Daytime Variation of Clinical Outcome in Cardiac Surgery: A Propensity-Matched Cohort Study

OBJECTIVE

The purpose of the present study was to investigate the hypothesis of a nychthemeral variation in the tolerance to ischemia and reperfusion injury in adult cardiac surgeries.

DESIGN

Retrospective cohort study.

SETTING

A single academic center.

PARTICIPANTS

All patients undergoing nonemergent aortic valve replacement (AVR) ± coronary artery bypass graft between January 2012 and May 2018 were included. They were divided into two groups (morning and afternoon) according to the time of the day at the beginning of surgery. Propensity score matching estimated by multivariate logistic regression with a 1:1 matching ratio was performed to ensure that the two groups were comparable. This allowed obtaining 269 pairs, for a total of 538 patients.

INTERVENTION

The objective of the study was to assess whether there were differences in perioperative and postoperative outcomes between the morning and the afternoon groups.

RESULTS

There was no between-group difference in the primary composite endpoints, namely the occurrence of death, myocardial infarction, low cardiac output, and stroke during the 30 days following the surgery. Regarding cardiac biomarkers, there were no between-group differences for both postoperative evolution of troponin T plasma levels and the maximum postoperative troponin T plasma level.

CONCLUSION

These results did not support the hypothesis that the timing of the surgery could influence the tolerance to ischemia and reperfusion injury, at least in patients undergoing nonemergent AVR or a combined AVR with coronary artery bypass graft.

Analysis of the COMPARE-AMI trial: First report of long-term safety of CD133+ cells

BACKGROUND

Data related to long-term safety of intracoronary (IC) injection of CD133+ bone marrow stem cells (BMSC) following an acute myocardial infarction (MI) are still lacking.

METHODS

COMPARE-AMI is a double-blind, placebo-controlled phase II clinical trial evaluating the safety and efficacy of IC injection of CD133+ enriched hematopoietic BMSC in patients with ST-elevation myocardial infarction (STEMI) and persistent left ventricular (LV) dysfunction following successful primary percutaneous coronary intervention (PCI). Herein, we report outcomes up to ten years of follow-up.

RESULTS

Between November 2007 and July 2012, we enrolled 38 patients in our study. Males were 89% and the median age was 50.5 years. Baseline left ventricular ejection fraction (LVEF) was 40.0%, and 90% of lesions were located in the left anterior descending (LAD) artery. The median follow-up time was 8.5 years IQR [7.9, 10.0]. Using Kaplan-Meier methods, MACE-free survival up to 10 years was 77.3% overall. IC injection of CD133+ BMSC was associated with a similar event-free survival rate compared to placebo (87.8% vs. 66.3%, p = .37). Two cancer cases in each group were recorded. No malignant arrhythmias were observed.

CONCLUSIONS

IC injection of CD133+ BMSC is safe up to 10 years of follow-up. The long-term efficacy needs to be confirmed by a larger randomized trial.

Frailty and Bleeding in Older Adults Undergoing TAVR or SAVR: Insights From the FRAILTY-AVR Study

OBJECTIVES

The aim of this study was to examine the value of frailty to predict in-hospital major bleeding and determine its impact on mid-term mortality following transcatheter (TAVR) or surgical (SAVR) aortic valve replacement.

BACKGROUND

Bleeding complications are harbingers of mortality and major morbidity in patients undergoing TAVR or SAVR. Despite the high prevalence of frailty in this population, little is known about its effects on bleeding risk.

METHODS

A post hoc analysis was performed of the multinational FRAILTY-AVR (Frailty Aortic Valve Replacement) cohort study, which prospectively enrolled older adults ≥70 years of age undergoing TAVR or SAVR. Trained researchers assessed frailty using a questionnaire and physical performance battery pre-procedure and ascertained clinical data from the electronic health record. The primary endpoint was major or life-threatening bleeding during the index hospitalization, and the secondary endpoint was units of packed red blood cells transfused.

RESULTS

The cohort consisted of 1,195 patients with a mean age of 81.3 ± 6.0 years. The incidence of life-threatening bleeding, major bleeding with a clinically apparent source, and major bleeding without a clinically apparent source was, respectively, 3%, 6%, and 9% in the TAVR group and 8%, 10%, and 31% in the SAVR group. Frailty measured using the Essential Frailty Toolset was an independent predictor of major bleeding and packed red blood cell transfusions in both groups. Major bleeding was associated with a 3-fold increase in 1-year mortality following TAVR (odds ratio: 3.40; 95% confidence interval: 2.22 to 5.21) and SAVR (odds ratio: 2.79; 95% confidence interval: 1.25 to 6.21).

CONCLUSIONS

Frailty is associated with post-procedural major bleeding in older adults undergoing TAVR and SAVR, which is in turn associated with a higher risk for mid-term mortality.

Outcomes following surgical revascularization with single versus bilateral internal thoracic arterial grafts in patients with left main coronary artery disease undergoing coronary artery bypass grafting: insights from the EXCEL trial†

OBJECTIVES

Observational data suggest that the use of a single internal thoracic artery (SITA) may result in inferior outcomes compared with bilateral internal thoracic artery (BITA) use for coronary artery bypass grafting (CABG)-a finding not yet supported by randomized trial outcomes. However, the optimal number of internal thoracic artery grafts in patients with left main coronary artery disease has not been investigated.

METHODS

The EXCEL trial randomized 1905 patients with left main coronary artery disease to percutaneous coronary intervention with everolimus-eluting stents versus CABG. Among the 905 patients undergoing CABG, 688 (76.0%) received SITA and 217 (24.0%) received BITA. Differences in clinical event rates were estimated using the Kaplan-Meier method and compared with the log-rank test. Multivariable Cox regression was used to adjust for differences in baseline covariates.

RESULTS

Compared to SITA, patients treated with BITA were younger (66.1 ± 9.5 vs 64.5 ± 9.3 years, P = 0.020), were less likely female (24.3% vs 14.3%, P = 0.002) and diabetic (28.8% vs 15.2%, P < 0.001), and had a lower prevalence of peripheral vessel disease (10.2% vs 5.5%, P = 0.040). The unadjusted 3-year composite primary endpoint of death, stroke or myocardial infarction (MI) occurred in 15.6% of SITA vs 11.6% of BITA patients (P = 0.17). The SITA group tended to have a higher 3-year rate of all-cause death compared with the BITA group (6.7% vs 3.3%; P = 0.070). Stroke, MI and ischaemia-driven revascularization outcomes were not significantly different between groups. After adjusting for baseline differences, neither the composite of death, stroke or MI [hazard ratio (HR) 1.12, 95% confidence interval (CI) 0.71-1.78; P = 0.62] nor mortality (HR 1.36, 95% CI 0.60-3.12; P = 0.46) was significantly higher with SITA. The rehospitalization rate after 3 years was higher in the SITA group (35.8% vs 26.0%, P = 0.008), a difference which was no longer present after multivariable adjustment (HR 1.27, 95% CI 0.93-1.74; P = 0.13). Sternal wound dehiscence within 30 days did not occur more often in the BITA group compared to the SITA group (1.8% vs 2.2%, P > 0.99).

CONCLUSIONS

In the EXCEL trial, there were no clinical differences at 3 years between SITA or BITA revascularization in patients with left main coronary artery disease.

Standardizing Postoperative Complications-Validating the Clavien-Dindo Complications Classification in Cardiac Surgery

Cardiac surgery lacks a method for quantifying postoperative morbidities. The Clavien-Dindo Complications Classification (CDCC) and the Comprehensive Complication Index (CCI) were successfully implemented as outcome reporting methods in other surgical specialties. This study aims to validate these complication scales in cardiac surgery. Between 2010 and 2019, we prospectively collected data on 41,218 adult patients (73% men, mean age 67 ± 11 years) undergoing cardiac surgery at 6 university hospitals. Complications were graded using the CDCC based on the complication's treatment invasiveness with adaptations for common treatments in cardiac surgery. CCI were calculated, representing multiple complications on a scale of 0 (no complication) to 100 (death). Associations with predictors of poor outcome were assessed using mixed-effects models accounting for center as a random effect. CDCC grade was 0 in 23.0%, I in 11.4%, II in 35.3%, IIIa in 6.4%, IIIb in 2.6%, IVa in 16.1%, IVb in 2.1%, and V in 3.1%. Median CCI was 23 (9, 40). A change from lowest to highest observed CDCC grade was associated with an increase in the Society of Thoracic Surgeons mortality score from 1.1% to 4.7%, surgery duration from 177 to 233 minutes, and hospital stay from 5.2 to 17 days (all P < 0.0001). The CCI also increased with greater procedure complexity (P < 0.0001). Increase in CDCC/CCI is associated with greater comorbidities, surgery durations, lengths of stay, and procedure complexity, accurately reflecting the nuances of the adult cardiac surgery postoperative course. These have great potential for uniform outcome reporting and quality improvement initiatives.

Heat shock protein 90 inhibition and multi-target approach to maximize cardioprotection in ischaemic injury

Despite several advances in medicine, ischaemic heart disease remains a major cause of morbidity and mortality. The unravelling of molecular mechanisms underlying disease pathophysiology has revealed targets for pharmacological interventions. However, transfer of these pharmcological possibilities to clinical use has been disappointing. Considering the complexity of ischaemic disease at the cellular and molecular levels, an equally multifaceted treatment approach may be envisioned. The pharmacological principle of 'one target, one key' may fall short in such contexts, and optimal treatment may involve one or many agents directed against complementary targets. Here, we introduce a 'multi-target approach to cardioprotection' and propose heat shock protein 90 (HSP90) as a target of interest. We report on a member of a distinct class of HSP90 inhibitor possessing pleiotropic activity, which we found to exhibit potent infarct-sparing effects.

Novel heat shock protein 90 inhibitor improves cardiac recovery in a rodent model of donation after circulatory death

OBJECTIVE

Organ donation after circulatory death (DCD) is a potential solution for the shortage of suitable organs for transplant. Heart transplantation using DCD donors is not frequently performed due to the potential myocardial damage following warm ischemia. Heat shock protein (HSP) 90 has recently been investigated as a novel target to reduce ischemia/reperfusion injury. The objective of this study is to evaluate an innovative HSP90 inhibitor (HSP90i) as a cardioprotective agent in a model of DCD heart.

METHODS

A DCD protocol was initiated in anesthetized Lewis rats by discontinuation of ventilation and confirmation of circulatory death by invasive monitoring. Following 15 minutes of warm ischemia, cardioplegia was perfused for 5 minutes at physiological pressure. DCD hearts were mounted on a Langendorff ex vivo heart perfusion system for reconditioning and functional assessment (60 minutes). HSP90i (0.01 μmol/L) or vehicle was perfused in the cardioplegia and during the first 10 minutes of ex vivo heart perfusion reperfusion. Following assessment, pro-survival pathway signaling was evaluated by western blot or polymerase chain reaction.

RESULTS

Treatment with HSP90i preserved left ventricular contractility (maximum + dP/dt, 2385 ± 249 vs 1745 ± 150 mm Hg/s), relaxation (minimum -dP/dt, -1437 ± 97 vs 1125 ± 85 mm Hg/s), and developed pressure (60.7 ± 5.6 vs 43.9 ± 4.0 mm Hg), when compared with control DCD hearts (All P = .001). Treatment abrogates ischemic injury as demonstrated by a significant reduction of infarct size (2,3,5-triphenyl-tetrazolium chloride staining) of 7 ± 3% versus 19 ± 4% (P = .03), troponin T release, and mRNA expression of Bax/Bcl-2 (P < .05).

CONCLUSIONS

The cardioprotective effects of HSP90i when used following circulatory death might improve transplant organ availability by expanding the use of DCD hearts.

The Effect of Improving Basic Preventive Measures in the Perioperative Arena on Staphylococcus aureus Transmission and Surgical Site Infections: A Randomized Clinical Trial

Importance

Surgical site infections increase patient morbidity and health care costs. The Centers for Disease Control and Prevention emphasize improved basic preventive measures to reduce bacterial transmission and infections among patients undergoing surgery.

Objective

To assess whether improved basic preventive measures can reduce perioperative Staphylococcus aureus transmission and surgical site infections.

Design, Setting, and Participants

This randomized clinical trial was conducted from September 20, 2018, to September 20, 2019, among 19 surgeons and their 236 associated patients at a major academic medical center with a 60-day follow-up period. Participants were a random sample of adult patients undergoing orthopedic total joint, orthopedic spine, oncologic gynecological, thoracic, general, colorectal, open vascular, plastic, or open urological surgery requiring general or regional anesthesia. Surgeons and their associated patients were randomized 1:1 via a random number generator to treatment group or to usual care. Observers were masked to patient groupings during assessment of outcome measures.

Interventions

Sustained improvements in perioperative hand hygiene, vascular care, environmental cleaning, and patient decolonization efforts.

Main Outcomes and Measures

Perioperative S aureus transmission assessed by the number of isolates transmitted and the incidence of transmission among patient care units (primary) and the incidence of surgical site infections (secondary).

Results

Of 236 patients (156 [66.1%] women; mean [SD] age, 57 [15] years), 106 (44.9%) and 130 (55.1%) were allocated to the treatment and control groups, respectively, received the intended treatment, and were analyzed for the primary outcome. Compared with the control group, the treatment group had a reduced mean (SD) number of transmitted perioperative S aureus isolates (1.25 [2.11] vs 0.47 [1.13]; P = .002). Treatment reduced the incidence of S aureus transmission (incidence risk ratio; 0.56; 95% CI, 0.37-0.86; P = .008; with robust variance clustering by surgeon: 95% CI, 0.42-0.76; P < .001). Overall, 11 patients (4.7%) experienced surgical site infections, 10 (7.7%) in the control group and 1 (0.9%) in the treatment group. Transmission was associated with an increased risk of surgical site infection (8 of 73 patients [11.0%] with transmission vs 3 of 163 [1.8%] without; risk ratio, 5.95; 95% CI, 1.62-21.86; P = .007). Treatment reduced the risk of surgical site infection (hazard ratio, 0.12; 95% CI, 0.02-0.92; P = .04; with clustering by surgeon: 95% CI, 0.03-0.51; P = .004).

Conclusions and Relevance

Improved basic preventive measures in the perioperative arena can reduce S aureus transmission and surgical site infections.

Trial Registration

ClinicalTrials.gov Identifier: NCT03638947.

Continuous-Flow Left Ventricular Assist Devices and Valvular Heart Disease: A Comprehensive Review

Mechanical circulatory support with implantable durable continuous-flow left ventricular assist devices (CF-LVADs) represents an established surgical treatment option for patients with advanced heart failure refractory to guideline-directed medical therapy. CF-LVAD therapy has been demonstrated to offer significant survival, functional, and quality-of-life benefits. However, nearly one-half of patients with advanced heart failure undergoing implantation of a CF-LVAD have important valvular heart disease (VHD) present at the time of device implantation or develop VHD during support that can lead to worsening right or left ventricular dysfunction and result in development of recurrent heart failure, more frequent adverse events, and higher mortality. In this review, we summarize the recent evidence related to the pathophysiology and treatment of VHD in the setting of CF-LAVD support and include a review of the specific valve pathologies of aortic insufficiency (AI), mitral regurgitation (MR), and tricuspid regurgitation (TR). Recent data demonstrate an increasing appreciation and understanding of how VHD may adversely affect the hemodynamic benefits of CF-LVAD support. This is particularly relevant for MR, where increasing evidence now demonstrates that persistent MR after CF-LVAD implantation can contribute to worsening right heart failure and recurrent heart failure symptoms. Standard surgical interventions and novel percutaneous approaches for treatment of VHD in the setting of CF-LVAD support, such as transcatheter aortic valve replacement or transcatheter mitral valve repair, are available, and indications to intervene for VHD in the setting of CF-LVAD support continue to evolve.

Five-Year Outcomes after PCI or CABG for Left Main Coronary Disease

BACKGROUND

Long-term outcomes after percutaneous coronary intervention (PCI) with contemporary drug-eluting stents, as compared with coronary-artery bypass grafting (CABG), in patients with left main coronary artery disease are not clearly established.

METHODS

We randomly assigned 1905 patients with left main coronary artery disease of low or intermediate anatomical complexity (according to assessment at the participating centers) to undergo either PCI with fluoropolymer-based cobalt-chromium everolimus-eluting stents (PCI group, 948 patients) or CABG (CABG group, 957 patients). The primary outcome was a composite of death, stroke, or myocardial infarction.

RESULTS

At 5 years, a primary outcome event had occurred in 22.0% of the patients in the PCI group and in 19.2% of the patients in the CABG group (difference, 2.8 percentage points; 95% confidence interval [CI], -0.9 to 6.5; P = 0.13). Death from any cause occurred more frequently in the PCI group than in the CABG group (in 13.0% vs. 9.9%; difference, 3.1 percentage points; 95% CI, 0.2 to 6.1). In the PCI and CABG groups, the incidences of definite cardiovascular death (5.0% and 4.5%, respectively; difference, 0.5 percentage points; 95% CI, -1.4 to 2.5) and myocardial infarction (10.6% and 9.1%; difference, 1.4 percentage points; 95% CI, -1.3 to 4.2) were not significantly different. All cerebrovascular events were less frequent after PCI than after CABG (3.3% vs. 5.2%; difference, -1.9 percentage points; 95% CI, -3.8 to 0), although the incidence of stroke was not significantly different between the two groups (2.9% and 3.7%; difference, -0.8 percentage points; 95% CI, -2.4 to 0.9). Ischemia-driven revascularization was more frequent after PCI than after CABG (16.9% vs. 10.0%; difference, 6.9 percentage points; 95% CI, 3.7 to 10.0).

CONCLUSIONS

In patients with left main coronary artery disease of low or intermediate anatomical complexity, there was no significant difference between PCI and CABG with respect to the rate of the composite outcome of death, stroke, or myocardial infarction at 5 years. (Funded by Abbott Vascular; EXCEL ClinicalTrials.gov number, NCT01205776.).

Association of Depression With Mortality in Older Adults Undergoing Transcatheter or Surgical Aortic Valve Replacement

Importance

Depression is increasingly recognized as a risk factor for adverse outcomes in cardiovascular disease. However, little is known about depression in older adults undergoing transcatheter (TAVR) or surgical (SAVR) aortic valve replacement.

Objective

To determine the prevalence of depression and its association with all-cause mortality in older adults undergoing TAVR or SAVR.

Design, Setting, and Participants

This preplanned analysis of the Frailty Aortic Valve Replacement (FRAILTY-AVR) prospective cohort study included 14 centers in 3 countries from November 15, 2011, through April 7, 2016. Individuals 70 years or older who underwent TAVR or SAVR were enrolled. Depressive symptoms were evaluated using the Geriatric Depression Scale Short Form at baseline and follow-up.

Main Outcomes and Measures

All-cause mortality at 1 and 12 months after TAVR or SAVR. Logistic regression was used to determine the association of depression with mortality after adjusting for confounders such as frailty and cognitive impairment.

Results

Among 1035 older adults (427 men [41.3%] and 608 women [58.7%]) with a mean (SD) age of 81.4 (6.1) years, 326 (31.5%) had a positive result of screening for depression, whereas only 89 (8.6%) had depression documented in their clinical record. After adjusting for clinical and geriatric confounders, baseline depression was found to be associated with mortality at 1 month (odds ratio [OR], 2.20; 95% CI, 1.18-4.10) and at 12 months (OR, 1.532; 95% CI, 1.03-2.24). Persistent depression, defined as baseline depression that was still present 6 months after the procedure, was associated with a 3-fold increase in mortality at 12 months (OR, 2.98; 95% CI, 1.08-8.20).

Conclusions and Relevance

One in 3 older adults undergoing TAVR or SAVR had depressive symptoms at baseline and a higher risk of short-term and midterm mortality. Patients with persistent depressive symptoms at follow-up had the highest risk of mortality.

Identification of Patients With High Mortality Risk and Prediction of Outcomes in Delirium by Bispectral EEG

BACKGROUND

Delirium is common and dangerous, yet underdetected and undertreated. Current screening questionnaires are subjective and ineffectively implemented in busy hospital workflows. Electroencephalography (EEG) can objectively detect the diffuse slowing characteristic of delirium, but it is not suitable for high-throughput screening due to size, cost, and the expertise required for lead placement and interpretation. This study hypothesized that an efficient and reliable point-of-care EEG device for high-throughput screening could be developed.

METHODS

This prospective study, which measured bispectral EEG (BSEEG) from elderly inpatients to assess their outcomes, was conducted at the University of Iowa Hospitals and Clinics from January 2016 to October 2017. A BSEEG score was defined based on the distribution of 2,938 EEG recordings from the 428 subjects who were assessed for delirium; primary outcomes measured were hospital length of stay, discharge disposition, and mortality.

RESULTS

A total of 274 patients had BSEEG score data available for analysis. Delirium and BSEEG score had a significant association (P < .001). Higher BSEEG scores were significantly correlated with length of stay (P < .001 unadjusted, P = .001 adjusted for age, sex, and Charlson Comorbidity Index [CCI] score) as well as with discharge not to home (P < .01). Hazard ratio for survival controlling for age, sex, CCI score, and delirium status was 1.35 (95% CI,1.04 to 1.76; P = .025).

CONCLUSIONS

In BSEEG, an efficient and reliable device that provides an objective measurement of delirium status was developed. The BSEEG score is significantly associated with pertinent clinical outcomes of mortality, hospital length of stay, and discharge disposition. The BSEEG score better predicts mortality than does clinical delirium status. This study identified a previously unrecognized subpopulation of patients without clinical features of delirium who are at increased mortality risk.

Off-Pump Versus On-Pump Bypass Surgery for Left Main Coronary Artery Disease

BACKGROUND

Concerns remain for a greater risk of incomplete revascularization and reduced survival with off-pump coronary artery bypass grafting (CABG) surgery compared with on-pump surgery particularly in patients with left main disease and extensive underlying myocardial ischemia.

OBJECTIVES

This study sought to compare outcomes following off-pump versus on-pump surgery for left main disease by performing a post hoc analysis from the multicenter, randomized EXCEL (Evaluation of XIENCE versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) trial.

METHODS

The EXCEL trial was designed to compare percutaneous coronary intervention with everolimus-eluting stents versus CABG in patients with left main disease. CABG was performed with or without cardiopulmonary bypass (on-pump vs. off-pump surgery) according to the discretion of the operator. The 3-year outcomes in the off-pump and on-pump groups were compared using inverse probability of treatment weighting (IPTW) for treatment effect estimation.

RESULTS

Among 923 CABG patients, 652 and 271 patients underwent on-pump and off-pump surgery, respectively. Despite a similar extent of disease, off-pump surgery was associated with a lower rate of revascularization of the left circumflex coronary artery (84.1% vs. 90.0%; p = 0.01) and right coronary artery (31.1% vs. 40.6%; p = 0.007). After IPTW adjustment for baseline differences, off-pump surgery was associated with a significantly increased risk of 3-year all-cause death (8.8% vs. 4.5%; hazard ratio: 1.94; 95% confidence interval: 1.10 to 3.41; p = 0.02) and a nonsignificant difference in the risk for the composite endpoint of death, myocardial infarction, or stroke (11.8% vs. 9.2%; hazard ratio: 1.28; 95% confidence interval: 0.82 to 2.00; p = 0.28).

CONCLUSIONS

Among patients with left main disease treated with CABG in the EXCEL trial, off-pump surgery was associated with a lower rate of revascularization of the coronary arteries supplying the inferolateral wall and an increased risk of 3-year all-cause death compared with on-pump surgery.

Pre-clinical Model of Cardiac Donation after Circulatory Death

Cardiac transplantation demand is on the rise; nevertheless, organ availability is limited due to a paucity of suitable donors. Organ donation after circulatory death (DCD) is a solution to address this limited availability, but due to a period of prolonged warm ischemia and the risk of tissue injury, its routine use in cardiac transplantation is seldom seen. In this manuscript we provide a detailed protocol closely mimicking current clinical practices in the context of DCD with continuous monitoring of heart function, allowing for the evaluation of novel cardioprotective strategies and interventions to decrease ischemia-reperfusion injury. In this model, the DCD protocol is initiated in anesthetized Lewis rats by stopping ventilation to induce circulatory death. When systolic blood pressure drops below 30 mmHg, the warm ischemic time is initiated. After a pre-set warm ischemic period, hearts are flushed with a normothermic cardioplegic solution, procured, and mounted onto a Langendorff ex vivo heart perfusion system. Following 10 min of initial reperfusion and stabilization, cardiac reconditioning is continuously evaluated for 60 min using intraventricular pressure monitoring. A heart injury is assessed by measuring cardiac troponin T and the infarct size is quantified by histological staining. The warm ischemic time can be modulated and tailored to develop the desired amount of structural and functional damage. This simple protocol allows for the evaluation of different cardioprotective conditioning strategies introduced at the moment of cardioplegia, initial reperfusion and/or during ex vivo perfusion. Findings obtained from this protocol can be reproduced in large models, facilitating clinical translation.