Lukas Altwegg

Inflammatory Markers at the Site of Ruptured Plaque in Acute Myocardial Infarction Locally Increased Interleukin-6 and Serum Amyloid A but Decreased C-Reactive Protein

Background—Acute myocardial infarction (AMI) is associated with inflammation. However, it remains unclear whether it originates from the ruptured plaque or represents a systemic process. Methods and Results—In 42 patients with AMI, a balloon-based embolization protection device and aspiration catheter (PercuSurge) were used during acute coronary interventions. Samples from the site of the ruptured plaque were taken under distal balloon occlusion. Systemic samples were taken from the aorta. Sera, plaques, and thrombi were analyzed for inflammatory markers and lipoproteins. Systemic levels of C-reactive protein (CRP), interleukin-6 (IL-6), and serum amyloid A (SAA) in the aorta amounted to 3.0 mg/L, 5.0 ng/L, and 22.1 mg/L, respectively (interquartile ranges [IQRs], 1.1 to 7.4 mg/L, 5.0 to 6.5 ng/L, and 13.9 to 27.0 mg/L, respectively). In blood surrounding ruptured plaques, local levels of IL-6 (8.9 ng/L; IQR, 5.0 to 16.9 ng/L) and SAA (24.3 mg/L; IQR, 16.3 to 44.0 mg/L) were significantly higher, whereas CRP levels (2.5 mg/L; IQR, 0.9 to 7.7 mg/L) were decreased compared with the aorta (all P<0.0001). The coronary levels of IL-6 determined in vivo showed biological activity in vitro. Harvested thrombus contained CD68-positive monocytes expressing IL-6 and showed extracellularly and intracellularly positive staining for SAA, whereas CRP was found exclusively in the cytoplasm of phagocyting white blood cells. Conclusions—Coronary levels of IL-6 and SAA at the site of plaque rupture were increased relative to the systemic circulation, indicating local production of biologically active inflammatory mediators. In contrast, CRP was locally decreased, at least in part by uptake by the phagocyting cells, suggesting a systemic origin of the protein.

Altered Activation of Endothelial Anti- and Proapoptotic Pathways by High-Density Lipoprotein from Patients with Coronary Artery Disease Role of High-Density Lipoprotein–Proteome Remodeling

Background— Endothelial dysfunction and injury are thought to play an important role in the progression of coronary artery disease (CAD). High-density lipoprotein from healthy subjects (HDLHealthy) has been proposed to exert endothelial antiapoptotic effects that may represent an important antiatherogenic property of the lipoprotein. The present study therefore aimed to compare effects of HDLCAD and HDLHealthy on the activation of endothelial anti- and proapoptotic pathways and to determine which changes of the lipoprotein are relevant for these processes. Methods and Results— HDL was isolated from patients with stable CAD (HDLsCAD), an acute coronary syndrome (HDLACS), and healthy subjects. HDLHealthy induced expression of the endothelial antiapoptotic Bcl-2 protein Bcl-xL and reduced endothelial cell apoptosis in vitro and in apolipoprotein E–deficient mice in vivo. In contrast, HDLsCAD and HDLACS did not inhibit endothelial apoptosis, failed to activate endothelial Bcl-xL, and stimulated endothelial proapoptotic pathways, in particular, p38-mitogen-activated protein kinase–mediated activation of the proapoptotic Bcl-2 protein tBid. Endothelial antiapoptotic effects of HDLHealthy were observed after inhibition of endothelial nitric oxide synthase and after delipidation, but not completely mimicked by apolipoprotein A-I or reconstituted HDL, suggesting an important role of the HDL proteome. HDL proteomics analyses and subsequent validations and functional characterizations suggested a reduced clusterin and increased apolipoprotein C-III content of HDLsCAD and HDLACS as mechanisms leading to altered effects on endothelial apoptosis. Conclusions— The present study demonstrates for the first time that HDLCAD does not activate endothelial antiapoptotic pathways, but rather stimulates potential endothelial proapoptotic pathways. HDL-proteome remodeling plays an important role for these altered functional properties of HDL. These findings provide novel insights into mechanisms leading to altered vascular effects of HDL in coronary disease.

Cellular actors, Toll-like receptors, and local cytokine profile in acute coronary syndromes

AIMSnInflammation plays a key role in acute coronary syndromes (ACS). Toll-like receptors (TLR) on leucocytes mediate inflammation and immune responses. We characterized leucocytes and TLR expression within coronary thrombi and compared cytokine levels from the site of coronary occlusion with aortic blood (AB) in ACS patients.nnnMETHODS AND RESULTSnIn 18 ACS patients, thrombi were collected by aspiration during primary percutaneous coronary intervention. Thrombi and AB from these patients as well as AB from 10 age-matched controls without coronary artery disease were assessed by FACS analysis for cellular distribution and TLR expression. For further discrimination of ACS specificity, seven non-coronary intravascular thrombi and eight thrombi generated in vitro were analysed. In 17 additional patients, cytokine levels were determined in blood samples from the site of coronary occlusion under distal occlusion and compared with AB. In coronary thrombi from ACS, the percentage of monocytes related to the total leucocyte count was greater than in AB (47 vs. 20%, P = 0.0002). In thrombi, TLR-4 and TLR-2 were overexpressed on CD14-labelled monocytes, and TLR-2 was increased on CD66b-labelled granulocytes, in comparison with leucocytes in AB. In contrast, in vitro and non-coronary thrombi exhibited no overexpression of TLR-4. Local blood samples taken under distal occlusion revealed elevated concentrations of chemokines (IL-8, MCP-1, eotaxin, MIP-1alpha, and IP-10) and cytokines (IL-1ra, IL-6, IL-7, IL-12, IL-17, IFN-alpha, and granulocyte-macrophage colony-stimulating factor) regulating both innate and adaptive immunity (all P < 0.05).nnnCONCLUSIONnIn ACS patients, monocytes accumulate within thrombi and specifically overexpress TLR-4. Together with the local expression patterns of chemokines and cytokines, the increase of TLR-4 reflects a concerted activation of this inflammatory pathway at the site of coronary occlusion in ACS.

Cardiovascular Aging Is Associated With Vitamin E Increase

Background—Aging is an independent risk factor for the development of cardiovascular disease. Therefore, therapies to delay vascular aging may have enormous medical consequences. In this context, vitamin E is of particular interest, mainly because of its antioxidative properties. Methods and Results—In 3-year-old rats, which are not susceptible to atherosclerosis, vitamin E levels, as measured by reversed-phase high-performance liquid chromatography, were markedly increased both in plasma and in major organs (P <0.01 to P <0.0001). The highest increase (at least 70-fold) was found in the aortic wall. Conclusions—This unexpected accumulation of vitamin E appears to be a compensatory mechanism that attempts to counterbalance age-associated oxidative stress and that may represent a self-regulatory protective adaptation.

Myeloid related proteins activate Toll-like receptor 4 in human acute coronary syndromes

INTRODUCTIONnWe previously reported increased expression of TLR4 on monocytes in thrombi from patients with acute coronary syndromes (ACS). In mice, myeloid related protein (MRP) 8 and MRP14, cytoplasmic proteins of neutrophils and monocytes, activate Toll-like receptor (TLR) 4 during sepsis. In human ACS, we investigated now whether the pro-inflammatory action of MRPs occurs through TLR4 in monocytes derived from thrombi.nnnMETHODSnCoronary thrombi and peripheral blood of 27 ACS patients were analyzed. CD14(+) monocytes were isolated and incubated with TLR2 ligand PM3SKA, TLR4 ligand lipopolysaccharide (LPS), MRP8, MRP14, or MRP8/14 heterocomplex. Anti-TLR4 antibodies (HTA125) were used to block TLR4 and polymyxin B (PMB) was employed to inhibit endotoxins. Before and after stimulation, the release of TNFα was measured by ELISA and the expression of TLR4 on CD14(+) monocytes was determined by flow cytometry. Further, selected pathways of downstream signaling were analyzed.nnnRESULTSnMRP8 and MRP8/14 increased release of TNFα in cultures of CD14(+) monocytes, more in cells derived from thrombi compared with matched peripheral blood cells (p<0.001). LPS, MRP8, and MRP8/14, but much less PM3SKA and MRP14 alone, stimulated TNFα release, which can be inhibited by HTA125. MRP8/14 enhanced TLR4 expression on monocytes from thrombi (p<0.001), but not on monocytes from peripheral blood of the same patients.nnnCONCLUSIONnIn ACS, MRP8 and MRP8/14 complex are specific ligands of TLR4, which induce the release of TNFα and probably other pro-inflammatory agents from monocytes. This specific MRP8/14-dependent pathway with striking similarities to sepsis increasing expression of TLR4 in thrombi appears to be involved in the pathogenesis of coronary occlusion and may represent a novel therapeutic target in ACS.

Nebivolol induces NO-mediated relaxations of rat small mesenteric but not of large elastic arteries

Nebivolol is a newer beta1-selective adrenergic receptor antagonist, which unlike classic beta-blockers, lowers systemic vascular resistance by direct vasodilator effects possibly involving NO. This study was designed to determine the effects of nebivolol on small arteries, which contribute to the most part of systemic vascular resistance. Mesenteric arteries, isolated from 9-week-old Wistar-Kyoto (WKY) rats, were studied under perfused and pressurized conditions using a video dimension analyzer. Aortic rings from the same animals were suspended in organ chambers, and isometric tension was measured. Experiments were performed during contraction to prostaglandin F2alpha. In small arteries, nebivolol (10(-9) to 3 x 10(-5) M) induced concentration-dependent relaxations (maximum, 55 +/- 8%). The relaxations were less pronounced as compared with those to acetylcholine (maximum, 99 +/- 2%; p < 0.05), but were significantly greater than those to atenolol (maximum, 2 +/- 0%; p < 0.05). Nebivolol-induced responses were markedly reduced by the NO-synthase inhibitor N(omega)-nitro-L-arginine methylester (L-NAME; 10(-4) M; maximum, 11 +/- 2%; p < 0.05). This inhibition could be entirely reversed by pretreatment with L-arginine (10(-3) M; maximum, 46 +/- 7%), a precursor of NO. In contrast to mesenteric arteries, nebivolol did not affect vascular tension of precontracted aortas. These findings indicate that nebivolol induces NO-mediated relaxations in small arteries but not large elastic vessels and therefore, independent of its antihypertensive action, might be effective in protecting the microcirculation in various cardiovascular disease states.

Age-related changes of vitamin A status.

Ageing is an independent risk factor for the development of cardiovascular disease. The ageing process is known to be associated with increased oxidative stress and an increased risk for cardiovascular and other diseases, such as cancer. To delay this process, therapeutic strategies involving the use of naturally occurring antioxidants, such as vitamin A, have gained considerable interest. Therefore, we wanted to investigate in a model of mammalian ageing whether changes in tissue and plasma levels of vitamin A occur with increasing age. This would constitute a prime rationale for its dietary supplementation. Experiments were performed in three different age groups (4–6 months old, 19 months old, 32–35 months old) of F1 (F344 × BN) healthy male rats that were fed a normal diet without any additional supplementation. Vitamin A and carotenoids in plasma and major organs were measured by reverse-phase high-performance liquid chromatography. In 3-year-old rats, vitamin A levels were found to be decreased in plasma (P < 0.0001) as compared with young and middle-aged animals. However, they were markedly increased in the main storage organ (ie, the liver) (P < 0.01–0.0001), and also in the aortic vessel wall. They were undetectable in the heart, irrespective of age. Increased tissue levels of vitamin A, especially in the vasculature, may be part of an age-associated self-regulatory process of adaptation, possibly as a counter-regulation against oxidative tissue damage. Based upon the assumption that in elderly humans, as in our animal model, a similar demand-regulated mechanism may work independently of additional dietary vitamin A supplementation, one may question the strategy of large clinical interventional trials using vitamin A or its derivatives beyond normal dietary intake.

Fractional flow reserve evaluation in patients considered for transfemoral transcatheter aortic valve implantation: a case series.

Objectives: Transcatheter aortic valve implantation (TAVI) has become an established therapy for severe aortic stenosis (AS) in high-risk elderly individuals. Concomitant coronary artery disease (CAD) is frequently encountered in this patient population and may have an impact on outcomes. Hence, in patients with both severe AS and CAD, a bespoke therapy of both AS and/or CAD appears mandatory. Methods: We report a series of 5 patients with severe AS and concomitant CAD considered for TAVI who underwent fractional flow reserve (FFR) for hemodynamic assessment of coronary lesions. Results: In 3 patients, a 2-staged procedure was undertaken with FFR measurements at the time of invasive assessment and TAVI thereafter. In the remaining 2 patients, FFR measurements were performed immediately prior to the TAVI procedure with deferral of percutaneous coronary intervention (PCI) in one and ad hoc PCI in the other patient. All 5 patients had uneventful FFR measurements and procedural TAVI outcomes. One patient with a staged approach noted a significant improvement in symptoms already after PCI. Conclusions: FFR provides an effective and safe strategy to assess hemodynamic significance of coronary lesions in patients with severe AS and concomitant CAD considered for TAVI.

Altered Activation of Endothelial Anti- and Pro-Apoptotic Pathways by High-Density Lipoprotein from Patients with Coronary Artery Disease: Role of HDL-Proteome Remodeling

Background— Endothelial dysfunction and injury are thought to play an important role in the progression of coronary artery disease (CAD). High-density lipoprotein from healthy subjects (HDLHealthy) has been proposed to exert endothelial antiapoptotic effects that may represent an important antiatherogenic property of the lipoprotein. The present study therefore aimed to compare effects of HDLCAD and HDLHealthy on the activation of endothelial anti- and proapoptotic pathways and to determine which changes of the lipoprotein are relevant for these processes. Methods and Results— HDL was isolated from patients with stable CAD (HDLsCAD), an acute coronary syndrome (HDLACS), and healthy subjects. HDLHealthy induced expression of the endothelial antiapoptotic Bcl-2 protein Bcl-xL and reduced endothelial cell apoptosis in vitro and in apolipoprotein E–deficient mice in vivo. In contrast, HDLsCAD and HDLACS did not inhibit endothelial apoptosis, failed to activate endothelial Bcl-xL, and stimulated endothelial proapoptotic pathways, in particular, p38-mitogen-activated protein kinase–mediated activation of the proapoptotic Bcl-2 protein tBid. Endothelial antiapoptotic effects of HDLHealthy were observed after inhibition of endothelial nitric oxide synthase and after delipidation, but not completely mimicked by apolipoprotein A-I or reconstituted HDL, suggesting an important role of the HDL proteome. HDL proteomics analyses and subsequent validations and functional characterizations suggested a reduced clusterin and increased apolipoprotein C-III content of HDLsCAD and HDLACS as mechanisms leading to altered effects on endothelial apoptosis. Conclusions— The present study demonstrates for the first time that HDLCAD does not activate endothelial antiapoptotic pathways, but rather stimulates potential endothelial proapoptotic pathways. HDL-proteome remodeling plays an important role for these altered functional properties of HDL. These findings provide novel insights into mechanisms leading to altered vascular effects of HDL in coronary disease.

Percutaneous double valve intervention

An 81-year-old woman was referred for NSTEMI complicated by cardiogenic shock. Urgent invasive assessment revealed a subtotal left anterior descending artery (LAD) stenosis, severe aortic stenosis (mean gradient 60 mmHg, aortic valve area 0.5 cm2), decreased left ventricular (LV) function [left ventricular ejection fraction (LVEF) 49%], grade 3+ mitral regurgitation (MR), and severe pulmonary hypertension. In view of her critical situation, acute LAD–percutaneous coronary intervention and aortic valvuloplasty were performed with …