Orthotopic Heart Transplant Recipients Research Articles

Recurrent infective endocarditis of the mitral valve after orthotopic heart transplantation

Introduction: Orthotopic heart transplantation is the gold standard for the treatment of advanced heart failure in the absence of contraindications. Infective endocarditis is a rare complication in patients after heart transplantation. The treatment of endocarditis after heart transplantation is challenging since there is a need for ongoing immunosuppression. Case description: We present the case of a 51-year-old orthotopic heart transplant recipient enrolled in a chronic dialysis program, in whom we diagnosed and successfully treated recurrent infective endocarditis of the mitral valve caused by Enterococcus and Enterobacter species. Despite the complicated course of the disease, the treatment was successful. Conclusions: Recurrent infective endocarditis after heart transplantation can be treated successfully with a multidisciplinary approach and robust antimicrobial therapy.

Cost-Effectiveness of Cardiovascular Magnetic Resonance for Rejection Surveillance After Cardiac Transplantation in the Australian Health Care System

Heart transplantation is an effective treatment for end-stage congestive heart failure, however, achieving the right balance of immunosuppression to maintain graft function while minimising adverse effects is challenging. Serial endomyocardial biopsies (EMBs) are currently the standard for rejection surveillance, despite being invasive. Replacing EMB-based surveillance with cardiac magnetic resonance (CMR)-based surveillance for acute cardiac allograft rejection has shown feasibility. This study aimed to assess the cost-effectiveness of CMR-based surveillance in the first year after heart transplantation. A prospective clinical trial was conducted with 40 orthotopic heart transplant (OHT) recipients. Participants were randomly allocated into two surveillance groups: EMB-based, and CMR-based. The trial included economic evaluations, comparing the frequency and cost of surveillance modalities in relation to quality-adjusted life years (QALYs) within the first year post-transplantation. Sensitivity analysis encompassed modelled data from observed EMB and CMR arms, integrating two hypothetical models of expedited CMR-based surveillance. In the CMR cohort, 238 CMR scans and 15 EMBs were conducted, versus (vs) 235 EMBs in the EMB group. CMR surveillance yielded comparable rejection rates (CMR 74 vs EMB 94 events, p=0.10) and did not increase hospitalisation risk (CMR 32 vs EMB 46 events, p=0.031). It significantly reduced the necessity for invasive EMBs by 94%, lowered costs by an average of AUD$32,878.61, and enhanced cumulative QALY by 0.588 compared with EMB. Sensitivity analysis showed that increased surveillance with expedited CMR Models 1 and 2 were more cost-effective than EMB (all p<0.01), with CMR Model 1 achieving the greatest cost savings (AUD$34,091.12±AUD$23,271.86 less) and utility increase (+0.62±1.49 QALYs, p=0.011), signifying an optimal cost-utility ratio. Model 2 showed comparable utility to the base CMR model (p=0.900) while offering the benefit of heightened surveillance frequency during periods of elevated rejection risk. CMR-based rejection surveillance in orthotopic heart transplant recipients provides a cost-effective alternative to EMB-based surveillance. Furthermore, it reduces the need for invasive procedures, without increased risk of rejection or hospitalisation for patients, and can be incorporated economically for expedited surveillance. These findings have important implications for improving patient care and optimising resource allocation in post-transplant management.

(197) - Incidence and Risk Factors for Rejection After Conversion to Sirolimus-Based Immunosuppression in Orthotopic Heart Transplant Recipients

(197) - Incidence and Risk Factors for Rejection After Conversion to Sirolimus-Based Immunosuppression in Orthotopic Heart Transplant Recipients

Association Between High Sensitivity Troponin Levels Following Pediatric Orthotopic Heart Transplantation and Intensive Care Unit Resource Utilization.

The utility of troponin levels, including high sensitivity troponin T (hs-TnT), after orthotopic heart transplant (OHT) is controversial. Conflicting data exist regarding its use as a marker of acute rejection. Few studies have examined possible associations of hs-TnT levels immediately after OHT with metrics of intensive care unit (ICU) resource utilization or risk of acute rejection. We performed a retrospective cohort chart review including all OHT recipients < 20years of age at our center between June 2019 and December 2022. Patients were divided into two groups based on supra- or sub-median initial hs-TnT levels (median 3462.5ng/L). Primary outcome was days requiring ICU-level care, secondary outcomes included days intubated, days requiring positive pressure ventilation (PPV), days on inotropic medications, actual ICU length of stay, Vasoactive Inotrope Scores (VIS) on postoperative days (POD) 0 through 7, and acute rejection at 30days and one year after OHT. Patients with higher hs-TnT required ICU level care for longer [13.5 (10-17.5) vs. 9.5 (8-12) days, p = 0.01] and spent more days intubated [6 (4-7) vs. 3 (3-5) days, p < 0.001], on PPV [9 (6-15) vs. 6 (5-8.5) days, p = 0.02], and on inotropes [11 (9-14) vs. 8 (7-11) days, p = 0.025]. VIS was only different between groups on POD7 [5 (3-7) vs. 3 (0-5), p = 0.04]. There was no difference in rejection between the groups. Higher hs-TnT immediately following pediatric OHT may predict higher ICU resource utilization, despite no difference in VIS, although it does not predict acute rejection in the first year after OHT.

Implementation of Patient Blood Management in Orthotopic Heart Transplants: A Single Centre Retrospective Observational Review

Blood transfusion in the perioperative cardiothoracic setting has accepted risks including deep sternal wound infection, increased intensive care unit length of stay, lung injury, and cost. It has an immunomodulatory effect which may cause allo-immunisation. This may influence long-term survival through immune-mediated factors. Targeting coagulation defects to reduce unnecessary or inappropriate transfusions may reduce these complications. In 2012, an institution-wide patient blood management evidence-based algorithmic bleeding management protocol was implemented at The Prince Charles Hospital, Brisbane, Australia. The benefit of this has been previously reported in our lung transplant and cardiac surgery (excluding transplants) cohorts. This study aimed to investigate the effect of this on our orthotopic heart transplant recipients. After the implementation of the protocol, despite no difference in preoperative haemoglobin levels and higher risk patients (EuroSCORE 20 vs 26; p=0.013), the use of packed red blood cells (13.0 U vs 4.4 U; p=0.046) was significantly lower postoperatively and fresh frozen plasma was significantly lower both intra- and postoperatively (7.4 U vs 0.6 U; p<0.001, and 3.3 U vs 0.6 U; p=0.011 respectively). Concurrently, the use of prothrombin complex concentrate (33% vs 78%; p<0.001) and desmopressin (5% vs 22%; p=0.0028) was significantly higher in the post-protocol group, while there was less use of recombinant factor VIIa (15% vs 4%; p=0.058). Intraoperative units of cryoprecipitate also rose from 0.9 to 2.0 (p=0.006). We have demonstrated that a targeted patient blood management protocol with point-of-care testing for heart transplant recipients is correlated with fewer blood products used postoperatively, with some increase in haemostatic products and no evidence of increased adverse events.

Kiosk 4Q-TA-09 - Recurrent Left Atrial Mass in an Orthotopic Heart Transplant Recipient

Kiosk 4Q-TA-09 - Recurrent Left Atrial Mass in an Orthotopic Heart Transplant Recipient

Kiosk 7R-FC-04 - Value of Quantitative Perfusion CMR Beyond Vasculopathy Assessment Among Orthotopic Heart Transplant Recipients

Kiosk 7R-FC-04 - Value of Quantitative Perfusion CMR Beyond Vasculopathy Assessment Among Orthotopic Heart Transplant Recipients

Comparing 3-year survival and readmissions between HeartMate 3 and heart transplant as primary treatment for advanced heart failure

ObjectiveTo compare 3-year survival and readmissions of patients who received the HeartMate 3 (HM3) left ventricular assist device (LVAD) or underwent orthotopic heart transplantation (OHT) as primary treatment for advanced heart failure. MethodsWe retrospectively analyzed 381 adult patients who received an HM3 LVAD or were listed for OHT between January 2014 and March 2021 at our center. To minimize crossover bias, OHT recipients with a prior LVAD were excluded, and HM3 patients were censored at the time of transplant. Cohorts were propensity score–matched to reduce confounding variables. The primary outcome was 3-year survival, and the secondary outcome was mean cumulative all-cause unplanned readmission. ResultsThe study population comprised 185 HM3 patients (49%) and 196 OHT patients (51%), with 104 propensity score–matched patients in each group. After propensity score matching, there was no statistical difference in 3-year survival (83.7% for HM3 vs 87.0% for OHT; P = .91; relative risk [RR], 1.00; 95% confidence interval [CI], 0.45-2.20). In the unmatched cohorts, patients age 18 to 49 years had comparable survival with HM3 and OHT (96.9% vs 95.9%; N = 91; P = 1.00; RR, 0.92; 95% CI, 0.09-9.78). Patients age 50+ years had slightly inferior survival with HM3 (75.0% vs 83.9%; N = 290; P = .60; RR, 1.51; 95% CI, 0.85-2.68). The mean number of readmissions at 3 years was higher in the HM3 group (3.89 vs 2.05; P < .001). ConclusionsThis exploratory analysis suggests that for similar patients, HM3 may provide comparable 3-year survival to OHT as a primary treatment for heart failure but may result in more readmissions.

Abstract 17534: Safety and Feasibility of Adenosine Stress CMR for CAV Detection in Orthotopic Heart Transplant Recipients

Background: Stress perfusion cardiac magnetic resonance (CMR) imaging is recommended in international guidelines in class I in patients with known or suspected CAD. Patients undergoing cardiac transplantation (OHT) are at risk of developing cardiac allograft vasculopathy (CAV). Adenosine is relatively contraindicated after transplantation because of a presumed risk of atrioventricular block in denervated hearts. We sought to evaluate the safety and feasibility of adenosine stress CMR in patients with OHT and suspected CAV. Methods: In an outpatient cohort study, we measured the incidence of adverse effects of adenosine stress CMR in consecutive OHT recipients undergoing quantitative stress perfusion CMR for suspected CAV. We additionally stratified patients based on presence of significant CAV (grades 2-3 versus 0-1) on either invasive or computed tomography coronary angiography to evaluate potential CMR biomarkers of significant coronary disease in this population. Results: We identified 50 adenosine stress CMR studies performed in 45 individual patients at a median of 19 years after transplantation (IQR 4.7-24.4); 9% of studies were conducted within the first year post-transplantation. No life-threatening adverse events, brief or prolonged atrioventricular block or other arrythmias occurred after adenosine infusion. Significant myocardial ischemia (≥ 1.5 segments) was reported in 17% of patients. When stratified by CAV severity, stress MBF index, but not inducible ischemia on visual inspection, was found to significantly differentiate patients with severe CAV from those without significant coronary disease (ANOVA p = 0.028). Conclusion: Adenosine stress perfusion CMR is safe and feasible in OHT recipients. Quantitative measurement of stress MBF index may represent a promising marker of coronary disease with incremental value over qualitative assessment of ischemia, and should be evaluated in future studies.

Need for cardiac implantable electronic devices and long-term follow-up in recipients of orthotopic heart transplants

BackgroundCardiac pacemaker implantation after orthotopic heart transplantation declined dramatically after development of the bicaval anastomosis technique. However, much less is known about the rate, indications, and predictors of device implantation procedures with the current surgical technique. ObjectiveThe purpose of this study was to evaluate the indications, patient characteristics, incidence, and survival related to cardiac implantable electronic device (CIED) implantation after heart transplantation. MethodsThis was a single-center study of 399 consecutive adult recipients of orthotopic heart transplants with bicaval anastomosis from 1991 to 2017. The primary end point was freedom from pacemaker or implantable cardioverter-defibrillator (ICD) implantation, and the secondary end point was all-cause mortality. ResultsAt the time of transplantation, the mean age of recipients was 50 ± 12 years and that of donors 31 ± 12 years. CIEDs were implanted in 8% of recipients (n = 31): 11 pacemakers (35%) for sinus node dysfunction, 17 (55%) for high-grade heart block, and 3 ICDs (10%) for the primary prevention of sudden cardiac death. Early CIED implantation (<30 days) was rare and absent for sinus node dysfunction. The risk for CIED implantation increased progressively during follow-up (0–30 years; median 11 years), with low-, moderate-, and high-risk periods between 0 and 10, between 10 and 20, and between 20 and 30 years, respectively. Recipients receiving CIEDs survived longer after transplantation (21 years vs 13 years; P < .01). Recipients receiving pacemakers for heart block were more likely to receive older donor hearts at the time of transplantation. ConclusionThe risk of pacemaker implantation increases progressively, while ICD implantation is rare. Donor age is the predominant risk factor for subsequent heart block. Early sinus node dysfunction requiring permanent pacing is rare.

Characterization of de novo malignancy after orthotopic heart transplantation: single-centre outcomes over 20 years.

Malignancy is the leading cause of late mortality after orthotopic heart transplantation (OHT), and the burden of post-transplantation cancer is expected to rise in proportion to increased case volume following the 2018 heart allocation score change. In this report, we evaluated factors associated with de novo malignancy after OHT with a focus on skin and solid organ cancers. Patients who underwent OHT at our institution between 1999 and 2018 were retrospectively reviewed (n = 488). Terminal outcomes of death and development of skin and/or solid organ malignancy were assessed as competing risks. Fine-Gray subdistribution hazards regression was used to evaluate the association between perioperative patient and donor characteristics and late-term malignancy outcomes. By 1, 5 and 10 years, an estimated 2%, 17% and 27% of patients developed skin malignancy, while 1%, 5% and 12% of patients developed solid organ malignancy. On multivariable Fine-Gray regression, age [1.05 (1.03-1.08); P < 0.001], government payer insurance [1.77 (1.20-2.59); P = 0.006], family history of malignancy [1.66 (1.15-2.38); P = 0.007] and metformin use [1.73 (1.15-2.59); P = 0.008] were associated with increased risk of melanoma and basal or squamous cell carcinoma. Age [1.08 (1.04-1.12); P < 0.001] and family history of malignancy [2.55 (1.43-4.56); P = 0.002] were associated with an increased risk of solid organ cancer, most commonly prostate and lung cancer. Vigilant cancer and immunosuppression surveillance is warranted in OHT recipients at late-term follow-up. The cumulative incidence of skin and solid organ malignancies increases temporally after transplantation, and key risk factors for the development of post-OHT malignancy warrant identification and routine monitoring.

Higher-risk SIPAT score predicts increased risk of long-term mortality in orthotopic heart transplant recipients

BackgroundOrthotopic heart transplantation (OHT) improves survival in eligible patients. Organ scarcity necessitates extensive clinical and psychosocial evaluations before listing. The Stanford Integrated Psychosocial Assessment for Transplant (SIPAT) predicts risk for poor psychosocial outcomes and morbidity in the first year post-transplant, yet it is unknown whether it predicts long-term outcomes. MethodsBlinded examiners obtained data from a retrospective cohort of 51 OHT recipients from a high-volume center. Patients with “Excellent” or “Good” SIPAT score indicating low psychosocial risk for transplant (E/G) were compared with those who met “Minimum Acceptable Criteria” or were “High Risk” (MAC/HR). Associations were examined between SIPAT group and outcomes. ResultsMAC/HR versus E/G recipients had significantly reduced survival in the 10 years post-OHT (mean 6.7 vs 8.8 years, p = 0.027; 55% vs 82% survival proportions, p = 0.037). MAC/HR patients were more likely to live in a county with greater income inequality (p = 0.025) and have psychiatric history pre-OHT (p = 0.046). Both groups had otherwise similar demographics and medical history. A lower proportion of MAC/HR patients adhered to medications post-OHT and a greater proportion had psychiatric illness, though differences were not significant. ConclusionsHigher-risk SIPAT scores predict reduced long-term survival post-OHT. Further efforts are crucial to improve outcomes in higher-risk patients.

Orthotopic Heart Transplant Recipient Presenting with Sudden Onset Homonymous Hemianopia

AbstractInfectious complications are common among heart transplant recipients due to immune suppressive therapy mandatorily given to prevent organ rejection. We share our experience regarding an orthotopic heart transplant recipient who underwent craniotomy and evacuation of intracerebral abscess under general anesthesia in our operation theater. An orthotopic heart transplant recipient presented with headache, fever, and left-sided homonymous hemianopia. Noncontrast computed tomography (NCCT) of the head showed a right occipital space-occupying lesion suggestive of an abscess. Craniotomy and evacuation of abscess was successfully performed under general anesthesia. There are several concerns pertinent to orthotopic heart transplant recipients mainly due to denervated heart status and immune suppressive therapy, which poses perioperative challenge. We report successful anesthetic management of this case.

Conversion between sirolimus and everolimus in heart transplant recipients.

Sirolimus and everolimus are mechanistic target of rapamycin inhibitors (mTORi) that may be included in immunosuppression regimens for orthotopic heart transplant (OHT) recipients. mTORi play a role in slowing progression of cardiac allograft vasculopathy; however, they have poor tolerability, sometimes necessitating a change between agents or therapies. The literature surrounding a conversion between mTORi are incongruent, thus this study was designed to assess the concentration/dose ratio for each medication around the time of conversion to provide guidance for a conversion strategy between mTORi. We conducted a retrospective study of adult OHT recipients who were maintained on both sirolimus- and everolimus-based immunosuppression regimens. The primary outcome was the concentration/dose (C/d) ratio of sirolimus to everolimus. Secondary outcomes included changes in hematologic and lipid labs and patient-reported intolerances. The C/d ratio of sirolimus was 4.42, whereas the everolimus ratio was 2.23, resulting in a sirolimus: everolimus ratio of 1.98. Secondarily, after converting between mTORi, 93% of patients who reported intolerance(s) to one agent had a resolution of that intolerance. In our patient population, everolimus appeared better tolerated than sirolimus, with significantly more patients having no reported intolerances and significantly fewer patients experiencing edema. Other lab values were similar between patients receiving sirolimus and everolimus, except for an increased hemoglobin level in those receiving everolimus. The conversion ratio of 1:2 observed in our population suggests OHT recipients may require an increased dose of EVL compared with SRL to maintain the same goal trough levels. A conversion between mTORi appeared to improve tolerability and did not lead to clinically significant worsening of any measured lab value.

Donor supply for partial heart transplantation in the United States.

Congenital heart disease (CHD) is the most common cause of birth defects worldwide. Valvular defects are a common form of CHDs, and, at this time, treatment options for children with unrepairable valve disease are limited. Issues with anticoagulation, sizing, and lack of growth in valve replacement options can lead to high mortality rates and incidence of reoperations. Partial heart transplantation, or transplantation of fresh valve allografts, has recently been described as a strategy to provide a durable and non-thrombogenic alternative to conventional prostheses and provide growth potential in pediatric patients. The United Network for Organ Sharing (UNOS) database was queried to analyze the number of pediatric donor hearts that were not recovered but had viable valves (n=3565) between January 2010 and September 2021. Recoverable valves were grouped by donor age: infants (age<1year), toddlers (age ≥1 and <3years), and children (age ≥3 and <18years). Demographic characteristics of donors were analyzed between age groups. Infants, toddlers, and children had a total of 344, 465, and 2756 hearts with recoverable valves, respectively, over the study period, representing an average of 29, 39, and 230 hearts with recoverable valves per year. The results of our study identify the minimum donor supply for partial heart transplantation. The actual number is likely higher because it includes hearts not entered in the UNOS database and domino transplants from orthotopic heart transplant recipients. Partial heart transplantation is logistically feasible as there are recoverable valves available for all age groups, fulfilling a clinical need in pediatric patients with unrepairable valve disease.

Management and outcomes of advanced stage cardiac AL amyloidosis in the daratumumab era.

e20058 Background: AL amyloidosis is plasma cell disorder involving irreversible deposition of amyloid fibrils, leading to end-organ damage. Treatment strategies include systemic therapy, autologous stem cell transplant (ASCT), and organ transplant. The ANDROMEDA trial established daratumumab (Dara) in combination with cyclophosphamide, bortezomib (Bor), and dexamethasone (CyBorD) as a new standard of care in newly diagnosed AL amyloidosis. Notably, only 2% of the trial population had stage IIIB cardiac disease by Mayo 2004 criteria. We present real world data of orthotopic heart transplantation (OHT) recipients with AL amyloidosis at our institution to understand the safety and outcomes of Dara use in the setting of advanced cardiac involvement. Methods: We performed a retrospective review of 9 patients at our institution who had received OHT since 2019 for AL amyloidosis. Demographics, disease details, treatment selection, response, and outcomes data were collected and described. Results: The cohort included 22% Black and 22% Hispanic patients, and the median age at diagnosis was 56. All patients had Revised Mayo stage 3 or 4 disease with advanced cardiac involvement requiring OHT. Patients had a median of 3 (2-4) suspected organs involved; none had symptomatic myeloma. Four patients received induction CyBorD; 2 achieved complete response (CR), 1 very good partial response (VGPR), and 1 partial response (PR) prior to OHT. Three of 4 received bridging therapy (Dara-Bor triplet or Bor alone) prior to ASCT, 2 due to inadequate response and 1 to maintain CR, and all achieved CR post-ASCT. Median time from OHT to ASCT was 13.5 months (range: 8-17), with bridging therapy starting at a median of 6 months post-OHT if received, with concomitant reduction in OHT immunosuppression. Five patients received DaraCyBorD induction: 2 achieved CR, 2 achieved VGPR, and 1 achieved PR prior to OHT. No patient who received DaraCyBorD received ASCT. Those not in CR received further therapy post-OHT. At the time of this analysis, 89% of patients remain in CR with 2 receiving ongoing therapy. All patients are alive with a median follow-up of 22 months (range: 11-35) since OHT without evidence for organ rejection. Conclusions: We demonstrate that the use of subcutaneous Dara is tolerable and effective in advanced stage cardiac AL amyloidosis, an underrepresented group in the literature. Patients who received DaraCyBorD followed by OHT without ASCT achieved similar outcomes to those who received CyBorD, OHT, and ASCT. The routine use of Dara may therefore negate the need for ASCT in this setting, given its favorable toxicity profile and reduced cost. [Table: see text]

Outcomes in orthotopic heart transplantation following pacemaker implantation.

Bradyarrhythmias including sinus node dysfunction (SND) and atrioventricular block (AVB) can necessitate pacemaker (PPM) implantation in orthotopic heart transplant (OHT) recipients. Prior studies have shown conflicting findings regarding the effect of PPM implantation on survival. We evaluated the effect of PPM indication on long-term re-transplant-free survival in OHT patients. We conducted a retrospective cohort study of OHT patients at UCLA Medical Center from 1985 to 2018. Indication for PPM (SND, AVB) was identified. Cox proportional hazards model with pacemaker implantation as a time-varying covariate was used to evaluate its effect on the primary endpoint of retransplant or death. We included 1609 OHTs in 1511 adult patients with median follow-up of 12 years. At transplant, patients were aged 53±13 years and 1125 (74.5%) were male. Pacemakers were implanted in 109 (7.2%) patients; 65 for SND (4.3%) and 43 for AVB (2.8%). Repeat OHT was performed in 103 (6.4%) cases and 798 (52.8%) patients died during the follow-up period. The risk of the primary endpoint was significantly higher in patients requiring PPM for AVB (HR 3.0, 95% CI 2.1-4.2, p<.01) after controlling for age at OHT, gender, hypertension, diabetes, renal disease, history of repeat OHT, acute rejection, transplant coronary vasculopathy, and atrial fibrillation, but not PPM for SND (HR 1.0, 95% CI 0.70-1.4, p=1.0). Patients who required PPM for AVB, but not SND, were at significantly higher risk of death or retransplant compared to patients who did not require PPM.

Prevalence of sustained atrial arrythmias and treatment with zero fluoroscopy or near zero fluoroscopy catheter ablation in Slovenian orthotopic heart transplant recipients

Abstract Funding Acknowledgements Type of funding sources: None. Background Due to advances in surgical techniques and immunosuppression survival of heart transplant (HT) recipients has improved significantly, with that the prevalence of sustained atrial arrhythmias (SAA) in these patients is increasing. In HT recipients antiarrhythmic therapy options are limited. Radiofrequency ablation (RFA) represents a viable but underutilized option after other etiologies of SAA such as acute allograft rejection and vasculopathy are excluded. Limiting radiation exposure in HT recipients, who are exposed to 3,5 times (1) greater radiation dose compared to general population and are significantly more susceptible to develop malignancies, is essential. Purpose Our aim was to analyse prevalence and type of SAA in Slovenian orthotopic HT recipients and analyse feasibility and procedural outcomes of zero (ZF) or near zero fluoroscopy (NZF) RFA treatment approaches. Methods We performed a retrospective analysis of HT recipients between 2002 and 2022. We re-evaluated all available ECGs of suspected arrhythmias of included patients for presence and type of SAA. We further analysed HT patients that underwent RFA for SAA at our centre. All procedures were performed primarily with 3D electroanatomical mapping system and intracardiac echocardiography guidance. Either ZF or NZF approaches were used. The primary endpoint of all procedures was SAA termination and acute success was deemed when subsequent attempts to reinduce SAA failed. Long-term success was defined as the absence of any spontaneous SAA during 12-month follow-up. Results Among 364 consecutive HT recipients 19 patients (5,2%) were evaluated for SAA. Of those 7 (37%) presented as typical atrial flutters (AFL), 9 (47%) as atypical AFL, 2 (11%) as focal atrial tachycardia (FAT) and 1 (5%) as slow-fast atrioventricular nodal reentry tachycardia. In 2 (11%) patients with AFL, SAA was a result of acute allograft rejection. In 10 (53%) patients SAA occurred in first 3 months after HT. In the remaining 9 patients SAA occurred late, median 6,6 years after HT (25th-75th IQR: 7,7 years). RFA was performed in 7 (37%) patients. In all patients procedures were acutely successful however in 2 patients additional RFA procedures were needed for long-term success. All in all, 10 RFA procedures were performed (Table 1). All cases had macro or micro reentrant AFL with a median of 2,0 re-entry circuits mapped (25th-75th IQR: 3,3 re-entry circuits) during the procedure – that included typical cavotricuspid isthmus AFL, perimitral AFL, and several right atrium (RA) scar-related or incision related AFL. In 2 cases additional RA FAT were ablated. Five (50%) procedures were performed with ZF. No major procedure related complications were observed. Conclusion In HT recipients ZF or NZF RFA of SAA appears to be feasible and safe, but still underutilised, treatment option. Our case series demonstrates favourable acute and long-term outcomes however larger data is needed to support these results.

Indexed donor cardiac output for improved size matching in heart transplantation: A United Network for Organ Sharing database analysis

ObjectiveImplantation of an appropriately sized donor heart is critical for optimal outcomes after heart transplantation. Although predicted heart mass has recently gained consideration, there remains a need for improved granularity in size matching, particularly among small donor hearts. We sought to determine if indexed donor cardiac output is a sensitive metric to assess the adequacy of a donor heart for a given recipient. MethodsA retrospective analysis was performed (2003-2021) in isolated orthotopic heart transplant recipients from the United Network for Organ Sharing database. Donor cardiac output was divided by recipient body surface area to compute cardiac index (donor cardiac index). Predicted heart mass ratio was computed as donor/recipient predicted heart mass. The primary outcome was mortality 1 year after transplant. ResultsAmong transplant recipients, median donor cardiac output was 7.3 (5.8-9.0) liters per minute and donor cardiac index was 3.7 (3.0-4.6) liters per minute/m2. Predicted heart mass ratio was 1.01 (0.91-1.13). After multivariable adjustment, higher donor cardiac index was associated with lower 1-year mortality risk (odds ratio, 0.92, P = .042). Recipients with predicted heart mass ratio less than 0.80 (n = 255) had a lower median donor cardiac index than those with a predicted heart mass ratio of 0.80 or greater (3.2 vs 3.7, P < .001). As predicted, heart mass ratio became smaller and the association between donor cardiac index and 1-year mortality became progressively stronger. ConclusionsHigher donor cardiac index was associated with a lower probability of 1-year mortality among patients undergoing heart transplantation and served to further quantify mortality risk among those with a small predicted heart mass ratio. Donor cardiac index appears to be an effective tool for size matching and may serve as an adjunctive strategy among small donor hearts with a low predicted heart mass ratio.

Epidemiology, management, and clinical outcomes of extrapulmonary Mycobacterium abscessus complex infections in heart transplant and ventricular assist device recipients

Nontuberculous mycobacteria are emerging pathogens, yet data on the epidemiology and management of extrapulmonary nontuberculous mycobacteria infections in orthotopic heart transplantation (OHT) and ventricular assist device (VAD) recipients are scarce. We retrospectively reviewed records of OHT and VAD recipients who underwent cardiac surgery at our hospital and developed Mycobacterium abscessus complex (MABC) infection from 2013 to 2016 during a hospital outbreak of MABC linked to heater-cooler units. We analyzed patient characteristics, medical and surgical management, and long-term outcomes. Ten OHT patients and 7 patients with VAD developed extrapulmonary M. abscessus subspecies abscessus infection. The median time from presumed inoculation during cardiac surgery to the first positive culture was 106 days in OHT and 29 days in VAD recipients. The most common sites of positive cultures were blood (n = 12), sternum/mediastinum (n = 8), and the VAD driveline exit site (n = 7). The 14 patients diagnosed when alive received combination antimicrobial therapy for a median of 21 weeks, developed 28 antibiotic-related adverse events, and underwent 27 surgeries. Only 8 (47%) patients survived longer than 12 weeks after diagnosis, including 2 patients with VAD who experienced long-term survival after an explantation of infected VADs and OHT. Despite aggressive medical and surgical management, OHT and VAD patients with MABC infection experienced substantial morbidity and mortality.