Faculty Bibliography

BACKGROUND:Despite the goal of the 2018 revision to the heart allocation policy to reduce reliance on exception requests through improved granularity in status criteria, there has been a dramatic rise in exception requests. OBJECTIVES/OBJECTIVE:This study evaluated trends in exception use over the first 6 years of the updated policy, assessing associated clinical factors, temporal changes, and impact on waitlist outcomes. METHODS:This retrospective transplant registry analysis included all adult isolated heart transplant candidates from October 18, 2018, to September 30, 2024. Candidates were stratified by exception use, listing era, and region. Exception use was compared using Wilcoxon rank-sum and chi-squared tests, with multilevel logistic regression assessing independent associations. Trends over time and across UNOS (United Network for Organ Sharing) regions were evaluated, and a competing risks framework examined time to transplant and waitlist mortality. RESULTS:Among 26,330 candidates, 38.6% used exception requests, with a statistically significant increase over time, particularly in higher priority statuses. Exception use was more common among Black, non-Hispanic candidates, and candidates with blood type O, and less likely for patients with blood type A (P < 0.001). Additionally, pretransplant isolated durable left ventricular assist devices were less common in candidates who requested exceptions (19.0% vs 31.6%; P < 0.001). Overall, 39.9% of exception candidates were listed at status 1 or 2 compared to 29% of nonexception candidates, and 69.2% of exception candidates were removed from the waitlist at status 1 or 2 compared with 37% of nonexception candidates. CONCLUSIONS:The rising use of exceptions underscores ongoing limitations in allocation criteria, and disparities suggesting inequities in access to higher listing status. Policy refinements are needed to ensure a balance between medical urgency and equitable allocation.

Since the development of the first heart allocation system in 1988 to the most recent heart allocation system in 2018, the road to heart transplantation has continued to evolve. Policies were shaped with advances in temporary and durable left ventricular assist devices as well as prioritization of patients based on degree of illness. Herein, we review the changes in the heart allocation system over the past several decades and the impact of practice patterns across the United States.

BACKGROUND:Recent studies suggest the transplantation of Hepatitis C (HCV) hearts from viremic donors is associated with comparable 1 year survival to nonviremic donors. Though HCV viremia is a known risk factor for accelerated atherosclerosis, data on cardiac allograft vasculopathy (CAV) outcomes are limited. We compared the incidence of CAV in heart transplant recipients from HCV viremic donors (nucleic acid amplification test positive; NAT+) compared to non-HCV infected donors (NAT-). METHODS:We retrospectively reviewed annual coronary angiograms with intravascular ultrasound from April 2017 to August 2020 at two large cardiac transplant centers. CAV was graded according to ISHLT guidelines. Maximal intimal thickness (MIT) ≥ 0.5 mm was considered significant for subclinical disease. RESULTS:Among 270 heart transplant recipients (mean age 54; 77% male), 62 patients were transplanted from NAT+ donors. CAV ≥ grade 1 was present in 8.8% of the NAT+ versus 16.8% of the NAT- group at 1 year, 20% versus 28.8% at 2 years, and 33.3% versus 41.5% at 3 years. After adjusting for donor age, donor smoking history, recipient BMI, recipient, hypertension, and recipient diabetes, NAT+ status did not confer increased risk of CAV (HR.80; 95% CI.45-1.40, p = 0.43) or subclinical IVUS disease (HR.87; 95% CI.58-1.30, p = 0.49). Additionally, there was no difference in the presence of rapidly progressive lesions on IVUS. CONCLUSION/CONCLUSIONS:Our data show that NAT+ donors conferred no increased risk for early CAV or subclinical IVUS disease following transplantation in a cohort of heart transplant patients who were treated for HCV, suggesting the short-term safety of this strategy to maximize the pool of available donor hearts.

BACKGROUND/UNASSIGNED:While not available for clinical use in the United States, dedicated drug-coated balloons (DCB) are currently under investigation for the management of coronary in-stent restenosis (ISR). Peripheral drug-coated balloons (P-DCB) have been used off-label for coronary ISR. Further data regarding this practice are needed. We aimed to describe outcomes in patients who underwent off-label P-DCB angioplasty for coronary ISR. METHODS/UNASSIGNED:We analyzed data on P-DCB angioplasty for coronary ISR at a single high-volume center between April 1, 2015, and December 30, 2017. Demographic and procedural details were collected, with systematic follow-up as clinically indicated. RESULTS/UNASSIGNED:Data from 31 patients treated with P-DCB angioplasty (mean age 68.0 ± 10.7 years) with coronary ISR (17 recurrent and 14 first time) were analyzed. Most patients presented with high-grade angina (81%) or myocardial infarction (13%). Treated ISR lesions were in native coronary arteries (68%), saphenous vein grafts (SVG, 23%), and the left internal mammary artery (10%). Diffuse intrastent ISR was common (69%) with a mean lesion length of 21.7 ± 12.4 mm. No postprocedural myocardial infarction occurred and 1 nonprocedural mortality occurred during index admission. At follow-up (median: 283, interquartile range [IQR]: 354 days), repeat angiography was performed in 19 patients (median: 212, IQR: 188 days), and 11 patients had target lesion recurrent ISR (Kaplan-Meier event-free survival estimate: 44.7%, 95% CI, 26.1%-76.5%). CONCLUSIONS/UNASSIGNED:In the absence of availability of dedicated coronary DCB, treatment of coronary ISR using P-DCB angioplasty was feasible, although follow-up demonstrated continued risk for recurrent ISR in this high-risk population.

BACKGROUND/UNASSIGNED:To compare the long-term incidence of myocardial infarction (MI) and death in patients randomized to coronary artery bypass grafting (CABG) vs percutaneous coronary intervention (PCI) for treatment of isolated left anterior descending (LAD) coronary artery disease. METHODS/UNASSIGNED:We systematically identified all randomized controlled trials comparing PCI with stenting to CABG with a left internal mammary artery (LIMA) graft in patients with isolated LAD disease who had at least 4 years of follow-up. The primary outcome of interest was MI. Secondary outcomes were all-cause mortality and target vessel revascularization (TVR). RESULTS/UNASSIGNED:< .001). CONCLUSIONS/UNASSIGNED:The current meta-analysis suggests that there is insufficient evidence that CABG with a LIMA confers protection against MI or death compared to PCI with a stent for isolated LAD disease. CABG was, however, associated with reduced rates of TVR.

The increase of intravenous drug use has led to an increase in right-sided infective endocarditis and its complications including septic pulmonary embolism. The objective of this study was to compare the outcomes of tricuspid valve (TV) operations in patients with drug-use infective endocarditis (DU-IE) complicated by septic pulmonary emboli (PE). Hospitalizations for DU-IE complicated by septic PE were identified from the National Inpatient Sample from 2002 to 2019. Outcomes of patients who underwent TV operations were compared with medical management. The primary outcome was the incidence of major adverse cardiovascular events (MACEs), defined as in-hospital mortality, myocardial infarction, stroke, cardiogenic shock, or cardiac arrest. An inverse probability of treatment weighted analysis was utilized to adjust for the differences between the cohorts. A total of 9,029 cases of DU-IE with septic PE were identified (mean age 33.6 years), of which 818 patients (9.1%) underwent TV operation. Surgery was associated with a higher rate of MACE (14.5% vs 10.8%, p <0.01), driven by a higher rate of cardiogenic shock (6.1% vs 1.2%, p <0.01) but a lower rate of mortality (2.7% vs 5.7%, p <0.01). Moreover, TV operation was associated with an increased need for permanent pacemakers, blood transfusions, and a higher risk of acute kidney injury. In the inverse probability treatment weighting analysis, TV operation was associated with an increased risk for MACE driven by a higher rate of cardiogenic shock and cardiac arrest, but a lower rate of mortality when compared with medical therapy alone. In conclusion, TV operations in patients with DU-IE complicated by septic PE are associated with an increased risk for MACE but a decreased risk of mortality. Although surgical management may be beneficial in some patients, alternative options such as percutaneous debulking should be considered given the higher risk.

The long-term safety of heart transplants from hepatitis C viremic (NAT+) donors remains uncertain. We conducted a prospective study of all patients who underwent heart transplantation at our center from January 2018 through August 2020. Routine testing was performed to assess for donor-derived cell-free DNA, acute cellular rejection (ACR), antibody-mediated rejection (AMR), and cardiac allograft vasculopathy (CAV). Allograft dysfunction and mortality were also monitored. Seventy-five NAT- recipients and 32 NAT+ recipients were enrolled in the study. All NAT+ recipients developed viremia detected by PCR, were treated with glecaprevir/pibrentasvir at the time of viremia detection, and cleared the virus by 59 days post-transplant. Patients who underwent NAT testing starting on post-operative day 7 (NAT+ Group 1) had significantly higher viral loads and were viremic for a longer period compared with patients tested on post-operative day 1 (NAT+ Group 2). Through 3.5 years of follow-up, there were no statistically significant differences in timing, severity, or frequency of ACR in NAT+ recipients compared with the NAT- cohort, nor were there differences in noninvasive measures of graft injury, incidence or severity of CAV, graft dysfunction, or mortality. There were five episodes of AMR, all in the NAT- group. There were no statistically significant differences between Group 1 and Group 2 NAT+ cohorts. Overall, these findings underscore the safety of heart transplantation from NAT+ donors.

OBJECTIVE:We sought to describe a technique for ultra-low-contrast angiography (ULCA) in patients with advanced chronic kidney disease (CKD) and previous coronary artery bypass surgery (CABG). BACKGROUND:Patients with advanced CKD and previous CABG are at high risk of developing contrast-induced nephropathy (CIN) because of the additional contrast often required to identify bypass grafts. Apart from hydration, reduced contrast administration is the only established method to minimize the risk of CIN. PATIENTS AND METHODS:Ten patients underwent ULCA, whereby an intracoronary injection of saline and coronary guidewires were used instead of test injections of contrast for engagement of bypass grafts with catheters. Estimated glomerular filtration rate (eGFR) before and 30 days following angiography were recorded as was the need for renal replacement therapy 1 year after the procedure. RESULTS:All patients completed a diagnostic angiogram without complications. The median volume of contrast delivered was 13.5 ml (interquartile range: 10.5-17.8). The median eGFR was 18.3 ml/min/1.73 m (interquartile range: 16.5-28.2). There was no statistically significant difference in eGFR before the procedure and 30 days after the procedure (P=0.79). No patient required dialysis 30 days after the procedure. Two patients required initiation of dialysis at 1 year after the procedure. CONCLUSION:In patients with advanced CKD and previous CABG, ULCA may be performed with high procedural success and without complications, minimizing the risk of CIN in these high-risk patients.