Targeted ablation of epicardial ganglionated plexi during cardiac surgery with pulsed field electroporation (NEURAL AF)

BACKGROUND

Modulation of the cardiac autonomic nervous system (ANS) is a promising adjuvant therapy in the treatment of atrial fibrillation (AF). In pre-clinical models, pulsed field (PF) energy has the advantage of selectively ablating the epicardial ganglionated plexi (GP) that govern the ANS. This study aims to demonstrate the feasibility and safety of epicardial ablation of the GPs with PF during cardiac surgery with a primary efficacy outcome of prolongation of the atrial effective refractory period (AERP).

METHODS

In a single-arm, prospective analysis, patients with or without a history of AF underwent epicardial GP ablation with PF during coronary artery bypass grafting (CABG). AERP was determined immediately pre- and post- GP ablation to assess cardiac ANS function. Holter monitors were performed to determine rhythm status and heart rate variability (HRV) at baseline and at 1-month post-procedure.

RESULTS

Of 24 patients, 23 (96%) received the full ablation protocol. No device-related adverse effects were noted. GP ablation resulted in a 20.7 ± 19.9% extension in AERP (P < 0.001). Post-operative AF was observed in 7 (29%) patients. Holter monitoring demonstrated an increase in mean heart rate (74.0 ± 8.7 vs. 80.6 ± 12.3, P = 0.01). There were no significant changes in HRV. There were no study-related complications.

CONCLUSIONS

This study demonstrates the safety and feasibility of epicardial ablation of the GP using PF to modulate the ANS during cardiac surgery. Large, randomized analyses are necessary to determine whether epicardial PF ablation can offer a meaningful impact on the cardiac ANS and reduce AF.

TRIAL REGISTRATION

Clinical trial registration: NCT04775264.

Selective epicardial pulsed field ablation of atrial ganglionated plexi causes anti-arrhythmic prolongation of refractoriness: demonstration of feasibility in cardiac surgery patients

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): EU Horizon 2020 SME Instrument.

Background

Epicardial ganglionated plexi (GP) play a significant role in the initiation and maintenance of atrial fibrillation. However, modulation of this effect, through GP ablation, has had limited success; outcomes being confounded by unnecessary atrial tissue ablation and inability to access and ablate all of the atrial GPs. Selective pulsed field ablation (PFA) of GPs, using epicardial access, provides the opportunity to better identify the role of GP ablation in the treatment of atrial fibrillation.

Purpose

This study aimed to assess the safety and feasibility of selective GP ablation in patients undergoing elective coronary artery bypass grafting (CABG). It was hypothesized that GP ablation would provide an acute extension of atrial tissue refractoriness, which constitutes its antiarrhythmic effect.

Methods

Using a monopolar, monophasic PFA system, atrial GPs were ablated in nineteen patients with or without atrial fibrillation, undergoing CABG. The Oblique Sinus GP, Right Superior GP, Transverse Sinus GP, Left Superior GP and Ligament of Marshall GP were each ablated with up to sixty PFA pulses of 1000 V amplitude and 100 µs pulse width. Atrial Effective Refractory Period (AERP) was measured before and after all GP ablations, at the left atrial appendage (LAA) and on the right atrium (RA). Patients were monitored through to discharge for post-operative atrial fibrillation (POAF).

Results

Complete ablation of the GPs was performed in nineteen patients (aged 63.4 ± 6.6 years, 63.1% male) immediately after sternotomy. Electric field pulses were ECG-gated, with energy delivery during the ventricular refractory period. All GP sites were successfully accessed and ablated; all patients progressed immediately to their planned elective surgery and were discharged on schedule. Procedure time, for all GP ablations and AERP measurements was in the range 35-45 minutes. Thirteen valid pre- and post-ablation datasets were obtained. AERP (LAA and RA combined) increased upon GP ablation on average by 23% (220 ± 46 ms pre-ablation versus 269 ± 59 ms post-ablation, p = 0.002). Four patients experienced POAF; there was no evident correlation between POAF and AERP data. Only three of the enrolled patients had a prior history of AF; none of these exhibited AF on 24-hour Holter monitoring at 3-month follow-up.

Conclusions

Selective epicardial PFA of GPs is feasible and safe. An acute increase in atrial tissue refractoriness is promising but further studies are required to see how this translates to longer term outcomes in symptomatic AF patients and in a percutaneous epicardial access setting.

Refractory cardiac arrrest treated with extracorporeal cardiopulmonary resuscitation, 2-year follow-up

Introduction

Extracorporeal cardiopulmonary resuscitation (ECPR) has been introduced as a life-saving procedure in refractory cardiac arrest.

Methods

Eligible patients for this analysis had to undergo ECPR after unsuccessful cardiopulmonary resuscitation with a minimum of three defibrillation attempts. For extracorporeal life support (ECLS) was used Cardiohelp system or Levitronix CentriMag blood pump. LUCAS II system was used for chest compressions during cardiac arrest. The relations of blood lactate and pH levels, measured before ECPR insertion and after 24 hours as well as comorbities (diabetes, hypertension, BMI) to the clinical outcomes at 2 years were evaluated.

Results

We analyzed data from 59 patients treated with ECPR for refractory cardiac arrest. The mean age of our patients was 61 years. Out-of-hospital cardiac arrest (OHCA) occurred in 33 patients, 26 patients suffered from in-hospital arrest (IHCA). Baseline value of lactate was 11.57±4.22 mmol/l, initial pH 6.95±0.31. In comparison with survivors, patients who died had significantly higher initial lactate levels (12.05±0.81 vs. 8.01±0.77; P&lt;0.05). Moreover, survivors had significantly lower lactate levels after 24 hours (7.39 vs 2.56) and lower BMI (27.4 vs 31.2; P&lt;0.05). Diabetes or hypertension in our group have no influence on the mortality. The difference of mortality in the group of OHCA or IHCA was also not significant. 32% patients survived one month with good neurological outcome (CPC 1–2), 30% six months, 23% one year and 21% two years.

Conclusions

ECPR give the last chance to survive refractory cardiac arrest. The levels of blood lactate are significantly associated with clinical outcomes of ECPR. Obesity was associated with significantly higher mortality in our group.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): MH CZ DRO (Nemocnice Na Homolce - NNH, 00023884)

Persistent reduction of mitral regurgitation by implantation of a transannular mitral bridge: durability and effectiveness of the repair at 2 years-results of a prospective trial†

OBJECTIVES

Ring annuloplasty reduces the septal-lateral diameter (SLD) indirectly by circumferential annular cinching and frequently results in the recurrence of mitral regurgitation (MR) in patients with functional MR (FMR). Our goal was to report the results from the trial and the 2-year post-trial surveillance data. We evaluated whether direct reduction of the SLD with a transannular mitral bridge could achieve significant and durable MR reduction in patients with FMR.

METHODS

In a prospective trial, 34 consecutive patients with FMR had a mitral bridge implanted surgically. Primary end points were MR ≤1+ at 1, 3 and 6 months postimplant and freedom from subsequent surgical mitral valve repair or replacement.

RESULTS

Thirty-two of 34 (94.1%) patients met the primary end points with MR ≤1+ at 6 months. At 2 years, there were no strokes or device-related adverse events. At 2 years, MR was reduced from 3.32 ± 0.47 to 0.50 ± 0.83 (P ≤ 0.001) with ≤1+ MR in 33/34 patients, including 4 reinterventions for periprosthetic recurrent MR ≥3 without mitral bridge explants or conventional mitral repair or replacement. At 2 years, the mean mitral gradient was 2.15 ± 0.82 mmHg; the mitral annular SLD decreased from 40.4 ± 2.91 mm to 28.9 ± 1.55 mm (P ≤ 0.001). The left ventricular ejection fraction increased (57.9 ± 10.4-62.4 ± 9.7%; P ≤ 0.001). The New York Heart Association functional class improved (2.19 ± 0.76-1.41 ± 0.61; P ≤ 0.001).

CONCLUSIONS

The single-centre trial data indicate that direct reduction in the SLD with a mitral bridge is feasible, safe and efficacious in patients with FMR. Validation in a larger population of patients and comparison to conventional annuloplasty ring are necessary.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03511716.

High-density epicardial activation mapping to optimize the site for video-thoracoscopic left ventricular lead implant

Background

The left ventricular (LV) lead local electrogram (EGM) delay from the beginning of the QRS complex (QLV) is considered a strong predictor of response to cardiac resynchronization therapy. We have developed a method for fast epicardial QLV mapping during video-thoracoscopic surgery to guide LV lead placement.

Methods

A three-port, video-thoracoscopic approach was used for LV free wall epicardial mapping and lead implantation. A decapolar electrophysiological catheter was introduced through one port and systematically attached to multiple accessible LV sites. The pacing lead was targeted to the site with maximum QLV. The LV free wall activation pattern was analyzed in 16 pre-specified anatomical segments.

Results

We implanted LV leads in 13 patients with LBBB or IVCD. The procedural and mapping times were 142 ± 39 minutes and 20 ± 9 minutes, respectively. A total of 15.0 ± 2.2 LV segments were mappable with variable spatial distribution of QLV-optimum. The QLV ratio (QLV/QRSd) at the optimum segment was significantly higher (by 0.17 ± 0.08, p < 0.00001) as compared to an empirical midventricular lateral segment. The LV lead was implanted at the optimum segment in 11 patients (at an adjacent segment in 2 patients) achieving a QLV ratio of 0.82 ± 0.09 (range 0.63–0.93) and 99.5 ± 0.6% match with intraprocedural mapping.

Conclusion

Video-thoracoscopic LV lead implantation can be effectively and safely guided by epicardial QLV mapping. This strategy was highly successful in targeting the selected LV segment and resulted in significantly higher QLV ratios compared to an empirical midventricular lateral segment.

[Operation of Ebstein anomaly in adulthood - our experience]

INTRODUCTION

The outcome of the operation of the Ebstein anomaly in adulthood depends on the experience of the surgical team.

METHODS AND RESULTS

We operated 38 adult patients with Ebstein anomaly at the age of 34.8 ± 12.7 (19-63) years at the Department of Cardiac Surgery, Hospital Na Homolce, Prague, in the period of 2005-2013. The majority of patients (71 %) had Ebstein anomaly type C or D. The 30-days postoperative mortality was 5.2 %. In the long-term follow-up 2 other patients died. Tricuspid valve repair was performed in 45 %, bioprosthesis was implanted in 53 %. Concomitant bi-directional cavo-pulmonary anastomosis was performed in 31.5 %, mitral valve repair in 8 %, closure of atrial communication in 83 %, right-sided MAZE or istmus cryo-ablation in 39 %. After the operation we found improvement of the functional NYHA class (from 2.2 ± 0.7 to 1.7 ± 0.6; p < 0.0001) as well as decrease of tricuspid regurgitation (from grade 3.8 ± 0.4 to 0.9 ± 1; p < 0.0001). The ejection fraction of the right ventricle (RVEF) improved in 86 % of patients, in 14 % RVEF decreased or did not change (RVEF before operation 36 ± 10.5 %, after operation 42 ± 9.5 %, p = 0.001). In the long-term follow-up we found dysfunction of the tricuspid valve repair in 12 % and degeneration of the bioprosthesis in 15 %. Among 86 adult patients with Ebstein anomaly from our database the mortality was significantly higher in unoperated compared to operated patients (26 % vs 12 %, p = 0.006). Patients with cyanosis had high mortality regardless of surgery (40 % with and 83 % without operation). Reoperation after surgery in childhood or adulthood was necessary in 20 % of adults.

CONCLUSION

The adult patients with Ebstein anomaly should be examined in a specialized center even if the symptoms are mild. The operation should be performed by a team with good results and experience in surgery and post-operative care in Ebstein anomaly. According to our knowledge Hospital Na Homolce represents such specialized center for Czech Republic.

Mitral valve repair versus replacement in simultaneous aortic and mitral valve surgery

BACKGROUND

Double valve replacement for concomitant aortic and mitral valve disease is associated with substantial morbidity and mortality. Excellent results with valve repair in isolated mitral valve lesions have been reported; therefore, whether its potential benefits would translate into better outcomes in patients with combined mitral-aortic disease was investigated.

METHODS

A retrospective observational study was performed involving 341 patients who underwent aortic valve replacement with either mitral valve repair (n=42) or double valve replacement (n=299). Data were analyzed for early mortality, late valve-related complications and survival.

RESULTS

The early mortality rate was 11.9% for valve repair and 11.0% for replacement (P=0.797). Survival (± SD) was 67±11% in mitral valve repair with aortic valve replacement and 81±3% in double valve replacement at five years of follow-up (P=0.187). The percentage of patients who did not experience major adverse valve-related events at five years of follow-up was 83±9% in those who underwent mitral valve repair with aortic valve replacement and 89±2% in patients who underwent double valve replacement (P=0.412). Age >70 years (HR 2.4 [95% CI 1.1 to 4.9]; P=0.023) and renal dysfunction (HR 1.9 [95% CI 1.2 to 3.7]; P=0.01) were independent predictors of decreased survival.

CONCLUSIONS

In patients with double valve disease, both mitral valve repair and replacement provided comparable early outcomes. There were no significant differences in valve-related reoperations, anticoagulation-related complications or prosthetic valve endocarditis. Patient-related factors appear to be the major determinant of late survival, irrespective of the type of operation.

Aortic dissections following heart transplantations

BACKGROUND

Aortic dissection in a cardiac allograft is an uncommon complication of heart transplantation with only few cases reported in the literature.

METHOD

We report a case of 46-year-old female who underwent orthotopic heart transplantation for dilated cardiomyopathy 22 years earlier. During surveillance echocardiographic examination she was diagnosed with type A aortic dissection limited to the donor aorta. The aortic root was successfully replaced using a valve-sparing David procedure. The pathogenesis and surgical management of these dissections is reviewed.

CONCLUSION

Appropriate surgical repair performed in a timely fashion leads to excellent results improving the prognosis of these patients.

Implantation of left ventricular assist device complicated by undiagnosed thrombophilia

A patient with dilated cardiomyopathy and no history of thromboembolic events received a surgically implanted axial-flow left ventricular assist device. After implantation, transesophageal echocardiography revealed a giant thrombus on the lateral and anterior aspects of the left ventricle. The inflow cannula inserted through the apex of the left ventricle was not obstructed, and the device generated satisfactory blood flow. Laboratory screening for thrombophilia showed protein S deficiency, heterozygous factor V Leiden mutation, and heterozygous MTHFR C667T mutation. During the entire duration of circulatory support, no significant suction events were detected, and the patient was listed for heart transplantation. Ventricular assist device implantation can unmask previously undiagnosed thrombophilia; therefore, it should be necessary to identify thrombophilic patients before cardiac support implantation.

Levitronix CentriMag pump as perioperative left ventricular support in a patient with critical aortic stenosis, mitral regurgitation, and cardiogenic shock

Severe aortic stenosis (AS) has a poor prognosis when associated with left ventricular dysfunction and congestive heart failure. Despite a relatively high operative mortality, most patients with severe AS and a depressed left ventricular ejection fraction (LVEF) should be considered candidates for aortic valve replacement. The CentriMag left ventricular assist system (Levitronix) can be used for perioperative or postcardiotomy circulatory support for the failing heart. In this case report, we report the successful use of the Levitronix CentriMag device as perioperative support in a high-risk patient with severe AS, significant mitral insufficiency, and a poor LVEF with advanced organ failure.

[Benefit of paracorporeal pulsatile assist device in multiorgan failing patients in terminal stage of heart failure]

BACKGROUND

Prevalence of terminal forms of heart failure is steadily increasing and thus waiting time for heart transplantation, too. Increasing mortality on waiting list has urged implementation of mechanical circulatory support as an adjunct to the programme of heart transplantation. The objective of the study is to review 7-years experience with paracorporeal assist device in bridging to transplantation.

MATERIAL AND METHODS

Retrospective review of 53 transplant candidates treated since April 2003. 50 patients received paracorporeal assist devices in biventricular configuration. Most frequent diagnosis was dilated cardiomyopathy in 51%.

RESULTS

Despite a high risk profile of the patients, 37 of them were successfully transplanted (69.8%). Cumulative support has reached 3513 days. Local exit sites infection was identified as a most frequent complication, sepsis as a most frequent cause of death on support (18.8%). 30-days post-transplant mortality remained low at 5.7%.

CONCLUSIONS

Paracorporeal mechanical circulatory assist devices remain effective alternative for terminal stage heart transplant candidates, especially for those in multiorgan failure who require biventricular support. Success rate of bridging to transplantation is acceptable, as well as complications rate and quality of life while on support. Long-term post-transplant survival is not inferior to the results of procedures performed without necessity of previous implantation of the assist device.

Single-stage extensive chronic type A dissecting aortic aneurysm repair and continuous-flow ventricular assist device implantation

The surgical technique of simultaneous heart transplantation and aortic aneurysm repair has been reported previously. However, there is a subgroup of patients with end-stage cardiomyopathy requiring major aortic surgery who do not meet heart transplant criteria. The optimal treatment strategy for these patients is still to be defined. In this report, we describe the use of an implantable continuous-flow left ventricular assist device (LVAD) as an adjunct to extensive aortic repair for providing patients with an acceptable risk surgical alternative to palliative treatment. To the best of our knowledge, this is the first report of this approach in the published literature.

Surgical ablation of post-infarction ventricular tachycardia guided by mapping in sinus rhythm: long term results☆

OBJECTIVE

Some patients after myocardial infarction have an increased risk of malignant ventricular tachyarrhythmias (VTA) or sudden cardiac death. The aim of the study was to evaluate long-term results of surgical ablation of an arrhythmogenic substrate guided by simplified intraoperative mapping of pathological ventricular electrograms during sinus rhythm.

METHODS

The study population consisted of 77 patients (9 women; mean age 62.4+/-8.5 years) with previous Q-wave myocardial infarction and at least one documented episode of sustained VT/VF more than one month after the last infarction. The left ventricular ejection fraction was 31.3+/-8.8%. All but eight patients had clinical indication for concomitant coronary artery bypass surgery. All underwent preoperative electrophysiologic study. Intraoperative epicardial and endocardial mapping during sinus rhythm was performed using a multielectrode with 16 bipolar electrodes in combination with a multichannel recording system. Myocardial regions revealing fractionated, low amplitude signals lasting > or =130 ms were surgically excised or cryoablated. All surviving patients were restudied within one to two weeks after surgery using identical programmed electrical stimulation protocol.

RESULTS

Five (6.5%) patients died in the perioperative (30-days) period. In the remaining cohort, inducibility of any sustained VTA after surgical procedure was observed in 21 subjects (29.2%). An implantable cardioverter-defibrillator (ICD) was implanted in these patients. Recurrence of sustained VTA was documented during follow-up period in two patients who were noninducible after the surgery (at the month 10 and 22, respectively), and both received ICD as well. No patient died of sudden cardiac death. In 14 ICD patients, no significant VTA was documented during the mean follow-up of 37.3+/-23.2 months. Altogether, 61 from the 72 patients surviving the surgery (84.7%) remained free of spontaneous recurrences of VTA during the follow-up.

CONCLUSIONS

Surgical ablation of an arrhythmogenic substrate guided by simplified intraoperative mapping in normothermic heart during sinus rhythm appears to be both safe and efficacious procedure that prevents recurrences of VTA in a substantial proportion of patients.

Percutaneous Extraction of a Severed and Frayed Permanent Pacing Lead

From the point of view of established practice, redundant permanent pacing leads have been abandoned or extracted using various catheter-based procedures. An unusual complication was caused by failed surgical lead extraction resulting in electrode severing and wire unbraiding with subsequent induction of electric interaction between the metallic, noninsulated part of the lead fragment and the defibrillating electrode. This interaction was sensed and detected by the ICD system. A modified catheter-based extraction procedure is described.