Impact of age over 70 years in the new allocation system on the outcomes of heart transplantation in the US

BACKGROUND

United Network for Organ Sharing (UNOS) allocation criteria changed in 2018 to accommodate the increased prevalence of patients on a ventricular assist device as a bridge to heart transplant and prioritize sicker people in anticipation of a heart graft. We aimed to assess the impact of patient age in the new allocation policy on mortality following heart transplantation. Secondary outcomes included the effect of age ≥70 on post-transplant events, including stroke, dialysis, pacemaker, and rejection requiring treatment.

METHODS

The UNOS Registry was queried to identify patients who underwent heart transplants alone in the US between 2000 and 2021. Patients were divided into groups according to their age (over 70 and under 70 years old).

RESULTS

Patients aged over 70 were more likely to require dialysis during follow-up, but less likely to experience rejection requiring treatment, compared with patients aged <70. Age ≥70 in the new allocation system was a significant predictor of 1-year mortality (adjusted HR: 1.41; 95% CI: 1.05-1.91; p = .024), but its effect on 5-year mortality was not significant after adjusting for potential confounders (adjusted HR: 1.27; 95% CI:.97-1.66; p = .077). Undergoing transplantation under the new allocation policy vs the old allocation policy was not a significant predictor of mortality in patients over 70 years old.

CONCLUSIONS

Age ≥70 is a significant predictor of 1-year mortality following heart transplantation, but not at 5 and 10 years; however, the new allocation does not seem to have changed the outcomes for this group of patients.

Right ventricular remodeling and clinical outcomes following transcatheter tricuspid valve intervention

AIMS

Characterize the impact of residual tricuspid regurgitation (TR) on right ventricle (RV) remodeling and clinical outcomes after transcatheter tricuspid valve intervention.

METHODS

We performed a single-center retrospective analysis of transcatheter tricuspid valve repair (TTVr) or replacement (TTVR) patients. The primary outcomes were longitudinal tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), pulmonary artery systolic pressure (PASP), and RV dimensions (RVd). We used multivariable linear mixed models to evaluate association with replacement versus repair and degree of TR reduction with changes in these echo measures over time. Multivariable Cox regression was used to identify associations between changes in these echo measures and a composite clinical outcome of death, heart failure hospitalization, or re-do tricuspid valve intervention.

RESULTS

We included a total of 61 patients; mean age was 77.5 ± 11.7 and 62% were female. TTVR was performed in 25 (41%) and TTVr in 36 (59%). Initially, 72% (n = 44) had ≤ severe TR and 28% (n = 17) had massive or torrential TR. The median number of follow up echos was 2: time to 1st follow-up was 50 days (interquartile range [IQR]: 20, 91) and last follow-up was 147 (IQR: 90, 327). Median TR reduction was 1 (IQR: 0, 2) versus 4 (IQR: 3, 6) grades in TTVr versus TTVR (p < 0.0001). In linear mixed modeling, TTVR was associated with decline in TAPSE and PASP, and TR reduction was associated with decreased RVd. In multivariable Cox regression, greater RVd was associated with the clinical outcome (hazard ratio: 9.27, 95% confidence interval: 1.23-69.88, p = 0.03).

CONCLUSION

Greater TR reduction is achieved by TTVR versus TTVr, which is in turn associated with RV reverse remodeling. RV dimension in follow-up is associated with increased risk of a composite outcome of death, heart failure hospitalization, or re-do tricuspid valve intervention.

Rejection Requiring Treatment within the First Year following Heart Transplantation: The UNOS Insight

(1) Background: Heart failure is an extremely impactful health issue from both a social and quality-of-life point of view and the rate of patients with this condition is destined to rise in the next few years. Transplantation remains the mainstay of treatment for end-stage heart failure, but a shortage of organs represents a significant problem that prolongs time spent on the waiting list. In view of this, the selection of donor and recipient must be extremely meticulous, considering all factors that could predispose to organ failure. One of the main considerations regarding heart transplants is the risk of graft rejection and the need for immunosuppression therapy to mitigate that risk. In this study, we aimed to assess the characteristics of patients who need immunosuppression treatment for rejection within one year of heart transplantation and its impact on mid-term and long-term mortality. (2) Methods: The United Network for Organ Sharing (UNOS) Registry was queried to identify patients who solely underwent a heart transplant in the US between 2000 and 2021. Patients were divided into two groups according to the need for anti-rejection treatment within one year of heart transplantation. Patients' characteristics in the two groups were assessed, and 1 year and 10 year mortality rates were compared. (3) Results: A total of 43,763 patients underwent isolated heart transplantation in the study period, and 9946 (22.7%) needed anti-rejection treatment in the first year. Patients who required treatment for rejection within one year after transplant were more frequently younger (49 ± 14 vs. 52 ± 14 years, p < 0.001), women (31% vs. 23%, p < 0.001), and had a higher CPRA value (14 ± 26 vs. 11 ± 23, p < 0.001). Also, the rate of prior cardiac surgery was more than double in this group (27% vs. 12%, p < 0.001), while prior LVAD (12% vs. 11%, p < 0.001) and IABP (10% vs. 9%, p < 0.01) were more frequent in patients who did not receive anti-rejection treatment in the first year. Finally, pre-transplantation creatinine was significantly higher in patients who did not need treatment for rejection in the first year (1.4 vs. 1.3, p < 0.01). Most patients who did not require anti-rejection treatment underwent heart transplantation during the new allocation era, while less than half of the patients who required treatment underwent transplantation after the new allocation policy implementation (65% vs. 49%, p < 0.001). Patients who needed rejection treatment in the first year had a higher risk of unadjusted 1 year (HR: 2.25; 95% CI: 1.88-2.70; p < 0.001), 5 year (HR: 1.69; 95% CI: 1.60-1.79; p < 0.001), and 10 year (HR: 1.47; 95% CI: 1.41-1.54, p < 0.001) mortality, and this was confirmed at the adjusted analysis at all three time-points. (4) Conclusions: Medical treatment of acute rejection was associated with significantly increased 1 year mortality compared to patients who did not require anti-rejection therapy. The higher risk of mortality was confirmed at a 10 year follow-up. Further studies and newer follow-up data are required to investigate the role of anti-rejection therapy in the heart transplant population.

Impact of new allocation system on length of stay following heart transplantation in the United States

BACKGROUND

United Network for Organ Sharing (UNOS) allocation criteria changed in 2018 to accommodate the increased prevalence of ventricular assist device use as a bridge to heart transplant, which consequently prioritized sicker patients. We aimed to assess the impact of this new allocation policy on the length of stay following heart transplantation. Secondary outcomes include other risk factors for prolonged hospitalization and its effect on mortality and postoperative complications.

METHODS

The UNOS Registry was queried to identify patients who underwent isolated heart transplants in the United States between 2001 and 2023. Patients were divided into quartiles according to their respective length of stay.

RESULTS

A total of 57 020 patients were included, 15 357 of which were allocated with the new system. The median hospital length of stay was 15 days (mean 22.7 days). Length of stay was longer in the new allocation era (25 ± 30 vs. 22 ± 27 days, p < .001). The longer length of stay was associated with increased 5-year mortality in the new allocation system (aHR: 1.18; 95% CI: 1.15, 1.20; p-value: < .001).

CONCLUSION

Longer hospital stays and associated observed increased risk for mortality in the era after the allocation criteria change reflect the rationale of this shift which was to prioritize heart transplants for sicker patients. Further studies are needed to track the progress of surgical and perioperative management of these studies over time.

The role of patient-oriented mHealth interventions in improving heart failure outcomes: A systematic review of the literature

Heart failure (HF) is a debilitating disease with 26 million patients worldwide. Consistent and complex self-care is required on the part of patients to adequately adhere to medication and to the lifestyle changes that the disease necessitates. Mobile health (mHealth) is being increasingly incorporated in patient interventions in HF, as smartphones prove to be ideal platforms for patient education and self-help assistance. This systematic review aims to summarize and report on all studies that have tested the effect of mHealth on HF patient outcomes. Our search yielded 17 studies, namely 11 randomized controlled trials and six non-randomized prospective studies. In these, patients with the assistance of an mHealth intervention regularly measured their blood pressure and/or body weight and assessed their symptoms. The outcomes were mostly related to hospitalizations, clinical biomarkers, patients' knowledge about HF, quality of life (QoL) and quality of self-care. QoL consistently increased in patients who received mHealth interventions, while study results on all other outcomes were not as ubiquitously positive. The first mHealth interventions in HF were not universally successful in improving patient outcomes but provided valuable insights for patient-oriented application development. Future trials are expected to build on these insights and deploy applications that measurably assist HF patients.

Contemporary Evaluation and Clinical Treatment Options for Aortic Regurgitation

Aortic regurgitation (AR) is the third most frequent form of valvular disease and has increasing prevalence with age. This will be of increasing clinical importance with the advancing age of populations around the globe. An understanding of the various etiologies and mechanisms leading to AR requires a detailed understanding of the structure of the aortic valve and aortic root. While acute and chronic AR may share a similar etiology, their hemodynamic impact on the left ventricle (LV) and management are very different. Recent studies suggest current guideline recommendations for chronic disease may result in late intervention and suboptimal outcomes. Accurate quantitation of ventricular size and function, as well as grading of the severity of regurgitation, requires a multiparametric and multimodality imaging approach with an understanding of the strengths and weaknesses of each metric. Echocardiography remains the primary imaging modality for diagnosis with supplemental information provided by computed tomography (CT) and cardiac magnetic resonance imaging (CMR). Emerging transcatheter therapies may allow the treatment of patients at high risk for surgery, although novel methods to assess AR severity and its impact on LV size and function may improve the timing and outcomes of surgical intervention.

Baseline Characteristics and Clinical Outcomes of a Tricuspid Regurgitation Referral Population

Adverse outcomes in tricuspid regurgitation (TR) have been associated with advanced regurgitation severity and right-sided cardiac remodeling, and late referrals for tricuspid valve surgery in TR have been associated with increase in postoperative mortality. The purpose of this study was to evaluate baseline characteristics, clinical outcomes, and procedural utilization of a TR referral population. We analyzed patients with a diagnosis of TR referred to a large TR referral center between 2016 and 2020. We evaluated baseline characteristics stratified by TR severity and analyzed time-to-event outcomes for a composite of overall mortality or heart-failure hospitalization. In total, 408 patients were referred with a diagnosis of TR: the median age of the cohort was 79 years (interquartile range 70 to 84), and 56% were female. In patients evaluated on a 5-grade scale, 10.2% had ≤moderate TR; 30.7% had severe TR; 11.4% had massive TR, and 47.7% had torrential TR. Increasing TR severity was associated with right-sided cardiac remodeling and altered right ventricular hemodynamics. In multivariable Cox regression analysis, New York Heart Association class symptoms, history of heart failure hospitalization, and right atrial pressure were associated with the composite outcome. One-third of patients referred underwent transcatheter tricuspid valve intervention (19%) or surgery (14%); patients who underwent transcatheter tricuspid valve intervention had greater preoperative risk than that of patients who underwent surgery. In conclusion, in patients referred for evaluation of TR, there were high rates of massive and torrential regurgitation and advanced right ventricle remodeling. Symptoms and right atrial pressure are associated with clinical outcomes in follow-up. There were significant differences in baseline procedural risk and eventual therapeutic modality.

Gender mismatch and outcomes following heart transplantation in the United States

Background

Available literature indicates the possible detrimental effect of gender mismatching on mortality in patients undergoing heart transplantion. Our objective was to examine the role of gender mismatching on mortality and graft rejection in patients undergoing heart transplantation in the US.

Methods

Data on adult patients January who underwent heart transplantation between January 2015 and October 2021, was queried from the United Network of Organ Sharing (UNOS) registry. The main outcomes were all-cause mortality, 1-year all-cause mortality and treated acute rejection.

Results

A total of 19,805 adult patients underwent heart transplant during the study period. Approximately, one out of ten patients in the M-F group had a PHM mismatch&lt;25%, while only four out of ten patients had such a mismatch in the F-M group. In both M-M and F-F groups, seven out of ten patients had a PHM mismatch&lt;25% (p=0.122). Proportion of PHM mismatch was similar throughout the study period. Unadjusted analysis showed that M-F was associated with increased risk for all-cause mortality (HR: 1.13; 95% CI: 1.02, 1.27; p=0.026) and 1-year mortality (HR: 1.26; 95% CI: 1.09, 1.45; p=0.002) compared to M-M. Graft failure incidence was higher in the M-F group compared to M-M (HR: 1.12; 95% CI: 1.01, 1.25; p=0.041).

Conclusions

Gender mismatching is associated with post-transplant mortality with transplantation of female donor grafts to male recipients demonstrating worse outcomes. Further research is required to elucidate pathways involved and possible changes in clinical practice.

Funding Acknowledgement

Type of funding sources: None.

Characteristics, predictors and outcomes of early mTOR inhibitor use after heart transplantation: insights from the UNOS database

Background

The clinical characteristics of mammalian target of rapamycin (mTOR) inhibitors use in heart transplant (HT) recipients and their outcomes have not been well described.

Methods

We compared patients that received mTOR inhibitors within the first 2 years after HT to patients that did not by inquiring the United Network for Organ Sharing database between 2010 and 2018. The primary endpoint was all-cause mortality with re-transplantation as a competing event. Rejection, malignancy, hospitalization for infection and renal transplantation were secondary endpoints.

Results

There were 1,619 (9%) and 15,686 (81%) mTORi+ and mTORi− patients respectively. Body mass index, induction, cardiac allograft vasculopathy, calculated panel reactive antibody and less days in 1A status were independently associated with mTORi+ status. Over a follow up of 10.4 years there was no difference in all cause mortality after adjusting for donor and recipient characteristics (adjusted subdistribution hazard ratio 1.03 [0.90–1.19], p=0.66) (Figure 2). mTORi+ was independently associated with increased risk for rejection (odds ratio 1.43 [1.11–1.83], p=0.005) but not for infection, malignancy or renal transplantation.

Conclusion

mTOR inhibitors are used in &lt;10% patients in the first 2 years after HT and are non-inferior to contemporary immunosuppression regimens in terms of all-cause mortality, infection, malignancy or renal transplantation. They are associated with risk for rejection.

Funding Acknowledgement

Type of funding sources: None.

Outcomes of patients after repeat heart transplantation – insights from the UNOS database

Background

Cardiac graft failure may require repeat heart transplantation (HTx). Outcomes of patients that undergo repeat HTx have not been well described.

Methods

We compared patients that received repeat HTx with patients that received initial HTx by inquiring the United Network for Organ Sharing database between 2015–2021. The primary endpoint was all-cause mortality.

Results

A total of 19,805 HTx patients were included in the study. Patients that underwent repeat HTx (n=578, 3%) were younger (43.8±15.3 vs. 53.7±12.7 years, p&lt;0.001) with lower body mass index (26.8±5.3 vs. 27.6±4.9 kg/m2, p&lt;0.001) and worse renal function (Cr 1.8±1.4 vs. 1.4±0.9 mg/dl). Patients with repeat HTx had increased risk for 1-year mortality (hazard ratio 1.49 [1.16–1.90], p=0.002) compared to patients with initial HTx after adjusting for age, ethnicity, use of left ventricular assist device, UNOS recipient status, diabetes, ischemic time, donor age and predicted heart mass mismatch (Figure 1). Results did not change with the new allocation system (10/2018).

Conclusion

Repeat HTx occurred in 3% of a contemporary UNOS cohort and carried an increased and independent risk for mortality.

Funding Acknowledgement

Type of funding sources: None.

Temporary Mechanical Circulatory Support in Cardiogenic Shock due to ST-Elevation Myocardial Infarction: Analysis of the National Readmissions Database

Despite advances in temporary mechanical circulatory support (TMCS), in-hospital mortality and morbidity related to cardiogenic shock due to ST elevation myocardial infarction (CS-STEMI) are highly prevalent. We identified admissions with CS-STEMI between 2016 and 2019 from the National Readmission Database (NRD). Among 80 997 patients with CS-STEMI, we identified 42,139 without TMCS, while the remaining received various types of TMCS (Extra corporeal membrane oxygenation [ECMO] alone: n = 753; Intra-aortic balloon pump [IABP] alone: n = 27 556; Impella alone: n = 9055; ECMO with IABP or Impella: n = 1494). 30-day readmission rates did not differ among groups, whereas 90-day readmissions were higher among those with combined ECMO and IABP or Impella support (P = .027). In-hospital mortality and complications including hemodialysis, transfusion, and stroke were the highest in the Impella and combined ECMO and IABP/Impella groups. Heart failure was the most common cause of readmission. Multivariable logistic regression revealed female gender, diabetes, prior myocardial infarction, heart failure, chronic kidney, and peripheral artery disease as risk factors for 90-day readmissions. Our study unveiled several important factors associated with readmission and mortality related to TMCS in CS-STEMI. Approaches to identify and prevent readmissions by addressing these factors may lead to lower morbidity, healthcare cost related to readmission, and improved quality of life.

Outcomes after heart transplantation in patients with cardiac sarcoidosis

Background

The number of patients with sarcoidosis requiring heart transplantation (HT) is increasing. The aim of this study was to evaluate outcomes of isolated HT in patients with sarcoid cardiomyopathy and compare them to recipients with non‐ischaemic restrictive or dilated cardiomyopathy.

Methods and results

Adult HT recipients were identified in the UNOS Registry between 1990 and 2020. Patients were grouped according to diagnosis. The cumulative incidences for the all‐cause mortality and rejection were compared using Fine and Gray model analysis, accounting for re‐transplantation as a competing risk. Rejection was evaluated using logistic regression analysis. We also reviewed characteristics and outcomes of all HT recipients with previous diagnosis of sarcoid cardiomyopathy from a single centre. A total of 30 160 HT recipients were included in the present study (n = 239 sarcoidosis, n = 1411 non‐ischaemic restrictive cardiomyopathy, and n = 28 510 non‐ischaemic dilated cardiomyopathy). During a total of 194 733 patient‐years, all‐cause mortality at the latest follow‐up was not significantly different when comparing sarcoidosis to non‐ischaemic dilated cardiomyopathy [adjusted subhazard ratio (aSHR) 1.46, 95% confidence intervals (CIs): 0.9–2.4, P = 0.12] or restrictive cardiomyopathy (aSHR 1.12, 95% CI: 0.65–1.95, P = 0.67). Accordingly, multivariable analysis suggested that 1 year mortality was not significantly different between sarcoidosis and non‐ischaemic dilated cardiomyopathy (aSHR 1.56, 95% CI: 0.9–2.7, P = 0.12) or restrictive cardiomyopathy (aSHR 1.15, 95% CI: 0.61–2.18, P = 0.66). No differences were observed regarding 30 day mortality, treated and hospitalized acute rejection, and 30 day death from graft failure after HT. Thirty‐day mortality did not improve significantly in more recent HT eras whereas there was a trend towards improved 1 year mortality in the latest HT era (P = 0.06). Data from the single‐centre case review showed excellent long‐term outcomes with sirolimus‐based immunosuppression.

Conclusions

Short‐term and long‐term post HT outcomes among patients with sarcoid cardiomyopathy are similar to those with common types of non‐ischaemic cardiomyopathy.

Incidence and long-term outcome of heart transplantation patients who develop postoperative renal failure requiring dialysis

BACKGROUND

Acute renal failure requiring dialysis after heart transplantation remains a significant clinical issue because of its increasing incidence. We aimed to investigate its time trends, clinical predictors, and long-term outcomes.

METHODS

Adult heart transplantation recipients registered in the United Network for Organ Sharing registry between 2009 and 2020 were identified. The patients were grouped according to the requirement for dialysis in the postoperative heart transplantation period. The independent risk predictors were identified, and the association between post-heart transplantation renal failure requiring dialysis and long-term mortality accounting for re-transplantation was investigated.

RESULTS

A total of 28,170 patients were included in the study, of which 3,371 (12%) required dialysis immediately post-heart transplantation. The incidence increased from 7.9% to 13.9% during the study period. Longer ischemic time, serum creatinine at transplantation >1.2 mg/dL, prior cardiac surgery, higher recipient body mass index, support of mechanical ventilation or extracorporeal membrane oxygenation, and history of congenital heart disease or restrictive/hypertrophic cardiomyopathy were its predictors (all p < 0.05). Patients on posttransplant dialysis had a higher risk of all-cause mortality (adjusted hazard ratio [aHR]: 5.2, 95% CI: 4.7-5.7, p < 0.001), 30 day mortality (aHR: 7.7, 95% CI: 6.3-9.6, p < 0.001) and 1 year mortality (aHR: 7.5, 95% CI: 6.6-8.6, p < 0.001). Post-transplant dialysis was associated with a risk of treated rejection at 1 year.

CONCLUSION

Acute renal failure requiring dialysis after heart transplantation is associated with significantly worse 30 day and long-term mortalities, and thus, early identification of high-risk patients is crucial to prevent severe renal complications.

Prediction of outcomes after heart transplantation by machine learning models

Background

Models based on traditional statistics for the prediction of outcomes after heart transplantation (HT) have moderate accuracy. We sought to develop and validate state-of-the-art machine learning (ML) models to predict mortality and acute rejection after contemporary HT.

Methods

We included adult HT recipients from the UNOS database between 2010–2018 using solely pre-transplant clinical and laboratory variables. The study cohort was randomly split in a derivation and a validation cohort with a 3:1 ratio. An effective feature selection algorithm was used to identify strong predictors of 1-year mortality and rejection in the training cohort. Results were used to train the ML models, which were then internally tested using the validation cohort. LIME explainability analysis was used for the best performing ML model. A similar subgroup analysis was performed for 3- and 5-year survival.

Results

The study cohort comprised of 18,625 patients (53±13 years, 73% males). At 1-year after cardiac transplant, there were 2,334 (12.5%) deaths. Out of a total of 134 pre-transplant variables, 39 and 27 were selected as highly predictive of 1-year mortality and acute rejection respectively, and were used in the ML models. Areas under the curve for the prediction of 1-year survival were 0.689, 0.642, 0.649, 0.637, 0.526 for the Adaboost, Logistic Regression, Decision Tree, Support Vector Machine and K-nearest neighbor models respectively, whereas the IMPACT score had an AUC of 0.569. For the prediction of 1-year acute rejection, Adaboost achieved the highest predictive performance (AUC 0.629). LIME explainability analysis identified the relative impact of the 10 strongest predictors of 1-year mortality and acute rejection. Subgroup analysis using a similar methodology for 3- and 5-year survival yielded AUC of 0.609 and 0.610 using 31 and 91 selected variables respectively.

Conclusion

ML models created and validated using a contemporary cohort of the UNOS database showed improved accuracy in predicting survival and acute rejection after HT.

Funding Acknowledgement

Type of funding sources: None.

Impact of induction therapy on outcomes after heart transplantation

Introduction

Approximately 50% of heart transplant (HT) programs currently employ a strategy of induction therapy (IT) with either interleukin-2 receptor antagonists (IL2RA) or polyclonal anti-thymocyte antibodies (ATG) during the early postoperative period. However, the overall utility of such therapy is uncertain and data comparing induction protocols are limited.

Methods

Adult HT recipients were identified in the United Network for Organ Sharing (UNOS) registry between 1990 and 2020. Patients were grouped according to administration of induction in the post-operative period after HT. Accounting for re-transplantation, Fine and Gray's test compared cumulative incidences of all-cause mortality between groups. Univariate and multivariate analysis were performed using the competing risk model. The risk of treated rejection and hospitalization for infection or rejection was analyzed with multivariable logistic regression.

Results

A total of 63,849 HT recipients were included in the study and among those 59% did not receive induction, 16.6% received ATG, 19.1% IL2RA, 0.7% alemtuzumab, and 4.6% OKT3. Since 2000 IL2RA is the most frequently used form of induction therapy whereas OK3 is not used in the past decade. In multivariable logistic regression models, use of ATG is associated with lower risk of treated rejection at one year after HT (relative risk ratio 0.55, 95% CI 0.47–0.63, p&lt;0.001) compared with no induction whereas IL2RA had similar risk of treated rejection. Similarly, the risk of rejection requiring hospitalization was significantly lower with ATG than no induction. No significant differences in rates of infection requiring hospitalization were noted between groups. Moreover, no differences in rates of post-transplant lymphoproliferative disease and any malignancy were noted between those receiving induction versus no induction. Adjusted all-cause mortality was significantly lower among those treated with ATG than patients that did not receive induction therapy (sub-hazard ratio 0.72, 95% CI 0.63–0.82, p&lt;0.001) (Figure).

Conclusion

Induction therapy with IL2RA is the most used approach. ATG is associated with lower risk of treated rejection and all-cause mortality than no induction and IL2RA.

Funding Acknowledgement

Type of funding sources: None.

Trends, risk factors and prognostic implications of postoperative stroke after heart transplantation: an analysis of the UNOS database

Background

Post-operative stroke increases morbidity and mortality after cardiac surgery. Data on characteristics and outcomes of stroke after heart transplantation (HT) are limited.

Methods

We conducted a retrospective analysis of the UNOS database from 2009 to 2020 to identify adults who developed stroke after orthotropic HT. HT recipients were divided according to the presence or absence of postoperative stroke. The primary endpoint was all-cause mortality after HT.

Results

A total of 25,015 HT recipients were analyzed, including 719 (2.9%) patients who suffered perioperative stroke. The rates of stroke increased from 2.1% in 2009 to 3.7% in 2019 and the risk of stroke was higher after the implantation of the new allocation system (odds ratio 1.29, 1.29, 95% Confidence Intervals [CI] 1.06–1.56, p=0.01). HT recipients with postoperative stroke were older (p=0.008), with higher rates of prior cerebrovascular accident (CVA) (p=0.004), prior cardiac surgery (p&lt;0.001), longer waitlist time (p=0.04), higher rates of extracorporeal membrane oxygenation support (ECMO) (p&lt;0.001), left ventricular assist devices (LVAD) (p&lt;0.001), mechanical ventilation (p=0.003) and longer ischemic time (p&lt;0.001). After multivariable adjustment for recipient and donor characteristics, age, prior cardiac surgery, CVA, support with LVAD, ECMO, ischemic time and mechanical ventilation at the time of HT were independent predictors of postoperative stroke. Stroke was associated with increased risk of 30-day and all-cause mortality after HT (hazard ratio [HR] 1.49, CI 1.12–1.99, p=0.007).

Conclusion

Perioperative stroke after HT is infrequent but associated with higher mortality. Redo sternotomy, LVAD and ECMO support at HT are among the risk factors identified.

Funding Acknowledgement

Type of funding sources: None. Risk factors for stroke

Surgical Treatment of Pulmonary Embolism and Chronic Thromboembolic Pulmonary Hypertension

Venous thromboembolism clinically presents as deep venous thrombosis or acute pulmonary embolism and is globally recognized as the third most frequent acute cardiovascular syndrome after myocardial infarction and stroke. Although pulmonary embolism does not typically cause severe pulmonary hypertension in the acute setting, thrombus organization and fibrosis can lead to stenosis or obliteration of pulmonary arteries in a minority of patients, which in turn result in severe pulmonary hypertension and right heart failure. This disease is labeled chronic thromboembolic pulmonary hypertension and can occur after a single episode or multiple ones of pulmonary embolism. The cornerstone of pulmonary embolism treatment is medical therapy, whereas systemic thrombolytic therapy has to be considered for patients with hemodynamic instability. Given the current acceptable short-term surgical mortality, the potential of first-line surgical embolectomy as an alternative to medical thrombolysis has gained momentum as far as pulmonary embolism treatment is concerned. In contrast to pulmonary embolism, bilateral complete pulmonary endarterectomy under short deep hypothermic circulatory arrest intervals is the treatment of choice against chronic thromboembolic pulmonary hypertension, given patients' operability. Pulmonary endarterectomy is suggested in every operable patient when the operation is offered by an experienced multidisciplinary team, including at least one experienced surgeon. Surgical embolectomy should also be limited to large institutions since it also requires an experienced heart team. This review concerns a thorough discussion regarding surgical treatment of pulmonary embolism and chronic thromboembolic pulmonary hypertension. Eligibility criteria, operation-related complications and postoperative outcomes are discussed in detail.

Electrocardiographic Correlates of Myocardial Injury After Transcatheter Aortic Valve Replacement

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is associated with several conduction abnormalities and a need for pacemaker placement. The study aim was to describe all electrocardiographic (ECG) changes seen after TAVR, to compare such changes between transapical (TA) and transfemoral (TF) patient cohorts, and to assess their impact on postoperative outcomes.

METHODS

Between March 2009 and July 2014, a total of 286 consecutive patients underwent TAVR at the present authors' institution. Perioperative data were collected prospectively, while preoperative and predischarge electrocardiograms were reviewed retrospectively by an independent cardiologist.

RESULTS

A greater proportion of TA patients experienced ECG changes than TF patients at the time of discharge (78% versus 42%; p <0.0001), with more intraventricular conduction abnormalities (29% versus 15%; p = 0.006), and a trend towards more frequent atrioventricular block and pacemaker placement. Troponin levels were higher in patients with new ECG changes (4.61ng/ml versus 2.12 ng/ml; p = 0.0009). New intraventricular conduction abnormalities were associated with increased one-year mortality only in the TF subgroup (65% versus 84%; p = 0.028). Six TA patients demonstrated new ECG findings of myocardial infarction, and this was associated with greater 30-day mortality (67% versus 98%; p = 0.012), although none met the clinical criteria for myocardial infarction.

CONCLUSIONS

New ECG changes after TAVR, including new conduction abnormalities, were seen more frequently in TA patients. When seen in TF patients, they were associated with decreased survival. ECG findings of new myocardial infarction, seen only in TA patients, were also associated with decreased survival.

Effect of myocardial perfusion pattern on frequency and severity of mitral regurgitation in patients with known or suspected coronary artery disease

Mitral regurgitation (MR) is common with coronary artery disease as altered myocardial substrate can affect valve performance. Single-photon emission computed tomography myocardial perfusion imaging (MPI) enables assessment of myocardial perfusion alterations. This study examined perfusion pattern in relation to MR. A total of 2,377 consecutive patients with known or suspected coronary artery disease underwent stress MPI and echocardiography within 1.6 ± 2.3 days. MR was present on echocardiography in 34% of patients, among whom 13% had advanced (moderate or more) MR. MR prevalence was higher in patients with abnormal MPI (44% vs 29%, p <0.001), corresponding to increased global ischemia (p <0.001). Regional perfusion varied in left ventricular segments adjacent to each papillary muscle: adjacent to the anterolateral papillary muscle, magnitude of baseline and stress-induced anterior/anterolateral perfusion abnormalities was greater in patients with MR (both p <0.001). Adjacent to the posteromedial papillary muscle, baseline inferior/inferolateral perfusion abnormalities were greater with MR (p <0.001), whereas stress inducibility was similar (p = 0.39). In multivariate analysis, stress-induced anterior/anterolateral and rest inferior/inferolateral perfusion abnormalities were independently associated with MR (both p <0.05) even after controlling for perfusion in reference segments not adjacent to the papillary muscles. MR severity increased in relation to magnitude of perfusion abnormalities in each territory adjacent to the papillary muscles, as evidenced by greater prevalence of advanced MR in patients with at least moderate anterior/anterolateral stress perfusion abnormalities (10.7% vs 3.6%), with similar results when MR was stratified based on rest inferior/inferolateral perfusion (10.4% vs 3.0%, both p <0.001). In conclusion, findings demonstrate that myocardial perfusion pattern in left ventricular segments adjacent to the papillary muscles influences presence and severity of MR.