Routine screening for HLA Antibodies in Heart Transplant patients-Does it affect clinical decision making?

BACKGROUND

We aimed to assess outcomes in patients with and without donor specific antibodies (DSA) and to evaluate the relationship between DSA presence and graft function, cardiac allograft vasculopathy (CAV), and mortality.

METHODS

The study population comprises 193 consecutive long-term heart transplanted (HTx) patients who underwent DSA surveillance between 2016 and 2022. The patients were prospectively screened for CAV through serial coronary angiograms, graft function impairment through serial echocardiograms, and cardiac biomarkers. The patients were followed from the first DSA measurement until death, 5 years follow-up or right censuring on the 30th of June 2023.

RESULTS

DSAs were detected in 50 patients using a cut-off at MFI ≥1000 and 45 patients using a cut-off at ≥2000 MFI. The median time since HTx was 9.0 years [3.0-14.4]. DSA positive patients had poorer graft function and higher values of NT-proBNP and troponin T, and more prevalent CAV than DSA negative patients. In total, 25 patients underwent endomyocardial biopsies due to DSA presence while another eight patients underwent endomyocardial biopsies for other reasons. Histological antibody mediated rejection (AMR) signs were seen in three biopsies. During a median follow-up of five years [4.7-5], a total of 41 patients died. Mortality rates did not differ between DSA positive and DSA negative patients (HR 1.2, 95% CI .6-2.4). DSA positive patients were more likely to experience CAV progression than DSA negative patients (HR 2.7, 95% CI 1.5-4.8) CONCLUSIONS: Routine screening reveals DSA in approximately 25% of long-term HTx patients but is rarely related to histopathological AMR signs. DSA presence was associated with poorer graft function and more prevalent and progressive CAV. However, DSA positive patients had similar survival rates to DSA negative patients.

Ex-situ oxygenated hypothermic machine perfusion in donation after circulatory death heart transplantation following either direct procurement or in-situ normothermic regional perfusion

BACKGROUND

Heart transplantation in donation after circulatory death (DCD) relies on warm perfusion using either in situ normothermic regional perfusion (NRP) or ex situ normothermic machine perfusion. In this study, we explore an alternative: oxygenated hypothermic machine perfusion (HMP) using a novel clinically applicable perfusion system, which is compared to NRP with static cold storage (SCS).

METHODS

In a porcine model, a DCD setting was simulated, followed by either (1) NRP and SCS (2) NRP and HMP with the XVIVO Heart preservation system or (3) direct procurement (DPP) and HMP. After preservation, heart transplantation (HTX) was performed. After weaning from cardiopulmonary bypass (CPB), biventricular function was assessed by admittance and Swan-Ganz catheters.

RESULTS

Only transplanted hearts in the HMP groups showed significantly increased biventricular contractility (end-systole elastance) 2 hour post-CPB (left ventricle absolute change: NRP HMP: +1.8 ± 0.56, p = 0.047, DPP HMP: +1.5 ± 0.43, p = 0.045 and NRP SCS: +0.97 ± 0.47 mmHg/ml, p = 0.21; right ventricle absolute change: NRP HMP: +0.50 ± 0.12, p = 0.025, DPP HMP: +0.82 ± 0.23, p = 0.039 and NRP SCS: +0.28 ± 0.26, p = 0.52) while receiving significantly less dobutamine to maintain a cardiac output >4l/min compared to SCS. Diastolic function was preserved in all groups. Post-HTX, both HMP groups showed significantly less increments in plasma troponin T compared to SCS.

CONCLUSION

In DCD HTX, increased biventricular contractility post-HTX was only observed in hearts preserved with HMP. In addition, the need for inotropic support and signs of myocardial damage were lower in the HMP groups. DCD HTX can be successfully performed using DPP followed by preservation with HMP in a preclinical setting.

Clamping of the Aortic Arch Vessels During Normothermic Regional Perfusion Does Not Negatively Affect Donor Cardiac Function in Donation After Circulatory Death

BACKGROUND

The hemodynamic effects of aortic arch vessel (AAV) clamping during normothermic regional perfusion (NRP) in donation after circulatory death is unknown. We investigated effects of AAV clamping during NRP compared with no clamping in a porcine model.

METHODS

In 16 pigs, hemodynamic parameters were recorded including biventricular pressure-volume measurements and invasive blood pressure. Additionally, blood gas parameters and inflammatory cytokines were used to assess the effect of AAV clamping. The animals were centrally cannulated for NRP, and baseline measurements were obtained before hypoxic circulatory arrest was induced by halting mechanical ventilation. During an 8-min asystole period, the animals were randomized to clamp (n = 8) or no-clamp (n = 8) of the AAV before commencement of NRP. During NRP, circulation was supported with norepinephrine (NE) and dobutamine. After 30 min of NRP, animals were weaned and observed for 180 min post-NRP.

RESULTS

All hearts were successfully reanimated and weaned from NRP. The nonclamp groups received significantly more NE to maintain a mean arterial pressure >60 mm Hg during and after NRP compared with the clamp group. There were no between group differences in blood pressure or cardiac output. Pressure-volume measurements demonstrated preserved cardiac function' including ejection fraction and diastolic and systolic function. No between group differences in inflammatory markers were observed.

CONCLUSIONS

AAV clamping did not negatively affect donor cardiac function or inflammation after circulatory death and NRP. Significantly less NE was used to support in the clamp group than in the nonclamp group.

Establishing an economical and widely accessible donation after circulatory death animal abattoir model for lung research using ex vivo lung perfusion

BACKGROUND

Ex vivo lung perfusion (EVLP), is a platform that allows simultaneous testing and treatment of the lungs. However, use of EVLP is costly and requires access to lab animals and accompanying facilities. To increase the use of EVLP for research, we developed a method to perform EVLP using abattoir procured lungs. Furthermore, we were also able to significantly decrease costs.

METHODS

Six pair of lungs were procured from abattoir sheep. The lungs were then flushed and stored in ice for 3 h. A low-flow (20% of cardiac output) approach, a tidal volume of 6 ml/kg bodyweight and total perfusion time of 3 h were chosen. Perfusion fluids and circuits were self-made. Lung biopsies, perfusate collection, respiratory values, circulatory pressures were recorded and hourly blood gas analyses were performed.

RESULTS

Mean pO₂ remained stable from 60 min (49.3 ± 7.1 kPa) to 180 min (51.5 kPa ± 8.0), p = 0.66. Pulmonary artery pressure remained ≤15 mm Hg and the left atrial pressure remained between 3 and 5 mm Hg and peak respiratory pressures ≤20 cmH₂ O. Lactate dehydrogenase increased from start (96.3 ± 56.4 U/L) to the end of perfusion (315.8 ± 85.0 U/L), p < 0.05. No difference was observed in ATP between procurement and post-EVLP, 129.7 ± 37.4 μmol/g protein to 132.0 ± 23.4 μmol/g, p = 0.92.

CONCLUSIONS

Sheep lungs, acquired from an abattoir, can be ex vivo perfused under similar conditions as lab animal lungs with similar results regarding e.g., oxygenation and ATP restoration. Furthermore, costs can be significantly reduced by making use of this abattoir model. By increasing accessibility and lowering costs for experiments using lung perfusion, more results may be achieved in the field of lung diseases.

Long-term neurological intact survival and quality of life after refractory out-of-hospital cardiac arrest treated with rescue mechanical circulatory support

Background

Mechanical circulatory support (MCS) with either veno-arterial extracorporeal membrane oxygenation (V-A ECMO) or Impella has emerged as a rescue therapy for refractory out-of-hospital cardiac arrest (OHCA). However, only short-term outcome is specified and most studies do not report follow-up beyond six months. Long-term survival and quality of life in this high-risk population remains unknown.

Purpose

To determine long-term neurological intact survival and quality of life in patients with refractory OHCA treated with MCS.

Methods

This was an observational, single-centre study of OHCA-patients from January 2015 to December 2019. Patients treated with MCS for OHCA were compared with patients receiving conventional cardiopulmonary resuscitation (CPR). A follow-up of long-term survivors in the MCS group was conducted (&gt;1 year after arrest). This included health related quality of life questionaries (Short Form-36 [SF-36]) and assessment of neurological function with Cerebral Performance Category (CPC). Good neurological outcome was defined as CPC 1 and CPC 2.

Results

A total of 1015 with OHCA were included; 101 received MCS for refractory cardiac arrest. Among these V-A ECMO was deployed in 97 patients and Impella in 4 patients. The MCS group had significantly longer low-flow times compared to the conventional group (105 [IQR, 94–123] minutes versus 18 [IQR 10–39] minutes) and were more metabolically deranged upon arrival at hospital (Table 1). In patients receiving MCS, the hospital discharge rate was 27% and good neurological outcome was seen in 93% among patients discharged. At follow-up, 15 out of 21 long-term survivors participated. Median follow-up time was 4.8±1.6 (range 2.8–6.1 years). Mean age at follow-up was 61±7.3 years, 11 (73%) were men. Neurological outcome with CPC 1 was found in 12 patients (80%), with CPC 2 in 2 patients (13%), and with CPC 3 in 1 patient (7%). Two had improved neurological status from CPC 2 to CPC 1 since discharge. Mean scores of the SF-36 revealed an overall high level of psychical and mental health in long-term survivors (Figure 1).

Conclusion

Long-term survival with good neurological outcome was high in patients with refractory OHCA treated with MCS despite prolonged resuscitation and severe metabolic derangement. These patients may expect a reasonable quality of life after discharge.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Department of Cardiology, Aarhus University HospitalSnedkermester Sophus Jacobsen og hustru Astrid Jacobsens Fond

Cardiac resynchronisation therapy and implantable cardioverter-defibrillator in non-ischaemic systolic heart failure: extended follow-up of the DANISH trial

Background

In the Danish Study to Assess the Efficacy of Implantable Cardioverter-Defibrillators [ICDs] in Patients with Non-ischaemic Systolic Heart Failure on Mortality (DANISH) trial, ICD implantation did not provide an overall survival benefit in patients with non-ischaemic systolic heart failure. A high proportion of patients in the DANISH trial received a cardiac resynchronisation therapy (CRT) device, which improves the prognosis in patients with heart failure. Therefore, it is of interest to examine whether the effect of ICD implantation in patients with non-ischaemic systolic heart failure is modified by CRT.

Purpose

Adding 4 years of additional follow-up to the DANISH trial, we examined the effect of ICD implantation according to status with respect to CRT implantation at baseline.

Methods

In the DANISH trial, 556 patients with non-ischaemic systolic heart failure were randomised to receive an ICD and 560 to receive usual clinical care (control). Patients fulfilling indications for a CRT device received a CRT-defibrillator (if randomised to ICD arm) or CRT-pacemaker (if randomised to control arm). In the ICD group, 322 patients (57.9%) received a CRT device; in the control group, 323 patients (57.7%) received a CRT device. In this extended follow-up study, patients were followed until May 18, 2020. The primary outcome was death from any cause; secondary outcomes were cardiovascular death and sudden cardiovascular death.

Results

During a median follow-up of 9.5 years, the ICD group did not have significantly lower all-cause mortality compared with the control group (hazard ratio [HR] 0.89 [95% CI, 0.74–1.08]). The results were independent of whether the patient received a CRT device at randomisation (patients with a CRT device: HR 0.92 [95% CI, 0.72–1.18]; patients without a CRT device: HR 0.86 [95% CI, 0.64–1.14]; P for interaction, 0.72). Similarly, ICD implantation did not reduce rates of cardiovascular death overall (HR 0.87 [95% CI, 0.70–1.09]), and this association was not modified by CRT (patients with a CRT device: HR 0.89 [95% CI, 0.66–1.19]; patients without a CRT device: HR 0.85 [95% CI, 0.60–1.20]; P for interaction, 0.86). The ICD group had significantly lower rates of sudden cardiovascular death in the overall population (HR, 0.60 [95% CI, 0.40–0.92]), and this association was not modified by CRT (patients with a CRT device: HR 0.69 [95% CI, 0.40–1.21]; patients without a CRT device: HR 0.51 [95% CI, 0.26–0.97]; P for interaction, 0.47). See Figure 1 for all results.

Conclusions

In this extended follow-up study of the DANISH trial, the effect of ICD implantation in patients with non-ischaemic systolic heart failure was not modified by CRT.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): The DANISH trial was supported by unrestricted grants from Medtronic, St Jude Medical, Tryg Fonden, and the Danish Heart Foundation. No further funding was obtained for this follow-up study.

Effect of implantable cardioverter-defibrillators in patients with non-ischaemic systolic heart failure and concurrent coronary atherosclerosis

Aims

Prophylactic implantable cardioverter‐defibrillators (ICD) reduce mortality in patients with ischaemic heart failure (HF), whereas the effect of ICD in patients with non‐ischaemic HF is less clear. We aimed to investigate the association between concomitant coronary atherosclerosis and mortality in patients with non‐ischaemic HF and the effect of ICD implantation in these patients.

Methods and results

Patients were included from DANISH (Danish Study to Assess the Efficacy of Implantable Cardioverter Defibrillators in Patients with Non‐Ischaemic Systolic Heart Failure on Mortality), randomizing patients to ICD or control. Study inclusion criteria for HF were left ventricular ejection fraction ≤ 35% and increased levels (>200 pg/mL) of N‐terminal pro‐brain natriuretic peptide. Of the 1116 patients from DANISH, 838 (75%) patients had available data from coronary angiogram and were included in this subgroup analysis. We used Cox regression to assess the relationship between coronary atherosclerosis and mortality and the effect of ICD implantation. Of the included patients, 266 (32%) had coronary atherosclerosis. Of these, 216 (81%) had atherosclerosis without significant stenoses, and 50 (19%) had significant stenosis. Patients with atherosclerosis were significantly older {67 [interquartile range (IQR) 61–73] vs. 61 [IQR 54–68] years; P < 0.0001}, and more were men (77% vs. 70%; P = 0.03). During a median follow‐up of 64.3 months (IQR 47–82), 174 (21%) of the patients died. The effect of ICD on all‐cause mortality was not modified by coronary atherosclerosis [hazard ratio (HR) 0.94; 0.58–1.52; P = 0.79 vs. HR 0.82; 0.56–1.20; P = 0.30], P for interaction = 0.67. In univariable analysis, coronary atherosclerosis was a significant predictor of all‐cause mortality [HR, 1.41; 95% confidence interval (CI), 1.04–1.91; P = 0.03]. However, this association disappeared when adjusting for cardiovascular risk factors (age, gender, diabetes, hypertension, smoking, and estimated glomerular filtration rate) (HR 1.05, 0.76–1.45, P = 0.76).

Conclusions

In patients with non‐ischaemic systolic heart failure, ICD implantation did not reduce all‐cause mortality in patients either with or without concomitant coronary atherosclerosis. The concomitant presence of coronary atherosclerosis was associated with increased mortality. However, this association was explained by other risk factors.

Mechanical circulatory support for refractory out-of-hospital cardiac arrest: a nationwide multicentre study

Background

Extracorporeal cardiopulmonary resuscitation (ECPR) has shown potential as a salvage therapy for patients with refractory out-of-hospital cardiac arrest (OHCA). Despite growing interest in and a growing body of literature on ECPR for refractory OHCA, robust evidence on patient eligibility is still lacking.

Purpose

To describe the survival, neurological outcome, and adherence to the national consensus with respect to use of ECPR for OHCA, and to identify factors associated with outcome.

Methods

Retrospective, observational cohort study of patients who underwent ECPR for OHCA at four cardiac arrest centres. Binary logistic regression and Kaplan-Meier survival curves were performed to assess association with 30-day mortality.

Results

A total of 259 patients receiving ECPR for OHCA between July 2011 and December 2020 were included in the study. Thirty-day survival was 26% and a good neurological outcome Cerebral Performance Category (CPC) 1–2 was observed in 94% of patients at discharge. Strict adherence to the national consensus showed a 30-day survival rate of 30%. Adding one or more of the following criteria to the national consensus: signs of life during cardiopulmonary resuscitation (CPR), pre-hospital low-flow &lt;100 minutes, pH &gt;6.8 and lactate &lt;15 mmol/L increased the survival rate to 48%, but would exclude 58% of the survivors from the current cohort. Logistic regression identified initial presenting rhythm with asystole (RR 1.36, 95% CI 1.18–1.57), pulseless electrical activity (PEA) (RR 1.20, 95% CI 1.03–1.41), initial pH &lt;6.8 (RR 1.28, 95% CI 1.12–1.46) and lactate levels &gt;15 mmol/L (RR 1.16, 95% CI 1.16–1.53) as factors associated with increased risk of 30-day mortality. Patients presenting signs of life during CPR had threefold higher survival rate than patients without signs of life (45% versus 13%, p&lt;0.001)

Conclusion

A high survival rate with a good neurological outcome was observed in this population of patients treated with ECPR for OHCA. Signs of life during CPR may aid the decision-making in the selection of appropriate candidates. Stringent patient selection for ECPR may produce higher survival rates but potentially withholds life-saving treatment in a significant proportion of survivors, why optimization of the selection criteria is still necessary.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): This work was supported by the Danish Heart Foundation [20-R142-A9498-22178]; and Health Research Foundation of Central Denmark Region [R64-A3178-B1349] Survival and adherence to consensusSigns of life during CPR

Association of Left Ventricular Systolic Dysfunction Among Carriers of Truncating Variants in Filamin C With Frequent Ventricular Arrhythmia and End-stage Heart Failure

Importance

Truncating variants in the gene encoding filamin C (FLNCtv) are associated with arrhythmogenic and dilated cardiomyopathies with a reportedly high risk of ventricular arrhythmia.

Objective

To determine the frequency of and risk factors associated with adverse events among FLNCtv carriers compared with individuals carrying TTN truncating variants (TTNtv).

Design, Setting, and Participants

This cohort study recruited 167 consecutive FLNCtv carriers and a control cohort of 244 patients with TTNtv matched for left ventricular ejection fraction (LVEF) from 19 European cardiomyopathy referral units between 1990 and 2018. Data analyses were conducted between June and October, 2020.

Main Outcomes and Measures

The primary end point was a composite of malignant ventricular arrhythmia (MVA) (sudden cardiac death, aborted sudden cardiac death, appropriate implantable cardioverter-defibrillator shock, and sustained ventricular tachycardia) and end-stage heart failure (heart transplant or mortality associated with end-stage heart failure). The secondary end point comprised MVA events only.

Results

In total, 167 patients with FLNCtv were studied (55 probands [33%]; 89 men [53%]; mean [SD] age at baseline evaluation, 43 [18] years). For a median follow-up of 20 months (interquartile range, 7-60 months), 29 patients (17.4%) reached the primary end point (19 patients with MVA and 10 patients with end-stage heart failure). Eight (44%) arrhythmic events occurred among individuals with baseline mild to moderate left ventricular systolic dysfunction (LVSD) (LVEF = 36%-49%). Univariable risk factors associated with the primary end point included proband status, LVEF decrement per 10%, ventricular ectopy (≥500 in 24 hours) and myocardial fibrosis detected on cardiac magnetic resonance imaging. The LVEF decrement (hazard ratio [HR] per 10%, 1.83 [95% CI, 1.30-2.57]; P < .001) and proband status (HR, 3.18 [95% CI, 1.12-9.04]; P = .03) remained independent risk factors on multivariable analysis (excluding myocardial fibrosis and ventricular ectopy owing to case censoring). There was no difference in freedom from MVA between FLNCtv carriers with mild to moderate or severe (LVEF ≤35%) LVSD (HR, 1.29 [95% CI, 0.45-3.72]; P = .64). Carriers of FLNCtv with impaired LVEF at baseline evaluation (n = 69) had reduced freedom from MVA compared with 244 TTNtv carriers with similar baseline LVEF (for mild to moderate LVSD: HR, 16.41 [95% CI, 3.45-78.11]; P < .001; for severe LVSD: HR, 2.47 [95% CI, 1.04-5.87]; P = .03).

Conclusions and Relevance

The high frequency of MVA among patients with FLNCtv with mild to moderate LVSD suggests that higher LVEF values than those currently recommended should be considered for prophylactic implantable cardioverter-defibrillator therapy in FLNCtv carriers.

Right ventricular hemodynamics and performance in relation to perfusion during first year after heart transplantation

Aims

We aim to evaluate changes in invasive haemodynamics, right ventricular (RV) function, and perfusion during the first year after heart transplantation (HTx) and to determine the relation between RV function and myocardial perfusion.

Methods and results

Thirty patients were prospectively enrolled at the time of HTx. Right heart catheterization (RHC), comprehensive 2D and 3D echocardiography and cardiac biomarkers were performed at baseline (≤2 weeks after HTx) and at follow‐up 1, 3, 6, and 12 months after HTx. At 12 months, HTx patients were subjected to an exercise stress test with assessment of maximal oxygen consumption (VO₂max). RV myocardial perfusion reserve was evaluated by ¹⁵O‐H₂O positron emission tomography at baseline and at 3 and 12 months after HTx. A group of 43 healthy subjects served as echocardiographic controls and a subgroup comprising 16 healthy controls underwent exercise stress test with simultaneous RHC. At baseline, HTx patients had higher pulmonary artery wedge pressure (PAWP) and right atrial pressure (RAP) and pulmonary vascular resistance (PVR) than healthy controls whereas cardiac index (CI) was reduced (PAWP; 14 mmHg [8;17] vs. 8 mmHg [7;10]; RAP: 7 mmHg [4;11] vs. 5 mmHg [4;6]; PVR: 1.9 wood units [1.3;2.6] vs. 1.1 wood units [1.0;1.4]; CI 2.4 L/min/m² [2.2;2.8] vs. 3.3 L/min/m² [2.8;.3.6], all P < 0.05). Normalization of filling pressures and CI was seen 3–6 months after HTx. During follow‐up, RV function in terms of 3D ejection fraction (EF) and longitudinal strain (LS) improved in HTx patients but remained reduced compared with healthy controls at 12 months follow‐up (3D RV EF: 52 ± 7% vs. 60 ± 8%; RV LS: 22 ± 4% vs. 28 ± 5%, both P < 0.001). During follow‐up, RV perfusion reserve improved (baseline 2.1 ± 0.9; 3 months follow‐up 3.2 ± 0.8; 12 months follow‐up 3.7 ± 1.1, P < 0.0001). RV perfusion reserve significantly correlated to cardiac markers in terms of troponin T (r = −0.62, P < 0.0001), NT‐proBNP (r = −0.65, P < 0.0001), RAP (r = −0.43, P < 0.01) and CI (r = 0.37, P < 0.01) and with VO₂max 12 months after HTx (r = 0.75, P < 0.01).

Conclusions

Normalization of left and right atrial filling pressures is demonstrated within the first 3 to 6 months after HTx. RV function and RV perfusion reserve correlated and gradually improved during the first year after HTx but RV function remained reduced in HTx patients compared with healthy controls.

Development of a human heart-sized perfusion system for metabolic imaging studies using hyperpolarized [1-13 C]pyruvate MRI

PURPOSE

Increasing worldwide demand for cardiac transplantation has spurred new developments to increase the donor pool. Normothermic preservation of heart grafts for transplantation is an emerging strategy to improve the utilization of marginal grafts. Hyperpolarized MR using metabolic tracers such as [1-¹³ C]pyruvate, provide a novel means of investigating metabolic status without the use of ionizing radiation. We demonstrate the use of this methodology to examine ex vivo perfused porcine heart grafts.

METHODS

Hearts from three 40-kg Danish domestic pigs were harvested and subsequently perfused in Langendorff mode under normothermic conditions, using an MR-compatible perfusion system adapted to the heart. Proton MRI and hyperpolarized [1-¹³ C]pyruvate were used to investigate and quantify the functional and metabolic status of the grafts.

RESULTS

Hearts were perfused with whole blood for 120 min, using a dynamic contrast-enhanced perfusion experiment to verify successful myocardial perfusion. Hyperpolarized [1-¹³ C]pyruvate MRI was used to assess the metabolic state of the myocardium. Functional assessment was performed using CINE imaging and ventricular pressure data. High lactate and modest alanine levels were observed in the hyperpolarized experiment. The functional assessment produced reduced functional parameters. This suggests an altered functional and metabolic profile compared with corresponding in vivo values.

CONCLUSION

We investigated the metabolic and functional status of machine-perfused porcine hearts. Utilizing hyperpolarized methodology to acquire detailed myocardial metabolic information-in combination with already established MR methods for cardiac investigation-provides a powerful tool to aid the progress of donor heart preservation.

Micro- and macrovascular cardiac allograft vasculopathy in relation to 91 cardiovascular biomarkers in heart transplant recipients-An exploratory study

BACKGROUND

Cardiac allograft vasculopathy (CAV) limits survival after heart transplantation (HTx), and the pathogenesis is not fully clarified. We aimed to investigate a wide range of biomarkers and their correlation with micro- and macrovascular CAV and major adverse cardiac events in HTx patients.

METHODS

We evaluated 91 cardiovascular disease-related proteins in 48 HTx patients using a novel proteomic panel. Patients were dichotomized according to micro- and macrovascular CAV burden determined by coronary angiography, optical coherence tomography, and ¹⁵ O-H₂ O positron emission tomography imaging. Major adverse cardiac events included significant CAV progression, heart failure, treated rejection, and cardiovascular death.

RESULTS

We found consistent differences in two proteins involved in cholesterol homeostasis: significantly increased proprotein convertase subtilisin/kexin type 9 (PCSK9) (p < .05) and significantly decreased paraoxonase 3 (PON3) (p < .05). N-terminal pro-brain natriuretic peptide (NT-proBNP) was significantly increased in patients with microvascular CAV (p < .05) and borderline significantly increased in patients experiencing major adverse cardiac events (p = .10) and patients with macrovascular CAV (p = .05).

CONCLUSIONS

We identified consistent changes in two proteins involved in cholesterol homeostasis which may be important players in the pathogenesis of CAV: PON3 and PCSK9. NT-proBNP also showed consistent changes across all groups but only reached statistical significance in patients with microvascular CAV. Our results warrant further validation in future studies.

Heart failure etiology and risk of right heart failure in adult left ventricular assist device support: the European Registry for Patients with Mechanical Circulatory Support (EUROMACS)

Objectives: Development of right ventricular failure (RVF) after left ventricular assist device (LVAD) implantation remains a leading cause of perioperative morbidity, end-organ dysfunction and mortality. The objective of this study was to investigate whether the etiology of HF (ischemic HF versus non-ischemic HF) affects the risk of RVF within admission for LVAD implantation and during long-term follow-up. Methods: Between January 2011 and June 27, 2018, 3536 patients were prospectively enrolled into EUROMACS registry. Adult patients (>18 years) who received a first time LVAD were included. When excluding patients with congenital, restrictive, hypertrophic, valvular cardiomyopathies, and myocarditis the total population consisted of 2404 patients. Results: The total cohort consists of 2404 patients. Mean age were 55 years and predominantly male sex [2024 (84.2%)]. At the time of LVAD implantation 1355 (56.4%) patients had ischemic HF and 1049 (43.6%) patients had non-ischemic HF. The incidence of RVF was significantly increased in the non-ischemic HF group in the adjusted model (p = .026). The relative risk difference for RVF in patients with non-ischemic HF was in the adjusted model increased by an absolute value of 5.1% (95% CI: 0.61-9.6). In the ischemic HF group 76 patients (13.4%) developed late RVF and 62 patients (14.8%) in the non-ischemic HF group (p = .56). No differences in occurrence of RVF between HF etiology was observed after 2 and 4 years of follow-up, respectively (crude: p = .25, adjusted (sex and age) p = .2 and crude: p = .59, adjusted (sex and age) p = .44). Conclusions: Patients with non-ischemic HF undergoing LVAD had an increased incidence of early RVF compared to patients with ischemic HF in a large European population. During follow-up after discharge 14% patients developed RVF. We recommend HF etiology to be considered in identifying patients who are at risk for postoperative RVF after LVAD implantation.

Cardiovascular Effects of Treatment With the Ketone Body 3-Hydroxybutyrate in Chronic Heart Failure Patients

Supplemental Digital Content is available in the text.

Background:

Myocardial utilization of 3-hydroxybutyrate (3-OHB) is increased in patients with heart failure and reduced ejection fraction (HFrEF). However, the cardiovascular effects of increased circulating plasma-3-OHB levels in these patients are unknown. Consequently, the authors’ aim was to modulate circulating 3-OHB levels in HFrEF patients and evaluate: (1) changes in cardiac output (CO); (2) a potential dose-response relationship between 3-OHB levels and CO; (3) the impact on myocardial external energy efficiency (MEE) and oxygen consumption (MVO₂); and (4) whether the cardiovascular response differed between HFrEF patients and age-matched volunteers.

Methods:

Study 1: 16 chronic HFrEF patients (left ventricular ejection fraction: 37±3%) were randomized in a crossover design to 3-hour of 3-OHB or placebo infusion. Patients were monitored invasively with a Swan-Ganz catheter and with echocardiography. Study 2: In a dose-response study, 8 HFrEF patients were examined at increasing 3-OHB infusion rates. Study 3 to 4: 10 HFrEF patients and 10 age-matched volunteers were randomized in a crossover design to 3-hour 3-OHB or placebo infusion. MEE and MVO₂ were evaluated using 11C-acetate positron emission tomography.

Results:

3-OHB infusion increased circulating levels of plasma 3-OHB from 0.4±0.3 to 3.3±0.4 mM (P<0.001). CO rose by 2.0±0.2 L/min (P<0.001) because of an increase in stroke volume of 20±2 mL (P<0.001) and heart rate of 7±2 beats per minute (bpm) (P<0.001). Left ventricular ejection fraction increased 8±1% (P<0.001) numerically. There was a dose-response relationship with a significant CO increase of 0.3 L/min already at plasma-3-OHB levels of 0.7 mM (P<0.001). 3-OHB increased MVO₂ without altering MEE. The response to 3-OHB infusion in terms of MEE and CO did not differ between HFrEF patents and age-matched volunteers.

Conclusions:

3-OHB has beneficial hemodynamic effects in HFrEF patients without impairing MEE. These beneficial effects are detectable in the physiological concentration range of circulating 3-OHB levels. The hemodynamic effects of 3-OHB were observed in both HFrEF patients and age-matched volunteers. 3-OHB may potentially constitute a novel treatment principle in HFrEF patients.

Mild acute cellular rejection and development of cardiac allograft vasculopathy assessed by intravascular ultrasound and coronary angiography in heart transplant recipients-a SCHEDULE trial substudy

To evaluate the association between mild acute cellular rejection (ACR) and the development of cardiac allograft vasculopathy (CAV) after heart transplantation (HTx). Substudy of the SCHEDULE trial (n = 115), where de novo HTx recipients were randomized to (i) everolimus with early CNI elimination or (ii) CNI-based immunosuppression. Seventy-six patients (66%) were included based on matched intravascular ultrasound (IVUS) examinations at baseline and year 3 post-HTx. Biopsy-proven ACR within year 1 post-HTx was recorded and graded (1R, 2R, 3R). Development of CAV was assessed by IVUS and coronary angiography at year 3 post-HTx. Median age was 53 years (45-61), and 71% were male. ACR was recorded in 67%, and patients were grouped by rejection profile: no ACR (33%), only 1R (42%), and ≥2R (25%). Median ∆MIT (maximal intimal thickness)_BL-3Y was not significantly different between groups (P = 0.84). The incidence of CAV was 49% by IVUS and 26% by coronary angiography with no significant differences between groups. No correlation was found between number of 1R and ∆MIT_BL-3Y (r = -0.025, P = 0.83). The number of 1R was not a significant predictor of ∆MIT_BL-3Y (P = 0.58), and no significant interaction with treatment was found (P = 0.98). The burden of mild ACR was not associated with CAV development.

P2627Diffuse coronary artery disease and effect of implantable cardioverter-defibrillators in patients with non-ischaemic systolic heart failure

Background

Implantable defibrillators reduce mortality in patients with ischaemic heart failure. The recent Danish Study to Assess the Efficacy of Implantable Cardioverter Defibrillators in Patients With Non-Ischaemic Systolic Heart Failure on Mortality (DANISH) found no overall effect on all-cause mortality with ICD implantation. Coronary artery disease (CAD) as the cause of heart failure had to be ruled out prior to inclusion into DANISH, but patients could have diffuse atherosclerosis, one- or two-vessel disease on the qualifying coronary angiogram if the investigator did not find that the degree of CAD could explain the severely reduced left ventricular ejection fraction. It is unknown if concomitant coronary atherosclerosis is related to outcome in patients with non-ischaemic cardiomyopathy and whether the effect of implanting an ICD is different in patients with non-ischaemic cardiomyopathy and coronary atherosclerosis.

Purpose

The aim of this study was to investigate the association between coronary atherosclerosis and all-cause mortality in patients with non-ischaemic systolic heart failure and the effect of ICD implantation in these patients.

Methods

Of the 1116 patients from the DANISH study, 838 patients with available coronary angiography data were included in this subgroup analysis. Patients were considered to have coronary atherosclerosis if the invasive cardiologist described diffuse atherosclerosis or coronary stenosis. We used cox regression to assess the relationship between coronary atherosclerosis and mortality and between ICD implantation and mortality in patients with and without coronary atherosclerosis. Data are presented as hazard ratios with 95% confidence intervals.

Results

Of the 838 patients, 266 (32%) had coronary atherosclerosis, 216 (81%) of whom were reported as having atherosclerosis without stenoses. Patients with coronary atherosclerosis were significantly older (median age 67 years vs 61 years), more often male (77% vs 70%) and had a higher prevalence of diabetes (30% vs 17%).

In univariable analysis, coronary atherosclerosis was a significant predictor of all-cause mortality (HR, 1.41; 95% CI, 1.04–1.91; P=0.03). However, the association between coronary atherosclerosis and all-cause mortality disappeared when adjusting for age, gender and diabetes (HR 1.02, 0.75–1.41, P=0.88). Adjusted hazard ratios are shown in Figure 1.

There was no association between ICD treatment and all-cause mortality in patients with or without coronary atherosclerosis (HR 0.94; 0.58–1.52; P=0.79 vs HR 0.82; 0.56–1.20; P=0.30), P for interaction=0.67.

Figure 1

Conclusions

In patients with non-ischaemic systolic heart failure, the concomitant presence of coronary atherosclerosis was associated with increased mortality. However, this association was not independent of other risk factors. ICD implantation was not associated with mortality risk in patients either with or without concomitant coronary atherosclerosis.

Acknowledgement/Funding

TrygFonden (Copenhagen, DK), Medtronic (US) and St. Jude Medical (US)

P4533Duration of heart failure and effect of defibrillator implantation in patients with non-ischemic systolic heart failure

Introduction

Patients with non-ischemic systolic heart failure have increased risk of sudden cardiac death (SCD) and death from progressive pump failure. Whether the risk of SCD changes over time is unknown. We seek to investigate the relationship between duration of heart failure, mode of death, and effect of implantable cardioverter defibrillator (ICD) implantation.

Methods

We examined the risk of all-cause death and SCD according to the duration of heart failure among patients with non-ischemic systolic heart failure enrolled in the Danish Study to Assess the Efficacy of ICDs in Patients with Non-ischemic Systolic Heart Failure on Mortality (DANISH) trial. Patients were divided according to quartiles of heart failure duration (Q1 ≤8 months, Q2 9 ≤18 months, Q3 19 ≤65 months, Q4 ≥66 months).

Results

A total number of 1116 patients were included. Patients with the longest duration of heart failure were older, more often men, had more comorbidity, and more often received cardiac resynchronizing therapy device. Doubling of heart failure duration was an independent predictor of both all-cause mortality (HR 1.26 95% CI 1.17–1.37, p<0.0001), and SCD (HR 1.29 95% CI 1.11–1.49, p=0.0009). The proportion of deaths caused by SCD was not different between heart failure quartiles (p=0.91), and the effect of ICD implantation on all-cause mortality was not modified by the duration of heart failure (p=0.59).

Duration of heart failure and death

Conclusions

Duration of heart failure predicted both all-cause mortality and risk of SCD independently of other risk indicators. However, the proportion of death caused by SCD did not change with longer duration of heart failure and the effect of ICD was not modified by the duration of heart failure.

Acknowledgement/Funding

The work was sponsored by The Danish Heart Foundation (Hjerteforeningen) and the Lundbeck Foundation (Lundbeckfonden). The DANISH trial was supported

256Heart transplant recipients with cardiac allograft vasculopathy have increased platelet aggregation before and after low-dose aspirin therapy

Background

Following heart transplantation (HTx), long-term survival is reduced mainly due to development of a specific form of coronary artery disease, coronary allograft vasculopathy (CAV). Using optical coherence tomography to visualize the coronary artery wall, we have recently shown that layered fibrotic plaques resembling organized clots are the dominant plaque component in CAV. Thus, thrombosis is suggested as a possible mechanism contributing to development and progression of CAV. Aspirin is widely used after HTx despite limited evidence and lack of specific guidelines. The antiplatelet effect of aspirin has not been thoroughly examined in HTx-patients.

Purpose

To investigate baseline platelet aggregation and the antiplatelet effect of aspirin in HTx-patients with and without CAV.

Methods

We included 68 HTx-patients (median 8.6 years from HTx). In 66 patients taking 75 mg aspirin for a minimum of 7 days, platelet aggregation was measured in whole blood using impedance aggregometry with the following agonists: Adenosine diphosphate (ADP) stimulating ADP-receptors and arachidonic acid (AA) for monitoring of aspirin treatment. Aspirin compliance was confirmed by measuring serum-thromboxane B2. Platelet aggregation prior to aspirin therapy was measured in 59 patients as it was not considered clinically safe to interrupt ongoing aspirin treatment for one week prior to blood sampling in 9 patients mainly due to previous coronary stenting. CAV burden was determined by coronary angiography and echocardiography based on international classification. Patients were divided into two groups; no CAV (n=37) and CAV (n=29).

Results

In HTx-patients not treated with aspirin, we found significantly increased ADP-induced platelet aggregation in patients with CAV vs. patients without CAV (904 (95% CI 813–995) vs. 786 (95% CI 728–843) AU*min, P=0.02). Baseline AA-induced aggregation was also higher in patients with CAV vs. patients without CAV, though non-significant (994 (95% CI 907–1081) vs. 905 (95% CI 839–972) AU*min, P=0.10). Even though aspirin reduced AA-induced platelet aggregation in both groups, patients with CAV had significantly increased AA-induced platelet aggregation compared with patients without CAV on aspirin treatment (380 (95% CI 295–465) vs. 286 (95% CI 239–334) AU*min, P=0.04) (Fig. 1).

Conclusions

HTx-patients with CAV have increased platelet aggregation before and after aspirin treatment compared with HTx-patients without CAV. Aspirin monotherapy may not provide sufficient platelet inhibition in HTx-patients with CAV.

Acknowledgement/Funding

Aarhus University (PhD-salary)

The clinical outcome of LMNA missense mutations can be associated with the amount of mutated protein in the nuclear envelope

AIMS

Lamin A/C mutations are generally believed to be associated with a severe prognosis. The aim of this study was to investigate disease expression in three affected families carrying different LMNA missense mutations. Furthermore, the potential molecular disease mechanisms of the mutations were investigated in fibroblasts obtained from mutation carriers.

METHODS AND RESULTS

A LMNA-p.Arg216Cys missense mutation was identified in a large family with 36 mutation carriers. Disease expression was unusual with a late onset and a favourable prognosis. Two smaller families with severe disease expression were shown to carry a LMNA-p.Arg471Cys and LMNA-p.Arg471His mutation, respectively. LMNA gene and protein expression was investigated in eight different mutation carriers by quantitative reverse transcriptase polymerase chain reaction, Western blotting, immunohistochemistry, and protein mass spectrometry. The results showed that all mutation carriers incorporated mutated lamin protein into the nuclear envelope. Interestingly, the ratio of mutated to wild-type protein was only 30:70 in LMNA-p.Arg216Cys carriers with a favourable prognosis while LMNA-p.Arg471Cys and LMNA-p.Arg471His carriers with a more severe outcome expressed significantly more of the mutated protein by a ratio of 50:50.

CONCLUSION

The clinical findings indicated that some LMNA mutations may be associated with a favourable prognosis and a low risk of sudden death. Protein expression studies suggested that a severe outcome was associated with the expression of high amounts of mutated protein. These findings may prove to be helpful in counselling and risk assessment of LMNA families.

Inotropic myocardial reserve deficiency is the predominant feature of exercise haemodynamics in cardiac amyloidosis

AIMS

This study aimed to characterize invasive haemodynamics during exercise in subjects with cardiac amyloidosis (CA).

METHODS AND RESULTS

The study population numbered 44 subjects. Group A (CA-positive, n = 24) comprised wild-type transthyretin patients (n = 10), familial transthyretin amyloidosis mutation carriers (ATTRm) with cardiac involvement (n = 5), and light-chain amyloidosis patients with cardiac involvement (n = 9). Group B (CA-negative, n = 20) comprised four healthy ATTRm subjects without cardiac involvement documented by ¹¹ C-PIB positron emission tomography and 16 healthy controls. All subjects underwent a symptom-limited, semi-supine exercise test with expired gas analysis and simultaneous right heart catheterization. CA patients had lower peak oxygen consumption [15 ± 6 mL/min/kg bodyweight (bwt) vs. 33 ± 7 mL/min/kg bwt; P < 0.0001] than controls. Myocardial reserve during exercise was significantly reduced in CA patients as reflected in a small increase in stroke volume index (SVI) and cardiac index (CI) compared with controls [ΔSVI: 4 mL/m² (range: -1 to 8) vs. 14 mL/m² (range: 5-25); P < 0.0001; ΔCI: 2 ± 2 L/min vs. 7 ± 2 L/min; P < 0.0001]. During exercise, CA patients had significantly higher left and right ventricular filling pressures than controls. Furthermore, CA patients had severely impaired pulmonary arterial compliance (PAC) compared with controls [2.9 mL/mmHg (range: 2.1-4.5) vs. 7.5 mL/mmHg (range: 5.7-10.4); P < 0.0001].

CONCLUSIONS

Cardiac amyloid deposits are associated with severely reduced inotropic myocardial reserve and increased left and right ventricular filling pressures during exercise. Furthermore, CA subjects have severely reduced PAC, which may contribute to right heart failure and reduced exercise capacity.

Extracorporeal cardiopulmonary resuscitation after out-of-hospital cardiac arrest in a Danish health region

BACKGROUND

Extracorporeal Cardiopulmonary Resuscitation (ECPR) has emerged as a feasible rescue therapy for refractory, normothermic out-of-hospital cardiac arrest (OHCA). Reported survival rates vary and comparison between studies is hampered by heterogeneous study populations, differences in bystander intervention and in pre-hospital emergency service organisation. We aimed to describe the first experiences, treatment details, complications and outcome with ECPR for OHCA in a Danish health region.

METHODS

Retrospective study of adult patients admitted at Aarhus University Hospital, Denmark between 1 January 2011 and 1 July 2015 with witnessed, refractory, normothermic OHCA treated with ECPR. OHCA was managed with pre-hospital advanced airway management and mechanical chest compression during transport. Relevant pre-hospital and in-hospital data were collected with special focus on low-flow time and ECPR duration. Survival to hospital discharge with Cerebral Performance Category (CPC) of 1 and 2 at hospital discharge was the primary endpoint.

RESULTS

Twenty-one patients were included. Median pre-hospital low-flow time was 54 min [range 5-100] and median total low-flow time was 121 min [range 55-192]. Seven patients survived (33%). Survivors had a CPC score of 1 or 2 at hospital discharge. Five survivors had a shockable initial rhythm. In all survivors coronary occlusion was the presumed cause of cardiac arrest.

CONCLUSION

Extracorporeal cardiopulmonary resuscitation is feasible as a rescue therapy in normothermic refractory OHCA in highly selected patients. Low-flow time was longer than previously reported. Survival with favourable neurological outcome is possible despite prolonged low-flow duration.

Everolimus Initiation With Early Calcineurin Inhibitor Withdrawal in De Novo Heart Transplant Recipients: Three-Year Results From the Randomized SCHEDULE Study

In a randomized, open-label trial, de novo heart transplant recipients were randomized to everolimus (3-6 ng/mL) with reduced-exposure calcineurin inhibitor (CNI; cyclosporine) to weeks 7-11 after transplant, followed by increased everolimus exposure (target 6-10 ng/mL) with cyclosporine withdrawal or standard-exposure cyclosporine. All patients received mycophenolate mofetil and corticosteroids. A total of 110 of 115 patients completed the 12-month study, and 102 attended a follow-up visit at month 36. Mean measured GFR (mGFR) at month 36 was 77.4 mL/min (standard deviation [SD] 20.2 mL/min) versus 59.2 mL/min (SD 17.4 mL/min) in the everolimus and CNI groups, respectively, a difference of 18.3 mL/min (95% CI 11.1-25.6 mL/min; p < 0.001) in the intention to treat population. Multivariate analysis showed treatment to be an independent determinant of mGFR at month 36. Coronary intravascular ultrasound at 36 months revealed significantly reduced progression of allograft vasculopathy in the everolimus group compared with the CNI group. Biopsy-proven acute rejection grade ≥2R occurred in 10.2% and 5.9% of everolimus- and CNI-treated patients, respectively, during months 12-36. Serious adverse events occurred in 37.3% and 19.6% of everolimus- and CNI-treated patients, respectively (p = 0.078). These results suggest that early CNI withdrawal after heart transplantation supported by everolimus, mycophenolic acid and steroids with lymphocyte-depleting induction is safe at intermediate follow-up. This regimen, used selectively, may offer adequate immunosuppressive potency with a sustained renal advantage.

Coronary Flow Reserve Predicts Longitudinal Myocardial Deformation Capacity in Heart-Transplanted Patients

AIMS

This study aimed to evaluate the role of microvascular dysfunction on left ventricular (LV) longitudinal deformation, filling pressures, and exercise capacity in heart-transplanted (HTx) patients.

METHODS AND RESULTS

Fifty-seven HTx patients underwent comprehensive echocardiographic graft function assessment during symptom-limited, semisupine exercise test with simultaneous right heart catheterization. Coronary flow velocity reserve (CFVR) was measured in the left anterior descending artery using pulsed Doppler echocardiography. We divided patients into two groups based on upper and lower median of CFVR. Twenty-six healthy subjects served as controls. Compared with healthy controls, HTx patients had reduced CFVR (P < 0.0001), exercise capacity (P < 0.0001), and LV longitudinal deformation capacity (P < 0.0001). HTx patients in the reduced CFVR group (CFVR < 2.73) were more symptomatic (P < 0.0001) and had higher prevalence of coronary cardiac allograft vasculopathy (CAV) (P < 0.0001) than patients in the high CFVR group. Systolic function improved in both HTx groups during exercise. However, LV longitudinal myocardial deformation improved significantly more in the high CFVR group (P < 0.0001). Peak exercise LV global longitudinal strain and CFVR were strongly correlated (r = 0.8, P < 0.0001). A weak correlation was observed between CFVR and invasive cardiac index at peak exercise (r = 0.35, P < 0.01) and CFVR and LV filling measured by E/e' ratio (r = -0.41, P < 0.01) and pulmonary capillary wedge pressure (r = -0.30, P < 0.05).

CONCLUSION

HTx patients have reduced CFVR, exercise capacity, and LV longitudinal myocardial deformation capacity compared with healthy individuals. HTx patients with reduced CFVR are more symptomatic and have increased prevalence of CAV. Furthermore, reduced CFVR is correlated with reduced LV longitudinal myocardial deformation and exercise capacity.

Outcome in patients treated with isolated liver transplantation for familial transthyretin amyloidosis to prevent cardiomyopathy

BACKGROUND

Familial transthyretin (TTR) amyloidosis is caused by different TTR mutations resulting in different clinical phenotypes of the disease. The Leu111Met mutation causes severe restrictive cardiomyopathy. Liver transplantation (LTx) is an established treatment option for patients with TTR amyloidosis; however, information on outcome after isolated LTx in patients with Leu111Met mutation amyloidosis is limited.

METHODS

Between 2005 and 2012, six patients with TTR Leu111Met amyloidosis underwent isolated orthotopic LTx. None suffered from neuropathy. Prior to LTx, patients presented with echocardiographic manifestations of early cardiac amyloid involvement and in five endomyocardial biopsy was positive for TTR amyloid.

RESULTS

Median age at LTx was 45.5 yr (range 39-54), and four were male (67%). All patients were alive at a median follow-up of 56.6 months (range 18-104). No surgical complications occurred. Two patients (33%) underwent cardiac transplantation during follow-up due to progressive cardiomyopathy. The remaining four patients experienced no echocardiographic or clinical deterioration of cardiac function following LTx.

CONCLUSION

Isolated LTx appears to be a valuable treatment option for patients with familial TTR amyloidosis due to Leu111Met mutation. Appropriate timing of LTx is of utmost importance to avoid development of severe amyloid cardiomyopathy and the need for combined heart and liver transplantation.

The Effect of Everolimus Initiation and Calcineurin Inhibitor Elimination on Cardiac Allograft Vasculopathy in De Novo Recipients: One-Year Results of a Scandinavian Randomized Trial

Early initiation of everolimus with calcineurin inhibitor therapy has been shown to reduce the progression of cardiac allograft vasculopathy (CAV) in de novo heart transplant recipients. The effect of de novo everolimus therapy and early total elimination of calcineurin inhibitor therapy has, however, not been investigated and is relevant given the morbidity and lack of efficacy of current protocols in preventing CAV. This 12-month multicenter Scandinavian trial randomized 115 de novo heart transplant recipients to everolimus with complete calcineurin inhibitor elimination 7-11 weeks after HTx or standard cyclosporine immunosuppression. Ninety-five (83%) patients had matched intravascular ultrasound examinations at baseline and 12 months. Mean (± SD) recipient age was 49.9 ± 13.1 years. The everolimus group (n = 47) demonstrated significantly reduced CAV progression as compared to the calcineurin inhibitor group (n = 48) (ΔMaximal Intimal Thickness 0.03 ± 0.06 and 0.08 ± 0.12 mm, ΔPercent Atheroma Volume 1.3 ± 2.3 and 4.2 ± 5.0%, ΔTotal Atheroma Volume 1.1 ± 19.2 mm(3) and 13.8 ± 28.0 mm(3) [all p-values ≤ 0.01]). Everolimus patients also had a significantly greater decline in levels of soluble tumor necrosis factor receptor-1 as compared to the calcineurin inhibitor group (p = 0.02). These preliminary results suggest that an everolimus-based CNI-free can potentially be considered in suitable de novo HTx recipients.

Everolimus initiation and early calcineurin inhibitor withdrawal in heart transplant recipients: a randomized trial

In a randomized, open-label trial, everolimus was compared to cyclosporine in 115 de novo heart transplant recipients. Patients were assigned within 5 days posttransplant to low-exposure everolimus (3–6 ng/mL) with reduced-exposure cyclosporine (n = 56), or standard-exposure cyclosporine (n = 59), with both mycophenolate mofetil and corticosteroids. In the everolimus group, cyclosporine was withdrawn after 7–11 weeks and everolimus exposure increased (6–10 ng/mL). The primary efficacy end point, measured GFR at 12 months posttransplant, was significantly higher with everolimus versus cyclosporine (mean ± SD: 79.8 ± 17.7 mL/min/1.73 m2 vs. 61.5 ± 19.6 mL/min/1.73 m2; p < 0.001). Coronary intravascular ultrasound showed that the mean increase in maximal intimal thickness was smaller (0.03 mm [95% CI 0.01, 0.05 mm] vs. 0.08 mm [95% CI 0.05, 0.12 mm], p = 0.03), and the incidence of cardiac allograft vasculopathy (CAV) was lower (50.0% vs. 64.6%, p = 0.003), with everolimus versus cyclosporine at month 12. Biopsy-proven acute rejection after weeks 7–11 was more frequent with everolimus (p = 0.03). Left ventricular function was not inferior with everolimus versus cyclosporine. Cytomegalovirus infection was less common with everolimus (5.4% vs. 30.5%, p < 0.001); the incidence of bacterial infection was similar. In conclusion, everolimus-based immunosuppression with early elimination of cyclosporine markedly improved renal function after heart transplantation. Since postoperative safety was not jeopardized and development of CAV was attenuated, this strategy may benefit long-term outcome.

Virtual histology assessment of cardiac allograft vasculopathy following introduction of everolimus--results of a multicenter trial

In this 12-month multicenter Scandinavian study, 78 maintenance heart transplant (HTx) recipients randomized to everolimus with reduced calcineurin inhibitor (CNI) exposure or continued standard CNI-therapy underwent matched virtual histology (VH) examination to evaluate morphological progression of cardiac allograft vasculopathy (CAV). Parallel measurement of a range of inflammatory markers was also performed. A similar rate of quantitative CAV progression was observed in the everolimus (n = 30) and standard CNI group (n = 48) (plaque index 1.9 ± 3.8% and 1.6 ± 3.9%, respectively; p = 0.65). However, VH analysis revealed a significant increase in calcified (2.4 ± 4.0 vs. 0.3 ± 3.1%; p = 0.02) and necrotic component (6.5 ± 8.5 vs. 1.1 ± 8.6%; p = 0.01) among everolimus patients compared to controls. The increase in necrotic and calcified components was most prominent in everolimus patients with time since HTx >5.1 years and was accompanied by a significant increase in levels of von Willebrand (vWF) factor (p = 0.04) and vascular cell adhesion molecule (VCAM) (p = 0.03). Conversion to everolimus and reduced CNI is associated with a significant increase in calcified and necrotic intimal components and is more prominent in patients with a longer time since HTx. A significant increase in vWF and VCAM accompanied these qualitative changes and the prognostic implication of these findings requires further investigation.

Pharmacokinetics in stable heart transplant recipients after conversion from twice-daily to once-daily tacrolimus formulations

BACKGROUND

A prolonged-release formulation of tacrolimus for once-daily administration (tacrolimus QD) has been developed. This phase II, open-label, multicenter, prospective single-arm study compared the pharmacokinetics (PK) of tacrolimus in stable heart transplant patients before and after conversion from twice-daily tacrolimus (tacrolimus BID) to tacrolimus QD.

METHODS

Heart transplant recipients (≥6 months after transplant), previously maintained on tacrolimus BID-based therapy, received tacrolimus BID from Days 1 to 7 and were converted on a 1:1 (mg/mg) basis to tacrolimus QD. Five 24-hour PK profiles were collected (Days 1, 7, 8, 14, 21). Safety parameters were also evaluated.

RESULTS

Of 85 patients, 45 (50.6%) completed all 5 evaluable PK profiles. Steady-state tacrolimus area under the curve, 0 to 24 hours (AUC(0-24)) and minimum concentration (C(min)) were comparable for both formulations, with treatment ratio means of 90.5% (90% confidence intervals [CI], 86.4%-94.6%) and 87.4% (95% CI, 82.9%-92.0%), respectively (acceptance interval, 80%-125%). There was good correlation between AUC(0-24) and C(min) for tacrolimus QD (r = 0.94) and BID (r = 0.91). The relationship between these 2 parameters was also similar.

CONCLUSIONS

This study provides evidence for successful conversion from tacrolimus BID to QD on a 1:1 (mg/mg) total daily dose basis. Approximately one-third of patients may require dose adjustments. Both formulations were well tolerated, with stable renal function during the study. Adverse events were reported by approximately one-tenth of patients receiving tacrolimus BID and a quarter of those who received QD.