Metabolomic profiling of cardiac allografts after controlled circulatory death

BACKGROUND

Assessment of myocardial viability during ex situ heart perfusion (ESHP) is based on the measurement of lactate concentrations. As this provides with limited information, we sought to investigate the metabolic signature associated with donation after circulatory death (DCD) and the impact of ESHP on the myocardial metabolome.

METHODS

Porcine hearts were retrieved either after warm ischemia (DCD group, N = 6); after brain-stem death (BSD group, N = 6); or without DCD nor BSD (Control group, N = 6). Hearts were perfused using normothermic oxygenated blood for 240 minutes. Plasma and myocardial samples were collected respectively every 30 and 60 minutes, and analyzed by an untargeted metabolomic approach using liquid chromatography coupled to high-resolution mass spectrometry.

RESULTS

Median duration of warm ischemia was 23 minutes [19-29] in DCD animals. Lactate level within myocardial biopsies was not significantly different between groups at T0 (p = 0.281), and remained stable over the 4-hour period of ESHP. More than 300 metabolites were detected in plasma and heart biopsy samples. Compared to BSD animals, metabolomics changes involving energy and nucleotide metabolisms were observed in plasma samples of DCD animals before initiation of ESHP, whereas 2 metabolites (inosine monophosphate and methylbutyrate) exhibited concentration changes in biopsy samples. Normalization of DCD metabolic profile was remarkable after 4 hours of ESHP.

CONCLUSION

A specific metabolic profile was observed in DCD hearts, mainly characterized by an increased nucleotide catabolism. DCD and BSD metabolomes proved normalized during ESHP. Complementary investigations are needed to correlate these findings to cardiac performances.

High prevalence of unkown dysglycemia and chronotropic response to exercise in patients admitted in cardiac rehabilitation program

Funding Acknowledgements

Type of funding sources: None.

Introduction : Some studies suggest a high rate of unknown glycemic abnormalities in coronary patients. The aim of the study was to determine the prevalence of dysglycemia detected by oral glucose load (OGL)  in patients ongoing Cardiac Rehab , and to analyse chronotropic response to exercise before and after Cardiac rehab in dysglycemic patients.

Patients and methods : We included 838 patients, mostly coronary patients after acute coronary syndrome, including 79% men and 375 were diabetics. OGL has been performed in non-diabetics and ergospirometry test performed in all patients before and after rehabilitation.

Results : At OGL, 189 of 463 non-diabetics (41%) had dysglycemia: Diabetes (n = 42 including 17 according to fasting glycemia), Glucose intolerance (GI) (n = 102 including 32 with fasting hyperglycemia (FH),  FH isolated (n = 45). We compared 417 patients with known or discovered diabetes, GI and 319 normoglycemic or FH. Diabetics were older and had a higher BMI than GI and normoglycemic-FH (p <0.001). Resting heart rate (HR) was higher and maximal HR on exercise is lower in diabetics than other 2 groups (p <0.001) without significantly differing between GI and normoglycaemia-FH. VO2max was lower in diabetics and GI than normoglycemic-FH s (p <0.001 and 0.01). After cardiac rehabilitation, resting HR is changed little, HR max and VO2max increased in 3 groups but kept the same inter-group differences

Conclusion :This data confirms the high prevalence of unknown dysglycemia and the importance of OGL  for their screening, especially in coronary patients. In diabetics, the higher resting HR and the lack of chronotropic reserve probably indicate autonomic dysregulation which partially improves after cardiac rehabilitation.

[Thoracoabdominal aneurysms]

Endovascular treatment of thoracoabdominal aneurysms: what's new? Thoracoabdominal aneurysms (T-AAA) are aortic aneurysms that involve both the thoracic and abdominal segments of the aorta and its associated visceral branches. Although the first successful open repair was reported over 50 years ago, the risks of treatment remain considerable. As the first generations of devices available for endovascular aneurysm repair (EVAR) were relatively simple tubes or bifurcated grafts, initial attempts to extend the benefits of EVAR to patients with T-AAA lead to "hybrid solution". Good results with hybrid repairs have not been universal and the approach does not exploit all of the potential advantages of a "pure" endovascular approach (lesser surgical insult). This unmet need, together with rapid technological advances, has encouraged the development of custom-made endografts with fenestrations and/or branches (F-BEVAR) for extension into the visceral vessel ostia. F-BEVAR requires considerably more complex device design and planning than conventional EVAR. Deployment is more technically demanding and takes longer to complete. Thus, patient, aneurysm anatomy and surgical team selection is paramount. Favorable outcomes have been widely reported following T-AAA repair with F-BEVAR in expert centers; more complex aortic lesions such as T-AAA in the context of chronic dissection or arch aneurysms are thus now also offered endovascular repair with F-BEVAR.