Denis Angoulvant

Effect of Cyclosporine on Reperfusion Injury in Acute Myocardial Infarction

BACKGROUND Experimental evidence suggests that cyclosporine, which inhibits the opening of mitochondrial permeability-transition pores, attenuates lethal myocardial injury that occurs at the time of reperfusion. In this pilot trial, we sought to determine whether the administration of cyclosporine at the time of percutaneous coronary intervention (PCI) would limit the size of the infarct during acute myocardial infarction. METHODS We randomly assigned 58 patients who presented with acute ST-elevation myocardial infarction to receive either an intravenous bolus of 2.5 mg of cyclosporine per kilogram of body weight (cyclosporine group) or normal saline (control group) immediately before undergoing PCI. Infarct size was assessed in all patients by measuring the release of creatine kinase and troponin I and in a subgroup of 27 patients by performing magnetic resonance imaging (MRI) on day 5 after infarction. RESULTS The cyclosporine and control groups were similar with respect to ischemia time, the size of the area at risk, and the ejection fraction before PCI. The release of creatine kinase was significantly reduced in the cyclosporine group as compared with the control group (P=0.04). The release of troponin I was not significantly reduced (P=0.15). On day 5, the absolute mass of the area of hyperenhancement (i.e., infarcted tissue) on MRI was significantly reduced in the cyclosporine group as compared with the control group, with a median of 37 g (interquartile range, 21 to 51) versus 46 g (interquartile range, 20 to 65; P=0.04). No adverse effects of cyclosporine administration were detected. CONCLUSIONS In our small, pilot trial, administration of cyclosporine at the time of reperfusion was associated with a smaller infarct by some measures than that seen with placebo. These data are preliminary and require confirmation in a larger clinical trial.

Cardioprotective c-kit+ cells are from the bone marrow and regulate the myocardial balance of angiogenic cytokines

Clinical trials of bone marrow stem/progenitor cell therapy after myocardial infarction (MI) have shown promising results, but the mechanism of benefit is unclear. We examined the nature of endogenous myocardial repair that is dependent on the function of the c-kit receptor, which is expressed on bone marrow stem/progenitor cells and on recently identified cardiac stem cells. MI increased the number of c-kit+ cells in the heart. These cells were traced back to a bone marrow origin, using genetic tagging in bone marrow chimeric mice. The recruited c-kit+ cells established a proangiogenic milieu in the infarct border zone by increasing VEGF and by reversing the cardiac ratio of angiopoietin-1 to angiopoietin-2. These oscillations potentiated endothelial mitogenesis and were associated with the establishment of an extensive myofibroblast-rich repair tissue. Mutations in the c-kit receptor interfered with the mobilization of the cells to the heart, prevented angiogenesis, diminished myofibroblast-rich repair tissue formation, and led to precipitous cardiac failure and death. Replacement of the mutant bone marrow with wild-type cells rescued the cardiomyopathic phenotype. We conclude that, consistent with their documented role in tumorigenesis, bone marrow c-kit+ cells act as key regulators of the angiogenic switch in infarcted myocardium, thereby driving efficient cardiac repair.

Long-Term Benefit of Postconditioning

Background— We previously demonstrated that ischemic postconditioning decreases creatine kinase release, a surrogate marker for infarct size, in patients with acute myocardial infarction. Our objective was to determine whether ischemic postconditioning could afford (1) a persistent infarct size limitation and (2) an improved recovery of myocardial contractile function several months after infarction. Methods and Results— Patients presenting within 6 hours of the onset of chest pain, with suspicion for a first ST-segment–elevation myocardial infarction, and for whom the clinical decision was made to treat with percutaneous coronary intervention, were eligible for enrollment. After reperfusion by direct stenting, 38 patients were randomly assigned to a control (no intervention; n=21) or postconditioned group (repeated inflation and deflation of the angioplasty balloon; n=17). Infarct size was assessed both by cardiac enzyme release during early reperfusion and by 201thallium single photon emission computed tomography at 6 months after acute myocardial infarction. At 1 year, global and regional contractile function was evaluated by echocardiography. At 6 months after acute myocardial infarction, single photon emission computed tomography rest-redistribution index (a surrogate for infarct size) averaged 11.8±10.3% versus 19.5±13.3% in the postconditioned versus control group (P=0.04), in agreement with the significant reduction in creatine kinase and troponin I release observed in the postconditioned versus control group (−40% and −47%, respectively). At 1 year, the postconditioned group exhibited a 7% increase in left ventricular ejection fraction compared with control (P=0.04). Conclusions— Postconditioning affords persistent infarct size reduction and improves long-term functional recovery in patients with acute myocardial infarction.

Cyclosporine before PCI in Patients with Acute Myocardial Infarction

BACKGROUND Experimental and clinical evidence suggests that cyclosporine may attenuate reperfusion injury and reduce myocardial infarct size. We aimed to test whether cyclosporine would improve clinical outcomes and prevent adverse left ventricular remodeling. METHODS In a multicenter, double-blind, randomized trial, we assigned 970 patients with an acute anterior ST-segment elevation myocardial infarction (STEMI) who were undergoing percutaneous coronary intervention (PCI) within 12 hours after symptom onset and who had complete occlusion of the culprit coronary artery to receive a bolus injection of cyclosporine (administered intravenously at a dose of 2.5 mg per kilogram of body weight) or matching placebo before coronary recanalization. The primary outcome was a composite of death from any cause, worsening of heart failure during the initial hospitalization, rehospitalization for heart failure, or adverse left ventricular remodeling at 1 year. Adverse left ventricular remodeling was defined as an increase of 15% or more in the left ventricular end-diastolic volume. RESULTS A total of 395 patients in the cyclosporine group and 396 in the placebo group received the assigned study drug and had data that could be evaluated for the primary outcome at 1 year. The rate of the primary outcome was 59.0% in the cyclosporine group and 58.1% in the control group (odds ratio, 1.04; 95% confidence interval [CI], 0.78 to 1.39; P=0.77). Cyclosporine did not reduce the incidence of the separate clinical components of the primary outcome or other events, including recurrent infarction, unstable angina, and stroke. No significant difference in the safety profile was observed between the two treatment groups. CONCLUSIONS In patients with anterior STEMI who had been referred for primary PCI, intravenous cyclosporine did not result in better clinical outcomes than those with placebo and did not prevent adverse left ventricular remodeling at 1 year. (Funded by the French Ministry of Health and NeuroVive Pharmaceutical; CIRCUS ClinicalTrials.gov number, NCT01502774; EudraCT number, 2009-013713-99.).

Effect of Cyclosporine on Left Ventricular Remodeling After Reperfused Myocardial Infarction

OBJECTIVES This study examined the effect of a single dose of cyclosporine administered at the time of reperfusion on left ventricular (LV) remodeling and function by cardiac magnetic resonance 5 days and 6 months after myocardial infarction. BACKGROUND In a human study, administration of cyclosporine at the time of acute reperfusion was associated with a smaller infarct size. METHODS Twenty-eight patients of the original cyclosporine study had an acute (at 5 days) and a follow-up (at 6 months) cardiac magnetic resonance study to determine LV volumes, mass, ejection fraction, myocardial wall thickness in infarcted and remote noninfarcted myocardium, and infarct size. RESULTS There was a persistent reduction in infarct size at 6 months in the cyclosporine group compared with the control group of patients (29 +/- 15 g vs. 38 +/- 14 g; p = 0.04). There was a significant reduction of LV end-systolic volume (and a trend for LV end-diastolic volume; p = 0.07) in the cyclosporine group compared with the control group, both at 5 days and 6 months after infarction. There was no significant difference between the 2 groups in either global LV mass or regional wall thickness of the remote noninfarcted myocardium at 5 days or 6 months. Attenuation of LV dilation and improvement of LV ejection fraction by cyclosporine at 6 months were correlated with infarct size reduction. CONCLUSIONS Cyclosporine used at the moment of acute myocardial infarction reperfusion persistently reduces infarct size and does not have a detrimental effect on LV remodeling. These results are preliminary and must be supported by further studies. (Ciclosporin A and Acute Myocardial Infarction; NCT00403728).

Cell Transplantation Improves Ventricular Function After a Myocardial Infarction A Preclinical Study of Human Unrestricted Somatic Stem Cells in a Porcine Model

Background—Cell transplantation offers the promise in the restoration of ventricular function after an extensive myocardial infarction, but the optimal cell type remains controversial. Human unrestricted somatic stem cells (USSCs) isolated from umbilical cord blood have great potential to differentiate into myogenic cells and induce angiogenesis. The present study evaluated the effect of USSCs on myocardial regeneration and improvement of heart function after myocardial infarction in a porcine model. Method and Results—The distal left anterior descending artery of Yorkshire pigs (30 to 35 kg) was occluded by endovascular implantation of a coil. Four weeks after infarction, single-photon emission computed tomography technetium 99m sestamibi scans (MIBI) and echocardiography were performed. USSCs (100×106) or culture media were then directly injected into the infarcted region (n=8 per group). Pigs were immunosuppressed by daily administration of cyclosporin A. At 4 weeks after transplantation, MIBI and echocardiography were repeated and heart function was also assessed with a pressure-volume catheter. The infarcted myocardium and implanted cells were studied histologically. MIBI showed improved regional perfusion (P<0.05) and wall motion (P<0.05) of the infarct region in the transplant group compared with the control. Ejection fraction evaluated by both MIBI and echocardiography decreased in the control group but increased in the transplant group (P<0.01). Scar thickness of the transplant group was higher than the control. The grafted cells were detected 4 weeks after transplantation by both immunohistochemistry and in situ hybridization. Conclusion—Engrafted USSCs were detected in the infarct region 4 weeks after cell transplantation, and the implanted cells improved regional and global function of the porcine heart after a myocardial infarction. This study suggests that the USSC implantation will be efficacious for cellular cardiomyoplasty.

Mesenchymal stem cell conditioned media attenuates in vitro and ex vivo myocardial reperfusion injury

BACKGROUND Previous studies have suggested that implantation of mesenchymal stem cells (MSC) or their conditioned media (MSC CM) improves heart function after myocardial infarction. We sought to determine whether MSC and MSC CM added at the onset of reperfusion attenuates myocardial reperfusion injury. METHODS Rat MSC and neonatal rat cardiomyocytes (NRC) were isolated and cultured separately. NRC were subjected to simulated in vitro ischemia/reperfusion (I/R). At the onset of reperfusion, NRC received either fresh medium (control group) or one of the following treatments: MSC in fresh medium; MSC CM alone (without MSC); MSC CM + inhibitors of PI3K (LY294002 or Wortmannin); MSC CM + antibodies neutralizing IGF-1 or VEGF; MSC + inhibitors of PI3K; or cyclosporine. Cell injury was assessed by LDH activity and MTT staining at the end of reperfusion. VEGF, IGF-1 and HGF were measured in each experimental treatment preparation. Ex vivo experimentation on isolated rat hearts subjected to I/R were performed to evaluate the protective effects of MSC CM on myocardial reperfusion injuries measured through CK release and infarct size after TTC staining. RESULTS In vitro cell injury was significantly reduced by MSC, MSC CM and CsA. PI3K inhibitors significantly attenuated the protection afforded by MSC CM but not growth factor inhibitors. Ex vivo experimentation showed that MSC CM significantly reduced myocardial I/R injury. CONCLUSION Our data suggest that MSC CM added at the onset of reperfusion can protect myocardium from I/R injury. In vitro data suggest a protection mediated by paracrine activation of the PI3K pathway.

Cardiovascular events and bleeding risk associated with intravitreal antivascular endothelial growth factor monoclonal antibodies: systematic review and meta-analysis.

IMPORTANCE Few data exist regarding the systemic safety of intravitreal antivascular endothelial growth factor (anti-VEGF) monoclonal antibody (mAb). OBJECTIVE To conduct a systematic review and meta-analysis to evaluate the risk of major cardiovascular and nonocular hemorrhagic events in patients with neovascular age-related macular degeneration (AMD), diabetes mellitus-associated macular edema (DME), or retinal vein occlusions (RVOs) who receive intravitreal anti-VEGF mAbs. DATA SOURCES The MEDLINE and Cochrane Central databases were searched for potentially eligible studies. STUDY SELECTION Randomized clinical trials comparing ranibizumab or bevacizumab with no anti-VEGF treatment, as well as those comparing ranibizumab with bevacizumab in patients with AMD, DME, or RVOs. DATA EXTRACTION AND SYNTHESIS We used a fixed-effects model and report the results as odds ratios (ORs) and 95% CIs. MAIN OUTCOMES AND MEASURES Primary end points were major cardiovascular and nonocular hemorrhagic events. Secondary end points were all-cause mortality, cardiovascular mortality, stroke, myocardial infarction, venous thromboembolic events (VTEs), and hypertension. RESULTS Twenty-one trials that evaluated 9557 patients were retrieved. Anti-VEGF mAbs did not significantly increase the risk of major cardiovascular events (OR, 1.18; 95% CI, 0.81-1.71) or nonocular hemorrhagic events (OR, 1.42; 95% CI, 0.95-2.13) in treatment groups compared with control populations. Bevacizumab did not increase the risk of major cardiovascular events (OR, 0.94; 95% CI, 0.59-1.52) or nonocular hemorrhagic events (OR, 2.56; 95% CI, 0.78-8.38) compared with ranibizumab, but significantly increased VTEs (OR, 3.45; 95% CI, 1.25-9.54). Subgroup analysis showed a significant increase of nonocular hemorrhagic events in patients with AMD in ranibizumab vs control trials (OR, 1.57; 95% CI, 1.01-2.44). Anti-VEGF mAbs did not significantly increase overall mortality, cardiovascular mortality, stroke, myocardial infarction, VTEs, or hypertension. CONCLUSIONS AND RELEVANCE We showed that intravitreal anti-VEGF-mAbs were not associated with significant increases in major cardiovascular or nonocular hemorrhagic events, but studies and meta-analyses were not powered enough to correctly assess these risks. Increased risks of VTEs with bevacizumab and nonocular hemorrhagic events in older patients with AMD with ranibizumab should be cautiously interpreted because more safety data are needed.

Anticoagulation in patients with atrial fibrillation undergoing coronary stent implantation

In patients with atrial fibrillation (AF) undergoing coronary stent implantation, the optimal antithrombotic strategy is unclear. We evaluated whether use of oral anticoagulation (OAC) was associated with any benefit in morbidity or mortality in patients with AF, high risk of thromboembolism (TE) (CHA2DS2-VASC score ≥ 2) and coronary stent implantation. Among 8,962 unselected patients with AF seen between 2000 and 2010, a total of 2,709 (30%) had coronary artery disease and 417/2,709 (15%) underwent stent implantation while having CHA2DS2-VASC score ≥ 2. During follow-up (median=650 days), all TE, bleeding episodes, and major adverse cardiac events (i.e. death, acute myocardial infarction, target lesion revascularisation) were recorded. At discharge, 97/417 patients (23%) received OAC, which was more likely to be prescribed in patients with permanent AF and in those treated for elective stent implantation. The incidence of outcome event rates was not significantly different in patients treated and those not treated with OAC. However, in multivariate analysis, the lack of OAC at discharge was independently associated with increased risk of death/stroke/systemic TE (relative risk [RR] =2.18, 95% confidence interval [CI] 1.02-4.67, p=0.04), with older age (RR =1.12, 1.04-1.20, p=0.003), heart failure (RR =3.26, 1.18-9.01, p=0.02), and history of stroke (RR =18.87, 3.11-111.11, p=0.001). In conclusion, in patients with AF and high thromboembolic risk after stent implantation, use of OAC was independently associated with decreased risk of subsequent death/stroke/systemic TE, suggesting that OAC should be systematically used in this patient population.

Cardiac fibroblasts protect cardiomyocytes against lethal ischemia–reperfusion injury

Roles of cardiac fibroblasts (CFs) in the regulation of myocardial structure and function have been emphasized in the last decade. Their implications in pathophysiological aspects of chronic heart diseases such as myocardial remodeling and fibrosis are now well established; however their contribution to the acute phase of ischemia-reperfusion injury still remains elusive. We hypothesized that CF may contribute to cardiomyocyte (CM) protection against ischemia-reperfusion injuries. Experiments performed on isolated neonatal rat CF and CM demonstrated that the presence of CF in co-cultures increases CM viability (58 ± 2% versus 30 ± 2% in control) against hypoxia-reoxygenation injury, in a paracrine manner. It was confirmed by a similar effect of hypoxic CF secretome alone on CM viability (51 ± 9% versus 31 ± 4% in untreated cells). These findings were corroborated by in vivo experiments in a mice model of myocardial infarction in which a 25% infarct size reduction was observed in CF secretome treated mice compared to control. Tissue inhibitor of metalloproteinases-1 (TIMPs-1) alone, abundantly detected in CF secretome, was able to decrease CM cell death (35%) and experiments with pharmacological inhibitors of PI3K/Akt and ERK1/2 pathways provided more evidence that this paracrine protection is partly mediated by these signaling pathways. In vivo experiments strengthened that TIMP-1 alone was able to decrease infarct size (37%) and were validated by depletion experiments demonstrating that CF secretome cardioprotection was abolished by TIMP-1 depletion. Our data demonstrated for the first time that CFs participate in cardioprotection during the acute phase of ischemia-reperfusion via a paracrine pathway involving TIMP-1.