208 The PKC Epsilon/AMPK ALPHA/ENOS Pathway is Implicated as a Mechanism by which Remote Ischaemic Conditioning Attenuates Endothelin-1 Mediated Cardiomyocyte Hypertrophy

BackgroundRemote ischaemic conditioning (rIC) is a cardioprotective tool which has shown promise in preclinical and clinical trials in the context of acute ischaemia. Repeated rIC post myocardial infarction may provide additional benefits which have not previously been tested clinically.MethodsThe trial assessed the role of daily rIC in enhancing left ventricular ejection fraction (LVEF) recovery in patients with impaired LVEF (<45%) after ST segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (P-PCI). Patients were recruited from four UK hospitals and randomised to receive either 4 weeks of daily rIC or sham conditioning using the autoRIC Device (CellAegis) starting on day 3 post P-PCI. The primary endpoint was the improvement in LVEF over 4 months assessed by cardiac MRI (CMR). Seventy-three patients (38 cases, 35 controls) completed the study.ResultsThe treatment and control groups were well matched at baseline including for mean LVEF (42.8% vs 44.3% respectively, p=0.952). There was no difference in the improvement in LVEF over 4 months between the treatment and control groups (4.8%±7.8% vs 4.6%±5.9% respectively, p=0.924). No differences were seen in the secondary outcome measures including changes in infarct size and left ventricular end-diastolic and systolic volumes, major adverse cardiac and cerebral event, mean Kansas City Cardiomyopathy Questionnaire score and change in N-terminal pro-brain natriuretic peptide levels.ConclusionsDaily rIC starting on day 3 and continued for 4 weeks following successful P-PCI for STEMI did not improve LVEF as assessed by CMR after 4 months when compared with a matched control group.Trial registration numberNCT0166461.

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Abstract 934: Contributory Role of VEGF Overexpression in Endothelin-1-induced Cardiomyocyte Hypertrophy: Involvement of Hyopoxia Inducible Factor

Circulation ◽

10.1161/circ.116.suppl_16.ii_184-a ◽

2007 ◽

Vol 116 (suppl_16) ◽

Author(s):

Nobutake Shimojo ◽

Subrina Jesmin ◽

Yuichi Hattori ◽

Seiji Maeda ◽

Takashi Miyauchi ◽

...

Keyword(s):

Fetal Liver ◽

Hypoxia Inducible Factor ◽

Neonatal Rat ◽

Cardiomyocyte Hypertrophy ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Rat Cardiomyocytes ◽

Endothelin 1 ◽

Vegf Signaling ◽

Endothelial Growth Factor

Although endothelin-1 (ET-1) stimulates vascular endothelial growth factor (VEGF) expression in a variety of cells, including endothelial cells and vascular smooth muscle cells, the effect of ET-1 on expression of VEGF and its receptors in cardiomyocytes is unknown. In the present study, we found that treatment of neonatal rat cardiomyocytes with ET-1 for 24 h resulted in upregulation of VEGF and its two principle receptors, fetal liver kinase (flk)-1 and fms-like tyrosine kinase (flt)-1, in a concentration-dependent manner (10 −12 -10 −6 M). ET-1 treatment also caused significant cardiomyocyte hypertrophy, as indicated by increases in cell surface area (2.0-fold compared to control) and 14 C-leucine uptake (1.8 fold) by cardiomyocytes. And this ET-1 mediated upregulation of VEGF in cardiomyocytes was associated with the induction of hypoxia inducible factor (HIF)-1β and HIF-2α, not HIF-1α. Treatment with TA-0201 (10 −6 M), an ET A selective blocker, eliminated ET-1-induced overexpression of VEGF and its receptors as well as cardiomyocyte hypertrophy. Treatment with VEGF neutralizing peptides (5–10 μg/ml) partially but significantly inhibited ET-1-induced cardiomyocyte hypertrophy. Both TA-0201 and VEGF neutralizing peptides also significantly prevented the increase of phosphorylated KDR, which implies the activation of VEGF system in ET-1 induced hypertrophied cardiomyocyte. These results suggest that ET-1 treatment of cardiomyocytes promotes overexpression of VEGF and its receptors via activation of ET A receptors, and consequently the upregulated VEGF signaling system appears to contribute, at least in part, to ET-1-induced cardiomyocyte hypertrophy.

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Remote ischaemic conditioning in ST elevation myocardial infarction: a registry-based randomised trial

Heart ◽

10.1136/heartjnl-2021-319455 ◽

2021 ◽

pp. heartjnl-2021-319455

Author(s):

Kevin R Bainey ◽

Yinggan Zheng ◽

Richard Coulden ◽

Emer Sonnex ◽

Richard Thompson ◽

...

Keyword(s):

Myocardial Infarction ◽

Myocardial Perfusion ◽

Clinical Outcomes ◽

St Elevation Myocardial Infarction ◽

Volume Index ◽

Cardiovascular Mri ◽

Randomised Study ◽

Remote Ischaemic Conditioning ◽

St Elevation ◽

Ischaemic Conditioning

ObjectivesRemote ischaemic conditioning (RIC) has been tested as a possible strategy for mitigating reperfusion injury in ST elevation myocardial infarction (STEMI) with primary percutaneous coronary intervention (PPCI). However, surrogate outcomes have shown inconsistent effects with lack of clinical correlation.MethodsWe performed a registry-based randomised study of patients with STEMI allocated to RIC (4 cycles of blood pressure cuff inflation to 200 mm Hg for 5 min of ischaemia followed by 5 min of reperfusion) or standard of care (SOC) during PPCI. We examined the associations of RIC on core laboratory measurements of myocardial perfusion, infarct size (IS), left ventricular (LV) performance and clinical outcomes.ResultsA total of 252 patients were enrolled. The median age was 61 (IQR: 55–70) years and 72.8% were male. Sum ST segment deviation resolution ≥50% was similar between RIC and SOC (65.2% vs 55.7%, p=0.269). In those with 3-day cardiovascular MRI (n=88), no difference in median (25th, 75th percentiles) IS (14.9% (4.5%, 23.1%) vs 16.1% (3.3%, 22.0%), p=0.980), LV dimensions (LV end-diastolic volume index: 78.7 (71.1, 91.2) mL/m2 vs 79.9 (71.2, 88.8) mL/m2, p=0.630; LV end-systolic volume index: 48.8 (35.7, 51.4) mL/m2 vs 37.9 (31.8, 47.5) mL/m2, p=0.551) or ejection fraction (50.0% (41.0%–55.0%) vs 50.0% (43.0%–56.0%), p=0.554) was demonstrated. Similar results were observed with 90-day cardiovascular MRI. At 1 year, the clinical composite of death, congestive heart failure, cardiogenic shock and recurrent myocardial infarction was similar in RIC and SOC (21.7% vs 13.3%, p=0.110).ConclusionsIn a contemporary registry-based randomised study of patients with STEMI undergoing PPCI, adjunctive therapy with RIC did not improve myocardial perfusion, reduce IS or alter LV performance. Consequently, there was no difference in clinical outcomes within 1 year.Trial registration numberNCT03930589.

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