Pacemaker Implantation Following Heart Transplantation - Incidence and Risk Factors. Single-Center Experience

BACKGROUND

Bradyarrhythmias, requiring pacemaker (PM) implantation, are common complications following orthotopic heart transplantation (HTx). Currently used heart transplantation methods are primarily the bicaval technique and the total heart transplantation technique. The aim of the study was to assess the incidence and risk factors, including donor parameters, of conduction disorders requiring pacing after HTx.

METHODS

A population of 111 (52 ± 13 years, 91 (82%) men) heart recipients was divided into a group requiring PM implantation post-HTx and a group not requiring PM. We compared groups in terms of donor parameters, time of graft ischemia, transport and transplantation, and surgical techniques as the potential risk factors for significant bradyarrhythmias.

RESULTS

Ten of 111 patients with HTx (9%) required PM implantation. The indication in 7 cases was sinus node dysfunction (SND), in 3 patients it was complete atrioventricular block (AV-block). In the PM group, the age of 48 ± 6 vs 40 ± 11 years (P = .0227) and the body mass index (BMI) 28 ± 3 vs 26 ± 4 kg/m2 (P = .0297) of the donor were significantly higher. There was no influence of organ transport time, ischemia time, and transplantation time. All patients requiring PM implantation were transplanted using the bicaval anastomosis: 10 (100%) vs 71 (70%) in the group not requiring PM (P = .044).

CONCLUSIONS

The need for PM implantation post-HTx despite using new techniques is still common, especially in the group operated with the bicaval method. In addition, higher donor's age and BMI are risk factors of PM implantation, what is of importance as qualification criteria of donor hearts have been gradually extended.

Pacemaker Implantation following Heart Transplantation: Analysis of a Nation-Wide Database

BACKGROUND

The 2018 United-Network-for-Organ-Sharing (UNOS) allocation-system changes resulted in greater recognition of mechanical circulatory support (MCS), leading to more heart transplantations (HTx) in patients with MCS. We aimed to investigate the effect of the new UNOS allocation system on the need for a permanent pacemaker and associated complications following HTx.

METHODS

The UNOS Registry was questioned, to identify patients that received HTx in the US between 2000 and 2021. The primary objectives were to identify risk factors for the need for a pacemaker implantation following HTx.

RESULTS

49,529 HTx patients were identified, 1421 (2.9%) requiring a pacemaker post-HTx. Patients who required a pacemaker were older (53.9 ± 11.5 vs. 52.6 ± 12.8 years, p < 0.001), more frequently white (73% vs. 67%; p < 0.001) and less frequently black (18% vs. 20%; p < 0.001). In the pacemaker group, UNOS status 1A (46% vs. 41%; p < 0.001) and 1B (31% vs. 27%; p < 0.001) were more prevalent, and donor age was higher (34.4 ± 12.4 vs. 31.8 ± 11.5 years; p < 0.001). One-year survival was no different between the groups (HR: 1.08; 95% CI: 0.85, 1.37; p = 0.515). An era effect was observed (per year: OR: 0.97; 95% CI: 0.96, 0.98; p = 0.003), while ECMO pre-transplant was associated with lower risk of a pacemaker (OR: 0.41; 95% CI: 0.19, 0.86; p < 0.001).

CONCLUSIONS

While associated with various patient and transplant characteristics, pacemaker implantation does not seem to impact one-year survival after HTx. The need for pacemaker implantation was lower in the more recent era and in patients who required ECMO pre-transplant, a finding explained by recent advances in perioperative care.

2021 PACES expert consensus statement on the indications and management of cardiovascular implantable electronic devices in pediatric patients

In view of the increasing complexity of both cardiovascular implantable electronic devices (CIEDs) and patients in the current era, practice guidelines, by necessity, have become increasingly specific. This document is an expert consensus statement that has been developed to update and further delineate indications and management of CIEDs in pediatric patients, defined as ≤21 years of age, and is intended to focus primarily on the indications for CIEDs in the setting of specific disease categories. The document also highlights variations between previously published adult and pediatric CIED recommendations and provides rationale for underlying important differences. The document addresses some of the deterrents to CIED access in low- and middle-income countries and strategies to circumvent them. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by class of recommendation and level of evidence. Several questions addressed in this document either do not lend themselves to clinical trials or are rare disease entities, and in these instances recommendations are based on consensus expert opinion. Furthermore, specific recommendations, even when supported by substantial data, do not replace the need for clinical judgment and patient-specific decision-making. The recommendations were opened for public comment to Pediatric and Congenital Electrophysiology Society (PACES) members and underwent external review by the scientific and clinical document committee of the Heart Rhythm Society (HRS), the science advisory and coordinating committee of the American Heart Association (AHA), the American College of Cardiology (ACC), and the Association for European Paediatric and Congenital Cardiology (AEPC). The document received endorsement by all the collaborators and the Asia Pacific Heart Rhythm Society (APHRS), the Indian Heart Rhythm Society (IHRS), and the Latin American Heart Rhythm Society (LAHRS). This document is expected to provide support for clinicians and patients to allow for appropriate CIED use, appropriate CIED management, and appropriate CIED follow-up in pediatric patients.

2021 PACES Expert Consensus Statement on the Indications and Management of Cardiovascular Implantable Electronic Devices in Pediatric Patients: Developed in collaboration with and endorsed by the Heart Rhythm Society (HRS), the American College of Cardiology (ACC), the American Heart Association (AHA), and the Association for European Paediatric and Congenital Cardiology (AEPC) Endorsed by the Asia Pacific Heart Rhythm Society (APHRS), the Indian Heart Rhythm Society (IHRS), and the Latin American Heart Rhythm Society (LAHRS)

In view of the increasing complexity of both cardiovascular implantable electronic devices (CIEDs) and patients in the current era, practice guidelines, by necessity, have become increasingly specific. This document is an expert consensus statement that has been developed to update and further delineate indications and management of CIEDs in pediatric patients, defined as ≤21 years of age, and is intended to focus primarily on the indications for CIEDs in the setting of specific disease categories. The document also highlights variations between previously published adult and pediatric CIED recommendations and provides rationale for underlying important differences. The document addresses some of the deterrents to CIED access in low- and middle-income countries and strategies to circumvent them. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by class of recommendation and level of evidence. Several questions addressed in this document either do not lend themselves to clinical trials or are rare disease entities, and in these instances recommendations are based on consensus expert opinion. Furthermore, specific recommendations, even when supported by substantial data, do not replace the need for clinical judgment and patient-specific decision-making. The recommendations were opened for public comment to Pediatric and Congenital Electrophysiology Society (PACES) members and underwent external review by the scientific and clinical document committee of the Heart Rhythm Society (HRS), the science advisory and coordinating committee of the American Heart Association (AHA), the American College of Cardiology (ACC), and the Association for European Paediatric and Congenital Cardiology (AEPC). The document received endorsement by all the collaborators and the Asia Pacific Heart Rhythm Society (APHRS), the Indian Heart Rhythm Society (IHRS), and the Latin American Heart Rhythm Society (LAHRS). This document is expected to provide support for clinicians and patients to allow for appropriate CIED use, appropriate CIED management, and appropriate CIED follow-up in pediatric patients.

2021 PACES expert consensus statement on the indications and management of cardiovascular implantable electronic devices in pediatric patients

In view of the increasing complexity of both cardiovascular implantable electronic devices (CIEDs) and patients in the current era, practice guidelines, by necessity, have become increasingly specific. This document is an expert consensus statement that has been developed to update and further delineate indications and management of CIEDs in pediatric patients, defined as ≤21 years of age, and is intended to focus primarily on the indications for CIEDs in the setting of specific disease categories. The document also highlights variations between previously published adult and pediatric CIED recommendations and provides rationale for underlying important differences. The document addresses some of the deterrents to CIED access in low- and middle-income countries and strategies to circumvent them. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by class of recommendation and level of evidence. Several questions addressed in this document either do not lend themselves to clinical trials or are rare disease entities, and in these instances recommendations are based on consensus expert opinion. Furthermore, specific recommendations, even when supported by substantial data, do not replace the need for clinical judgment and patient-specific decision-making. The recommendations were opened for public comment to Pediatric and Congenital Electrophysiology Society (PACES) members and underwent external review by the scientific and clinical document committee of the Heart Rhythm Society (HRS), the science advisory and coordinating committee of the American Heart Association (AHA), the American College of Cardiology (ACC), and the Association for European Paediatric and Congenital Cardiology (AEPC). The document received endorsement by all the collaborators and the Asia Pacific Heart Rhythm Society (APHRS), the Indian Heart Rhythm Society (IHRS), and the Latin American Heart Rhythm Society (LAHRS). This document is expected to provide support for clinicians and patients to allow for appropriate CIED use, appropriate CIED management, and appropriate CIED follow-up in pediatric patients.

2021 PACES Expert Consensus Statement on the Indications and Management of Cardiovascular Implantable Electronic Devices in Pediatric Patients

In view of the increasing complexity of both cardiovascular implantable electronic devices (CIEDs) and patients in the current era, practice guidelines, by necessity, have become increasingly specific. This document is an expert consensus statement that has been developed to update and further delineate indications and management of CIEDs in pediatric patients, defined as ≤21 years of age, and is intended to focus primarily on the indications for CIEDs in the setting of specific disease categories. The document also highlights variations between previously published adult and pediatric CIED recommendations and provides rationale for underlying important differences. The document addresses some of the deterrents to CIED access in low- and middle-income countries and strategies to circumvent them. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by class of recommendation and level of evidence. Several questions addressed in this document either do not lend themselves to clinical trials or are rare disease entities, and in these instances recommendations are based on consenus expert opinion. Furthermore, specific recommendations, even when supported by substantial data, do not replace the need for clinical judgment and patient-specific decision-making. The recommendations were opened for public comment to Pediatric and Congenital Electrophysiology Society (PACES) members and underwent external review by the scientific and clinical document committee of the Heart Rhythm Society (HRS), the science advisory and coordinating committee of the American Heart Association (AHA), the American College of Cardiology, (ACC) and the Association for European Paediatric and Congenital Cardiology (AEPC). The document received endorsement by all the collaborators and the Asia Pacific Heart Rhythm Society (APHRS), the Indian Heart Rhythm Society (IHRS), and the Latin American Heart Rhythm Society (LAHRS). This document is expected to provide support for clinicians and patients to allow for appropriate CIED use, appropriate CIED management, and appropriate follow-up in pediatric patients.

Cardiac Implantable Electronic Devices Following Heart Transplantation

Permanent pacemaker (PPM) implantation is required in a subset of patients (∼10%) for sinus node dysfunction or atrioventricular block both early and late after heart transplantation. The incidence of PPM implantation has decreased to <5% with the advent of bicaval anastamosis transplantation surgery. Pacing dependence upon follow-up has been variably reported. An even smaller percentage of transplantation recipients (1.5% to 3.4%) undergo implantable cardioverter-defibrillator (ICD) placement. Rigorous data are lacking for the use of ICDs in the transplantation population and is largely derived from cohort studies and case series. Sudden cardiac death occurs in approximately 10% of transplantation recipients, but multiple nonarrhythmic factors are believed to be responsible, including acute rejection, late graft failure with electromechanical dissociation, and ischemia due to cardiac allograft vasculopathy. This review provides a comprehensive analysis of the existing data regarding the role for PPMs and ICDs in this population, including leadless PPMs and subcutaneous ICDs, special considerations, and future directions.

Risk factors and survival of patients with permanent pacemaker implantation after heart transplantation

Background

Permanent pacemaker (PPM) implantation after heart transplantation (HTX) may be required due to severe bradycardia. The aim of this study was to investigate the risk factors, indications, perioperative outcomes and complications of PPM implantation after HTX as well as the underlying effect on post-transplant mortality including causes of death.

Methods

This registry study included 621 patients receiving HTX at Heidelberg Heart Center between 1989 and 2018. Patients were stratified by PPM implantation after HTX. Data analysis of risk factors for PPM implantation included donor and recipient demographics, post-transplant medication, mortality, and causes of death.

Results

Thirty-six patients (5.8%) received PPM implantation after HTX, 12 (33.3%) with early PPM and 24 (66.7%) with late PPM. Indications for PPM implantation after HTX included sinus node dysfunction (SND) (n=15; 41.7%) and atrioventricular block (AVB) (n=21; 58.3%). Multivariate analysis revealed recipient body mass index (BMI) [hazard ratio (HR): 1.10; confidence interval (CI): 1.01-1.21; P=0.03], donor age (HR: 1.07; CI: 1.03-1.10; P<0.01), and biatrial HTX (HR: 2.63; CI: 1.22-5.68; P=0.01) as significant risk factors for PPM implantation after HTX. Kaplan-Meier estimator displayed a statistically significant inferior 5-year post-transplant survival among patients with early PPM after HTX in comparison to patients with late PPM or no PPM after HTX (P<0.01) along with a higher percentage of death due to infection (P<0.01).

Conclusions

Multivariate risk factors for PPM implantation after HTX include recipient BMI, donor age, and biatrial HTX. Early PPM implantation after HTX is associated with increased 5-year post-transplant mortality due to infection.

Catheter ablation of organized atrial arrhythmias in orthotopic heart transplantation

BACKGROUND

Organized atrial arrhythmias (OAAs) are common after orthotopic heart transplantation (OHT). Some controversies remain about their clinical presentation, relationship with atrial anastomosis and electrophysiologic features. The objectives of this retrospective study were to determine the mechanisms of OAAs after OHT and describe the outcomes of radiofrequency catheter ablation (RFCA).

METHODS

Thirty consecutive transplanted patients (mean age 48 ± 17 years, 86.6% male) underwent 3-dimensional electroanatomic mapping and RFCA of their OAA from 2004 to 2012 at our center.

RESULTS

Twenty-two patients had biatrial anastomosis and 8 had bicaval anastomosis. Macro-reentry was the arrhythmia mechanism for 96% of patients. The electrophysiologic diagnoses were: cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL) in 93% of patients (n = 28); perimitral AFL in 3% (n = 1); and focal atrial tachycardia (FAT) in 3% (n = 1). In 5 patients with biatrial anastomosis, a right FAT was inducible. Primary RFCA success was obtained in 93% of patients. Mean follow-up time was 39 ± 26.8 months. Electrical repermeation between recipient and donor atria, present in 20% of patients (n = 6), did not account for any of the OAAs observed. Survival without OAA relapse at 12, 24 and 60 months was 93%, 89% and 79%, respectively.

CONCLUSIONS

CTI-dependent AFL accounted for most instances of OAA after OHT, regardless of anastomosis type. Time from transplantation to OAA was shorter with bicaval than with biatrial anastomosis. RFCA was safe and provided good long-term results.

Electrocardiographic alterations associated with heart transplantation. Triggers, mechanisms and meaning

Introducción. Las alteraciones del ritmo cardíaco están asociadas con un aumento en la morbimortalidad; sin embargo, en pacientes con trasplante cardíaco no son claros sus desencadenantes ni implicaciones.Objetivos. Realizar una búsqueda en la literatura para identificar y explicar los determinantes en la generación de alteraciones de la conducción eléctrica en pacientes con trasplante cardíaco, así como describir las principales arritmias que pueden presentarse, explicando sus implicaciones patológicas.Materiales y métodos. Se realizó una búsqueda en la base de datos PubMed que arrojó un total de 411 resultados. Además, se buscaron las guías de práctica clínica sobre trasplante cardíaco, electrofisiología cardiovascular y endocarditis infecciosa. Se eligieron 60 artículos que lograban responder a los objetivos de este estudio.Resultados. La técnica quirúrgica, la denervación cardíaca, las lesiones del nodo sinusal, el rechazo del injerto, las biopsias endomiocárdicas y las infecciones son los principales factores que comprometen la viabilidad del órgano y la vida del paciente trasplantado, manifestándose como alteraciones del ritmo sinusal.Conclusiones. Ante la detección de alguna arritmia cardíaca, el equipo médico debe proporcionar un manejo que no se limite al control sintomático y del ritmo sinusal, sino que se debe iniciar una búsqueda activa de su etiología, ya que esta puede ser la manifestación de un proceso patológico subyacente.

Latent variable modeling and its implications for institutional review board review: variables that delay the reviewing process

Background

To investigate the factors related to approval after review by an Institutional Review Board (IRB), the structure equation model was used to analyze the latent variables ‘investigators’, ‘vulnerability’ and ‘review process’ for 221 proposals submitted to our IRB.

Methods

The vulnerability factor included vulnerable cases, and studies that involved drug tests and genetic analyses. The principal investigator (PI) factor included the license level of the PI and whether they belonged to our institution. The review factor included administration time, total review time, and revision frequency. The revision frequency and total review time influenced the efficiency of review.

Results

The latent variable of reviewing was the most important factor mediating the PIs and vulnerability to IRB review approval. The local PIs moderated with genetic study and revision frequency had an impact on the review process and mediated non-approval.

Conclusions

Better guidance of the investigators and reviewers might improve the efficiency with which IRBs function.

Long-term outcomes after 1000 heart transplantations in six different eras of innovation in a single center

The objective of this study was to evaluate long-term outcomes of cardiac transplantation (HTx) in different eras of innovation at a single center during a period of 27 years. We performed a retrospective analysis of 960 cardiac allograft recipients (40 re-HTx) between 1981 and 2008. The results of six different eras based on milestones in HTx were analysed: Era 1: the early years (n = 222,1981-1992); era 2: introduction of inhalative nitric oxide, prostanoids, University of Wisconsin solution (UW) replacing Bretschneider's solution (HTK,n = 118, 1992-1994); era 3: statins (n = 102, 1994-1995); era 4: tacrolimus(n = 115, 1995-1996); era 5: mycophenolate mofetil (MMF, n = 143, 1997-2000) and era 6: sirolimus (n = 300, 2000-2008). Outcome variables weresurvival, freedom from cardiac allograft vasculopathy (CAV) and from acute rejection episodes (AREs). Differences in survival was found comparing era 1 and era 2 with era 4 and era 6 (P < 0.001). Organ preservation through UW demonstrated a significantly better survival as compared with HTK(P < 0.001). Less AREs occurred in patients receiving tacrolimus-sirolimus ortacrolimus-MMF (P < 0.001). Patients receiving tacrolimus-MMF showed less CAV than when treated with cyclosporine-MMF (P < 0.005). There were more ventricular assist device implantations and more re-HTx in era 6 (P < 0.0001)than when compared with other eras. Although the causes for improvement in survival over time are multifactorial, we believe that changes in immunosuppressive therapy have had a major impact on survival.