Evaluating the Association Between Social Vulnerability and Outcomes of Heart Transplantation in the United States.

INTRODUCTION: The Social Vulnerability Index (SVI) is a tool that was developed by the Centers for Disease Control and Prevention to help identify communities that are at risk of harm from social, economic, or environmental factors. This study evaluates the association between SVI and outcomes of adult heart transplantation (HT) in the United States. METHODS: The United Network for Organ Sharing registry was used to identify all isolated adult (≥18 y) HT recipients and their home address zip codes between 2010 and 2021. Recipients were classified into three SVI risk groups: low risk (SVI: <0.33), intermediate risk (SVI: 0.33-0.65), and high risk (SVI: ≥0.66). Kaplan-Meier analysis was used to estimate recipient survival probability based on SVI risk. Multivariable Cox proportional hazard models were built to evaluate the association of SVI with 1- and 5-y mortality. RESULTS: A total of 22,400 recipients distributed over 9753 zip codes were included. Unadjusted 1-y survival rates in the three risk groups were as follows: low risk: 90.5%, intermediate risk: 91.1%, high risk 90.9%, and Log-rank P = 0.550 and 5-y survival rates were as follows: low risk: 80.8%, intermediate risk: 78.6%, high risk: 76.1%, and Log-rank P < 0.001. Compared to low-risk recipients, risk-adjusted 1-y mortality hazard ratio was 1.02 (0.92-1.14, P = 0.657) for intermediate risk and 1.09 (0.95-1.24, P = 0.222) for high-risk recipients. Risk-adjusted 5-y mortality hazard ratio was 1.07 (0.99-1.16, P = 0.095) for intermediate-risk recipients and 1.17 (1.06-1.28, P = 0.002) for high-risk recipients. CONCLUSIONS: Social vulnerability is associated with HT outcomes. The Centers for Disease Control and Prevention SVI may be a useful tool in identifying at-risk geographic areas where targeted efforts may be prudent for reducing disparities in HT outcomes.

Early Stroke Following Durable Left Ventricular Assist Device (LVAD) Implantation: An Analysis of The Society of Thoracic Surgeons Intermacs National Database.

BACKGROUND: Stroke remains a devastating complication of durable left ventricular assist device (LVAD) therapy. This study evaluated the incidence and risk factors for early stroke within 7 days following LVAD implantation investigating both traditional pre-implant and new intraoperative variables collected by The Society of Thoracic Surgeons (STS) Intermacs National Database. METHODS: STS Intermacs was queried for patients undergoing implantation of a fully magnetically levitated centrifugal LVAD between 11/25/2020 and 6/30/2023. STS Intermacs stroke definitions were used to identify patients who suffered a stroke within the first 7 postoperative days (POD). A multivariable logistic regression model was created to generate adjusted odd ratios (OR) for variables associated with early stroke. RESULTS: Among 6950 patients in the study cohort, 5.9% (413/6950) developed a stroke after a median follow-up of 11 months, with 50% (205/413) of strokes occurring within 7 days after LVAD implantation. Of the strokes occurring during POD 0-7, 70% (144/205) occurred on POD 0-2. By multivariable analysis, the following factors were associated with early stroke: older age (70 vs. 50; OR 1.4, P=0.0129), white race (OR 1.5, P=0.0078), pre-implant temporary MCS bridge (temporary LVAD only: OR 1.6, ECMO only: OR 1.7, combination of both devices: OR 3.3; P=0.0001) and presence of an unremoved left atrial clot (OR 8.0, P<0.0001). CONCLUSION: A significant proportion of strokes occur within the first 7 days following LVAD implantation, particularly within the first 2 days. In addition to pre-implant variables, we identified modifiable intraoperative factors associated with stroke that provide an opportunity for further risk mitigation and improvement in quality of care.

A clinical comparison of glycol and water-based heater-cooler systems for cardiopulmonary bypass.

INTRODUCTION: While newer heater-cooler technologies using ethylene glycol-based (GB) solutions during cardiothoracic surgery have become commercially available, there is a paucity of clinical data describing their effectiveness during cardiopulmonary bypass (CPB) support. This analysis aimed to compare clinical characteristics and procedural outcomes using water-based (WB) and GB heater-cooler systems. METHODS: A retrospective analysis was performed on consecutive adult patients undergoing CPB from June to October 2022 comparing WB or GB groups. The primary outcome was a composite of operative death or major morbidity. Secondary endpoints included transfusion requirements on CPB, patient cooling and warming rates, and vasoactive-inotropic scores (VIS) at case completion. P-control charts were used to monitor the weekly incidence of the composite outcome. A sub-analysis was performed to evaluate the primary outcome for cardiac surgery cases indexed by the Society of Thoracic Surgeons (STS). RESULTS: There were 167 patients included for analysis; 87 (52.1%) underwent CPB with a WB system and 80 (47.9%) with a GB system. GB procedure subjects were younger (p = .01), experienced longer CPB times (p = .034), and were more likely to receive thoracic transplant or aortic surgery (p = 0.015). The composite outcome of operative mortality or major morbidity occurred in 29.9% and 24% of the WB and GB groups, respectively (p = .372). P-control charts indicated a weekly mean incidence of 30% during WB practice, which decreased to 24% with GB practice. Among 106 STS-indexed cardiac surgery cases, mean composite outcome incidence decreased from 19% to 6% following our GB transition. Additionally, cooling, and warming rates indexed to patient BSA and VIS at case completion were not significantly different. CONCLUSION: Our analysis demonstrated a safe transition from WB to GB heater-cooler technologies in our practice. This early analysis suggests that GB heater coolers may be safely adopted to mitigate the risks of nontuberculous mycobacterium infections for cardiac surgical patients.

Aortic Root Thromboembolism and Associated Acute Myocardial Infarction in Patients With Contemporary Durable LVADs.

Patients with HeartMate 3 left ventricular assist devices may develop aortic root thrombus, yet its prevalence and associated risks are unknown. We present 2 patients who developed aortic root thromboembolism and acute coronary occlusions. We additionally present heart transplantation as viable treatment for thromboembolic disease and refractory right ventricular failure.

Impact of institutional variables on centre performance in long-term survival after heart transplant.

OBJECTIVES: The gold standard metric for centre-level performance in orthotopic heart transplantation (OHT) is 1-year post-OHT survival. However, it is unclear whether centre performance at 1 year is predictive of longer-term outcomes. This study evaluated factors impacting longer-term centre-level performance in OHT. METHODS: Patients who underwent OHT in the USA between 2010 and 2021 were identified using the United Network of Organ Sharing data registry. The primary outcome was 5-year survival conditional on 1-year survival following OHT. Multivariable Cox proportional hazard models assessed the impact of centre-level 1-year survival rates on 5-year survival rates. Mixed-effect models were used to evaluate between-centre variability in outcomes. RESULTS: Centre-level risk-adjusted 5-year mortality conditional on 1-year survival was not associated with centre-level 1-year survival rates [hazard ratio: 0.99 (0.97-1.01, P = 0.198)]. Predictors of 5-year mortality conditional on 1-year survival included black recipient race, pre-OHT serum creatinine, diabetes and donor age. In mixed-effect modelling, there was substantial variability between centres in 5-year mortality rates conditional on 1-year survival, a finding that persisted after controlling for recipient, donor and institutional factors (P < 0.001). In a crude analysis using Kaplan-Meier, the 5-year survival conditional on 1-year survival was: low volume: 86.5%, intermediate volume: 87.5%, high volume: 86.7% (log-rank P = 0.52). These measured variables only accounted for 21.4% of the between-centre variability in 5-year mortality conditional on 1-year survival. CONCLUSIONS: Centre-level risk-adjusted 1-year outcomes do not correlate with outcomes in the 1- to 5-year period following OHT. Further research is needed to determine what unmeasured centre-level factors contribute to longer-term outcomes in OHT.

American Heart Association Cardiogenic Shock Registry: Design and Implementation.

BACKGROUND: Cardiogenic shock is a morbid complication of heart disease that claims the lives of more than 1 in 3 patients presenting with this syndrome. Supporting a unique collaboration across clinical specialties, federal regulators, payors, and industry, the American Heart Association volunteers and staff have launched a quality improvement registry to better understand the clinical manifestations of shock phenotypes, and to benchmark the management patterns, and outcomes of patients presenting with cardiogenic shock to hospitals across the United States. METHODS: Participating hospitals will enroll consecutive hospitalized patients with cardiogenic shock, regardless of etiology or severity. Data are collected through individual reviews of medical records of sequential adult patients with cardiogenic shock. The electronic case record form was collaboratively designed with a core minimum data structure and aligned with Shock Academic Research Consortium definitions. This registry will allow participating health systems to evaluate patient-level data including diagnostic approaches, therapeutics, use of advanced monitoring and circulatory support, processes of care, complications, and in-hospital survival. Participating sites can leverage these data for onsite monitoring of outcomes and benchmarking versus other institutions. The registry was concomitantly designed to provide a high-quality longitudinal research infrastructure for pragmatic randomized trials as well as translational, clinical, and implementation research. An aggregate deidentified data set will be made available to the research community on the American Heart Association's Precision Medicine Platform. On March 31, 2022, the American Heart Association Cardiogenic Shock Registry received its first clinical records. At the time of this submission, 100 centers are participating. CONCLUSIONS: The American Heart Association Cardiogenic Shock Registry will serve as a resource using consistent data structure and definitions for the medical and research community to accelerate scientific advancement through shared learning and research resulting in improved quality of care and outcomes of shock patients.

Prediction of coronary artery bypass graft outcomes using a single surgical note: An artificial intelligence-based prediction model study.

BACKGROUND: Healthcare providers currently calculate risk of the composite outcome of morbidity or mortality associated with a coronary artery bypass grafting (CABG) surgery through manual input of variables into a logistic regression-based risk calculator. This study indicates that automated artificial intelligence (AI)-based techniques can instead calculate risk. Specifically, we present novel numerical embedding techniques that enable NLP (natural language processing) models to achieve higher performance than the risk calculator using a single preoperative surgical note. METHODS: The most recent preoperative surgical consult notes of 1,738 patients who received an isolated CABG from July 1, 2014 to November 1, 2022 at a single institution were analyzed. The primary outcome was the Society of Thoracic Surgeons defined composite outcome of morbidity or mortality (MM). We tested three numerical-embedding techniques on the widely used TextCNN classification model: 1a) Basic embedding, treat numbers as word tokens; 1b) Basic embedding with a dataloader that Replaces out-of-context (ROOC) numbers with a tag, where context is defined as within a number of tokens of specified keywords; 2) ScaleNum, an embedding technique that scales in-context numbers via a learned sigmoid-linear-log function; and 3) AttnToNum, a ScaleNum-derivative that updates the ScaleNum embeddings via multi-headed attention applied to local context. Predictive performance was measured via area under the receiver operating characteristic curve (AUC) on holdout sets from 10 random-split experiments. For eXplainable-AI (X-AI), we calculate SHapley Additive exPlanation (SHAP) values at an ngram resolution (SHAP-N). While the analyses focus on TextCNN, we execute an analogous performance pipeline with a long short-term memory (LSTM) model to test if the numerical embedding advantage is robust to model architecture. RESULTS: A total of 567 (32.6%) patients had MM following CABG. The embedding performances are as follows with the TextCNN architecture: 1a) Basic, mean AUC 0.788 [95% CI (confidence interval): 0.768-0.809]; 1b) ROOC, 0.801 [CI: 0.788-0.815]; 2) ScaleNum, 0.808 [CI: 0.785-0.821]; and 3) AttnToNum, 0.821 [CI: 0.806-0.834]. The LSTM architecture produced a similar trend. Permutation tests indicate that AttnToNum outperforms the other embedding techniques, though not statistically significant verse ScaleNum (p-value of .07). SHAP-N analyses indicate that the model learns to associate low blood urine nitrate (BUN) and creatinine values with survival. A correlation analysis of the attention-updated numerical embeddings indicates that AttnToNum learns to incorporate both number magnitude and local context to derive semantic similarities. CONCLUSION: This research presents both quantitative and clinical novel contributions. Quantitatively, we contribute two new embedding techniques: AttnToNum and ScaleNum. Both can embed strictly positive and bounded numerical values, and both surpass basic embeddings in predictive performance. The results suggest AttnToNum outperforms ScaleNum. With regards to clinical research, we show that AI methods can predict outcomes after CABG using a single preoperative note at a performance that matches or surpasses the current risk calculator. These findings reveal the potential role of NLP in automated registry reporting and quality improvement.

Changes in heart transplant outcomes of elderly patients in the new allocation era.

OBJECTIVE: Studies demonstrate that heart transplantation can be performed safely in septuagenarians. We evaluate the outcomes of septuagenarians undergoing heart transplantation after the US heart allocation change in 2018. METHODS: The United Network for Organ Sharing registry was used to identify heart transplant recipients aged 70 years or more between 2010 and 2021. Primary outcomes were 90-day and 1-year mortality. Kaplan-Meier, multivariable Cox proportional hazards, and accelerated failure time models were used for unadjusted and risk-adjusted analyses. RESULTS: A total of 27,403 patients underwent heart transplantation, with 1059 (3.9%) aged 70 years or more. Patients aged 70 years or more increased from 3.7% before 2018 to 4.5% after 2018 (P = .003). Patients aged 70 years or more before 2018 had comparable 90-day and 1-year survivals relative to patients aged less than 70 years (90 days: 93.8% vs 94.2%, log-rank P = .650; 1 year: 89.4% vs 91.1%, log-rank P = .130). After 2018, septuagenarians had lower 90-day and 1-year survivals (90 days: 91.4% vs 95.0%, log-rank P = .021; 1 year: 86.5% vs 90.9%, log-rank P = .018). Risk-adjusted analysis showed comparable 90-day mortality (hazard ratio, 1.29; 0.94-1.76, P = .110) but worse 1-year mortality (hazard ratio, 1.32; 1.03-1.68, P = .028) before policy change. After policy change, both 90-day and 1-year mortalities were higher (90 days: HR, 1.99; 1.23-3.22, P = .005; 1 year: hazard ratio, 1.71; 1.14-2.56, P = .010). An accelerated failure time model showed comparable 90-day (0.42; 0.16-1.44; P = .088) and 1-year (0.48; 0.18-1.26; P = .133) survival postallocation change. CONCLUSIONS: Septuagenarians comprise a greater proportion of heart transplant recipients after the allocation change, and their post-transplant outcomes relative to younger recipients have worsened.

Heart Transplantation for Adults With Congenital Heart Disease Can Be Performed at Adult or Pediatric Hospitals With Comparable Outcomes.

INTRODUCTION: The goal of this study was to evaluate the relationship between hospital-related factors and hospital type on outcomes of heart transplantation for patients with adult congenital heart disease (ACHD). METHODS: Patients with ACHD who underwent heart transplant between 2010 and 2021 were identified using the United Network for Organ Sharing data registry. The primary outcome was post-transplant mortality. Kaplan-Meier unadjusted survival curves were compared using the log-rank test. Multivariable Cox proportional hazard models were used for risk-adjustment in evaluating the independent effect of hospital type on post-transplant mortality. RESULTS: Of 70 centers, 54 (77.1%) adult centers performed 415 (87.0%) heart transplants and 16 (22.9%) pediatric centers performed 62 (13.0%) heart transplants. Patients transplanted at pediatric centers were younger, had lower creatinine levels, and had lower body mass index. The unadjusted 1-y and 5-y survival was comparable in pediatric versus adult centers, respectively: 93.4% versus 86.6% (log-rank P = 0.16) and 87.4% versus 73.9% (log-rank P = 0.06). These findings persisted after risk-adjustment. One-year mortality hazard ratio for pediatric hospitals: 0.64 (0.22-1.89, P = 0.416) and 5-y mortality hazard ratio for pediatric hospitals: 0.53 (0.21-1.33, P = 0.175). Rates of acute rejection, postoperative stroke, and new-onset postoperative dialysis were also comparable. CONCLUSIONS: Heart transplantation for patients with ACHD can be performed safely in adult centers. The majority of heart transplant for ACHD in the United States are performed at adult hospitals. However, further research is needed to delineate the impact of individual surgeon characteristics and hospital-related factors on outcomes.

Patient Characteristics and Early Clinical Outcomes With Impella 5.5: A Systematic Review and Meta-Analysis.

Data regarding outcomes with Impella 5.5 are limited. The aim of this systematic review and meta-analysis was to summarize patient and treatment characteristics and early clinical outcomes among patients supported by Impella 5.5. A systematic literature search was conducted in PubMed, Scopus, and Cochrane databases from September 2019 to March 2023. Studies reporting outcomes in greater than or equal to 5 patients were included for review. Patient characteristics, treatment characteristics, and early clinical outcomes were extracted. Outcomes included adverse events, survival to hospital discharge, and 30 day survival. Random-effect models were used to estimate pooled effects for survival outcomes. Assessment for bias was performed using funnel plots and Egger's tests. Fifteen studies were included for qualitative review, representing 707 patients. Mean duration of support was 9.9 ± 8.2 days. On meta-analysis of 13 studies reporting survival outcomes, survival to hospital discharge was 68% (95% confidence interval [CI], 58-78%), and 30 day survival was 65% (95% CI, 56-74%) among patients with Impella devices predominantly supported by Impella 5.5 (>60%). There was significant study heterogeneity for these outcomes. Among 294 patients with Impella 5.5 only, survival to discharge was 78% (95% CI, 72-82%) with no significant study heterogeneity. This data present early benchmarks for outcomes with Impella 5.5 as clinical experience with these devices accrues.

A multicenter evaluation of the HeartMate 3 risk score.

BACKGROUND: The Heartmate 3 (HM3) risk score (HM3RS) was derived and validated internally from within the Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy with HeartMate 3 (MOMENTUM 3) trial population and provides 1- and 2-year mortality risk prediction for patients in those before HM3 left ventricular assist device (LVAD) implantation. We aimed to evaluate the HM3RS in nontrial unselected patients, including those not meeting inclusion criteria for MOMENTUM 3 trial enrollment. METHODS: Patients who underwent HM3 LVAD implant at 1 of 7 US centers between 2017 and 2021, with at least 1-year follow-up, were included in this analysis. Patients were retrospectively assessed for their eligibility for the MOMENTUM 3 trial based on study inclusion and exclusion criteria. HM3RS risk discrimination was evaluated using time-dependent receiver operating characteristic curve analysis for 1-year mortality for all patients and further stratified by MOMENTUM 3 trial eligibility. Kaplan-Meier curves were constructed using the HM3RS-based risk categories. RESULTS: Of 521 patients included in the analysis, 266 (51.1%) would have met enrollment criteria for MOMENTUM 3. The 1- and 2-year survival for the total cohort was 85% and 81%, respectively. There was no statistically significant difference in survival between those who met and did not meet enrollment criteria at 1 (87% vs 83%; p = 0.21) and 2 years postimplant (80% vs 78%; p = 0.39). For the total cohort, HM3RS predicted 1-year survival with an area under the curve (AUC) of 0.63 (95% confidence interval [CI]: 0.57-0.69, p < 0.001). HM3RS performed better in the subset of patients meeting enrollment criteria: AUC 0.69 (95% CI:0.61-0.77, p < 0.001) compared to the subset that did not: AUC 0.58 (95% CI: 0.49-0.66, p = 0.078). CONCLUSIONS: In this real-world evidence, multicenter cohort, 1- and 2-year survival after commercial HM3 LVAD implant was excellent, regardless of trial eligibility. The HM3RS provided adequate risk discrimination in "trial-like" patients, but predictive value was reduced in patients who did not meet trial criteria.

Quality and Impact of Manuscripts Using The Society of Thoracic Surgeons National Databases.

BACKGROUND: The Society of Thoracic Surgeons (STS) National Databases contain the largest and most comprehensive cardiac, thoracic, and congenital surgery data available. In this analysis characteristics of manuscripts that used the STS National Databases were examined to evaluate the quality and impact of these publications. METHODS: Manuscripts published from 2010 to 2020 that used the STS National Databases (Adult Cardiac, General Thoracic, and Congenital Heart Surgery) were examined. The number of times cited per published manuscript, journal of publication, and journal CiteScore were assessed. Author characteristics, including institutional association and h-index, were evaluated for first and last authors. RESULTS: Of 539 published manuscripts, 179 (33.2%) used the Adult Cardiac Surgery, 128 (23.7%) the Congenital Heart Surgery, 85 (15.8%) the General Thoracic Surgery, and 136 (25.2%) used unspecified STS National Databases. Collectively the analyzed manuscripts were cited 18,943 times, with a mean of 35.1 (range, 0-528) citations per manuscript. Manuscripts were published in 97 journals with a mean year-adjusted CiteScore of 5.6 (range, 0.1-60.2). Authors associated with 361 institutions contributed to published manuscripts. The mean h-index of first authors was 24.6 (range, 0-100) and of last authors was 44.1 (range, 0-164). From 2010 to 2020 first authors wrote a mean of 1.6 (range, 1-31) and last authors wrote a mean of 1.9 (range, 1-29) STS National Databases publications. CONCLUSIONS: The STS National Databases are some of the most robust data collection sources available to cardiothoracic surgeons. These data have enabled valuable research in respected journals from authors of varying experience levels.

Waitlist and transplant outcomes in heart transplant candidates bridged with temporary endovascular right ventricular assist devices.

BACKGROUND: Advances in mechanical circulatory support and changes in allocation policy have shifted waitlisting practices for heart transplantation (HT) in the United States. This analysis reports waitlist and transplant outcomes among HT candidates bridged with temporary endovascular right ventricular assist devices (tRVADs). METHODS: Patients awaiting HT from 2008 to 2022 in the United Network of Organ Sharing registry were grouped by the presence of tRVAD while waitlisted and propensity matched. Waitlist outcomes were HT and a competing outcome of death/deterioration requiring waitlist inactivation. Competing-risks regression was used to model waitlist outcomes. Subanalyses were performed to compare waitlist outcomes among patients with durable and temporary left ventricular assist devices (LVADs) with and without concomitant tRVADs. One-year posttransplant mortality was estimated using Kaplan-Meier analysis. RESULTS: Of 41,507 HT candidates, 133 (0.3%) had tRVADs. After propensity matching, patients with tRVAD had a similar likelihood of HT and an elevated hazard for death/deterioration (hazard ratio 2.2, 95% confidence interval 1.4-3.2, p < 0.001) compared to those without tRVAD. Most patients with tRVAD (84%) had concomitant LVADs. tRVAD was associated with an elevated risk for deterioration/death among those with temporary LVADs but not durable LVADs. For patients undergoing HT, tRVAD was associated with an increased risk for 1-year mortality compared to propensity-matched recipients. CONCLUSIONS: Bridging with tRVAD is uncommon and primarily used in patients requiring biventricular support. tRVADs are associated with waitlist inactivation or death, particularly with concomitant temporary LVAD support. As temporary devices are increasingly used as a bridge to HT, outcomes of patients with tRVADs should inform future allocation policy, particularly for candidates with biventricular failure.

Donor utilization in heart transplant with donation after circulatory death in the United States.

Heart transplantation using donation after circulatory death (DCD) was recently adopted in the United States. This study aimed to characterize organ yield from adult (≥18 years) DCD heart donors in the United States using the United Network for Organ Sharing registry. The registry does not identify potential donors who do not progress to circulatory death, and only those who progressed to death were included for analysis. Outcomes included organ recovery from the donor operating room and organ utilization for transplant. Multiple logistic regression was used to identify predictors of heart recovery and utilization. Among 558 DCD procurements, recovery occurred in 89.6%, and 92.5% of recovered hearts were utilized for transplant. Of 506 DCD procurements with available data, 65.0% were classified as direct procurement and perfusion and 35.0% were classified as normothermic regional perfusion (NRP). Logistic regression identified that NRP, shorter agonal time, younger donor age, and highest volume of organ procurement organizations were independently associated with increased odds for heart recovery. NRP independently predicted heart utilization after recovery. DCD heart utilization in the United States is satisfactory and consistent with international experience. NRP procurements have a higher yield for DCD heart transplantation compared with direct procurement and perfusion, which may reflect differences in donor assessment and acceptance criteria.

Risk Factors for 1-Year Mortality After Heart Transplant in Obese Patients Bridged With an LVAD.

BACKGROUND: Heart transplantation is relatively contraindicated in morbidly obese patients because of increased morbidity and mortality. This study identified risk factors for post-heart transplantation mortality in obese patients with a left ventricular assist device (LVAD). METHODS: The United Network for Organ Sharing database was used to identify patients with a body mass index ≥35 kg/m2 who had a durable LVAD at the time of isolated heart transplantation between 2010 and 2021. The primary outcome was post-heart transplantation 1-year mortality. Multivariable Cox regression modeling was used to identify significant risk factors for 1-year mortality. Receiver-operating characteristic analyses were performed to identify optimal thresholds for continuous variables associated with the primary outcome. Patients were stratified by the number of risk factors, and Kaplan-Meier analysis was used to compare survival. RESULTS: A total of 1222 obese patients were bridged to heart transplantation with a durable LVAD. Six risk factors were identified as significantly associated with 1-year post-heart transplantation mortality: recipient age >62.5 years, body mass index >36.6 kg/m2, bilirubin level >0.95 mg/dL, cold ischemic time >3.7 hours, recipient-donor sex mismatch, and pretransplantation mechanical ventilation. The distribution of cumulative risk factors was as follows: 8.6% with 0, 30.6% with 1, 37.0% with 2, and 23.8% patients with ≥3 risk factors. The 1-year survival rate decreased significantly from 96.0% in those patients with 0 risk factors to 77.6% in those with 3 or more risk factors. CONCLUSIONS: These data provide a useful guide for risk stratification and patient selection in obese LVAD candidates being considered for heart transplantation.

Right Ventricular Contractility and Pulmonary Arterial Coupling After Less Invasive Left Ventricular Assist Device Implantation.

Right ventricular failure contributes significantly to morbidity and mortality after left ventricular assist device implantation. Recent data suggest a less invasive strategy (LIS) via thoracotomy may be associated with less right ventricular failure than conventional median sternotomy (CMS). However, the impact of these approaches on load-independent right ventricular (RV) contractility and RV-pulmonary arterial (RV-PA) coupling remains uncertain. We hypothesized that the LIS approach would be associated with preserved RV contractility and improved RV-PA coupling compared with CMS. We performed a retrospective study of patients who underwent durable, centrifugal left ventricular assist device implantation and had paired hemodynamic assessments before and after implantation. RV contractility (end-systolic elastance [Ees]), RV afterload (pulmonary effective arterial elastance [Ea]), and RV-PA coupling (Ees/Ea) were determined using digitized RV pressure waveforms. Forty-two CMS and 21 LIS patients were identified. Preimplant measures of Ees, Ea, and Ees/Ea were similar between groups. After implantation, Ees declined significantly in the CMS group (0.60-0.40, p = 0.008) but not in the LIS group (0.67-0.58, p = 0.28). Coupling (Ees/Ea) was unchanged in CMS group (0.54-0.59, p = 0.80) but improved significantly in the LIS group (0.58-0.71, p = 0.008). LIS implantation techniques may better preserve RV contractility and improve RV-PA coupling compared with CMS.

Trends and Outcomes of Combined Heart-Kidney and Heart-Lung Transplantation Over the Past Two Decades.

INTRODUCTION: Combined heart-kidney transplantation (HKTx) and combined heart-lung transplantation (HLTx) remain the definitive therapy for patients with end-stage heart failure with concomitant end-stage renal or lung failure. We sought to study trends and outcomes of HKTx and HLTx over the last two decades. METHODS: The United Network for Organ Sharing registry was used to identify all adult patients (aged >18 y) who underwent HKTx and HLTx between 2001 and 2021. Patients were divided into 5-y groups by the year of transplantation (2001-2006, 2007-2011, 2012-2016, and 2017-2021). Primary outcome was 1-y posttransplantation mortality. Kaplan-Meier and multivariable Cox proportional hazards models were used for unadjusted and risk-adjusted survival analyses, respectively. RESULTS: A total of 2301 HKTx and 567 HLTx patients were included. Between 2001 and 2021, HKTx volume increased from 25 to 344 patients (P < 0.001) and centers performing HKTx increased from 19 to 76 (P < 0.001). On unadjusted analysis, 1-y survival after HKTx improved from 86.7% in 2001-2006 to 89.0% in 2017-2021 (log-rank, P = 0.005). On risk-adjusted analysis, the hazard ratio of 1-y mortality for 2017-2021 was 0.62 (0.39-1.00, P = 0.048) compared with that for 2001-2006. Between 2001 and 2021, HLTx volume increased from 21 to 43 patients (P < 0.001) and centers performing HLTx increased from 12 to 20 (P = 0.047). On unadjusted analysis, 1-y survival after HLTx improved from 68.9% in 2001-2006 to 83.9% in 2017-2021 (log-rank, P = 0.600). On risk-adjusted analysis, the hazard ratio of 1-y mortality for 2017-2021 was 0.37 (0.21-0.67, P = 0.001) compared with that for 2001-2006. CONCLUSIONS: Over the last two decades, HKTx volume substantially increased and HLTx experienced resurgent growth. One-year survival persistently improved for both procedures, especially over the past 5 y.