Leadless pacemaker implantation following tricuspid interventions: multicenter collaboration of feasibility and safety

BACKGROUND

Permanent pacing is often required following valve intervention (either surgical or percutaneous); however, tricuspid interventions pose specific challenges to conventional pacing. Therefore, leadless pacemaker (LP) implantation may be the preferred strategy when permanent pacing is required after tricuspid valve intervention.

PURPOSE

To report periprocedural outcomes and follow-up of patients undergoing implantation of a LP system following tricuspid valve interventions.

METHODS

Patients with previous tricuspid valve intervention at the time of attempted implantation of a LP (MicraTM, Medtronic, Minneapolis, MN, USA) were included.

RESULTS

Between 2019 and 2022, 40 patients underwent LP implantations following tricuspid interventions in 5 large tertiary centers. The mean age was 68.9 ± 13.7 years, and 48% patients were male. The indication for pacing was as following: AVB in 27 (68%) patients, AF with slow ventricular response in 10 (25%) patients, and refractory rapid atrial fibrillation (AF) referred to AV junction ablation in 3 (7%) patients. Most of the patients received Micra VR (78%). The procedure was successful in all patients. The mean procedural time is 58 ± 32 min, and the median fluoroscopy time is 7.5 min. Electrical parameters were within normal range (threshold: 1.35 ± 1.2 V@0.24 ms, impedance: 772 ± 245 Ohm, R-wave: 6.9 ± 5.4 mV). No acute complications were observed. During a mean follow-up of 10 months, electrical parameters remained stable, and 4 deaths were occurred (not related to the procedure).

CONCLUSION

A LP is a safe and efficient option following tricuspid valve interventions.

Heart transplantation as a rescue strategy for patients with refractory electrical storm

AIMS

Heart transplantation (HT) can be proposed as a therapeutic strategy for patients with severe refractory electrical storm (ES). Data in the literature are scarce and based on case reports. We aimed at determining the characteristics and survival of patients transplanted for refractory ES.

METHODS AND RESULTS

Patients registered on HT waiting list during the following days after ES and eventually transplanted, from 2010 to 2021, were retrospectively included in 11 French centres. The primary endpoint was in-hospital mortality. Forty-five patients were included [82% men; 55.0 (47.8-59.3) years old; 42.2% and 26.7% non-ischaemic dilated or ischaemic cardiomyopathies, respectively]. Among them, 42 (93.3%) received amiodarone, 29 received (64.4%) beta blockers, 19 (42.2%) required deep sedation, 22 had (48.9%) mechanical circulatory support, and 9 (20.0%) had radiofrequency catheter ablation. Twenty-two patients (62%) were in cardiogenic shock. Inscription on wait list and transplantation occurred 3.0 (1.0-5.0) days and 9.0 (4.0-14.0) days after ES onset, respectively. After transplantation, 20 patients (44.4%) needed immediate haemodynamic support by extracorporeal membrane oxygenation (ECMO). In-hospital mortality rate was 28.9%. Predictors of in-hospital mortality were serum creatinine/urea levels, need for immediate post-operative ECMO support, post-operative complications, and surgical re-interventions. One-year survival was 68.9%.

CONCLUSION

Electrical storm is a rare indication of HT but may be lifesaving in those patients presenting intractable arrhythmias despite usual care. Most patients can be safely discharged from hospital, although post-operative mortality remains substantial in this context of emergency transplantation. Larger studies are warranted to precisely determine those patients at higher risk of in-hospital mortality.

Epidemiology, Pathophysiology, and Management of Native Atrioventricular Valve Regurgitation in Heart Failure Patients

Atrioventricular regurgitation is frequent in the setting of heart failure. It is due to atrial and ventricular remodelling, as well as rhythmic disturbances and loss of synchrony. Once atrioventricular regurgitation develops, it can aggravate the underlying heart failure, and further participate and aggravate its own severity. Its presence is therefore concomitantly a surrogate of advance disease and a predictor of mortality. Heart failure management, including medical therapy, cardiac resynchronization therapy, and restoration of sinus rhythm, are the initial steps to reduce atrioventricular regurgitation. In the current review, we analyse the current data assessing the epidemiology, pathophysiology, and impact of non-valvular intervention on atrioventricular regurgitation including medical treatment, cardiac resynchronization and atrial fibrillation ablation.

Late arrhythmias in patients with new-onset persistent left bundle branch block after transcatheter aortic valve replacement using a balloon-expandable valve

BACKGROUND

The arrhythmic burden after discharge in patients with new-onset left bundle branch block (LBBB) undergoing transcatheter aortic valve replacement (TAVR) with the balloon-expandable SAPIEN 3 (S3) valve remains largely unknown.

OBJECTIVE

The purpose of this study was to determine the incidence of late arrhythmias in patients with new-onset LBBB undergoing TAVR with the balloon-expandable S3 valve.

METHODS

This was a multicenter, prospective study that included 104 consecutive TAVR patients with new-onset persistent LBBB following TAVR with the S3 valve. An implantable cardiac monitor (Reveal XT, Reveal LINQ) was implanted before discharge. The primary endpoint was the incidence of high-degree atrioventricular block or complete heart block (HAVB/CHB).

RESULTS

A total of 40 patients (38.5%) had at least 1 significant arrhythmic event, leading to a treatment change in 17 (42.5%). Significant bradyarrhythmias occurred in 20 of 104 patients (19.2%) (34 HAVB/CHB episodes, 252 severe bradycardia episodes), with 10 of 20 patients (50%) exhibiting at least 1 episode of HAVB/CHB. Most HAVB/CHB episodes (60%) occurred within 4 weeks after discharge. Nine patients (8.7%) underwent permanent pacemaker implantation at 12 months based on the Reveal findings (6 HAVB/CHB, 3 severe bradycardia).

CONCLUSION

S3 valve recipients with new-onset LBBB have a high arrhythmic burden, with more than one-third of patients exhibiting at least 1 significant arrhythmic episode within 12 months (HAVB/CHB in 10% of patients). About one-half of bradyarrhythmic events occurred within 4 weeks after discharge. These results should inform future strategies on the use of continuous electrocardiographic monitoring in TAVR S3 patients with new conduction disturbances following the procedure.

[Fighting against unexplained sudden death]

Sudden cardiac death, mostly related to ventricular arrhythmia, is a major public health issue, with still very poor survival at hospital discharge. Although coronary artery disease remains the leading cause, other etiologies should be systematically investigated. Exhaustive and standardized exploration is required to eventually offer specific therapeutics and management to the patient as well as his/her family members in case of inherited cardiac disease. Identification and establishing direct causality of the detected cardiac anomaly may remain challenging, underlying the need for a multidisciplinary and experimented team.

Comparison of Outcomes and Mortality in Patients Having Left Ventricular Assist Device Implanted Early -vs- Late After Diagnosis of Cardiomyopathy

LVAD implantation in patients with a recently diagnosed cardiomyopathy has been poorly investigated. This work aims at describing the characteristics and outcomes of patients receiving a LVAD within 30 days following the diagnosis of cardiomyopathy. Patients from the ASSIST-ICD study was divided into recently and remotely diagnosed cardiomyopathy based on the time from initial diagnosis of cardiomyopathy to LVAD implantation using the cut point of 30 days. The primary end point of the study was all-cause mortality at 30-day and during follow-up. A total of 652 patients were included and followed during a median time of 9.1 (2.5 to 22.1) months. In this population, 117 (17.9%) had a recently diagnosed cardiomyopathy and had LVAD implantation after a median time of 15.0 (9.0 to 24.0) days following the diagnosis. This group of patients was significantly younger, with more ischemic cardiomyopathy, more sudden cardiac arrest (SCA) events at the time of the diagnosis and were more likely to receive temporary mechanical support before LVAD compared with the remotely diagnosed group. Postoperative in-hospital survival was similar in groups, but recently diagnosed patients had a better long-term survival after hospital discharge. SCA before LVAD and any cardiac surgery combined with LVAD implantation were identified as 2 independent predictors of postoperative mortality in recently diagnosed patients. In conclusion, rescue LVAD implantation for recently diagnosed severe cardiomyopathy is common in clinical practice. Such patients experience a relatively low postoperative mortality and have a better long-term survival compared with remotely diagnosed patients.

External Validation of a Risk Prediction Model for Ventricular Arrhythmias in Arrhythmogenic Right Ventricular Cardiomyopathy

The new 5-year ventricular arrhythmia (VA) occurrence risk model is a major breakthrough for arrhythmia risk stratification in the challenging population of patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). In the original study, the model resulted in a 20.6% reduction in implantable cardioverter-defibrillator (ICD) placement compared with the 2015 consensus, for the same protection level. However, only internal validation was performed, limiting generalisation. We externally validated the model in a European tertiary care cohort of 128 patients with ARVC with restrictive indications for primary prevention ICD placement. Overall, 74% were men, none had VA history, and a single patient had an ICD at baseline. Median age at diagnosis was 38 years (interquartile range [IQR] 28-50). During a median follow-up of 7.8 years (IQR 6.1-9.7), 15 patients (12%) experienced VA. The model provided good discrimination, with a C-index for 5-year VA risk prediction of 0.84 (95% confidence interval 0.74-0.93). However, the model led to an overestimation of the 5-year VA risk when applying thresholds < 50%. With a < 10% predicted risk, no patient showed VA. With a 7.5% predicted risk, the ICD:VA ratio was 6.3 vs 3.4 in the original study. The model still outperformed the 2015 International Task Force Consensus. Overall, in a relatively large European ARVC cohort with restrictive indications for ICD placement, the ARVC model for VA prediction successfully identified ARVC patients with VA during follow-up. Yet, our study underscores the need for careful threshold selection, considering the model's associated risk overestimation in low- to intermediate-risk patients.

Impact of Coronary Lesion Stability on the Benefit of Emergent Percutaneous Coronary Intervention After Sudden Cardiac Arrest

BACKGROUND

Conflicting data exist regarding the benefit of urgent coronary angiogram and percutaneous coronary intervention (PCI) after sudden cardiac arrest, particularly in the absence of ST-segment elevation. We hypothesized that the type of lesions treated (stable versus unstable) influences the benefit derived from PCI.

METHODS

Data were taken between May 2011 and 2014 from a prospective registry enrolling all sudden cardiac arrest in Paris and suburbs (6.7 million inhabitants). Patients undergoing emergent coronary angiogram were included. Decision to perform PCI was left to the discretion of local teams. We assessed the impact of emergent PCI on survival at discharge according to whether the treated lesion was angiographically unstable or stable, and we investigated the predictive factors for unstable coronary lesions.

RESULTS

Among 9265 sudden cardiac arrests occurring during the study period, 1078 underwent emergent coronary angiogram (median age: 59.6 years, 78.3% males): 463 (42.9%) had an unstable lesion, 253 (23.5%) only stable lesions, and 362 (33.6%) no significant lesions. Emergent PCI was performed in 478 patients (91.4% of unstable and 21.7% of stable lesions). At discharge, PCI of unstable lesions was associated with twice-higher survival rate compared with untreated unstable lesions (47.9% versus 25.6%, P=0.013), while stable lesions PCI did not improve survival (25.5% versus 26.3%, P=1.00). After adjustment, PCI of unstable coronary lesions was independently associated with improved survival (odds ratio, 2.09 [95% CI, 1.42-3.09], P<0.001), contrary to PCI of stable lesions (odds ratio, 0.92 [95% CI. 0.44-1.87], P=0.824). Angina, initial shockable rhythm, ST-segment elevation, and absence of known coronary artery disease were independent predictors of unstable lesions.

CONCLUSIONS

Emergent PCI of unstable lesions is associated with improved survival after sudden cardiac arrest, contrary to PCI of stable lesions. Accordingly, early PCI should only be performed in patients with unstable lesions. Four factors (chest pain, ST-elevation, absence of coronary artery disease history, and shockable initial rhythm) could help identify patients with unstable lesions who would, therefore, benefit from emergent coronary angiogram.

Radiotherapy in Patients With a Cardiac Implantable Electronic Device

Recently, the Heart Rhythm Society published recommendations on management of patients with cardiac implantable electronic device (CIED) who require radiotherapy (RT). We aimed to report the experience of a teaching hospital, and discuss our practice in the context of recently published guidelines. We identified all consecutive CIED recipients (12,736 patients) who underwent RT between March 2006 and June 2017. Among them, 90 (1%) patients (78.2 ± 10 years, 73% male) had a CIED: 82 pacemakers and 8 implantable cardioverter-defibrillators. Two patients required CIED extraction prior to RT for ipsilateral breast cancer (no device replacement in 1 patient). Four patients (5%) were considered at high-risk, 35 (39%) at intermediate-risk, and the remaining 50 (56%) at low-risk for CIED dysfunction. Overall, only a minority of patients followed recommended local protocol during RT delivery (31%) and during follow-up (56%). CIED malfunction was detected in 5 patients (6%), mainly back-up mode resetting (80%), with 4 (including 3 pelvic cancer location) patients initially classified as being at intermediate-risk and 1 at low-risk. Four out of the 5 patients with CEID malfunction had received neutron producing beams. In conclusion, our findings underline the lack of rigorous monitoring of patients undergoing RT (though CIED malfunction appears to be rare and relatively benign in nature), and emphasize the interest of considering neutron producing beam for risk stratification as recommended in recent guidelines. Optimization of patient's management requires a close collaboration between both CIED clinicians and radiation oncologists, and more systematic remote CIED monitoring may be helpful.

Frequency of Recovery from Complete Atrioventricular Block After Cardiac Surgery

Best timing for permanent pacemaker implantation to treat complete atrioventricular block (AVB) after cardiac surgery is unclear, as late pacemaker dependency was found low in recent observational studies. This study aimed to identify factors associated with spontaneous recovery from AVB. In a prospective and observational cohort, all patients who underwent cardiothoracic surgery during a 14-month-period were included (n = 1,200). Risk factors of postoperative AVB were assessed by logistic regression. Among patients who developed AVB, variables associated with recovery from AVB were assessed by Cox and logistic regression. Overall incidence of postoperative AVB was 6.0%. Risk factors of AVB were age (OR 1.03 [1.00 to 1.06], p = 0.023); female gender (OR 2.06 [1.24 to 3.41], p = 0.005), active endocarditis (OR 3.31 [1.33 to 8.26], p = 0.01), and aortic valve replacement (OR 3.17 [1.92 to 5.25], p <0.001). Among aortic valve replacement, sutureless aortic valve replacement was associated with more AVB (26.7% vs 8.1%, p <0.01). Recovery from AVB occurred in 30 patients (41.7%) in a median period of 3 days [interquartile range = 1;5]. Among patients who would recover from AVB, 90% of patients did so before day 7. None of the studied variable was independently associated with recovery from AVB. In conclusion, identified risk factors of postoperative AVB after cardiac surgery were age, female gender, endocarditis, and aortic valve replacement. Because most patients who would recover did so before day 7, this study validates modern guidelines suggesting permanent pacemaker implantation on day 7.