Association of Circulating PCSK9 With Ischemia-Reperfusion Injury in Acute ST-Elevation Myocardial Infarction.

BACKGROUND: Beyond therapeutic implications, PCSK9 (proprotein convertase subtilisin/kexin 9) has emerged as a promising cardiovascular biomarker. The exact role of PCSK9 in the setting of acute ST-elevation myocardial infarction (STEMI) is incompletely understood. We aimed to investigate the association of PCSK9 with ischemia-reperfusion injury, visualized by cardiac magnetic resonance imaging, in patients with STEMI revascularized by primary percutaneous coronary intervention (PCI). METHODS: In this prespecified substudy from the prospective MARINA-STEMI (NCT04113356) registry, we included 205 patients with STEMI. PCSK9 concentrations were measured from venous blood samples by an immunoassay 24 and 48 hours after PCI. The primary end point was defined as presence of intramyocardial hemorrhage according to cardiac magnetic resonance T2* mapping. Secondary imaging end points were the presence of microvascular obstruction (MVO) and infarct size. The clinical end point was the occurrence of major adverse cardiac events. RESULTS: We observed a significant increase in PCSK9 levels from 24 to 48 hours (268-304 ng/mL; P<0.001) after PCI. PCSK9 24 hours after PCI did not show any relation to intramyocardial hemorrhage, MVO, and infarct size (all P>0.05). PCSK9 concentrations 48 hours post-STEMI were higher in patients with intramyocardial hemorrhage (333 versus 287 ng/mL; P=0.004), MVO (320 versus 292 ng/mL; P=0.020), and large infarct size (323 versus 296 ng/mL; P=0.013). Furthermore, patients with increased PCSK9 levels >361 ng/mL at 48 hours were more likely to experience major adverse cardiac events (15% versus 8%; P=0.002) during a median follow-up of 12 months. CONCLUSIONS: In patients with STEMI, a significant increase in PCSK9 was observed from 24 to 48 hours after PCI. While PCSK9 levels after 24 hours were not related to myocardial or microvascular injury, PCSK9 after 48 hours was significantly associated with intramyocardial hemorrhage, MVO, and infarct size as well as worse subsequent clinical outcomes. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier; NCT04113356.

Relation of plasma neuropeptide-Y with myocardial function and infarct severity in acute ST-elevation myocardial infarction.

BACKGROUND: Acute myocardial infarction is associated with the release of the co-transmitter neuropeptide-Y (NPY). NPY acts as a potent vasoconstrictor and is associated with microvascular dysfunction after ST-elevation myocardial infarction (STEMI). This study comprehensively evaluated the association of plasma NPY with myocardial function and infarct severity, visualized by cardiac magnetic resonance (CMR) imaging, in STEMI patients revascularized by primary percutaneous coronary intervention (PCI). METHODS: In this observational study, we included 260 STEMI patients enrolled in the prospective MARINA-STEMI (NCT04113356) study. Plasma NPY concentrations were measured by an immunoassay 24h after PCI from peripheral venous blood samples. Left ventricular ejection fraction (LVEF), global longitudinal strain (GLS), infarct size (IS) and microvascular obstruction (MVO) were determined using CMR imaging. RESULTS: Median plasma concentrations of NPY were 70 [interquartile range (IQR):35-115] pg/ml. NPY levels above median were significantly associated with lower LVEF (48%vs.52%, p=0.004), decreased GLS (-8.8%vs.-12.6%, p<0.001) and larger IS (17%vs.13%, p=0.041) in the acute phase after infarction as well as after 4 months (LVEF:50%vs.52%, p=0.030, GLS:-10.5vs.-12.9,p<0.001,IS:13%vs.10%,p=0.011). In addition, NPY levels were significantly related to presence of MVO (58%vs.52%, p=0.041). Moreover, in multivariable linear regression analysis, NPY remained significantly associated with all investigated CMR parameters (LVEF:p<0.001,GLS:p<0.001,IS:p=0.003,MVO:p=0.042) independent of other established clinical variables including high-sensitivity cardiac troponin T, pre-interventional TIMI flow 0 and left anterior descending artery as culprit lesion location. CONCLUSION: High plasma levels of NPY, measured 24h after STEMI, were independently associated with lower LVEF, decreased GLS, larger IS as well as presence of MVO, indicating plasma NPY as a novel clinical risk marker post STEMI.

Association of dysglycaemia with persistent infarct core iron in patients with acute ST-segment elevation myocardial infarction.

BACKGROUND: Dysglycaemia increases the risk of myocardial infarction and subsequent recurrent cardiovascular events. However, the role of dysglycaemia in ischemia/reperfusion injury with development of irreversible myocardial tissue alterations remains poorly understood. In this study we aimed to investigate the association of ongoing dysglycaemia with persistence of infarct core iron and their longitudinal changes over time in patients undergoing primary percutaneous coronary intervention (PCI) for acute ST-segment elevation myocardial infarction (STEMI). METHODS: We analyzed 348 STEMI patients treated with primary PCI between 2016 and 2021 that were included in the prospective MARINA-STEMI study (NCT04113356). Peripheral venous blood samples for glucose and glycated hemoglobin (HbA1c) measurements were drawn on admission and 4 months after STEMI. Cardiac magnetic resonance (CMR) imaging including T2 * mapping for infarct core iron assessment was performed at both time points. Associations of dysglycaemia with persistent infarct core iron and iron resolution at 4 months were calculated using multivariable regression analysis. RESULTS: Intramyocardial hemorrhage was observed in 147 (42%) patients at baseline. Of these, 89 (61%) had persistent infarct core iron 4 months after infarction with increasing rates across HbA1c levels (<5.7%: 33%, ≥5.7: 79%). Persistent infarct core iron was independently associated with ongoing dysglycaemia defined by HbA1c at 4 months (OR: 7.87 [95% CI: 2.60-23.78]; p < 0.001), after adjustment for patient characteristics and CMR parameters. The independent association was present even after exclusion of patients with diabetes (pre- and newly diagnosed, n = 16). CONCLUSIONS: In STEMI patients treated with primary PCI, ongoing dysglycaemia defined by HbA1c is independently associated with persistent infarct core iron and a lower likelihood of iron resolution. These findings suggest a potential association between ongoing dysglycaemia and persistent infarct core iron, which warrants further investigation for therapeutic implications.

Aspergillus fumigatus Spores Are Not Able to Penetrate Silicone Breast Implant Shells.

INTRODUCTION: Bacterial contamination is hypothesized to be one reason for the development of capsular contracture after alloplastic breast reconstruction using silicone breast implants. The role of fungal colonization or infection in this context as well as the question if microorganisms can penetrate the shell of silicone breast implants remains an unresolved question to date. Therefore, the aim of this study was to assess whether fungal spores are able to penetrate the shell of silicone implants. MATERIALS AND METHODS: In an experimental in vitro setup with different arrangements of growth compartments, silicone chambers were placed in culture dishes filled with Aspergillus minimal medium or liquid culture medium. Inoculation was performed with conidia of Aspergillus fumigatus and incubated for seven days. On a daily basis, plates were inspected for conidial germination and hyphal growth. RESULTS: In none of the different experimental settings nutrients or hyphae of Aspergillus fumigatus were able to penetrate the silicone material. CONCLUSIONS: Fungal spores and hyphae do not permeate through an intact silicone shell used in breast implants; thus, the silicone material serves as an impenetrable barrier.