The role of donor age and ischemic time on survival following orthotopic heart transplantation

Short-term outcomes after heart transplantation using donor hearts preserved with ex vivo perfusion

The standard Conventional Cold Storage (CCS) during heart transplantation procurement is associated with time-dependent ischemic injury to the graft, which is a significant independent risk factor for post-transplant early morbidity and mortality - especially when cold ischemic time exceeds four hours. Since 2018, Rigshospitalet (Copenhagen, Denmark) has been utilising ex vivo perfusion (Organ Care System, OCS) in selected cases. The objective of this study was to compare the short-term clinical outcomes of patients transplanted with OCS compared to CCS. Methods: This retrospective single-centre study was based on consecutive patients undergoing a heart transplant between January 2018 and April 2021. Patients were selected for the OCS group when the cold ischemic time was expected to exceed four hours. The primary outcome measure was six-month event-free survival. Results: In total, 48 patients were included in the study; nine were transplanted with an OCS heart. The two groups had no significant differences in baseline characteristics. Six-month event-free survival was 77.8% [95% CI: 54.9-100%] in the OCS group and 79.5% [95% CI: 67.8-93.2%] in the CCS group (p = 0.91). While the OCS group had a median out-of-body time that was 183 min longer (p < 0.0001), the cold ischemic time was reduced by 51 min (p = 0.007). Conclusion: In a Scandinavian setting, our data confirms that utilising OCS in heart procurement allows for a longer out-of-body time and a reduced cold ischemic time without negatively affecting safety or early post-transplant outcomes.

Severe primary graft dysfunction of the heart transplant is associated with increased plasma and intragraft proinflammatory cytokine expression

INTRODUCTION

Heart transplant results have constantly improved but primary left ventricle graft dysfunction (LV-PGD) remains a devastating complication early after transplantation. Donor and recipient systemic inflammatory response may be involved in immune activation of the transplant, and LV-PGD development. Here, we investigated donor and recipient plasma and intragraft cytokine profiles preoperatively and during LV-PGD and searched for predictive markers for LV-PGD.

METHODS

Donor and recipient plasma samples (n = 74) and myocardial biopsies of heart transplants (n = 64) were analyzed. Plasma and intragraft cytokine levels were determined by multiplexed and next-generation sequencing platforms, respectively. The development of LV-PGD during the first 24 hours, and graft function and mortality up to 1 year after transplantation, were examined.

RESULTS

Severe LV-PGD, but not mild or moderate LV-PGD, was significantly associated with early mortality, plasma high-sensitivity troponin elevation, and an increase in intragraft and plasma proinflammatory cytokines during reperfusion. Preoperative donor and recipient plasma cytokine levels failed to predict LV-PGD. Cytokine network analysis identified interleukins -6, -8, -10, and -18 as key players during reperfusion. Prolonged cold and total ischemia time, and increased need for red blood cell transfusions during operation were identified as clinical risk factors for severe LV-PGD.

CONCLUSIONS

Severe LV-PGD was associated with a poor clinical outcome. Donor and recipient plasma cytokine profile failed to predict LV-PGD, but severe LV-PGD was associated with an increase in post-reperfusion intragraft and recipient plasma proinflammatory cytokines. Identified key cytokines may be potential therapeutic targets to improve early and long-term outcomes after heart transplantation.

Impact of donor blood type on outcomes after prolonged allograft ischemic times

OBJECTIVE

The study objective was to determine the influence of allograft ischemic time on heart transplant outcomes among ABO donor organ types given limited prior reports of its survival impact.

METHODS

We identified 32,454 heart transplants (2000-2016) from the United Network for Organ Sharing database. Continuous and categoric variables were analyzed by parametric and nonparametric testing. Survival was determined using log-rank or Cox regression tests. Propensity matching adjusted for preoperative variables.

RESULTS

By comparing allograft ischemic time less than 4 hours (n = 6579) with 4 hours or more (n = 25,875), the hazard ratios for death at 15 years after prolonged ischemic time (≥4 hours) for blood types O, A, B, and AB were 1.106 (P < .001), 1.062 (P < .001), 1.059 (P = .062), and 1.114 (P = .221), respectively. Unadjusted data demonstrated higher mortality for transplantation of O versus non-O donor hearts for ischemic time 4 hours or more (hazard ratio, 1.164; P < .001). After propensity matching, O donor hearts continued to have worse survival if preserved for 4 hours or more (hazard ratio, 1.137, P = .008), but not if ischemic time was less than 4 hours (hazard ratio, 1.042, P = .113). In a matched group with 4 hours or more of ischemic time, patients receiving O donor organs were more likely to experience death from primary graft dysfunction (2.5% vs 1.7%, P = .052) and chronic allograft rejection (1.9% vs 1.1%, P = .021). No difference in death from primary graft dysfunction or chronic allograft rejection was seen with less than 4 hours of ischemic time (P > .150).

CONCLUSIONS

Compared with non-O donor hearts, transplantation with O donor hearts with ischemic time 4 hours or more leads to worse survival, with higher rates of primary graft dysfunction and chronic rejection. Caution should be practiced when considering donor hearts with the O blood type when anticipating extended cold ischemic times.

Interaction between donor obesity and prolonged donor ischemic time in heart transplantation

BACKGROUND

The purpose of the study was to determine the impact of donor obesity on outcomes following heart transplantation in the setting of routine (<4 h) and prolonged (≥4 h) organ ischemic times.

METHODS

Retrospective review of the 2000-2020 United Network for Organ Sharing Database was performed to identify adult heart transplant recipients and donors. Nearest-neighbor propensity score matching by donor obesity was performed separately among routine and prolonged cohorts, with Kaplan-Meier survival estimates used to assess survival at 5 years following transplantation.

RESULTS

A total of 43,304 heart transplant recipients were included in analysis, with 15,925 (36.8 %) receiving obese donor hearts. After propensity-score matching, 30-day mortality and 5-year survival following transplantation were not statistically different between recipients of obese and non-obese donor hearts when organ ischemic times were routine. In the setting of prolonged organ ischemic times, those receiving obese donor hearts experienced lower 30-day mortality (5.1 % vs 6.7 %, p = 0.04) and improved 5-year survival (74.9 % vs 71.2 %, p < 0.01) compared to non-obese donor hearts.

CONCLUSIONS

Recipients of obese donor hearts experienced improved outcomes compared to those receiving non-obese donor hearts when organ ischemic times exceeded 4 h. These findings suggest that the detrimental impact of prolonged organ ischemic time may be attenuated by donor obesity.

Expanding Selection Criteria to Repairable Diseased Hearts to Meet the Demand of Shortage of Donors in Heart Transplantation

Heart transplant surgery is considered the destination therapy for end-stage heart disease. Unfortunately, many patients in the United States of America who are eligible candidates for transplants cannot undergo surgery due to donor shortage. In addition, some donors' hearts are being labeled as unacceptable for transplant surgery because of the rigorous and restricted rules placed on the approval process of using a donor's heart. Over the last few decades, the rising discrepancy between the scarcity of donor hearts and the demand for such organs has led to the discussion of expanding the donor heart selection criteria. A softer view on using marginal hearts for transplants would help those on the waitlist to receive a heart transplant. Marginal hearts that contain the hepatitis c virus (HCV), COVID-19, older age, or repairable heart defects have become viable options to use for a heart transplant. Also, the prioritization based on the new heart allocation system would help efficiently decide which recipients would be the first to get a donor's heart. Recently there has been a consensus to broaden the eligibility of donor's hearts by accepting valvular abnormalities, coronary artery disease, and congenital abnormalities. This review highlights some of those expansions in selection criteria in particular using repairable hearts, which could be fixed in the operating room on the back table before transplantation.

Determining optimal donor heart ischemic times in adult cardiac transplantation

Objectives

Unsupervised statistical determination of optimal allograft ischemic time (IT) on heart transplant outcomes among ABO donor heart types.

Methods

We identified 36,145 heart transplants (2000–2018) from the United Network for Organ Sharing database. Continuous and categorical variables were analyzed with parametric and nonparametric testing. Determination of IT cutoffs for survival analysis was performed using Contal and O'Quigley univariable method and Vito Muggeo multivariable segmented modeling.

Results

Univariable and multivariable IT threshold determination revealed a cutoff at about 3 h. The hourly increase in survival risk with ≥3 h IT is asymmetrically experienced at the early 90 days (hazard ratio [HR] = 1.29, p < .001) and up to 1‐year time point (HR = 1.16, p < .001). Beyond 1 year the risk of prolonged IT is less impactful (HR = 1.04, p = .022). Longer IT was associated with more postoperative complications such as stroke (2.7% vs. 2.3, p = .042), dialysis (11.6% vs. 9.1%, p < .001) and death from primary graft dysfunction (1.8% vs. 1.2%, p < .001). O blood type donor hearts with IT ≥ 3 h has significantly increased hourly mortality risk at 90 days (HR = 1.27, p < .001), 90 days to 1 year (HR = 1.22, p < .001) and >1 year (HR = 1.05, p = .041). For non‐O blood types with ≥3 h IT hourly mortality risk was increased at 90 days (HR = 1.33, p < .001), but not at 90 days to 1 year (HR = 1.09, p = .146) nor ≥1 year (HR = 1.08, p = .237).

Conclusions

The donor heart IT threshold for survival determined from unbiased statistical modeling occurs at 3 h. With longer preservation times, transplantation with O donor hearts was associated with worse survival.

Geographic Variation in Heart Transplant Extended Criteria Donors in the United States

BACKGROUND

Recent research has explored the use of higher risk extended criteria donors (ECDs) as a means of expanding the donor pool for heart transplantation. Here we sought to explore the current geographic distribution and survival outcomes of ECD utilization in various regions across the United States.

METHODS

The United Network for Organ Sharing database was retrospectively queried for adult primary heart transplantation from 2000 to 2019. The EXPAND trial definition of ECD was used: ischemic time ≥ 4 hours, ejection fraction < 50%, age > 55 years, and history of coronary artery disease. Geographic data and 2019 population estimates were obtained from the US Census Bureau.

RESULTS

Of the 42 642 transplants included in our analysis, 11 750 (27.6%) used ECDs. Region utilization of ECDs ranged from 18.4% to 46.5% of transplants. Region 6 had the highest utilization rate at 46.5%; this was primarily driven by the number of transplants with ischemic time ≥ 4 hours. Region 6 encompasses the largest total area (1.08 million square miles) and smallest population density (15.6 people per square mile). Region 8 had the lowest marginal donor utilization rate at 18.4%. Regions with high utilization of low ejection fractions, older donors, and donors with coronary artery disease (ie, regions 1 and 2) were able to maintain an average utilization rate of ECDs by maintaining short ischemic times.

CONCLUSIONS

Large discrepancies in the use of ECDs exist across the different United Network for Organ Sharing regions. This is primarily driven by longer ischemic times, likely guided by variance in population densities between different regions.

Heart Transplantation of the Elderly-Old Donors for Old Recipients: Can We Still Achieve Acceptable Results?

As society is ageing, an increasing prevalence of elderly heart failure patients will be expected. In order to increase the donor pool, acceptance of older donors might be a reasonable choice. All patients undergoing heart transplantation between 2010 and 2021 at a single department were retrospectively reviewed and divided into different study groups with regard to recipient (≤60 years (R^Y) or >60 years (R^O)) and donor age (≤50 years (D^Y) or >50 years (D^O). A total of n = 201 patients were included (D^Y/R^Y, n = 91; D^O/R^Y, n = 38; D^Y/R^O, n = 41; D^O/R^O, n = 31). Neither incidence of severe primary graft dysfunction (p = 0.64) nor adverse events, such as kidney failure (p = 0.27), neurological complications (p = 0.63), infections (p = 0.21) or acute graft rejection (p = 1.00), differed between the groups. However, one-year survival was impaired in the D^O/R^O group (56.0%) compared to the other groups (D^Y/R^Y: 86.1%, D^Y/R^O: 78.8%, D^O/R^Y: 74.2%, p = 0.02). Given the impaired one-year survival, acceptance of grafts from old donors for old recipients should be performed with caution and by experienced centres only. Nevertheless, because of the otherwise dismal prognosis of elderly heart failure patients, transplantation of patients may still improve the therapy outcome.

Interaction Between Ischemic Time and Donor Age Under the New Donor Heart Allocation System: Effect on Post-Transplant Survival

BACKGROUND

Ischemic time (IT) under the new heart transplant (HTx) allocation system has increased compared to the old system. We investigated the effect of IT and donor age on post-HTx survival.

METHODS

The United Network for Organ Sharing (UNOS) database was analyzed to identify adult HTx between October 2015 and August 2020. Recipients were stratified by donor age, transplantation era, and IT. Kaplan-Meier and log-rank tests were used to compare 180-day post-HTx mortality. Cox proportional hazards modeling and propensity score matching were performed to adjust for confounders.

RESULTS

Under the new system (N = 3654), IT≥4 hours led to decreased survival compared to IT<4 hours (91.4% vs. 93.7%; P = 0.02), although this decrease was undetectable among those with donors ≥39 years old (90.4% vs. 91.1%; P = 0.73). IT≥4 hours led to decreased survival with donors <39 years old (91.7% vs. 94.6%; P<0.01). Under the old system (N = 5987), IT≥4 hours resulted in decreased survival (89.8% vs. 93.9%; P<0.01), including with donors ≥39 years old (86.9% vs. 92.4%; P<0.01).

CONCLUSIONS

IT≥4 hours remains a risk for post-HTx mortality under the new system. However, the magnitude of this effect is blunted when donor age is ≥39 years, likely secondary to increased allocation of these organs to lower status, more stable recipients. This article is protected by copyright. All rights reserved.

Risk factors for heart transplant survival with greater than 5 h of donor heart ischemic time

OBJECTIVE

Implantation of donor hearts with prolonged ischemic times is associated with worse survival. We sought to identify risk factors that modulate the effects of prolonged preservation.

METHODS

Retrospective review of the United Network for Organ Sharing database (2000-2018) to identify transplants with >5 (n = 1526) or ≤5 h (n = 35,733) of donor heart preservation. In transplanted hearts preserved for >5 h, Cox-proportional hazards identify modifiers for survival.

RESULTS

Compared to ≤5 h, transplanted patients with >5 h of preservation spent less time in status 1B (76 ± 160 vs. 85 ± 173 days, p = .027), more commonly had ischemic cardiomyopathy (42.3% vs. 38.3%, p = .002), and less commonly received a blood type O heart (45.4% vs. 50.8%, p < .001). Longer heart preservation time was associated with a higher incidence of postoperative stroke (4.5% vs. 2.5%, p < .001), and dialysis (16.4% vs. 10.6%, p < .001). Prolonged preservation was associated with a greater likelihood of death from primary graft dysfunction (2.8% vs. 1.5%, p < .001) but there was no difference in death from acute (2.0% vs. 1.7%, p = .402) or chronic rejection (2.0% vs. 1.9%, p = .618). In transplanted patients with >5 h of heart preservation, multivariable analysis identified greater mortality with ischemic cardiomyopathy etiology (hazard ratio [HR] = 1.36, p < 0.01), pre-transplant dialysis (HR = 1.84, p < .01), pre-transplant extracorporeal membrane oxygenation (ECMO, HR = 2.36, p = .09), and O blood type donor hearts (HR = 1.35, p < .01).

CONCLUSION

Preservation time >5 h is associated with worse survival. This mortality risk is further amplified by preoperative dialysis and ECMO, ischemic cardiomyopathy etiology, and use of O blood type donor hearts.

Outcomes of Orthotopic Heart Transplantation in the Setting of Acute Kidney Injury and Renal Replacement Therapy

OBJECTIVE

Heart transplantation in the setting of renal insufficiency is controversial. The objective of this study was to perform a descriptive analysis of patients who underwent orthotopic heart transplantation and renal replacement therapy (RRT) due to acute kidney injury (AKI).

DESIGN

An observational cohort study with retrospective data collection.

SETTING

A tertiary care hospital.

PARTICIPANTS

Fifty-one patients underwent orthotopic heart transplantation with cardiogenic shock under inotrope dependence, with nine patients having preoperative RRT and 42 patients not having preoperative RRT.

INTERVENTIONS

There were no interventions.

MEASUREMENTS AND MAIN RESULTS

Hospital mortality occurred in eight (15.6%) patients. Although there were no significant differences between the study groups (preoperative RRT 33.3% v controls 11.9%, p = 0.1), this study was underpowered to detect differences in mortality. Dialysis also was required in 52.4% of patients who were not on preoperative RRT. All survivors had full recovery of kidney function with similar timing after transplant (18.5 days v 15 days, p = 0.75). Actuarial survival was 82.4%, 76.5%, and 66.5% at six months, one year, and five years, respectively. A cold ischemic time greater than 180 minutes (hazard ratio [HR] 4.37 95% confidence interval [CI] 1.51-12.6; p = 0.006) and pretransplant RRT (HR = 7.19 95% CI 1.13-45.7; p = 0.04) were independent predictors of long-term mortality.

CONCLUSIONS

In a health system with limited funding and availability of mechanical circulatory support, heart transplantation in the setting of AKI, RRT, and low Interagency Registry for Mechanically Assisted Circulatory Support profile was associated with important hospital mortality. Among hospital survivors, however, all patients had full renal recovery and by 25 months there was no difference in mortality between those who required preoperative RRT and those who did not.

Impact of increased donor distances following adult heart allocation system changes: A single center review of 1-year outcomes

BACKGROUND

On October 18, 2018, several changes to the donor heart allocation system were enacted. We hypothesize that patients undergoing orthotopic heart transplantation (OHT) under the new allocation system will see an increase in ischemic times, rates of primary graft dysfunction, and 1-year mortality due to these changes.

METHODS

In this single-center retrospective study, we reviewed the charts of all OHT patients from October 2017 through October 2019. Pre- and postallocation recipient demographics were compared. Survival analysis was performed using the Kaplan-Meier method.

RESULTS

A total of 184 patients underwent OHT. Recipient demographics were similar between cohorts. The average distance from donor increased by more than 150 km (p = .006). Patients in the postallocation change cohort demonstrated a significant increase in the rate of severe left ventricle primary graft dysfunction from 5.4% to 18.7% (p = .005). There were no statistically significant differences in 30-day mortality or 1-year survival. Time on the waitlist was reduced from 203.8 to 103.7 days (p = .006).

CONCLUSIONS

Changes in heart allocation resulted in shorter waitlist times at the expense of longer donor distances and ischemic times, with an associated negative impact on early post-transplantation outcomes. No significant differences in 30-day or 1-year mortality were observed.

Impact of age mismatch between donor and recipient on heart transplant mortality

The effect of donor-to-recipient (D-R) age mismatch in adult heart transplant population is not clearly described, and we undertook this study to determine the impact of age mismatch on mortality. Heart transplant recipients from 2000 to 2017 were identified using the United Network of Organ Sharing database. The cohort was divided into three groups: donor age within 5 years of recipient age (Group 1), donors >5 years younger than recipient (group 2), and donors >5 years older than recipients (Group 3). We also evaluated if this finding changed by recipient age. Twenty eight thousand, four hundred and eleven patients met the inclusion criteria. Compared to group 1, the adjusted hazard ratio (aHR) for mortality for group 2 was 0.91 (0.83-0.99, p value <.039) and for group 3 was 1.36 (1.21-1.52, p value <.001); however, when looking at recipient age as continuous variable, receiving a younger heart was protective only for recipients younger than 45 years of age, and receiving a heart transplant from an older donor was detrimental only in recipients aged 25-35.

The Effect of Supplemental Cardioplegia Infusion before Anastomosis in Patients Undergoing Heart Transplantation with Long Ischemic Times

Background

Prolonged ischemic time is a risk factor for primary graft dysfunction in patients who undergo heart transplantation. We investigated the effect of a supplemental cardioplegia infusion before anastomosis in patients with long ischemic times.

Methods

We identified 236 consecutive patients who underwent orthotopic heart transplantation between February 2010 and December 2014. Among them, the patients with total ischemic times of longer than 3 hours (n=59) were categorized based on whether they were administered a complementary cardioplegia solution (CPS) immediately before implantation (CPS+, n=30; CPS−, n=29).

Results

The mean total ischemic times in the CPS+ and CPS− groups were 238.1±30.1 minutes and 230.1±28.2 minutes, respectively (p=0.3). The incidence of left ventricular primary graft dysfunction (CPS+, n=6 [20.0%]; CPS−, n=5 [17.2%]; p=0.79) was comparable between the groups. In the Kaplan-Meier survival analysis, no significant difference in overall survival at 5 years was observed between the CPS+ and CPS− groups (83.1%±6.9% vs. 89.7%±5.7%, respectively; log-rank p=0.7). No inter-group differences in early mortality (CPS+, n=0; CPS−, n=1 [3.4%]; p=0.98) or complications were observed.

Conclusion

The additional infusion of a cardioplegia solution immediately before implantation in patients with longer ischemic times is a simple, reproducible, and safe procedure. However, we did not observe benefits of this strategy in the present study.

Increased sensitivity to ischemic interval of donor hearts with diminished left ventricular function

BACKGROUND

Previous studies have demonstrated that carefully selected donor hearts (DHs) with poor left ventricular ejection fraction (EF) may be transplanted with long-term survival equivalent to hearts with normal function. The purpose of this study is to facilitate their selection.

METHODS

Using the United Network for Organ Sharing database, we reviewed all adult heart transplants between January 2000 and March 2016. Regression models were developed to estimate hazard ratios with 95% confidence intervals of post-transplant 1-year mortality and failure of EF to recover at 1 year for DHs with EF ≥50%, EF 40%-49.9%, and EF 30%-30.9%.

RESULTS

During the study period, 31,979 DHs were transplanted. Compared with DHs with left ventricular ejection fraction ≥50%, DHs with reduced EF were younger and had slightly lower body mass index. There were no differences in the mechanism of death between groups and no differences in recipient characteristics, except for a higher incidence of African American recipients of hearts with an EF of 40%-49.9%. Of the variables analyzed, only a 1-hour increase in ischemia time had different hazard ratios for 1-year mortality between groups, with increasing hazard as EF diminished. It was also the only variable that predicted failure of recovery of normal EF and that was in the lowest EF group.

CONCLUSIONS

The impact of DH traits associated with adverse outcomes after heart transplantation that we studied are similar between DHs with EF <50% and those with EF ≥50%. However, limiting ischemic time may be even more important for DHs with diminished left ventricular function, particularly at the low end of the EF spectrum.

Sex-mismatch influence on survival after heart transplantation: A systematic review and meta-analysis of observational studies

INTRODUCTION AND OBJECTIVES

Heart transplantation (HT) is the treatment for patients with end-stage heart disease. Despite contradictory reports, survival seems to be worse when donor/recipient sex is mismatched. This systematic review and meta-analysis aims to synthesize the evidence on the effect of donor/recipient sex mismatch after HT.

METHODS

We searched PubMed and EMBASE until November 2017. Comparative cohort and registry studies were included. Published articles were systematically selected and, when possible, pooled in a meta-analysis. The primary endpoint was one-year mortality.

RESULTS

After retrieving 556 articles, ten studies (76 175 patients) were included in the quantitative meta-analysis. Significant differences were found in one-year survival between sex-matched and mismatched recipients (odds ratio (OR) 1.30, 95% confidence interval (CI) 1.25-1.35, P < .001). In female recipients, we found that sex mismatch was not a risk factor for one-year mortality (OR = 0.93, 95% CI = 0.85-1.00, P = .06). However, in male recipients, we found that it was a risk factor for one-year mortality (OR = 1.38, 95% CI = 1.31-1.44, P < .001).

CONCLUSIONS

Sex mismatch increases one-year mortality after HT in male recipients. Its influence in long-term survival should be further explored with high-quality studies.

Donor and recipient age matching in heart transplantation: analysis of the UNOS Registry

The association of donor and recipient age with survival following adult heart transplantation has not been well characterized. The purpose of this study was to examine the impact of the relationship between donor and recipient age on post-transplant survival. We retrospectively reviewed the 2005-2018 UNOS heart transplant database for all adult recipients undergoing first-time isolated heart transplantation. The impact of donor and recipient age on survival was analyzed with Cox proportional hazards modeling using restricted cubic splines. A total of 25 480 heart transplant donor and recipient pairs met inclusion criteria. Unadjusted and adjusted Cox proportional hazards modeling demonstrated a near-linear association between increasing donor age and decreased survival; in addition, older and younger recipient age was associated with decreased survival. After adjustment, there was no significant interaction between donor and recipient age. Older donors decreased survival similarly in both older and younger recipients. Increasing donor age and both younger and older recipient age are independently associated with worsened post-heart transplant survival. The relationship between donor and recipient age does not significantly affect survival following heart transplant.

Variability in donor selection among pediatric heart transplant providers: Results from an international survey

There is considerable variability in donor acceptance practices among adult heart transplant providers; however, pediatric data are lacking. The aim of this study was to assess donor acceptance practices among pediatric heart transplant professionals. The authors generated a survey to investigate clinicians' donor acceptance practices. This survey was distributed to all members of the ISHLT Pediatric Council in April 2018. A total of 130 providers responded from 17 different countries. There was a wide range of acceptable criteria for potential donors. These included optimal donor-to-recipient weight ratio (lower limit: 50%-150%, upper limit: 120%-350%), maximum donor age (25-75 years), and minimum acceptable left ventricular EF (30%-60%). Non-US centers demonstrated less restrictive donor selection criteria and were willing to accept older donors (50 vs 35 years, P < 0.001), greater size discrepancy (upper limit weight ratio 250% vs 200%, P = 0.009), and donors with a lower EF (45% vs 50%, P < 0.001). Recipient factors were most influential in the decision to accept marginal donors including recipients requiring ECMO support, ventilator support, and highly sensitized patients with a negative XM. However, programmatic factors impacted the decision to decline marginal donors including recent programmatic mortalities and concerns for programmatic restrictions from regulatory bodies. There is significant variation in donor acceptance practices among pediatric heart transplant professionals. Standardization of donor acceptance practices through the development of a consensus statement may help to improve donor utilization and reduce waitlist mortality.

Does ex vivo perfusion lead to more or less intimal thickening in the first-year post-heart transplantation?

BACKGROUND

The Organ Care System (OCS), an ex vivo heart perfusion platform, represents an alternative to the current standard of cold organ storage that sustains the donor heart in a near-physiologic state. Previous reports showed that this system had significantly shortened the cold ischemic time from standard cold storage (CS). However, the effect of reduced ischemic injury against the coronary vascular bed has not been examined by intravascular ultrasound (IVUS).

METHODS

Between August 2011 and February 2013, heart transplant (HTx) candidates enrolled in the PROCEED 2 trial were randomized to either CS or OCS. IVUS was performed at 4-6 weeks (baseline) and repeated 1 year after transplantation. The change in maximal intimal thickness (MIT) and other clinical outcomes were examined.

RESULTS

Thirty-nine patients were randomized and underwent HTx by OCS (n=16) or CS (n=18). Of these, 18 patients (OCS: n=5, CS: n=13) with paired IVUS were examined. There were no significant differences in the change of MIT and other clinical outcomes between the groups.

CONCLUSION

The incidence of cardiac allograft vasculopathy in donor hearts preserved with the OCS versus CS was similar. These results suggest that this ex vivo allograft perfusion system is a promising and valid platform for donor heart transportation.

Bioengineering approaches to organ preservation ex vivo

IMPACT STATEMENT

Over the past several decades, ex vivo perfusion has emerged as a promising technology for the assessment, preservation, and recovery of donor organs. Many exciting pre-clinical findings have now been translated to clinical use, and successful transplantation following ex vivo perfusion has been achieved for heart, lung, and liver. While machine perfusion provides distinct advantages over traditional cold preservation, many challenges remain, including that of long-term (multi-day) ex vivo support. Here, we provide an overview of the current status of ex vivo machine perfusion in the pre-clinical and clinical setting and share our perspective on the future direction of the field.

Interaction Between Ischemic Time and Donor Age on Adult Heart Transplant Outcomes in the Modern Era

BACKGROUND

We examined the effect of cold ischemic interval on modern outcomes to determine whether advances in patient management have made an impact.

METHODS

Using the United Network of Organ Sharing database, we reviewed adult heart transplants between January 2000 and March 2016. We divided donor age into terciles: younger than 18 years, 18 to 33 years, and 34 years and older. Within each tercile, transplants were divided by cold ischemic interval of less than 4 hours, 4 to 6 hours, and more than 6 hours. Survival curves were compared between cold ischemic interval categories within each tercile. Covariate-adjusted and donor age-stratified Cox proportional hazards regression models were used to estimate overall mortality and graft failure hazards ratios.

RESULTS

Of 29,192 transplants, no significant differences between cold ischemic interval groups in survival or graft failure were apparent in the group aged younger than 18. For donors older than 18, significant differences were found for survival and graft failure with cold ischemic interval exceeding 4 hours in both univariate and multivariate analysis, and survival functions at different ischemic intervals continued to diverge beyond 1 year. The interaction effect between donor age and cold ischemic interval on overall mortality was not significant when analyzed as continuous variables, however younger donor age appeared to attenuate increase in overall mortality with longer cold ischemic intervals.

CONCLUSIONS

Despite advances in perioperative management during the past 30 years, for donors older than 18 years, cold ischemic interval exceeding 4 hours is associated with gradual but significantly diminished survival that persists well beyond the perioperative period. Comparison to historical data suggests that advances in management have somewhat attenuated the hazard associated with longer ischemic times.

Predicting the Readmission of Heart Failure Patients through Data Analytics

Reducing the costs and improving the quality of treatment in hospital systems as well as demands for better treatment from patients in order to keep them away from readmissions are two main issues healthcare systems have faced. In order to solve such challenges, predicting the occurrence of re-hospitalisation with data mining techniques would be so worthwhile. In this study, we are seeking to predict the occurrence of re-hospitalisation of the heart failure patients in two time-horizons (1-month and 3-month) via deployment of classification algorithms (i.e. decision trees, artificial neural networks, support vector machines and logistic regression). Two criterions (as main criterions) such as AUC (area under curve) and ACC (accuracy) have been calculated and assessed for classifying the prediction-power of the models in each time-horizon (outcome/target). We also have calculated some other criterions such as recall, precision and F1-Score. Then, we identified the importance and contribution of the variables for each outcome. Therefore, the variables whose contribution/importance changes over time are differentiated. It is noteworthy to say that this study is done under the scrutiny of an expert cardiologist. Trained nurses and expert cardiologist monitored the dataset every day, which was a hard and valuable measure to conduct. Finally, the dataset does not have missing values and noises. This research can be the basis for prospective medical studies and projects.

How to obtain and maintain favorable results after heart transplantation: keys to success?

We compared survival in our heart recipients with survival rates reported by the International Society of Heart and Lung Transplantation (ISHLT) Registry. As recipient and donor characteristics are changing over time, we studied four different eras. In order to differentiate between short- and long-term survival, we analyzed both overall survival and survival at one year. Obviously, this exercise is only relevant when baseline donor and recipient characteristics are comparable, as these differences may affect the outcome in opposite directions. To overcome this potential bias as much as possible, we calculated the Index for Mortality Prediction After Cardiac Transplantation (IMPACT)-scores and the Donor Risk Index (DRI). Looking to our results, we found that our DRIs in the different eras are almost equal to those obtained from the United Network for Organ Sharing database in the very same eras. Our IMPACT-scores, on the other hand, seem higher than those reported by ISHLT. Survival after transplantation and conditional on 1-year survival was higher than the outcome reported by the ISHLT Registry. As our operation technique and post-transplant immunosuppressive schedule did not differ from most centers, we speculated on potential factors that might contribute to our positive results. Patient selection and a relatively short waiting time are important contributors to the overall survival benefit. Our centralized follow-up may also have played an important role. Finally, the indefinite compulsory health insurance coverage in our country and easy access to different screening programs might also have influenced our outcome in a positive way. We are well aware that with challenges like donor organ shortage, more and more patients on mechanical circulatory support (MCS) will affect outcomes in the future.

Longer Ischemic Time is Associated with Increased Ventricular Stiffness as Measured by Pressure-Volume Loop Analysis in Pediatric Heart Transplant Recipients

BACKGROUND

The purpose of this study was to investigate the associations between clinical factors and cardiac function as measured by pressure-volume loops (PVLs) in a pediatric heart transplant cohort.

METHODS

Patients (age < 20 years) who underwent heart transplantation presenting for a clinically indicated catheterization were enrolled. PVLs were recorded using microconductance catheters (CD Leycom^®, Zoetermeer, Netherlands). Demographic data, serum B-type natriuretic peptide (BNP), time from transplant, ischemic time, presence of transplant coronary artery disease, donor-specific antibodies, and history of rejection were recorded at the time of catheterization. PVL data included contractility indices: end-systolic elastance and preload recruitable stroke work; ventricular-arterial coupling index; ventricular stiffness constant, Beta; and isovolumic relaxation time constant, tau. Associations between PVL measures and clinical data were investigated using non-parametric statistical tests.

RESULTS

A total of 18 patients were enrolled. Median age was 8.7 years (IQR 5-14 years). There were ten males and eight females. Six patients had a history of rejection and ten had positive donor-specific antibodies. There was no transplant coronary artery disease. Median BNP was 100 pg/mL (IQR 46-140). Time from transplant to PVL obtained during catheterization procedure was 4.1 years (IQR 1.7-7.8 year). No single clinical characteristic was statistically significant when correlated with PVL data. However, longer ischemic time was associated with worse Beta (r = 0.49, p = 0.05).

CONCLUSIONS

Our study found that longer ischemic times are associated with increased left ventricular stiffness. No other single clinical variable is associated with cardiac dysfunction as determined by PVL analysis.

Effects of Older Donor Age and Cold Ischemic Time on Long-Term Outcomes of Heart Transplantation

Using older donor hearts in cardiac transplantation may lead to inferior outcomes: older donors have more comorbidities that reduce graft quality, including coronary artery disease, hypertension, diabetes mellitus, and dyslipidemia. Shorter cold ischemic times might overcome the detrimental effect of older donor age. We examined the relationship between donor allograft age and cold ischemic time on the long-term outcomes of heart transplant recipients. rom 1994 through 2010, surgeons at our hospital performed 745 heart transplantations. We retrospectively classified these cases by donor ages of <50 years (younger) and ≥50 years (older), then by cold ischemic times of <120 min (short), 120 to 240 min (intermediate), and >240 min (long). Endpoints included recipient and graft survival, and freedom from cardiac allograft vasculopathy, nonfatal major adverse cardiac events, and rejection. For intermediate ischemic times, the 5-year recipient survival rate was lower when donors were older (70% vs 82.6%; P=0.02). This was also true for long ischemic times (69.8% vs 87.6%; P=0.09). For short ischemic times, we found no difference in 5-year recipient or graft survival rates (80% older vs 85.6% younger; P=0.79), in freedom from nonfatal major adverse cardiac events (83.3% vs 91.5%; P=0.46), or in freedom from cardiac allograft vasculopathy (50% vs 70.6%; P=0.66). Rejection rates were mostly similar. Long-term graft survival in heart transplantation patients with older donor allografts may improve when cold ischemic times are shorter.

CARE guidelines for case reports: explanation and elaboration document

BACKGROUND

Well-written and transparent case reports (1) reveal early signals of potential benefits, harms, and information on the use of resources; (2) provide information for clinical research and clinical practice guidelines, and (3) inform medical education. High-quality case reports are more likely when authors follow reporting guidelines. During 2011-2012, a group of clinicians, researchers, and journal editors developed recommendations for the accurate reporting of information in case reports that resulted in the CARE (CAse REport) Statement and Checklist. They were presented at the 2013 International Congress on Peer Review and Biomedical Publication, have been endorsed by multiple medical journals, and translated into nine languages.

OBJECTIVES

This explanation and elaboration document has the objective to increase the use and dissemination of the CARE Checklist in writing and publishing case reports.

ARTICLE DESIGN AND SETTING

Each item from the CARE Checklist is explained and accompanied by published examples. The explanations and examples in this document are designed to support the writing of high-quality case reports by authors and their critical appraisal by editors, peer reviewers, and readers.

RESULTS AND CONCLUSION

This article and the 2013 CARE Statement and Checklist, available from the CARE website [www.care-statement.org] and the EQUATOR Network [www.equator-network.org], are resources for improving the completeness and transparency of case reports.

91-Year-Old Allograft: Oldest Surviving Donor Heart Still Going: A Case Report

For patients with end-stage heart failure, heart transplantation remains one of the most successful therapies with excellent long-term survival rates. However, over the past few decades, there has been a worsening supply/demand mismatch given the rising epidemic of heart failure and the relatively fixed availability of donor hearts. In this case report, we describe the case of a 30-year-old woman who underwent transplantation with a 68-year-old donor heart and who has survived for 23 years without any major cardiac problems. To our knowledge, this patient has one of the oldest surviving donor hearts (91-year-old heart). Review of the latest guidelines and recent studies have demonstrated a gradual expansion of donor criteria to meet this critical shortage of donor organs.

Effect of Cold Preservation on Chronic Rejection in a Rat Hindlimb Transplantation Model

BACKGROUND

Previous studies on solid organ transplantation have shown that cold ischemia contributes to the development of chronic allograft vasculopathy. The authors evaluated the effect of cold ischemia on the development of chronic rejection in vascularized composite allotransplantation.

METHODS

Thirty rat hindlimbs were transplanted and divided into two experimental groups: immediate transplantation and transplantation after 7 hours of cold ischemia. The animals received daily low-dose immunosuppression with cyclosporine A for 2 months. Intimal proliferation, arterial permeability rate, leukocyte infiltration, and tissue fibrosis were assessed. The CD3, CD4, CD8, CD20, and CD68 cells per microscopic field (200×) were counted, and C4d deposition was investigated. Cytokine RNA analysis was performed to measure tumor necrosis factor-α, interleukin-6, and interleukin-10 levels.

RESULTS

Significant differences were found in the intimal proliferation and arterial permeability rate between the two groups (p = 0.004). The arterial permeability rate worsened in the most distal and small vessels (p = 0.047). The numbers of CD3, CD8, CD20, and CD68 were also statistically higher in the cold ischemia group (p < 0.05, all levels). A trend toward significance was observed with C4d deposition (p = 0.059). No differences were found in the RNA of cytokines.

CONCLUSIONS

An association between cold ischemia and chronic rejection was observed in experimental vascularized composite allotransplantation. Chronic rejection intensity and distal progression were significantly related with cold ischemia. The leukocyte infiltrates in vascularized composite allotransplantation components were a rejection marker; however, their exact implication in monitoring and their relation with cold ischemia are yet to be clarified.

Aging and the immune response to organ transplantation

An increasing number of older people receive organ transplants for various end-stage conditions. Although organ transplantation is an effective therapy for older patients (i.e., older than 65 years of age), such as in end-stage renal disease, this therapy has not been optimized for older patients because of our lack of understanding of the effect of aging and the immune response to organ transplantation. Here, we provide an overview of the impact of aging on both the allograft and the recipient and its effect on the immune response to organ transplantation. We describe what has been determined to date, discuss existing gaps in our knowledge, and make suggestions on necessary future studies to optimize organ transplantation for older people.

Interaction of older donor age and survival after weight-matched pediatric heart transplantation

BACKGROUND

Donors are matched for weight in pediatric heart transplantation (PHT), yet age differences are not considered in this decision. In this study we attempt to identify the effect of age differences in weight-matched patients and the effect these differences have on post-transplant survival.

METHODS

The United Network of Organ Sharing (UNOS) database was queried for the period from October 1987 to March 2014 for all pediatric heart transplant patients. Transplants with donor-to-recipient (D-R) weight ratios of 0.8 to 1.5 were identified (weight-matched). D-R age differences were categorized as: donors 5 years younger than recipients (D<R-5); donors within 5 years of recipients (D=R±5); and donors 5 years older than recipients (D>R+5).

RESULTS

A total of 4,408 patients were identified as weight-matched transplants. Of these transplants, 681 were D>R+5, 3,596 were D=R±5 and 131 were D<R-5. D>R+5 transplants were found to be associated with decreased post-transplant survival compared with D=R±5 (p = 0.002). Rates of acute rejection were similar among all groups but post-transplant coronary allograft vasculopathy (CAV) was more prevalent in D>R+5 than D=R±5 patients (28% and 18%, respectively; p < 0.001). Increasing age difference by each year was associated with decreasing median post-transplant survival time (p < 0.001; hazard ratio 1.018, range 1.011 to 1.025). The overall negative association with mortality was due to the adolescent cohort (11 to 17 years), specifically D>R+5 transplants, utilizing organs from donors >25 of age.

CONCLUSION

In PHT, increasing D-R age difference decreases survival; however, this effect is driven by recipients 11 to 17 years old and donors >25 years old. Allocation of younger donor organs to adolescent recipients should be a priority.

Targeting the Innate Immune Response to Improve Cardiac Graft Recovery after Heart Transplantation: Implications for the Donation after Cardiac Death

Heart transplantation (HTx) is the ultimate treatment for end-stage heart failure. The number of patients on waiting lists for heart transplants, however, is much higher than the number of available organs. The shortage of donor hearts is a serious concern since the population affected by heart failure is constantly increasing. Furthermore, the long-term success of HTx poses some challenges despite the improvement in the management of the short-term complications and in the methods to limit graft rejection. Myocardial injury occurs during transplantation. Injury initiated in the donor as result of brain or cardiac death is exacerbated by organ procurement and storage, and is ultimately amplified by reperfusion injury at the time of transplantation. The innate immune system is a mechanism of first-line defense against pathogens and cell injury. Innate immunity is activated during myocardial injury and produces deleterious effects on the heart structure and function. Here, we briefly discuss the role of the innate immunity in the initiation of myocardial injury, with particular focus on the Toll-like receptors and inflammasome, and how to potentially expand the donor population by targeting the innate immune response.

Impact of donor age on cardiac transplantation outcomes and on cardiac function

OBJECTIVES

Although the impact of older donors on heart transplant outcomes has been previously published, the survival results are conflicting. We herein analyse the impact of older donors on transplant survival and myocardial function.

METHODS

The records of the patients who underwent heart transplant at Baylor University Medical Center at Dallas from November 2012 until March 2015 were reviewed and the data were extracted. The heart recipients were divided into two groups based on donors age; 50 years of age was the division point. The two groups were compared with regard to the following transplant outcomes: in-hospital and 1-year survival, severe (3R) rejection, primary graft dysfunction, myocardial performance as reflected by the inotropic score, left ventricular ejection fraction, intensive care unit and overall length of stay.

RESULTS

Anoxia was more common cause of death in younger donors (43.9%), whereas intracranial bleeding was more frequent in older donors (48.1%, P = 0.016). The in-hospital survival and 1-year survival were the same between the two groups. Additionally, cardiac transplantation from older donors was not associated with higher incidence of graft dysfunction, higher inotropic support score, longer intensive care unit and total hospital length of stay or more frequent severe rejection episodes. The left ventricular ejection fraction was similar between the two groups.

CONCLUSIONS

Heart transplant from older donors is not associated with lower in-hospital and mid-term survival if donors are carefully selected; furthermore, the graft function is comparable. The use of hearts from donors older than 50 years of age can be expanded beyond critically ill recipients in carefully selected recipients.

Advances in the understanding and management of heart transplantation

Cardiac transplantation represents one of the great triumphs in modern medicine and remains the cornerstone in the treatment of advanced heart failure. In this review, we contextualize pivotal developments in our understanding and management of cardiac transplant immunology, histopathology, rejection surveillance, drug development and surgery. We also discuss current limitations in their application and the impact of the left ventricular assist devices in bridging this gap.

Supplemental Cardioplegia Immediately before Graft Implantation may Improve Early Post-Transplantation Outcome

Background: Preservation of cardiac grafts for transplantation is not standardized and most centers use a single administration of crystalloid solution at the time of harvesting. We investigated possible benefits of an additional dose of cardioplegia dispensed immediately before implantation.

Methods: Consecutive adult cardiac transplantations (2005–2012) were reviewed. Hearts were harvested following a standard protocol (Celsior 2L, 4–8°C). In 2008, 100 ml crystalloid cardioplegic solution was added and administered immediately before implantation. Univariate and logistic regression analyses were used to investigate risk factors for post-operative graft failure and mid-term outcome.

Results: A total of 81 patients, 44 standard (“Cardio⁻”) vs. 37 with additional cardioplegia (“Cardio⁺”) were analyzed. Recipients and donors were comparable in both groups. Cardio⁺ patients demonstrated a reduced need for defibrillation (24 vs. 48%, p = 0.03), post-operative ratio of CK-MB/CK (10.1 ± 3.9 vs. 13.3 ± 4.2%, p = 0.001), intubation time (2.0 ± 1.6 vs. 7.2 ± 11.5 days, p = 0.05), and ICU stay (3.9 ± 2.1 vs. 8.5 ± 7.8 days, p = 0.001). Actuarial survival was reduced when graft ischemic time was >180 min in Cardio⁻ but not in Cardio⁺ patients (p = 0.033). Organ ischemic time >180 min (OR: 5.48, CI: 1.08–27.75), donor female gender (OR: 5.84, CI: 1.13–33.01), and recipient/donor age >60 (OR: 6.33, CI: 0.86–46.75), but not the additional cardioplegia or the observation period appeared independent predictors of post-operative acute graft failure.

Conclusion: An additional dose of cardioplegia administered immediately before implantation may be a simple way to improve early and late outcome of cardiac transplantation, especially in situations of prolonged graft ischemia. A large, ideally multicentric, randomized study is desirable to verify this preliminary observation.

Impact of warm ischemia time on survival after heart transplantation

BACKGROUND

There is little data available on the specific effects of warm ischemia time (WIT) as opposed to cold ischemia or storage time. With current research endeavors focusing on warm continuous perfusion, storage of donor hearts, and utilization of hearts from non-heart-beating donors, the impact of WIT on outcomes is increasingly relevant. The aim of this study was to analyze our results in cardiac transplantation with specific focus on the impact of WIT.

METHODS

A retrospective review of 206 patients who underwent orthotopic heart transplantation at our institution between June 2001 and November 2010 was performed. Donor, recipient, and operative factors were analyzed. The main outcome variables were all cause mortality, survival, and primary graft failure.

RESULTS

WIT of >80 minutes was associated with reduced survival compared with a shorter WIT of <60 minutes. Multivariate analysis showed increasing donor age to be the most significant variable associated with increased risk of mortality (hazard ratio 1.04; P = .004) per year of increasing donor age.

CONCLUSIONS

This study has demonstrated a reduced survival in heart transplant recipients with increased WIT. This finding may be of particular relevance to potential future heart transplantation using organs procured from non-heart-beating donors.

Frequency, time course, and possible causes of right ventricular systolic dysfunction after cardiac transplantation: a single center experience

BACKGROUND

The frequency and causes of right ventricular (RV) systolic dysfunction early after cardiac transplantation are not well defined.

METHODS

We investigated the prevalence and causes of RV dysfunction in 27 heart transplant recipients, as measured by lateral tricuspid annular plane excursion (TAPSE) and fractional area change (FAC) at a mean of 15 ± 11 days after transplant. Tissue Doppler imaging was used to assess systolic time velocity integral (TVI) of the RV basal free wall. A subset of 22 patients had follow-up TAPSE measurement at 406 ± 121 days.

RESULTS

RV systolic dysfunction, defined as TAPSE > 2 standard deviation (SD) below values in a control group, was present in 100% (27/27) of patients (P < 0.05). FAC was also significantly lower in patients compared with controls (P < 0.0001). TVI confirmed the presence of RV dysfunction in all 16 patients with both TAPSE and TVI (P < 0.05). Ischemic time (P = 0.017) and posttransplant tricuspid regurgitation (P = 0.024) were independent predictors of early RV dysfunction (r = 0.753). On follow-up, RV function improved in 15 of 22 patients but all patients remained with TAPSE > 2 SD below controls.

CONCLUSION

This study showed that 100% of patients had reduced RV function early after transplant. Two thirds of patients had partial recovery of RV function during the first year. In all patients, however, RV function remained significantly lower than in controls.

Ischemic time as a predictor of physical recovery in the first months after heart transplantation

Functional results after heart transplantation range from modest to spectacular improvement. Little is known about factors to predict functional result. This study aimed to identify these factors. We present a prospective study including all consecutive transplant recipients (n = 55) in a two-year period whose survival was greater than two months. Perioperative, donor, and recipient issues were systematically analyzed. Exercise capacity was assessed by symptom-limited treadmill exercise testing two months after transplantation. Exercise capacity was classified as satisfactory or poor depending on achieving or not 4.5 METs (metabolic equivalents), respectively. Thirty-three patients (60%) showed a good exercise capacity (>4.5 METs), whereas the remaining twenty-two patients (40%) were unable to exceed this threshold. The variables which correlated with exercise capacity in univariate analysis were recipient age, inotropic treatment, ischemic time, ventricular assist device, etiology, urgent transplant, and INTERMACS score. Among them only recipient age and ischemic time were proved to be correlated with exercise capacity in the multiple regression analysis. Thus, younger patients and those who had received an organ with shorter ischemic time showed greater exercise capacity after transplant. These findings strengthen the trend toward reducing ischemic time as much as possible to improve both survival and clinical recovery.

The hypoxia-inflammation link and potential drug targets

PURPOSE OF REVIEW

Hypoxia represents one of the strongest transcriptional stimuli known to us. In most cases, hypoxia-induced changes in gene expression are directed towards adapting tissues to conditions of limited oxygen availability.

RECENT FINDINGS

As a well known example, physical exercise at high altitude results in the transcriptional induction of erythropoietin that functions to increase oxygen carrying capacity and red cell volume. Studies of the transcriptional pathway responsible for the induction of erythropoietin during conditions of hypoxia led to the discovery of the transcription factor hypoxia-inducible factor (HIF) that is known today as the key transcription factor for hypoxia adaptation. Surgical patients are frequently at risk for experiencing detrimental effects of hypoxia or ischemia, for example, in the context of acute kidney injury, myocardial, intestinal or hepatic ischemia, acute lung injury, or during organ transplantation.

SUMMARY

In the present review, we discuss the mechanisms of transcriptional adaptation to hypoxia and provide evidence supporting the hypothesis that targeting hypoxia-induced inflammation can represent novel pharmacologic strategies to improve perioperative outcomes. Currently, such strategies are being explored at an experimental level, but we hope that some of these targets can be translated into perioperative patient care within the next decade.