Comparison of Different Ex-Vivo Preservation Strategies on Cardiac Metabolism in an Animal Model of Donation after Circulatory Death

Transplantation of heart following donation after circulatory death (DCD) was recently introduced into clinical practice. Ex vivo reperfusion following DCD and retrieval is deemed necessary in order to evaluate the recovery of cardiac viability after the period of warm ischemia. We tested the effect of four different temperatures (4 °C-18 °C-25 °C-35 °C) on cardiac metabolism during 3-h ex vivo reperfusion in a porcine model of DCD heart. We observed a steep fall in high-energy phosphate (ATP) concentrations in the myocardial tissue at the end of the warm ischemic time and only limited regeneration during reperfusion. Lactate concentration in the perfusate increased rapidly during the first hour of reperfusion and slowly decreased afterward. However, the temperature of the solution does not seem to have an effect on either ATP or lactate concentration. Furthermore, all cardiac allografts showed a significant weight increase due to cardiac edema, regardless of the temperature.

Adherence to quality indicators for ST-elevation myocardial infarction and its relation to mortality: a hospital network analysis from the Belgian STEMI database

AIMS

To assess the adherence to established quality indicators (QIs) for ST-elevation myocardial infarction (STEMI) at the hospital-network level and its relation to outcome.

METHODS AND RESULTS

The data of 7774 STEMI patients admitted to 32 STEMI networks during the period 2014-18 were extracted from the Belgian STEMI database. Five QIs [primary percutaneous coronary intervention use, diagnosis-to-balloon time (DiaTB) <90 min, door-to-balloon time (DoTB) <60 min, P2Y12 inhibitor and statin prescription at discharge, and a composite QI score ranging from 0 to 10] were correlated with in-hospital mortality adjusted for differences in baseline risk profile (TIMI risk score). The median composite QI score was 6.5 [interquartile range (IQR) 6-8]. The most important gaps in quality adherence were related to time delays: the recommended DiaTB and DoTB times across the different networks were achieved in 68% (IQR 53-71) and 67% (IQR 50-78), respectively. Quality adherence was better in networks taking care of more high-risk STEMI patients. The median in-hospital mortality among the STEMI networks was 6.4% (IQR 4.1-7.9%). There was a significant independent inverse correlation between the composite QI score and in-hospital mortality (partial correlation coefficient: -0.45, P = 0.013). Stepwise regression analysis revealed that among the individual QIs, prolonged DiaTB was the most important independent outcome predictor.

CONCLUSION

Among established STEMI networks, the time delay between diagnosis and treatment was the most variable and the most relevant prognostic QI, underscoring the importance of assessing quality of care throughout the whole network.

Impact of COVID-19-related public containment measures on the ST elevation myocardial infarction epidemic in Belgium: a nationwide, serial, cross-sectional study

AIMS

The current study assessed the impact of COVID-19-related public containment measures (i.e. lockdown) on the ST elevation myocardial infarction (STEMI) epidemic in Belgium.

METHODS AND RESULTS

Clinical characteristics, reperfusion therapy modalities, COVID-19 status and in-hospital mortality of consecutive STEMI patients who were admitted to Belgian hospitals for percutaneous coronary intervention (PCI) were recorded during a three-week period starting at the beginning of the lockdown period on 13 March 2020. Similar data were collected for the same time period for 2017-2019. An evaluation of air quality revealed a 32% decrease in ambient NO₂ concentrations during lockdown (19.5 µg/m³ versus 13.2 µg/m³, p < .001). During the three-week period, there were 188 STEMI patients admitted for PCI during the lockdown versus an average 254 STEMI patients before the lockdown period (incidence rate ratio = 0.74, p = .001). Reperfusion strategy was predominantly primary PCI in both time periods (96% versus 95%). However, there was a significant delay in treatment during the lockdown period, with more late presentations (>12 h after onset of pain) (14% versus 7.6%, p = .04) and with longer door-to-balloon times (median of 45 versus 39 min, p = .02). Although the in-hospital mortality between the two periods was comparable (5.9% versus 6.7%), 5 of the 7 (71%) COVID-19-positive STEMI patients died.

CONCLUSION

The present study revealed a 26% reduction in STEMI admissions and a delay in treatment of STEMI patients. Less exposure to external STEMI triggers (such as ambient air pollution) and/or reluctance to seek medical care are possible explanations of this observation.

Study design and rationale of the pAtients pResenTing with cOngenital heaRt dIseAse Register (ARTORIA-R)

Aim

Due to improved therapy in childhood, many patients with congenital heart disease reach adulthood and are termed adults with congenital heart disease (ACHD). ACHD often develop heart failure (HF) as a consequence of initial palliative surgery or complex anatomy and subsequently require advanced HF therapy. ACHD are usually excluded from trials evaluating heart failure therapies, and in this context, more data about heart failure trajectories in ACHD are needed to guide the management of ACHD suffering from HF.

Methods and results

The pAtients pResenTing with cOngenital heaRt dIseAse Register (ARTORIA‐R) will collect data from ACHD evaluated or listed for heart or heart‐combined organ transplantation from 16 countries in Europe and the Asia/Pacific region. We plan retrospective collection of data from 1989–2020 and will include patients prospectively. Additional organizations and hospitals in charge of transplantation of ACHD will be asked in the future to contribute data to the register. The primary outcome is the combined endpoint of delisting due to clinical worsening or death on the waiting list. The secondary outcome is delisting due to clinical improvement while on the waiting list. All‐cause mortality following transplantation will also be assessed. The data will be entered into an electronic database with access to the investigators participating in the register. All variables of the register reflect key components important for listing of the patients or assessing current HF treatment.

Conclusion

The ARTORIA‐R will provide robust information on current management and outcomes of adults with congenital heart disease suffering from advanced heart failure.

Symptomatic Val122del mutated hereditary transthyretin amyloidosis: Need for early diagnosis and prioritization for heart and liver transplantation

BACKGROUND

Hereditary transthyretin (ATTRv) amyloidosis is an autosomal dominant disease linked to transthyretin gene mutations which cause instability of the transthyretin tetramer. After dissociation and misfolding they reassemble as insoluble fibrils (i.e. amyloid). Apart from the common Val30Met mutation there is a very heterogeneous group of non-Val30Met mutations. In some cases, the clinical picture is dominated by a rapidly evolving restrictive and hypertrophic cardiomyopathy.

METHODS

A case series of four liver recipients with the highly clinically relevant, rare and particularly aggressive Val122del mutation is presented. Medical and surgical therapeutic options, waiting list policy for ATTRv-amyloidosis, including the need for heart transplantation, and status of heart-liver transplantation are discussed.

RESULTS

Three patients needed a staged (1 patient) or simultaneous (2 patients) heart-liver transplant due to rapidly progressing cardiac failure and/or neurologic disability. Domino liver transplantation was impossible in two due to fibrotic hepatic transformation caused by cardiomyopathy. After a follow-up ranging from 3.5 to 9.5 years, cardiac (allograft) function was maintained in all patients, but neuropathy progressed in three patients, one of whom died after 80 months.

CONCLUSIONS

This is the first report in (liver) transplant literature about the rare Val122del ATTRv mutation. Due to its aggressiveness, symptomatic patients should be prioritized on the liver and, in cases with cardiomyopathy, heart waiting lists in order to avoid the irreversible neurological and cardiac damage that leads to a rapid lethal outcome.

Hypothermic continuous machine perfusion enables preservation of energy charge and functional recovery of heart grafts in an ex vivo model of donation following circulatory death

OBJECTIVES

Cardiac transplantation using hearts from donors after circulatory death (DCD) is critically limited by the unavoidable warm ischaemia and its related unpredictable graft function. Inasmuch as hypothermic machine perfusion (MP) has been shown to improve heart preservation, we hypothesized that MP could enable the use of DCD hearts for transplantation.

METHODS

We recovered 16 pig hearts following anoxia-induced cardiac arrest and cardioplegia. Grafts were randomly assigned to two different groups of 4-h preservation using either static cold storage (CS) or MP (Modified LifePort© System, Organ Recovery Systems©, Itasca, Il). After preservation, the grafts were reperfused ex vivo using the Langendorff method for 60 min. Energetic charge was quantified at baseline, post-preservation and post-reperfusion by measuring lactate and high-energy phosphate levels. Left ventricular contractility parameters were assessed both in vivo prior to ischaemia and ex vivo during reperfusion.

RESULTS

Following preservation, the hearts that were preserved using CS exhibited higher lactate levels (57.1 ± 23.7 vs 21.4 ± 12.2 µmol/g; P < 0.001), increased adenosine monophosphate/adenosine triphosphate ratio (0.53 ± 0.25 vs 0.11 ± 0.11; P < 0.001) and lower phosphocreatine/creatine ratio (9.7 ± 5.3 vs 25.2 ± 11; P < 0.001) in comparison with the MP hearts. Coronary flow was similar in both groups during reperfusion (107 ± 9 vs 125 ± 9 ml/100 g/min heart; P = ns). Contractility decreased in the CS group, yet remained well preserved in the MP group.

CONCLUSION

MP preservation of DCD hearts results in improved preservation of the energy and improved functional recovery of heart grafts compared with CS.

Hypothermic continuous machine perfusion improves metabolic preservation and functional recovery in heart grafts

The number of heart transplants is decreasing due to organ shortage, yet the donor pool could be enlarged by improving graft preservation. Hypothermic machine perfusion (MP) has been shown to improve kidney, liver, or lung graft preservation. Sixteen pig hearts were recovered following cardioplegia and randomized to two different groups of 4-hour preservation using either static cold storage (CS) or MP (Modified LifePort© System, Organ Recovery Systems, Itasca, Il). The grafts then underwent reperfusion on a Langendorff for 60 min. Energetic metabolism was quantified at baseline, postpreservation, and postreperfusion by measuring lactate and high-energy phosphates. The contractility index (CI) was assessed both in vivo prior to cardioplegia and during reperfusion. Following reperfusion, the hearts preserved using CS exhibited higher lactate levels (56.63 ± 23.57 vs. 11.25 ± 3.92 μmol/g; P < 0.001), increased adenosine monophosphate/adenosine triphosphate (AMP/ATP) ratio (0.4 ± 0.23 vs. 0.04 ± 0.04; P < 0.001), and lower phosphocreatine/creatine (PCr/Cr) ratio (33.5 ± 12.6 vs. 55.3 ± 5.8; P <0.001). Coronary flow was similar in both groups during reperfusion (107 ± 9 vs. 125 + /-9 ml/100 g/min heart; P = ns). CI decreased in the CS group, yet being well-preserved in the MP group. Compared with CS, MP resulted in improved preservation of the energy state and more successful functional recovery of heart graft.

Giant venous aneurysm jeopardising internal mammary arterial graft patency

The authors report a 79-year old man with a history of coronary bypass surgery, presenting with acute heart failure and elevated troponin. Coronarography revealed a giant saphenous vein graft aneurysm, which was compressing the left internal mammary artery bypass graft. This was confirmed by a multislice enhanced-ECG gated cardiac CT, showing the venous aneurysm responsible for external compression of the arterial graft and its functional occlusion. Myocardial ischaemia, the mechanism leading to cardiac failure, was confirmed by hypoperfusion of the sub-endocardial area shown by the CT. The aneurysm was surgically removed without complications. The patient recovered and his cardiac function improved. This is the first recorded case of compression of the left internal mammary artery by an giant saphenous vein graft aneurysm having triggered severe myocardial ischaemia and heart failure. The authors review the incidence and complications of giant venous bypass graft aneurysms reported in the literature.

Adult respiratory distress syndrome caused by 2009 H1N1 influenza during pregnancy: success of ECMO for both the mother and the child

Extracorporeal membrane oxygenation (ECMO) is a technique that provides support to selected patients with severe respiratory failure. During the 2009 H1N1 influenza infection outbreak, ECMO was used with a good impact on survival for pregnant women, who are at higher risk of H1N1 influenza infection. However, there is little information about the survival of fetus post-ECMO therapy in the literature. We present a case report of a pregnant patient with severe adult respiratory distress syndrome secondary to 2009 H1N1 influenza treated with ECMO. The outcome was good both for the mother and her fetus. At 1-year follow-up, her child had no neurological or clinical abnormalities. We conclude that ECMO can be used safely during pregnancy with a good neurological and clinical outcome for the fetus.

Reoperation for severe right ventricular dilatation after tetralogy of Fallot repair: pulmonary infundibuloplasty should be added to homograft implantation

BACKGROUND AND AIM OF THE STUDY

Right ventricular dilatation observed after tetralogy of Fallot repair regresses after pulmonary valve implantation, unless the dilation is too severe. The presence of an akinetic patch in the right ventricular outflow tract (RVOT), a known factor promoting right ventricular dilatation, may prevent right ventricular recovery after valve implantation. The exclusion of a large akinetic RVOT area during reoperation of patients presenting with severe post-repair right ventricular dilatation was investigated.

METHODS

Eight patients underwent a pulmonary infundibuloplasty between May 2000 and October 2002. Their mean preoperative cardothoracic index was 0.66 +/- 0.08, and preoperative NYHA class II (n = 4), III (n = 3) or IV (n = 1). Three patients were offered heart transplantation but refused. All had severe pulmonary regurgitation and underwent a RVOT valve implantation except one patient who had a previous homograft pulmonary valve insertion. Concomitant procedures were tricuspid ring implantation (n = 3), atrial septal defect closure (n = 2), mitral valve repair (n = 1) and modified right atrial Maze (n = 1).

RESULTS

Median follow up time was 13 months (range: 6 -29 months). One patient suffered a fatal ventricular fibrillation at home. All patients but one were in NYHA class I. After a mean of 5 +/- 3 months, their mean workload capacity rose from 115 +/- 19 W to 155 +/- 62 W, and mean VO2max rose from 16.5 +/- 2 to 18.3 +/- 2 ml/min/kg.

CONCLUSION

Pulmonary infundibuloplasty may be a useful adjunct in reoperation of tetralogy of Fallot patients presenting with severe right ventricular dilatation and large akinetic area of the RVOT.

Outcome of cardiac surgery patients with complicated intensive care unit stay

Risk stratification has become an essential element in the practice of cardiac surgery. Several studies have identified preoperative risk factors for adverse outcome. However, outcome is mostly defined by 30-day mortality and morbidity. These data reflect poorly the benefit for the patient. Long-term survival, quality of life, and functional status should be included in a more global analysis of the outcome, particularly in patients with complicated ICU stay. By reviewing the recent data reported in the literature, we can identify a number of preoperative predictive factors for complicated ICU stay, including advanced age, chronic obstructive pulmonary disease, preoperative low ejection fraction, previous myocardial infarction, reoperation, renal failure, combined surgery (coronary artery bypass grafting plus valve surgery), low hematocrit, and neurologic impairment. Short- and long-term outcomes are dependent on the type of postoperative complication. Unfortunately, data regarding the long-term outcome in these situations are very scarce.