Steidley, D. Eric

Abstract Aims Cardiac amyloidosis (CA) is common in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR). Cardiac amyloidosis has poor outcomes, and its assessment in all TAVR patients is costly and challenging. Electrocardiogram (ECG) artificial intelligence (AI) algorithms that screen for CA may be useful to identify at-risk patients. Methods and results In this retrospective analysis of our institutional National Cardiovascular Disease Registry (NCDR)-TAVR database, patients undergoing TAVR between January 2012 and December 2018 were included. Pre-TAVR CA probability was analysed by an ECG AI predictive model, with >50% risk defined as high probability for CA. Univariable and propensity score covariate adjustment analyses using Cox regression were performed to compare clinical outcomes between patients with high CA probability vs. those with low probability at 1-year follow-up after TAVR. Of 1426 patients who underwent TAVR (mean age 81.0 ± 8.5 years, 57.6% male), 349 (24.4%) had high CA probability on pre-procedure ECG. Only 17 (1.2%) had a clinical diagnosis of CA. After multivariable adjustment, high probability of CA by ECG AI algorithm was significantly associated with increased all-cause mortality [hazard ratio (HR) 1.40, 95% confidence interval (CI) 1.01–1.96, P = 0.046] and higher rates of major adverse cardiovascular events (transient ischaemic attack (TIA)/stroke, myocardial infarction, and heart failure hospitalizations] (HR 1.36, 95% CI 1.01–1.82, P = 0.041), driven primarily by heart failure hospitalizations (HR 1.58, 95% CI 1.13–2.20, P = 0.008) at 1-year follow-up. There were no significant differences in TIA/stroke or myocardial infarction. Conclusion Artificial intelligence applied to pre-TAVR ECGs identifies a subgroup at higher risk of clinical events. These targeted patients may benefit from further diagnostic evaluation for CA.

Abstract Aims Graft dysfunction (GD) after heart transplantation (HTx) can develop without evidence of cell- or antibody-mediated rejection. Cardiac magnetic resonance imaging (CMR) has an evolving role in detecting rejection; however, its role in biopsy-negative GD has not been described. This study examines CMR findings, evaluates outcomes based on CMR results, and seeks to identify the possibility of rejection missed through endomyocardial biopsy by using CMR in HTx recipients with biopsy-negative GD. Methods and results HTx recipients with GD [defined as a decrease in left ventricular ejection fraction (LVEF) by >5% and LVEF < 50%] in the absence of rejection by biopsy or allograft vasculopathy and who underwent CMR were included in the study. The primary outcome was a composite of all-cause mortality, re-transplantation, or persistent LVEF < 50%. Overall, 34 HTx recipients developed biopsy-negative GD and underwent CMR. Left ventricular late gadolinium enhancement (LGE) on CMR was observed in 16 patients with two distinct patterns: diffuse epicardial (n = 13) and patchy (n = 3) patterns. Patients with LGE developed GD later after HTx [4 (1.4–6.8) vs. 0.8 (0.3–1.2) years, P < 0.001], were more often symptomatic (88% vs. 56%, P = 0.06), and had greater haemodynamic derangement (pulmonary capillary wedge pressure: 19 ± 7 vs. 13 ± 3 mmHg, P = 0.002) as compared with those without LGE. No significant difference was observed in the primary composite outcome between patients with LGE and those without LGE (50% vs. 38% of patients with events, P = 0.515). During a median follow-up of 3.8 years, mean LVEF improved similarly in the LGE-negative (37–55%) and LGE-positive groups (32–55%) (P = 0.16). Conclusions Biopsy-negative GD occurs with and without LGE when assessed by CMR, indicative of possible rejection/inflammation occurring only in a subset of patients. Irrespective of LGE, LVEF improvement occurs in most GD patients, suggesting that other neurohormonal or immunomodulatory mechanisms may also contribute to GD development.

Background. End-stage kidney disease patients with concomitant heart failure (HF) with reduced ejection fraction are often denied kidney transplantation. The aims of this study were to explore factors predictive of suitability for kidney transplant and to assess cardiovascular outcomes in patients with impaired left ventricular ejection fraction (LVEF) after transplant. Methods. We evaluated 109 consecutive adults with LVEF ≤40% at the time of initial kidney transplant evaluation between 2013 and 2018. Posttransplant cardiovascular outcomes were defined as nonfatal myocardial infarction (MI), admission for HF, cardiovascular death, and all-cause mortality. Results. A cardiologist participated in kidney transplant evaluation for 87% of patients and was present at 49% of transplant selection conferences. Twenty-four patients (22%) were denied by a cardiologist for kidney transplant‚ and 59 (54%) were denied by the selection committee, of whom 43 were because of cardiovascular risk. Forty-two (38%) patients were approved for kidney transplant. On univariate analysis, the variables associated with denial for kidney transplant included cardiologist denial, higher cardiac troponin T, prior coronary intervention, cardiovascular event, positive stress study, lower ejection fraction, and lower VO2 max (all P < 0.05). Cardiologist denial was the most significant predictor of denial for kidney transplant in different multivariate models. At a median follow-up of 15 mo, 5 (5%) suffered nonfatal MI, 13 (12%) were hospitalized for HF exacerbation, and 17 (16%) died. Only 22 patients, 52% of those approved, underwent kidney transplant. After kidney transplant, there was 1 death, 1 nonfatal MI, and 3 hospitalizations for HF. Median LVEF improved from 38% before listing to 55% posttransplant. Conclusions. Cardiologist denial was the primary predictor of rejection for kidney transplant. Despite careful selection, prevalence of cardiovascular events and mortality after kidney transplant was 23%. There is need for a structured multidisciplinary approach for patients with impaired LVEF.

Abstract Aims Current non-invasive screening methods for cardiac allograft rejection have shown limited discrimination and are yet to be broadly integrated into heart transplant care. Given electrocardiogram (ECG) changes have been reported with severe cardiac allograft rejection, this study aimed to develop a deep-learning model, a form of artificial intelligence, to detect allograft rejection using the 12-lead ECG (AI-ECG). Methods and results Heart transplant recipients were identified across three Mayo Clinic sites between 1998 and 2021. Twelve-lead digital ECG data and endomyocardial biopsy results were extracted from medical records. Allograft rejection was defined as moderate or severe acute cellular rejection (ACR) based on International Society for Heart and Lung Transplantation guidelines. The extracted data (7590 unique ECG-biopsy pairs, belonging to 1427 patients) was partitioned into training (80%), validation (10%), and test sets (10%) such that each patient was included in only one partition. Model performance metrics were based on the test set (n = 140 patients; 758 ECG-biopsy pairs). The AI-ECG detected ACR with an area under the receiver operating curve (AUC) of 0.84 [95% confidence interval (CI): 0.78–0.90] and 95% (19/20; 95% CI: 75–100%) sensitivity. A prospective proof-of-concept screening study (n = 56; 97 ECG-biopsy pairs) showed the AI-ECG detected ACR with AUC = 0.78 (95% CI: 0.61–0.96) and 100% (2/2; 95% CI: 16–100%) sensitivity. Conclusion An AI-ECG model is effective for detection of moderate-to-severe ACR in heart transplant recipients. Our findings could improve transplant care by providing a rapid, non-invasive, and potentially remote screening option for cardiac allograft function.

Mammalian target of rapamycin (mTOR) inhibitors have been shown to reduce proliferation of lymphoid cells; thus, their use for immunosuppression after heart transplantation (HT) may reduce post-transplant lymphoproliferative disorder (PTLD) risk. This study sought to investigate whether the sirolimus (SRL)-based immunosuppression regimen is associated with a decreased risk of PTLD compared with the calcineurin inhibitor (CNI)-based regimen in HT recipients. We retrospectively analyzed 590 patients who received HTs at two large institutions between 1 June 1988 and 31 December 2014. Cox proportional-hazard modeling was used to examine the association between type of primary immunosuppression and PTLD after adjustment for potential confounders, including Epstein–Barr virus (EBV) status, type of induction therapy, and rejection. Conversion from CNI to SRL as primary immunosuppression occurred in 249 patients (42.2%). During a median follow-up of 6.3 years, 30 patients developed PTLD (5.1%). In a univariate analysis, EBV mismatch was strongly associated with increased risk of PTLD (HR 10.0, 95% CI: 3.8–26.6; p < 0.001), and conversion to SRL was found to be protective against development of PTLD (HR 0.19, 95% CI: 0.04–0.80; p = 0.02). In a multivariable model and after adjusting for EBV mismatch, conversion to SRL remained protective against risk of PTLD compared with continued CNI use (HR 0.12, 95% CI: 0.03–0.55; p = 0.006). In conclusion, SRL-based immunosuppression is associated with lower incidence of PTLD after HT. These findings provide evidence of a benefit from conversion to SRL as maintenance therapy for mitigating the risk of PTLD, particularly among patients at high PTLD risk.

Abstract Background Invasive fungal infection (IFI) in heart transplant recipients is associated with poor outcomes. Estimated risk of 1‐year IFI in heart transplant recipients is 3.4–8.6% with risk factors inconsistently identified in previous studies. The role of antifungal prophylaxis is unclear. The transplant program at Mayo Clinic provides 6 months of universal azole prophylaxis for those heart transplant recipients in Arizona. We sought to define risk factors for 1‐year IFI and determine the effect of antifungal prophylaxis. Methods We conducted a retrospective cohort study of patients undergoing heart transplantation at Mayo Clinic from January 2000 to March 2019. We analyzed demographics, details of transplant hospitalization, antifungal prophylaxis, and fungal infection. Multivariable Cox analyses were performed to identify risk factors of 1‐year IFI and impact of IFI on posttransplant mortality. Results A total of 966 heart transplant recipients were identified with a median age of 56 years (IQR 47, 62). A total of 444 patients received antifungal prophylaxis. Over 1‐year follow‐up, 62 patients developed IFI with a cumulative incidence of 6.4%. In multivariable analysis, factors associated with IFI were renal replacement therapy (RRT) (HR 3.24, 95% CI 1.65–6.39), allograft rejection (HR 2.33, 95% CI 1.25–4.34), and antifungal prophylaxis (HR 0.32, 95% CI 0.11–0.96). RRT was also associated with invasive mold infection (HR 3.00, 95% CI 1.29–6.97). Conclusions RRT and allograft rejection after transplantation are associated with 1‐year IFI, and RRT is also associated with invasive mold infection. Antifungal prophylaxis appears to be protective and further study is needed in the heart transplant population.

Introduction: End stage renal disease (ESRD) patients with concomitant heart failure (HF) are often denied kidney transplantation (KTx). The aims of this study were to explore factors predictive of suitability for KTx and to assess cardiovascular (CV) outcomes in patients with impaired left ventricular ejection fraction (LVEF) presenting for KTx evaluation. Methods: We evaluated 109 consecutive adults with LVEF≤40% at the time of initial KTx evaluation between 2013 and 2018. Post-transplant CV outcomes were defined as non-fatal MI, admission for HF, CV death and all-cause mortality. Results: Mean age was 58.2 years (SD11.9), 78% were male, 58% had diabetes, 70% had history of CV events and 42% had ischemic cardiomyopathy. Mean LVEF was 31.5% (SD 6.47). Eighty patients had nuclear stress imaging; 10% were positive for reversible ischemia and 43% for prior infarct. Mean VO2max was 14.4(SD 5.71)ml/kg/min (31 patients). A cardiologist evaluated 93% of patients and was present at 58% of selection committee meetings. Twenty-four patients (22%) were denied by a cardiologist for KTx and 59 (54%) were denied by the selection committee, of whom 43 were due to CV risk. On univariate analysis, the variables associated with denial for KTx were: cardiologist denial, denial due to CV risk, Native American race (6% of cohort), higher NT-pro-BNP, prior MI, coronary intervention, positive stress study, anemia, lower EF and lower VO2max (all p<0.05). On multivariate analysis, cardiologist denial was the only significant predictor of denial for KTx (OR: 29.4, p=0.0007). At median follow-up of 15 months, 5 (5%) suffered non-fatal MI, 13 (12%) were hospitalized for HF exacerbation and 17 (16%) died. Only 22 (20%) underwent KTx. Post-KTx, there was one death, one non-fatal MI and 3 hospitalizations for HF. Mean LVEF improvement was 16% (SD12.9). Conclusions: Only 38% of ESRD patients with LVEF≤40% presenting for KTx evaluation were approved and of those, only 52% received KTx. Cardiologist approval was the primary predictor of suitability for KTx. Despite careful selection, prevalence of CV events and mortality after KTx was 23%. There is need for a consistent multidisciplinary approach during KTx evaluation, including cardiologist input, to improve CV outcomes.

Abstract Background Invasive fungal infection (IFI) in heart transplant recipients is associated with increased mortality and poor outcome. Reports have estimated the risk of 1-year IFI to be 3.4-8.6% with renal replacement therapy, delayed chest closure, and reoperation suggested as risk factors. However, the role of antifungal prophylaxis is unclear, though previous studies have suggested a reduced incidence of invasive Aspergillosis. The transplant program in Mayo Arizona provides 6 months of universal azole prophylaxis for Coccidioides, while Rochester and Florida only provide prophylaxis to high risk patients. We sought to define epidemiology and risk factors for 1-year IFI and determine the effect of antifungal prophylaxis. Methods We conducted a retrospective cohort study of patients undergoing single-organ heart transplantation at Mayo Rochester, Florida, or Arizona from January 2000 to March 2019. We identified baseline characteristics, details of transplant hospitalization such as need for renal replacement therapy, open chest, reoperation, and operative time, receipt of antifungal prophylaxis, and diagnosis of IFI. Multivariable Cox analysis was performed to identify risk factors of time to 1-year IFI. Results A total of 966 heart transplant recipients were identified with a median age of 56 years (IQR 47, 62) and 72% male. 444 patients received antifungal prophylaxis which included 32% fluconazole, 34% itraconazole, 18% voriconazole, 15% echinocandin, and &lt; 1% amphotericin or posaconazole. Over 1-year follow-up, 62 patients developed IFI with a cumulative prevalence of 6.4%. The most common organisms were Aspergillus (50%) and Candida (27%). In a multivariable model, factors associated with 1-year IFI were post-transplant renal replacement therapy (HR 3.34, 95% CI 1.69-6.60; P &lt; 0.001) and antifungal prophylaxis (HR 0.32, 95% CI 0.11-0.96; P=0.042). Operative time, recent hospitalization, open chest, and post-transplant mechanical circulatory support were not associated with 1-year IFI. Conclusion Renal replacement therapy after transplantation is associated with 1-year IFI. Antifungal prophylaxis appears to be protective and further prospective study is warranted to verify this finding. Disclosures All Authors: No reported disclosures