Successful LAAI was performed in 19/20 (95%). TEE after 6 weeks detected LAA thrombus in 3/10 (30%) patients (CB2 group) and 3/10 patients (30%) (CB4 group), p = 0.99. Successful LAA-closure was performed in 16/20 patients (80%) after a mean of 75+/-59 days. The LAA was durable isolated in 8/9 patients (89%, CB2) and 6/8 patients (75%, CB4), p = 0.56). AF recurrence after 6 weeks was 1/10 (10%, CB2) and 3/9 (33%, CB4), p = 0.26.

Conclusions

Here we used – to our knowledge – for the first time a CB4 for LAAI, followed by a combined check for LAAI and LAA-closure after 6 weeks, compared to the CB2. LAAI was successfully isolated by both cryo-balloons in the majority of patients. Hence the use of newest cryo-balloon generation for LAAI seems a safe and successful procedure compared to earlier balloon generations. However, a relatively high rate of LAA-Thrombus was detected after LAAI. Therefore, LAA closure is mandatory in this population.

Novel cryoballoon ablation system for single shot pulmonary vein isolation: The prospective ICE-AGE-X Study

Funding Acknowledgements

Type of funding sources: None.

Background

The arctic front cryoballon (AF-CB) provides effective and durable pulmonary vein isolation (PVI) associated with encouraging clinical outcome data. The POLARx cryoballoon incorporates unique features which may translate into improved efficacy and safety.

Purpose

To assess efficacy and safety of the novel POLARx cryoballoon in comparison to the fourth generation arctic front cryoballon (AF-CB4).

Methods

Twenty-five consecutive patients with paroxysmal or persistent atrial fibrillation (AF) were prospectively enrolled, underwent POLARx based PVI (POLARx group) and were compared to 25 consecutive patients treated with the fourth generation AF-CB (AF-CB4 group).

Results

A total of 100 (POLARx) and 97 (AF-CB4) pulmonary veins (PV) were identified and all PVs were successfully isolated utilizing the POLARx and AF-CB4, respectively. A significant difference regarding the mean minimal cryoballoon temperatures reached using the AF-CB4 and POLARx (-50 ± 6°C vs. -57 ± 7°C, p = 0.004) was observed. Real-time PVI was visualized in 81% of POLARx patients and 42% of AF-CB4 patients (p < 0.001). Despite a certain learning curve utilizing the POLARx a trend towards shorter median procedure time (POLARx: 45 (39, 53) minutes vs. AF-CB4: 55 (50, 60) minutes (p = 0.062) was found. No differences were observed for periprocedural complications.

Conclusions

The novel POLARx showed similar safety and efficacy compared to the AF-CB4. A higher rate of real-time electrical PV recordings and significantly lower balloon temperatures were observed using the POLARx as compared to AF-CB4.

P1025Incidence and characteristics of pulmonary vein reconduction after second-generation cryoballoon-based pulmonary vein isolation: Impact of different ablation strategies

Funding Acknowledgements

none

Introduction

The second-generation CB (CB2, Arctic Front Advance, Medtronic Inc., Minneapolis, USA) has demonstrated high procedural success rates, relatively short procedure times, high durability of PVI and convincing long-term clinical success rates. Nevertheless, data on the impact of different ablations protocols on durability after CB2 based PVI is limited.

Purpose

We aimed at comparing durability of pulmonary vein isolation (PVI) following three different ablation strategies utilizing the second-generation cryoballoon (CB2) in patients with recurrence of atrial fibrillation (AF) or atrial tachycardia (AT) undergoing repeat procedures.

Methods

In 192 patients a total of 751 PVs were identified. All PVs (751/751, 100%) were successfully isolated during index PVI. Thirty-one out of 192 (16%) patients were treated with a bonus-freeze protocol (group 1), 67/192 (35%) patients with a no bonus-freeze protocol (group 2), and 94/192 (49%) patients with a "time-to-effect"-guided ablation protocol without bonus freezes (group 3).

Results

Persistent PVI was documented in 419/751 (55.8%) PVs, and in 41/192 (21%) patients all PVs were persistently isolated. The number of patients with all PVs being persistently isolated was not significant between the groups (p = 0.594). The total rate of PV reconnection was not significantly different between the three groups (p = 0.134) and the comparison of individual PVs revealed also no differences for different ablation protocols (p-values for RSPV: 0.424, RIPV: 0.541, LSPV: 0.788, LIPV: 0.346, LCPV: 0.865). The procedure times were significantly reduced in non-bonus freeze ablation protocols and/or when applying individualized application times (group 1: 123.4 ± 31.5min, group 2: 112.9 ± 39.8 min, group 3:  86.67 ± 28.4 min, p <0.001).

Conclusions

A considerably high rate of persistent PVI was demonstrated in patients after index CB2-based PVI. No differences for durable PVI were detected for different ablation protocols. Therefore, individualized ablation protocols might be a beneficial ablation strategy during CB2-based PVI.

P1026Second-generation visually guided laser balloon ablation system for pulmonary vein isolation: Learning curve, safety and efficacy: The MERLIN registry

Funding Acknowledgements

Cardiofocus

Background

Radiofrequency (RF) based pulmonary vein isolation (PVI) results in favourable clinical outcome, although its complexity demands a long learning curve. Balloon-based systems, have been developed to possibly solve these limitations. The second-generation laser balloon (LB2) offers optimized features for improved tissue contact and visibility.

Purpose

We determined safety, efficacy and learning curve of the LB2 for PVI.

Method

A total of 45 consecutive patients (89% persistent AF) were prospectively enrolled and divided in three groups (T1, T2, T3) of n = 15 patients per group. All patients underwent PVI using the LB2 by two operators. The operators were experienced in RF and cryothermal procedures, but not in laser ablations.

Results

A total 174/177 PVs (98%) were successfully isolated. The median procedure time significantly declined from 132 (114, 158) to 119 (102, 127) and 91 (86, 105) min in T 1–3, respectively (P = 0.0009). Similarly, the median fluoroscopy time significantly decreased from T1 until T3 (22 (17, 27) vs. 21 (16, 24) vs. 13 (10, 17) min, respectively, P = 0.045. Adverse events occurred in 6.7% with a trend towards a lower complication rate with increasing experience.

Conclusion

The LB2 was safe and effective for PVI even for operators without any previous experience in laser balloon based PVI. Procedure time LA dwelling time and fluoroscopy time decreased after a learning curve of 15 cases.

6121Phrenic nerve injury during pulmonary vein isolation using the second-generation cryoballoon: characteristics and follow-up - The YETI registry

Background

Second-generation cryoballoon (CB2) based pulmonary vein isolation (PVI) has emerged as a safe and effective treatment option for symptomatic atrial fibrillation (AF). Although published complication rates of CB2 based-PVI are relatively low and several safety algorithms have been implemented in the protocols the most frequent complication is right-sided phrenic nerve injury (PNI). The reported incidence of PNI varies from 2–5% of patients. However data on PNI characteristics as well as follow-up is sparse.

Purpose

We aimed to evaluate the incidence, characteristics and outcome of PNI during after CB2 based-PVI in a large patients population.

Methods and results

From July 2012 to November 2018 a total of 13693 patients received CB2 or CB3 (third-generation) based-PVI in 23 EP centers (Germany: 12, China: 1, Turkey: 3, Japan: 3, USA: 1, Austria: 1, Poland: 1, Swizerland: 1). A total of 596 (4.4%) of patients experienced PNI during treatment of the right superior (84%) right inferior (15%) right middle (0.3%) (and left superior (0.3%) pulmonary veins. The mean time to PNI was 127±51 seconds and the mean temperature at the time of PNI was −49±7 °C. The target PV was isolated at time of PNI in 84% of cases. The applications were interrupted using double-stop technique in (71%). In 212/306 (52%) a CMAP was utilized.

At the end of the procedure PNI persistent in 45% of patients. Fluoroscopic or sonographic evaluation of PNI was performed 1–3 days after the procedure and revealed persistent PNI in 35% of patients. Dyspnea before discharge was reported in 18% of patients with persistent PNI. Patients follow up at 1–3, and 6–12 months included fluoroscopy and a visit in an outpatient clinic. After 1–3 months 18% of patients showed persistent PNI including 13% of patients complaining of dyspnea. After 6–12 months of follow-up including fluoroscopic evaluation PNI was persistent in 1.8% of patients while dyspnea was reported by 1.7% patients. Only 0.08% of the overall population of 13693 patients showed permanent and symptomatic PNI.

Conclusion

The incidence of PNI during CB2-based PVI is low. About 55% of PNI recovered until the end of the procedure. Most of PNI recovered within 12 months. Symptomatic permanent PNI is very rare in patients after CB2/CB3-based PVI.

Treating resistant hypertension with new devices

Arterial hypertension is a frequent, chronic disease, which is one of the main risk factor for cardiovascular and renal diseases such as heart failure, chronic kidney disease, hypertensive heart disease, stroke as well as cardiac arrhythmias. In the clinical setting it remains challenging to accomplish the thresholds of guideline blood pressure (BP) levels now defined as office based BP to be below <140 mmHg. Patients on three or more antihypertensive drugs, with systolic BP values above ≥160 mmHg (≥150 mmHg for patients with type 2 diabetes) are classified as having resistant hypertension. In the past six years the development of interventional sympathetic renal artery denervation (RDN) opened a new treatment option targeting the afferent and efferent sympathetic nerves of the kidney to reduce BP. A large variety of devices are available on the market. Newly developed devices try to focus on new strategies such as ultrasound or irrigated catheters, which might reduce the post-procedural complications and increase the success rate. The first generation SymplicityTM device (Medtronic, Palo Alto, CA, USA) was shown to be safe, with side effects rarely occurring. Clinical trials demonstrate that this procedure is successful in about 70% of patients. However current data from Simplicity HTN-3 with 25% african-americans and a massive BP-lowering effect in the control "sham" group was not able to find a significant effect in the overall patient cohort. Possibly devices which allow to safely destroy sympathetic renal innervation more efficiently might allow for a higher responder rate. Irrigated RDN and ultrasound devices could deliver more energy to deeper tissue levels. This article provides an overview of currently available data on devices.