Evolving Trends and Impact of Waitlist Transfusion on Recipient Outcomes Following Heart Transplantation.

BACKGROUND: This study evaluates the clinical trends, risk factors, and impact of waitlist blood transfusion on outcomes following isolated heart transplantation. METHODS: The UNOS registry was queried to identify adult recipients from January 1, 2014, to June 30, 2022. The recipients were stratified into two groups depending on whether they received a blood transfusion while on the waitlist. The incidence of waitlist transfusion was compared before and after the 2018 allocation policy change. The primary outcome was survival. Propensity score-matching was performed. Multivariable logistic regression was performed to identify predictors of waitlist transfusion. A sub-analysis was performed to evaluate the impact of waitlist time on waitlist transfusion. RESULTS: From the 21 926 recipients analyzed in this study, 4201 (19.2%) received waitlist transfusion. The incidence of waitlist transfusion was lower following the allocation policy change (14.3% vs. 23.7%, p < 0.001). The recipients with waitlist transfusion had significantly reduced 1-year posttransplant survival (88.8% vs. 91.9%, p < 0.001) compared to the recipients without waitlist transfusion in an unmatched comparison. However, in a propensity score-matched comparison, the two groups had similar 1-year survival (90.0% vs. 90.4%, p = 0.656). Multivariable analysis identified ECMO, Impella, and pretransplant dialysis as strong predictors of waitlist transfusion. In a sub-analysis, the odds of waitlist transfusion increased nonlinearly with longer waitlist time. CONCLUSION: There is a lower incidence of waitlist transfusion among transplant recipients under the 2018 allocation system. Waitlist transfusion is not an independent predictor of adverse posttransplant outcomes but rather a marker of the patient's clinical condition. ECMO, Impella, and pretransplant dialysis are strong predictors of waitlist transfusion.

Outcomes of Impella 5.0 and 5.5 for cardiogenic shock: A single-center 137 patient experience.

BACKGROUND: This study evaluated the outcomes of patients with cardiogenic shock (CS) supported with Impella 5.0 or 5.5 and identified risk factors for in-hospital mortality. METHODS: Adults with CS who were supported with Impella 5.0 or 5.5 at a single institution were included. Patients were stratified into three groups according to their CS etiology: (1) acute myocardial infarction (AMI), (2) acute decompensated heart failure (ADHF), and (3) postcardiotomy (PC). The primary outcome was survival, and secondary outcomes included adverse events during Impella support and length of stay. Multivariable logistic regression was performed to identify risk factors for in-hospital mortality. RESULTS: One hundred and thirty-seven patients with CS secondary to AMI (n = 47), ADHF (n = 86), and PC (n = 4) were included. The ADHF group had the highest survival rates at all time points. Acute kidney injury (AKI) was the most common complication during Impella support in all 3 groups. Increased rates of AKI and de novo renal replacement therapy were observed in the PC group, and the AMI group experienced a higher incidence of bleeding requiring transfusion. Multivariable analysis demonstrated diabetes mellitus, elevated pre-insertion serum lactate, and elevated pre-insertion serum creatinine were independent predictors of in-hospital mortality, but the etiology of CS did not impact mortality. CONCLUSIONS: This study demonstrates that Impella 5.0 and 5.5 provide effective mechanical support for patients with CS with favorable outcomes, with nearly two-thirds of patients alive at 180 days. Diabetes, elevated pre-insertion serum lactate, and elevated pre-insertion serum creatinine are strong risk factors for in-hospital mortality.

The Clinical Significance of Unplanned Coronary Artery Bypass Grafting in Aortic Root Replacement.

OBJECTIVES: Unexpected coronary artery bypass grafting (CABG) is occasionally required during aortic root replacement (ARR). However, the impact of unplanned CABG remains unknown. DESIGN: A single-center, retrospective observational study. SETTING: At university-affiliated tertiary hospital. PARTICIPANTS: All patients who underwent ARR from 2011 through 2022. INTERVENTIONS: Aortic root replacement with or without unplanned CABG. MEASUREMENTS AND MAIN RESULTS: A total of 795 patients underwent ARR. Among them, 131 (16.5%) underwent planned concomitant CABG, and 34 (4.3%) required unplanned CABG. The most common indication of unplanned CABG was ventricular dysfunction (33.3%), followed by disease pathology (25.6%), anatomy (15.4%), and surgical complications (10.3%). A vein graft to the right coronary artery was the most commonly performed bypass. Infective endocarditis and aortic dissection were observed in 27.8% and 12.8%, respectively. Prior cardiac surgery was seen in 40.3%. The median follow-up period was 4.3 years. Unplanned CABG was not associated with operative mortality (odds ratio [OR] 1.54, 95% CI 0.33-7.16, p = 0.58) or long-term mortality (hazard ratio 0.91, 95% CI 0.44-1.89, p = 0.81). Body surface area smaller than 1.7 was independently associated with an increased risk of unplanned CABG (OR 4.51, 95% CI 1.85-11.0, p < 0.001). CONCLUSIONS: Unplanned CABG occurred in 4.3% of patients during ARR, but was not associated with operative mortality or long-term mortality. A small body surface area was a factor associated with unplanned CABG.

Robotically assisted outflow graft anastomosis in minimally invasive left-ventricular assist device implantation: feasibility, surgeon comfort, and operative times in an anatomical study.

Upper hemi-sternotomy is a common approach for outflow graft anastomosis to the ascending aorta in minimally invasive left-ventricular assist device implantation. Right mini-thoracotomy may also be used, but use of robotic assistance has been reported only anecdotally. The aim of our study was to confirm the feasibility of robotically assisted suturing of the outflow graft anastomosis and to assess performance metrics for the robotic suturing part of the procedure. The procedure was carried out in eight cadaver studies by two surgeons. The assist device pump head was inserted through a left-sided mini-thoracotomy and the outflow graft was passed toward a right-sided second interspace mini-thoracotomy through the pericardium. After placement of a partial occlusion clamp on the ascending aorta, a longitudinal aortotomy was performed and the outflow graft to ascending aorta anastomosis was carried out robotically. The procedure was feasible in all eight attempts. The mean outflow graft anastomotic time was 20.1 (SD 6.8) min and the mean surgeon confidence and comfort levels to complete the anastomoses were 8.3 (SD 2.4) and 6.9 (SD2.2), respectively, on a ten-grade Likert scale. On open inspection of the anastomoses, there was good suture alignment in all cases. We conclude that suturing of a left-ventricular assist device outflow graft to the human ascending aorta is very feasible with good surgeon comfort. Anastomotic times are acceptable and suture placement can be performed with appropriate alignment.

Can we safely expand the donation after circulatory death donor heart pool by extending the donor age limit?

OBJECTIVE: This study evaluates the impact of donor age on outcomes following donation after circulatory death heart transplantation. METHODS: The United Network for Organ Sharing registry was queried to analyze adult recipients who underwent isolated donation after circulatory heart transplantation from January 1, 2019, to September 30, 2023. The cohort was stratified into 2 groups according to donor age, where advanced donor age was defined as 40 years or more. Outcomes were 90-day and 1-year post-transplant survival. Propensity score matching was performed. Subgroup analysis was performed to evaluate the effects of recipient age on 90-day survival among the recipients with advanced-age donors. RESULTS: A total of 994 recipients were included in the study period, and 161 patients (17.1%) received allografts from advanced-age donors. During the study period, the annual incidence of donation after circulatory heart transplantation with advanced-age donors substantially increased. The recipients with advanced-age donors had similar 90-day and 1-year post-transplant survivals compared with the recipients with younger donors. The comparable 90-day survival persisted in a propensity score-matched comparison. In the subgroup analysis among the recipients with advanced-age donors, the recipients aged 60 years or more had significantly reduced 90-day survival compared with the recipients aged less than 60 years. CONCLUSIONS: The use of appropriately selected donation after circulatory donors aged 40 years or more has similar survival compared with that of younger donors. With careful candidate risk stratification and selection, consideration of using donation after circulatory donors aged more than 40 years may further ameliorate ongoing organ shortage with comparable early post-transplant outcomes.

Extended Duration of Impella 5.5 Support Does Not Adversely Impact Outcomes Following Heart Transplantation: A National Registry Analysis.

Prior studies assessing the effects of Impella 5.5 support duration on posttransplant outcomes have been limited to single-center case reports and series. This study evaluates the impact of Impella 5.5 support duration on outcomes following heart transplantation using the United Network for Organ Sharing database. Adult heart transplant recipients who were directly bridged to primary isolated heart transplantation with Impella 5.5 were included. The cohort was stratified into two groups based on the duration of Impella support: less than or equal to 14 and greater than 14 days. The primary outcome was 90 day posttransplant survival. Propensity score matching was performed. Sub-analysis was conducted to evaluate the impact of greater than 30 days of Impella support on 90 day survival. Three hundred thirty-two recipients were analyzed. Of these, 212 recipients (63.9%) were directly bridged to heart transplantation with an Impella support duration of greater than 14 days. The two groups had comparable 90 day posttransplant survival and complication rates. The comparable posttransplant survival persisted in a propensity score-matched comparison. In the sub-analysis, Impella support duration of greater than or equal to 30 days did not adversely impact 90 day survival. This study demonstrates that extended duration of support with Impella 5.5 as a bridge to transplantation does not adversely impact posttransplant outcomes. Impella 5.5 is a safe and effective bridging modality to heart transplantation.

Concomitant use of extracorporeal membrane oxygenation and percutaneous microaxial assist device support for cardiogenic shock.

Objectives: Venoarterial extracorporeal membrane oxygenation (VA-ECMO) with concomitant percutaneous microaxial left ventricular assist device support is an emerging treatment modality for cardiogenic shock (CS). Survival outcomes by CS etiology with this support strategy have not been well described. Methods: This study was a retrospective, single-center analysis of patients with CS due to acute myocardial infarction (AMI-CS) or decompensated heart failure (ADHF-CS) supported with VA-ECMO with concomitant percutaneous microaxial left ventricular assist device support from December 2020 to January 2023. Results: A total of 44 patients were included (AMI-CS, n = 20, and ADHF-CS, n = 24). Patients with AMI-CS and ADHF-CS had similar survival at 90 days postdischarge (P = .267) with similar destinations after support (P = .220). Patients with AMI-CS initially supported with VA-ECMO were less likely to survive 90 days postdischarge (P = .038) when compared with other cohorts. Limb ischemia and acute kidney injury occurred more frequently in patients presenting with AMI-CS (P =.013; P = .030). Subanalysis of ADHF-CS patients into acute-on-chronic decompensated HF and de novo HF demonstrated no difference in survival or destination. Conclusions: VA-ECMO with concomitant percutaneous microaxial left ventricular assist device support can be used to successfully manage patients with CS. There is no difference in survival or destination for AMI-CS and ADHF-CS with this support strategy. AMI-CS patients with initial VA-ECMO support have increased mortality in comparison to other cohorts. Future multicenter studies are required to fully analyze the differences between AMI-CS and ADHF-CS with this support strategy.

Midterm Outcomes After Aortic Valve Neocuspidization (Ozaki Procedure) in Adults.

BACKGROUND: Trileaflet aortic valve neocuspidization (AVN) using autologous pericardium (Ozaki procedure) is an emerging surgical treatment option for aortic valve diseases. Although excellent results have been reported from Japan, data pertaining to its use in the United States are sparse. METHODS: All adult patients who underwent AVN (AVN group) or surgical aortic valve replacement (SAVR) with a bioprosthetic valve (SAVR group) between 2015 and 2022 were identified. Propensity score matching was used to adjust the baseline characteristics between the 2 groups. RESULTS: A total of 101 patients underwent AVN, and 1816 patients underwent SAVR with a bioprosthetic valve. None in the AVN group required conversion to SAVR. Before matching, mean age in the AVN group was 68.5 ± 8.8 years, and 56 patients (55.4%) underwent concomitant procedures. Preoperatively, 3 (3%) had endocarditis. Bicuspid valve was observed in 38 (38.4%). None died at 30 days in the AVN group. The median follow-up duration was 3.2 years. After propensity score matching, the expected survival and freedom from at least moderate aortic regurgitation at 5 years was 91.7% ± 3.1% and 97.6% ± 1.7%, respectively. Propensity score matching yielded 77 patients in each group. The Kaplan-Meier curve demonstrated equivalent survival at 5 years between the 2 groups (P = .95). Additionally, freedom from at least moderate aortic regurgitation was comparable at 5 years (P = .23). CONCLUSIONS: AVN can be safely performed for a variety of aortic valve diseases, with or without concomitant operations. AVN demonstrated similar midterm outcomes compared with SAVR with a bioprosthetic valve in the United States adult population.

External validation of the ARCH score in patients undergoing aortic arch reconstruction under circulatory arrest.

BACKGROUND: Aortic arch surgery with hypothermic circulatory arrest (HCA) carries a higher risk of morbidity and mortality compared to routine cardiac surgical procedures. The newly developed ARCH (arch reconstruction under circulatory arrest with hypothermia) score has not been externally validated. We sought to externally validate this score in our local population. METHODS: All consecutive open aortic arch surgeries with HCA performed between 2014 and 2023 were included. Univariable and multivariable analyses were performed. Model discrimination was assessed by the C-statistic with 95% confidence intervals as part of the receiver operating characteristic (ROC) curve analysis. Model performance was visualized by a calibration plot and quantified by the Brier score. RESULTS: A total of 760 patients (38.3% females) were included. The mean age was 61 (±13.6) years, with 56.4% of patients' age >60 years. The procedures were carried out mostly emergently or urgently (59.6%). Total arch replacement was performed in 32.5% of the patients, and aortic root procedures were carried out in 74.6%. In-hospital death occurred in 64 patients (8.4%), and stroke occurred in 5.4%. The C-statistic revealed a low discriminatory ability for predicting in-hospital mortality (area under the ROC curve, 0.62; 95% confidence interval, 0.54-0.69; P = .002); however, model calibration was found to be excellent (Brier score of 0.07). CONCLUSIONS: The ARCH score for in-hospital mortality showed low discriminatory ability in our local population, although with excellent ability for prediction of mortality.

Impact of post-transplant stroke and subsequent functional independence on outcomes following heart transplantation under the 2018 United States heart allocation system.

BACKGROUND: This study evaluates the clinical trends, risk factors, and effects of post-transplant stroke and subsequent functional independence on outcomes following orthotopic heart transplantation under the 2018 heart allocation system. METHODS: The United Network for Organ Sharing registry was queried to identify adult recipients from October 18, 2018 to December 31, 2021. The cohort was stratified into 2 groups with and without post-transplant stroke. The incidence of post-transplant stroke was compared before and after the allocation policy change. Outcomes included post-transplant survival and complications. Multivariable logistic regression was performed to identify risk factors for post-transplant stroke. Sub-analysis was performed to evaluate the impact of functional independence among recipients with post-transplant stroke. RESULTS: A total of 9,039 recipients were analyzed in this study. The incidence of post-transplant stroke was higher following the policy change (3.8% vs 3.1%, p = 0.017). Thirty-day (81.4% vs 97.7%) and 1-year (66.4% vs 92.5%) survival rates were substantially lower in the stroke cohort (p < 0.001). The stroke cohort had a higher rate of post-transplant renal failure, longer hospital length of stay, and worse functional status. Multivariable analysis identified extracorporeal membrane oxygenation, durable left ventricular assist device, blood type O, and redo heart transplantation as strong predictors of post-transplant stroke. Preserved functional independence considerably improved 30-day (99.2% vs 61.2%) and 1-year (97.7% vs 47.4%) survival rates among the recipients with post-transplant stroke (p < 0.001). CONCLUSIONS: There is a higher incidence of post-transplant stroke under the 2018 allocation system, and it is associated with significantly worse post-transplant outcomes. However, post-transplant stroke recipients with preserved functional independence have improved survival, similar to those without post-transplant stroke.

The history of cardiac xenotransplantation: early attempts, major advances, and current progress.

In light of ongoing shortage of donor organs for transplantation, alternative sources for donor organ sources have been examined to address this supply-demand mismatch. Of these, xenotransplantation, or the transplantation of organs across species, has been considered, with early applications dating back to the 1600s. The purpose of this review is to summarize the early experiences of xenotransplantation, with special focus on heart xenotransplantation. It aims to highlight the important ethical concerns of animal-to-human heart xenotransplantation, identify the key immunological barriers to successful long-term xenograft survival, as well as summarize the progress made in terms of development of pharmacological and genetic engineering strategies to address these barriers. Lastly, we discuss more recent attempts of porcine-to-human heart xenotransplantation, as well as provide some commentary on the current concerns and possible applications for future clinical heart xenotransplantation.