Effects of Implantable Cardioverter-Defibrillator Leads on the Tricuspid Valve and Right Ventricle: A Randomized Trial.

BACKGROUND: There are no randomized data to inform the extent to which transvenous cardiac leads cause tricuspid regurgitation (TR). OBJECTIVES: This study sought to determine the effect of a transvenous implantable cardioverter-defibrillator (TV-ICD) on TR severity, and secondarily, on right ventricular (RV) size and function. METHODS: We evaluated TR severity before and 6 months after implantable cardioverter-defibrillator insertion in a post hoc analysis of adults randomized to receive a transvenous (n = 252) or subcutaneous implantable cardioverter-defibrillator (S-ICD) (n = 251) device. TR and RV size and systolic function were assessed by echocardiographic images analyzed in a core laboratory. RESULTS: At baseline, at least mild TR was present in 30% of individuals. At 6 months, the proportion of participants with any TR in the TV-ICD group was 42% vs 19% in the S-ICD group (P < 0.001). The proportion with moderate or severe TR was 7% in the TV-ICD group vs 2% in the S-ICD group (P = 0.021). At 6 months, the OR of at least 1 grade worsening of TR in the TV-ICD group as compared with the S-ICD group was 7.2 (95% CI: 3.3-15.8; P < 0.001). There were no differences between groups with respect to RV size or systolic function. CONCLUSIONS: Six months following TV-ICD insertion, there was a 7-fold increase in the risk of at least 1 grade worsening of TR, with 7% of individuals having TR that was moderate or severe. There was no detectable difference in RV size or function; however, longer follow-up is needed.

Device-specific quality of life: Results from the ATLAS trial-Avoid Transvenous Leads in Appropriate Subjects.

AIM: Patient reported outcomes (PROs) provide important insights into patients' acceptance of their medical devices. ATLAS, a randomized, multi-center, open-label clinical trial, recently reported fewer perioperative complications in S-ICD compared to TV-ICD patients. This study reports PROs, including device-specific and generic quality of life (QOL) from the ATLAS trial. METHODS AND RESULTS: Device-specific QOL was the primary PRO using the Florida Patient Acceptance Survey (FPAS) at 1-and 6-months post-implantation. Secondary outcomes included generic QOL using the Medical Outcomes Survey (SF-36) pre-implant and 6-months post-implantation. FPAS and SF-36 were analyzed using ANCOVA. Pain measured using a Numeric Rating Scale, at 1-and 6-months, anesthetic, BMI and within/between differences were analyzed using descriptive statistics and mixed-effects linear models (MLM). Of the 503 patients randomized in ATLAS, 404 had complete FPAS data to include in this analysis. Participant characteristics were balanced. There were no significant differences between S-ICD and TV-ICD for FPAS or SF-36, across timepoints. Mean total FPAS scores increased from 73.73 (16.09) to 77.05 (16.13) and 74.43 (15.35) to 78.25 (15.88) for S-ICD and TV-ICD, respectively, (p <0.001). PROs suggested that both devices were associated with good QOL. CONCLUSION: Device-specific and generic QOL were similar between S-ICD and TV-ICD groups up to 6-months post-implantation indicating that regardless of device type, both groups reported good device specific QOL in ATLAS patients. S-ICD patients reported higher pain scores at implant, but pain decreased by 6 months. The findings offer evidence that can be included during shared decision-making. The inclusion of patient partners in ATLAS provided opportunity to measure PROs that were deemed important to patients.

Long-term outcomes of surgical aortic valve replacement in patients receiving chronic dialysis.

BACKGROUND: Surgical aortic valve replacement (SAVR) has been the standard treatment for symptomatic severe aortic stenosis, which is common among patients receiving long-term dialysis. The aim of this study was to report the long-term outcomes of SAVR in patients receiving chronic dialysis and to identify independent risk factors for early and late mortality. METHODS: Every consecutive patient with SAVR with or without concomitant cardiac procedures in British Columbia between January 2000 and December 2015 was identified from the provincial cardiac registry. The Kaplan-Meier method was used to estimate survival. Univariate and multivariable models were conducted to determine independent risk factors for short-term mortality and reduced long-term survival. RESULTS: Between 2000 and 2015, 654 patients receiving dialysis underwent SAVR with or without concomitant procedures. The mean follow-up was 2.3 (standard deviation 2.4) years (median 2.5 yr). The overall 30-day mortality was 12.8%. The 5-year and 10-year survival rates were 45.6% and 23.5%, respectively. Twelve patients (1.8%) had redo aortic valve surgery. There was no difference in 30-day mortality or long-term survival between 2 age groups (> 65 yr v. ≤ 65 yr). Anemia and cardiopulmonary bypass (CPB) were independent risk factors for both longer hospital stay and reduced long-term survival. The impact of CPB pump time on mortality occurred mainly within the first 30 days after surgery. When CPB pump time extended beyond 170 minutes, there was a significant increase in 30-day mortality with further prolongation of CPB pump time, and the relationship between 30-day mortality and CPB pump time became approximately linear. CONCLUSION: Patients receiving dialysis have poor long-term survival with a very low rate of redo aortic valve surgery following SAVR with or without concomitant procedures. Older age (> 65 yr) is not an independent risk factor for either 30-day mortality or reduced long-term survival. Using alternative strategies to limit CPB pump time is an important way to reduce 30-day mortality.

Association of the Timing and Extent of Cardiac Implantable Electronic Device Infections With Mortality.

Importance: Cardiac implantable electronic device (CIED) infection is a potentially devastating complication with an estimated 12-month mortality of 15% to 30%. The association of the extent (localized or systemic) and timing of infection with all-cause mortality has not been established. Objective: To evaluate the association of the extent and timing of CIED infection with all-cause mortality. Design, Setting, and Participants: This prospective observational cohort study was conducted between December 1, 2012, and September 30, 2016, in 28 centers across Canada and the Netherlands. The study included 19 559 patients undergoing CIED procedures, 177 of whom developed an infection. Data were analyzed from April 5, 2021, to January 14, 2023. Exposures: Prospectively identified CIED infections. Main Outcomes and Measures: Time-dependent analysis of the timing (early [≤3 months] or delayed [3-12 months]) and extent (localized or systemic) of infection was performed to determine the risk of all-cause mortality associated with CIED infections. Results: Of 19 559 patients undergoing CIED procedures, 177 developed a CIED infection. The mean (SD) age was 68.7 (12.7) years, and 132 patients were male (74.6%). The cumulative incidence of infection was 0.6%, 0.7%, and 0.9% within 3, 6, and 12 months, respectively. Infection rates were highest in the first 3 months (0.21% per month), reducing significantly thereafter. Compared with patients who did not develop CIED infection, those with early localized infections were not at higher risk for all-cause mortality (no deaths at 30 days [0 of 74 patients]: adjusted hazard ratio [aHR], 0.64 [95% CI, 0.20-1.98]; P = .43). However, patients with early systemic and delayed localized infections had an approximately 3-fold increase in mortality (8.9% 30-day mortality [4 of 45 patients]: aHR, 2.88 [95% CI, 1.48-5.61]; P = .002; 8.8% 30-day mortality [3 of 34 patients]: aHR, 3.57 [95% CI, 1.33-9.57]; P = .01), increasing to a 9.3-fold risk of death for those with delayed systemic infections (21.7% 30-day mortality [5 of 23 patients]: aHR, 9.30 [95% CI, 3.82-22.65]; P < .001). Conclusions and Relevance: Findings suggest that CIED infections are most common within 3 months after the procedure. Early systemic infections and delayed localized infections are associated with increased mortality, with the highest risk for patients with delayed systemic infections. Early detection and treatment of CIED infections may be important in reducing mortality associated with this complication.

Perioperative Safety and Early Patient and Device Outcomes Among Subcutaneous Versus Transvenous Implantable Cardioverter Defibrillator Implantations : A Randomized, Multicenter Trial.

BACKGROUND: Implantable cardioverter defibrillators (ICDs) improve survival in patients at risk for cardiac arrest, but are associated with intravascular lead-related complications. The subcutaneous ICD (S-ICD), with no intravascular components, was developed to minimize lead-related complications. OBJECTIVE: To assess key ICD performance measures related to delivery of ICD therapy, including inappropriate ICD shocks (delivered in absence of life-threatening arrhythmia) and failed ICD shocks (which did not terminate ventricular arrhythmia). DESIGN: Randomized, multicenter trial. (ClinicalTrials.gov: NCT02881255). SETTING: The ATLAS trial. PATIENTS: 544 eligible patients (141 female) with a primary or secondary prevention indication for an ICD who were younger than age 60 years, had a cardiogenetic phenotype, or had prespecified risk factors for lead complications were electrocardiographically screened and 503 randomly assigned to S-ICD (251 patients) or transvenous ICD (TV-ICD) (252 patients). Mean follow-up was 2.5 years (SD, 1.1). Mean age was 49.0 years (SD, 11.5). MEASUREMENTS: The primary outcome was perioperative major lead-related complications. RESULTS: There was a statistically significant reduction in perioperative, lead-related complications, which occurred in 1 patient (0.4%) with an S-ICD and in 12 patients (4.8%) with TV-ICD (-4.4%; 95% CI, -6.9 to -1.9; P = 0.001). There was a trend for more inappropriate shocks with the S-ICD (hazard ratio [HR], 2.37; 95% CI, 0.98 to 5.77), but no increase in failed appropriate ICD shocks (HR, 0.61 (0.15 to 2.57). Patients in the S-ICD group had more ICD site pain, measured on a 10-point numeric rating scale, on the day of implant (4.2 ± 2.8 vs. 2.9 ± 2.2; P < 0.001) and 1 month later (1.3 ± 1.8 vs. 0.9 ± 1.5; P = 0.035). LIMITATION: At present, the ATLAS trial is underpowered to detect differences in clinical shock outcomes; however, extended follow-up is ongoing. CONCLUSION: The S-ICD reduces perioperative, lead-related complications without significantly compromising the effectiveness of ICD shocks, but with more early postoperative pain and a trend for more inappropriate shocks. PRIMARY FUNDING SOURCE: Boston Scientific.

Treatment and Prevention of Cardiovascular Implantable Electronic Device (CIED) Infections.

An expanded role for cardiac implantable electronic devices (CIEDs) in recent decades reflects an aging population and broader indications for devices, including both primary prevention and management of dysrhythmias. CIED infection is one of the most important device-related complications and has a major impact on mortality, quality of life, healthcare utilization, and cost. Unfortunately, the investigation and management of CIED infection remain complex, often necessitating complete and timely removal of the device and leads in order to eradicate the infection. In addition, the translation of knowledge from an extensive literature to a disparate group of medical practitioners has often been inadequate. This review of CIED infection management highlights the significant advances made during the past decade, including diagnostic criteria, advanced imaging, and next-generation sequencing for culture-negative cases or those in which uncertainty remains. We also outline the role and indication for powered lead extraction, the process of antibiotic choice and treatment duration, considerations related to the timing and location for reimplantation, and preimplantation risk stratification and associated interventions to reduce the risk of CIED infection.

L'élargissement du rôle des dispositifs électroniques cardiaques implantables (DECI) au cours des dernières décennies reflète le vieillissement de la population et les indications plus vastes des dispositifs, notamment dans la prévention primaire et la prise en charge des dysrythmies. Les infections liées aux DECI sont l'une des plus importantes complications liées aux dispositifs et ont des conséquences majeures sur la mortalité, la qualité de vie, l'utilisation et les coûts des soins de santé. Malheureusement, le dépistage et la prise en charge des infections liées aux DECI demeurent complexes et nécessitent souvent le retrait complet et rapide du dispositif et des sondes en vue d'éradiquer l'infection. De plus, l'application des connaissances issues d'une vaste littérature à un groupe disparate de médecins praticiens a souvent été inadéquate. La présente revue sur la prise en charge des infections liées aux DECI illustre les avancées importantes réalisées au cours de la dernière décennie, notamment les critères diagnostiques, l'imagerie avancée et le séquençage de prochaine génération des cas à culture négative ou de ceux pour lesquels des incertitudes demeurent. Nous avons aussi décrit le rôle et les indications d'extraction des sondes fonctionnelles, le processus du choix des antibiotiques et de la durée du traitement, les considérations relatives au moment et au lieu de la réimplantation, et la stratification du risque en préimplantation et les interventions associées afin de réduire le risque d'infections liées aux DECI.

Location of Superior Vena Cava Tears in Transvenous Lead Extraction.

BACKGROUND: Superior vena cava (SVC) tears are rare but potentially lethal complications associated with transvenous lead extraction. When lacerations occur, surgeons need to be prepared for an emergent response. Nonetheless, little is known about the precise whereabouts of these lesions. Understanding the location and injury patterns enables a more anticipated and targeted surgical response. METHODS: We collected data via physician interviews after an SVC laceration occurred. These physicians were identified through the US Food and Drug Administration's Manufacturer and User Facility Device Experience database and independent physician reports of adverse events. We identified 116 reports of SVC tears between July 1, 2016, and July 31, 2018. For an SVC tear to be included in our registry, a cardiothoracic surgeon had to be physically present to confirm the injury via emergent sternotomy. In each case, the surgeon recorded the SVC injury's exact location after a repair was attempted. RESULTS: During the study period, 116 SVC tears were confirmed by sternotomy. Tears occurred in any combination of the following locations: SVC-innominate vein, body of the SVC, and SVC-right atrial junction. The majority of tears (n = 72; 62%) were located in the isolated body of the SVC, followed by the SVC-right atrial junction (n = 23;19.8%) and the SVC-innominate junction (n = 17;14.6%). Combined tears were rare, accounting for only 3.6% (n = 4) of the adverse events recorded. CONCLUSIONS: Most SVC tears occurred in the isolated body of the SVC. The second most common location was the SVC-right atrial junction. The SVC-innominate junction was the third most common location for these injuries. Combined tears were uncommon.

Predictors of perforation during lead extraction: Results of the Canadian Lead ExtrAction Risk (CLEAR) study.

BACKGROUND: Transvenous lead extraction can have serious adverse events, such as cardiac or vascular perforation. Risk factors have not been well characterized. OBJECTIVE: The purpose of this study was to identify factors associated with perforation and death, and to characterize lead extraction in a large contemporary population. METHODS: We performed a retrospective multicenter study examining patients undergoing lead extraction at 8 Canadian institutions from 1996 through 2016. Demographic and clinical data were used to identify variables associated with perforation and mortality using logistic regression modeling. RESULTS: A total of 2325 consecutive patients (age 61.9 ±16.5 years) underwent extraction of 4527 leads. Perforation rate was 2.7% (63/2325) and 30-day mortality was 1.6% (38/2325), with mortality of 0.4% due to perforation (10/2325). Variables associated with perforation included no previous cardiac surgery (odds ratio [OR] 3.33; 95% confidence interval [CI] 1.54-7.19; P = .002), female sex (OR 3.27; 95% CI 1.91-5.60; P <.001); left ventricular ejection fraction ≥40% (OR 2.81; 95% CI 1.28-6.14; P = .010); lead age >8 years (OR 2.64; 95% CI 1.52-4.60; P <.001); ≥2 leads extracted (OR 2.49; 95% CI 1.23-5.04; P = .011); and diabetes (OR 2.12; 95% CI 1.16-3.86; P = .014). Variables associated with death included infection as indication for extraction (OR 3.85; 95% CI 1.38-10.73; P = .010); anemia (OR 3.14; 95% CI 1.38-6.61; P = .003), and patient age (OR 1.04; 95% CI 1.01-1.07; P = .012). CONCLUSION: Risk factors associated with perforation in lead extraction include no history of cardiac surgery, female sex, preserved left ventricular ejection fraction, lead age >8 years, ≥2 leads extracted, and diabetes.

Impact of Choice of Prophylaxis on the Microbiology of Cardiac Implantable Electronic Device Infections: Insights From the Prevention of Arrhythmia Device Infection Trial (PADIT).

BACKGROUND: The Prevention of Arrhythmia Device Infection Trial (PADIT) investigated whether intensification of perioperative prophylaxis could prevent cardiac implantable electronic device (CIED) infections. Compared with a single dose of cefazolin, the perioperative administration of cefazolin, vancomycin, bacitracin, and cephalexin did not significantly decrease the risk of infection. Our objective was to compare the microbiology of infections between study arms in PADIT. METHODS: This was a post hoc analysis. Differences between study arms in the microbiology of infections were assessed at the level of individual patients and at the level of microorganisms using the Fisher exact test. RESULTS: Overall, 209 microorganisms were reported from 177 patients. The most common microorganisms were coagulase-negative staphylococci (CoNS; 82/209 [39.2%]) and S. aureus (75/209 [35.9%]). There was a significantly lower proportion of CoNS in the incremental arm compared with the standard arm (30.1% vs 46.6%; P = .04). However, there was no significant difference between study arms in the frequency of recovery of other microorganisms. In terms of antimicrobial susceptibility, 26.5% of microorganisms were resistant to cefazolin. CoNS were more likely to be cefazolin-resistant in the incremental arm (52.2% vs 26.8%, respectively; P = .05). However, there was no difference between study arms in terms of infections in which the main pathogen was sensitive to cefazolin (77.8% vs 64.3%; P = .10) or vancomycin (90.8% vs 90.2%; P = .90). CONCLUSIONS: Intensification of the prophylaxis led to significant changes in the microbiology of infections, despite the absence of a decrease in the overall risk of infections. These findings provide important insight on the physiopathology of CIED infections. TRIAL REGISTRATION: NCT01002911.

Canadian Heart Rhythm Society Task Force Report on Physician Training and Maintenance of Competency for Cardiovascular Implantable Electronic Device Therapies: Executive Summary.

Physicians engaged in cardiovascular implantable electronic device (CIED)-related practice come from diverse training backgrounds with variable degrees of CIED implant training. The objective of the Canadian Heart Rhythm Society Task Force on CIED Implant Training was to establish a common structure and content for training programs in CIED implantation, related activities and maintenance of competency. This executive summary presents the essence of the report with key recommendations included, with the complete version made available in a linked supplement. The goals are to ensure that future generations of CIED implanters are better prepared for continuously evolving CIED practice and quality care for all Canadians.

A pragmatic parallel group implementation study of a prehospital-activated ECPR protocol for refractory out-of-hospital cardiac arrest.

OBJECTIVES: Extracorporeal membrane oxygenation within CPR (ECPR) may improve survival among patients with refractory out-of-hospital cardiac arrest (OHCA). We evaluated outcomes after incorporating ECPR into a conventional resuscitation system. METHODS: We introduced a prehospital-activated ECPR protocol for select refractory OHCAs into one of four metropolitan regions in British Columbia. We prospectively identified ECPR-eligible patients in both the ECPR region and the three other regions to serve as the control group. We compared the proportion with favorable neurological outcomes at hospital discharge (cerebral performance category ≤2) and used logistic regression to estimate the association with treatment region. RESULTS: The study was terminated prematurely due to changes in hospital protocols and COVID-19. In the ECPR region, 15/58 (25.9%) patients had favourable neurological outcomes owing to conventional resuscitation and 2/58 (3.4%) owing to ECPR, for a total of 17/58 (29.3%). In the control regions, 67/250 (26.8%) patients had a favourable outcome owing to conventional resuscitation, for a between-group difference of 2.5% (95% CI -10 to 15%). We did not detect a statistically significant association between treatment region and outcomes. CONCLUSION: In this prematurely-terminated study of ECPR for refractory OHCA, we did not detect an association between a regional ECPR protocol and neurologically favorable outcomes. However, our data suggests that outcomes owing to conventional resuscitation were similar, with the potential for additional survivors due to ECPR therapies.

Anticoagulation management of postoperative atrial fibrillation after cardiac surgery: A systematic review.

BACKGROUND: Postoperative atrial fibrillation (POAF) often complicates cardiac surgery and is associated with increased mortality and risk of thromboembolism. However, the optimal oral anticoagulation (OAC) strategy is uncertain. We performed a systematic review to examine the OAC practice patterns and efficacy in these circumstances. METHODS: MEDLINE and EMBASE were searched from 2000 to 2019 using the search terms cardiac surgical procedures, cardiac surgery, postoperative complications, atrial fibrillation, atrial flutter, and terms for anticoagulants. Collected data included anticoagulation patterns (time of initiation, type, and duration) and outcomes (stroke, bleeding, and mortality). RESULTS: From 763 records, 4 prospective and 13 retrospective studies were included totaling 44,908 patients with 8929 (19.9%) who developed POAF. Anticoagulation rates ranged from 4% to 43% (mean 21% overall). Sixteen studies used warfarin, 3 nonvitamin K OAC (NOAC), and 2 both. Four studies reported the use of bridging unfractionated or low-molecular-weight heparin. Concomitant antiplatelet therapy was reported in half the studies, ranging from 80% to 99%. OAC use was associated with lower risk of thromboembolic events in two retrospective studies (including a national Danish cohort with 2108 patients with POAF). Patients discharged on warfarin experienced reduced mortality in a large, single center, retrospective analysis, but no association was observed in the Danish cohort. CONCLUSION: There is wide practice variation in the uptake, timing of initiation, duration, and choice of OAC for POAF following cardiac surgery. The evidence is largely retrospective and insufficient to assess the efficacy of different OAC strategies. Further studies are warranted to guide clinical practice.

Fracture of an epicardial left ventricular lead implanted at open-heart surgery in anticipation of future need for cardiac resynchronization therapy.

Epicardial left ventricular leads can be implanted at open-heart surgery for cardiac resynchronization therapy. We report a 2-year-old fractured epicardial left ventricular lead detected at generator implant. It highlights the importance of good surgical implant technique and of rigorous lead evaluation for signs of impending failure at generator implant.

Risk Factors for Infections Involving Cardiac Implanted Electronic Devices.

BACKGROUND: Cardiac implantable electronic device infection is a major complication that usually requires device removal. PADIT (Prevention of Arrhythmia Device Infection Trial) was a large cluster crossover trial of conventional versus incremental antibiotics. OBJECTIVES: This study sought to investigate independent predictors of device infection in PADIT and develop a novel infection risk score. METHODS: In brief, over 4 6-month periods, 28 centers used either conventional or incremental prophylactic antibiotic treatment in all patients. The primary outcome was hospitalization for device infection within 1 year (blinded endpoint adjudication). Multivariable logistic prediction modeling was used to identify the independent predictors and develop a risk score for device infection. The prediction models were internally validated with bootstrap methods. RESULTS: Device procedures were performed in 19,603 patients, and hospitalization for infection occurred in 177 (0.90%) within 1 year of follow-up. The final prediction model identified 5 independent predictors of device infection (prior procedures [P], age [A], depressed renal function [D], immunocompromised [I], and procedure type [T]) with an optimism-corrected C-statistic of 0.704 (95% confidence interval: 0.660 to 0.744). A PADIT risk score ranging from 0 to 15 points classified patients into low (0 to 4), intermediate (5 to 6) and high (≥7) risk groups with rates of hospitalization for infection of 0.51%, 1.42%, and 3.41%, respectively. CONCLUSIONS: This study identified 5 independent predictors of device infection and developed a novel infection risk score in the largest cardiac implantable electronic device trial to date, warranting validation in an independent cohort. The 5 independent predictors in the PADIT score are readily adopted into clinical practice. (Prevention of Arrhythmia Device Infection Trial [PADIT Pilot]; NCT01002911).

Impact of Donor Origin on Survival After Orthotopic Heart Transplantation.

Heart transplantation is the definitive management for select patients with end-stage heart failure. Owing to an ongoing organ donor shortage, organs are sometimes allocated from distant locales. These organs may be perceived as less desirable because of donor risk factors and ischemic times. We compared survival after heart transplantation by donors originating from British Columbia (BC), other Canadian provinces, and the United States. This retrospective cohort analysis included all patients transplanted in BC between December 1, 1988, and October 21, 2014, and excluded those with missing data or retransplantation. Among 382 patients, 297 (77.7%) recipients and 238 (62.3%) donors were male. The median recipient age was 54.6 years (interquartile range, 46.0-61.0 years) and the median donor age was 33 years (interquartile range, 22-46 years). Overall 10-year survival was 62.1% (95% confidence interval, 56.3-67.4). There was no difference in 10-year survival when comparing donors from BC, other Canadian provinces, and the United States despite significantly lower median ischemic times in donors from BC. Donor location was not predictive of mortality after controlling for recipient age, donor age, and cold ischemic time. Donor origin did not impact 10-year survival after heart transplantation despite increased ischemic time, suggesting that distant donors result in similar outcomes in BC.

The Potential Impact of Intrathoracic Impedance on Defibrillation Threshold Testing in S-ICDs.

A man with an ischemic cardiomyopathy and chronic obstructive pulmonary disease underwent subcutaneous implantable cardioverter-defibrillator (S-ICD) placement under general anesthesia. Following induction of ventricular fibrillation (VF), defibrillation testing (65J) failed, requiring external rescue. Repeat shock testing with reversed polarity (65J) failed. A third shock and external defibrillation failed (80J and 200J), followed by a second external defibrillation (200J), which did not immediately terminate VF, and a device shock 2 seconds later (80J, successful). Repeat shock testing (80J) under conscious sedation without mechanical ventilation was successful. We discuss this case of failed defibrillation testing during S-ICD placement, potentially due to lung hyperinflation, requiring double sequential defibrillation.

Oligonucleotide-based Preconditioning of DCD Cardiac Donors and Its Impact on Cardiac Viability.

BACKGROUND: While clinical donation after circulatory death (DCD) cardiac transplantation is being implemented with increasing frequency to address the supply/demand mismatch of donor grafts, no research to date has examined a strategy of donor preconditioning to optimize the viability of DCD hearts for transplantation. In our rat model of the DCD protocol, we investigate the impact of pretreating donors with phosphorothioate-linked cytosine and guanine rich oligodeoxynucleotides (CpG ODN) and their effects on cardiac function, injury, and a novel left ventricular (LV) mRNA biomarker panel. METHODS: DCD rats were subjected to a withdrawal protocol, followed by 20 minutes of warm acirculatory standoff, representing a group of severely injured hearts as previously demonstrated. Beating heart controls and DCD rats were pretreated with vehicle or stimulatory CpG ODN (beating heart control and DCD stimulated with CpG ODN, BST and DST). Hearts were harvested for ex situ heart perfusion (ESHP), where LV function, histochemical injury, and differences in gene expression were characterized between groups. RESULTS: Donor pretreatment with CpG ODN doubled the number of functional DCD hearts at ESHP. Pretreatment was associated with improved systolic and diastolic LV function, a reduction in histological injury, and markedly reduced elaboration of cardiac troponin-I in coronary effluent during ESHP. Pretreatment was also associated with a reduction in mRNA biomarkers associated with myocardial injury. CONCLUSIONS: A single dose of CpG ODN was associated with reduced biomarkers of cardiac injury and a 100% increase in cardiac viability in this rodent model of marginal DCD cardiac donation.