Five-Year Outcomes After Coronary Computed Tomography Angiography (From 110,599 Patients in a Danish Nationwide Register-Based Follow-Up Study).

The long-term cardiovascular risk for patients examined with coronary computed tomography angiography (CCTA) to rule out coronary heart disease compared with population controls remains unexplored. A nationwide register-based study including first-time CCTA-examined patients between 2007 and 2017 in Denmark alive 180 days post-CCTA was conducted. We evaluated 5-year outcomes of myocardial infarction (MI) or revascularization and all-cause mortality in 3 distinct CCTA-groups: (1) no post-CCTA preventive pharmacotherapy use (cholesterol-lowering drugs, antiplatelets, or anticoagulants); (2) post-CCTA preventive pharmacotherapy use; and (3) revascularization or MI within 180 days post-CCTA. For each patient group, population controls were matched on age, gender, and calendar year. Absolute risks standardized to the age, gender, selected co-morbidity, and anti-anginal pharmacotherapy distributions of the specific CCTA-examined patients and respective controls were obtained from multivariable Cox regression. Of 110,599 CCTA-examined patients, (1) 48,231 patients were not prescribed preventive pharmacotherapy 180 days post-CCTA; (2) 42,798 patients were prescribed preventive pharmacotherapy within 180 days post-CCTA; and (3) 19,570 patients were diagnosed with MI or revascularized within 180 days post-CCTA. For patient groups 1 to 3 versus respective controls, 5-year MI or revascularization risks were <0.1% versus 2.0%, <0.1% versus 3.8%, and 19.0% versus 2.5%, all p<0.001. Five-year all-cause mortality were 2.8% versus 4.2%, 5.5% versus 8.8%, and 6.7% versus 8.5%, all p <0.001. In conclusion, the 5-year MI or revascularization risk can be considered very low for CCTA-examined patients without ischemic events within 180 days post-CCTA. Conversely, CCTA-examined patients with MI or revascularization events within 180 days post-CCTA have significantly elevated 5-year MI or revascularization risk.

New strict left bundle branch block criteria reflect left ventricular activation differences.

AIMS: Pacing lead electrical delays and strict left bundle branch block (LBBB) criteria were assessed against cardiac resynchronization therapy (CRT) outcome. METHODS: Forty-nine patients with LBBB and QRS duration >130 milliseconds underwent CRT-implantation. Sensed right ventricular to left ventricular electrical delay (RV-LV-IED) was measured. Response to CRT was defined as ≥15% decrease in left ventricular end-systolic volume. RESULTS: Eighteen of 20 (90%) patients with non-ischemic dilated cardiomyopathy (DCM) and 18 of 29 (62%) with ischemic heart disease (IHD) responded to CRT, p<0.01. When applying new strict ECG criteria subsequent rates of response in DCM were 18/19 (95%) and in IHD of 18/23 (78%) respectively, p<0.05 between IHD groups. Correspondingly, RV-LV-IED was longer in DCM compared to IHD patients and in responders compared to non-responders, p=0.017 and p<0.001, respectively. CONCLUSION: Interventricular electrical delay predicts left ventricular remodeling after CRT and new, strict ECG criteria of LBBB are superior in predicting remodeling.

Comparison of human adipose-derived stem cells and bone marrow-derived stem cells in a myocardial infarction model.

Treatment of myocardial infarction (MI) with bone marrow-derived mesenchymal stem cells and recently also adipose-derived stem cells has shown promising results. In contrast to clinical trials and their use of autologous bone marrow-derived cells from the ischemic patient, the animal MI models are often using young donors and young, often immune-compromised, recipient animals. Our objective was to compare bone marrow-derived mesenchymal stem cells with adipose-derived stem cells from an elderly ischemic patient in the treatment of MI using a fully grown non-immune-compromised rat model. Mesenchymal stem cells were isolated from adipose tissue and bone marrow and compared with respect to surface markers and proliferative capability. To compare the regenerative potential of the two stem cell populations, male Sprague-Dawley rats were randomized to receive intramyocardial injections of adipose-derived stem cells, bone marrow-derived mesenchymal stem cells, or phosphate-buffered saline 1 week following induction of MI. After 4 weeks, left ventricular ejection fraction (LVEF) was improved in the adipose-derived stem cell group, and scar wall thickness was greater compared with the saline group. Adipose-derived as well as bone marrow-derived mesenchymal stem cells prevented left ventricular end diastolic dilation. Neither of the cell groups displayed increased angiogenesis in the myocardium compared with the saline group. Adipose-derived stem cells from a human ischemic patient preserved cardiac function following MI, whereas this could not be demonstrated for bone marrow-derived mesenchymal stem cells, with only adipose-derived stem cells leading to an improvement in LVEF. Neither of the stem cell types induced myocardial angiogenesis, raising the question whether donor age and health have an effect on the efficacy of stem cells used in the treatment of MI.

Activation of protease-activated receptor 2 induces VEGF independently of HIF-1.

BACKGROUND: Human adipose stem cells (hASCs) can promote angiogenesis through secretion of proangiogenic factors such as vascular endothelial growth factor (VEGF). In other cell types, it has been shown that induction of VEGF is mediated by both protease activated receptor 2 (PAR2) and hypoxia inducible factor 1(HIF-1). The present study hypothesized that PAR2 stimulation through activation of kinase signaling cascades lead to induction of HIF-1 and secretion of VEGF. METHODOLOGY/PRINCIPAL FINDINGS: Immunohistochemistry revealed the expression of PAR2 receptors on the surface of hASCs. Blocking the PAR2 receptors with a specific antibody prior to trypsin treatment showed these receptors are involved in trypsin-evoked increase in VEGF secretion from hASCs. Blocking with specific kinase inhibitors suggested that that activation of MEK/ERK and PI3-kinase/Akt pathways are involved in trypsin-eveoked induction of VEGF. The effect of the trypsin treatment on the transcription of VEGF peaked at 6 hours after the treatment and was comparable to the activation observed after keeping hASCs for 24 hours at 1% oxygen. In contrast to hypoxia, trypsin alone failed to induce HIF-1 measured with ELISA, while the combination of trypsin and hypoxia had an additive effect on both VEGF transcription and secretion, results which were confirmed by Western blot. CONCLUSION: In hASCs trypsin and hypoxia induce VEGF expression through separate pathways.

Isolation and growth of adipose tissue-derived stem cells.

Fat tissue provides a rich and easily accessible supply of stem cells that feature the general differentiation potential and plasticity of mesenchymal stem cells. These stem cells, variably designated adipose-derived stem cells (ASCs), hold a great promise for regeneration in vivo and tissue engineering. In order to be able to obtain ASC preparations suitable for basic investigations as well as development of future therapeutic protocols, it is important that the critical isolation steps are properly carried out. Here, we describe in detail enzyme-based procedure for isolation and propagation of ASCs from the human subcutaneous fat tissue that is also adaptable to several animal species. The critical steps and impact of possible modifications on the final outcome are discussed, and useful hints are provided to streamline the troubleshooting.

Isolation and expansion of adipose-derived stem cells for tissue engineering.

For treatment of cardiac failure with bone marrow-derived mesenchymal stem cells, several clinical trials are ongoing. However, more attention is gathering on the use of adipose tissue-derived stem cells (ASCs). This paper describes the optimization of isolation and propagation of ASCs for subsequent clinical use. In the isolation step, several enzymes were compared with respect to yield of nucleated cells and precursor cells. Our results showed, that the interdonor variablility was greater than differences between individual enzymes. For propagation of cells, different types of media, sera and serum replacers were evaluated regarding their ability to support cell growth and preserve differentiation potential. Most of serum replacers proved inferior to fetal calf serum. Among the media tested, modified Eagle's media alpha was superior in promoting cell growth while preserving the ability to differentiate. Also, the effect of cell seeding density and hypoxic culture was evaluated. In this study, we show that it is possible to maximize cell yield regardless of donor individual characteristics by simple manipulations of media composition, cell seeding density and gaseous environment.

Prolonged hypoxic culture and trypsinization increase the pro-angiogenic potential of human adipose tissue-derived stem cells.

BACKGROUND AIMS: Transplantation of mesenchymal stromal cells (MSC), including adipose tissue-derived stem cells (ASC), is a promising option in the treatment of vascular disease. Short-term hypoxic culture of MSC augments secretion of anti-apoptotic and angiogenic cytokines. We hypothesized that prolonged hypoxic (1% and 5% oxygen) culture and trypsinization would augment ASC expression of anti-apoptotic and angiogenic cytokines and increase the angiogenic potential of ASC-conditioned media. METHODS: The effects of prolonged hypoxic culture on growth and pro-angiogenic properties were investigated using human ASC cultured at 1%, 5% and 21% oxygen. The effect of trypsinization on the expression of pro-angiogenic genes was also determined. RESULTS: Trypsinization induced up-regulation of the vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 (IGF-1) genes independent of oxygen concentration. The expression of VEGF and IGF-1 was up-regulated in ASC cultured at 1% oxygen for 13 days compared with 4 days. The VEGF concentration in ASC-conditioned media was higher after prolonged hypoxic culture compared with short-term culture, while the IGF-1 and chemokine (CXC motif) ligand 12 (CXCL12) concentrations were unchanged. The VEGF receptor blocker SU5416 abolished angiogenesis in a cultured rat aortic ring model. Media from cells exposed to hypoxia increased angiogenesis, an effect that was dependent on factors other than just the VEGF concentration in the added media. CONCLUSIONS: Optimization of the angiogenic potential of stem cell-based therapy in the treatment of vascular disease is important. We have demonstrated that prolonged hypoxic culture and trypsinization augment the therapeutic angiogenic potential of ASC.

Flow-mediated vasodilatation: variation and interrelationships with plasma lipids and lipoproteins.

OBJECTIVE: Endothelial dysfunction is a critical, prerequisite step in atherosclerosis, and may be evaluated by flow-mediated vasodilatation (FMD). The objective of this study was to examine interrelationships between FMD and plasma lipids and lipoproteins, and to determine the between-operator and within-subject variability associated with this technique. MATERIAL AND METHODS: FMD, plasma lipids and lipoproteins, including small dense LDL (sdLDL), were measured twice in 40 healthy volunteers, 4 weeks apart. Interrelationships between mean FMD responses and plasma lipids and lipoproteins were examined by correlation analysis. FMD measurements were taken by two independent operators, allowing determination of between-operator variability. Within-subject variability was determined by obtaining two measurements, 4 weeks apart, in every subject, and carried out by the same operator. RESULTS: FMD was inversely related to plasma triglycerides (r = -0.47, p = 0.002), total cholesterol/HDL cholesterol (r = -0.35, p = 0.03) and apolipoprotein B (r = -0.36, p = 0.02), but not to other plasma lipids and lipoproteins. When measuring variation in FMD, the following results were found: Between operators (SD = 4.0 FMD%) and within subjects (SD = 2.9 FMD%). CONCLUSIONS: The associations between FMD, plasma triglycerides and apoB provide evidence supporting a role for triglyceride-rich lipoproteins in endothelial dysfunction.

Adiponectin and marine n-3 fatty acids in patients referred for coronary angiography.

Marine n-3 polyunsaturated fatty acids (n-3 PUFAs) in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) may reduce the risk of coronary heart disease (CHD) and have anti-inflammatory effects. We examined whether levels of serum adiponectin were related to the occurrence and extent of CHD, and whether intake of n-3 PUFAs was associated to high levels of adiponectin. Serum adiponectin and the content of n-3 PUFAs in subcutaneous adipose tissue, platelets and granulocytes were measured in 291 patients referred to elective coronary angiography. Significantly lower levels of serum adiponectin were observed in patients with coronary stenoses compared to patients without stenoses (7336+/-3598 ng/ml vs 10,203+/-8396 ng/ml; p=0.003), but no significant correlation was seen between serum adiponectin and the extent of CHD. In men, serum adiponectin correlated to levels of the content of EPA in platelets (r=0.26; p<0.01) and in granulocytes (r=0.23; p<0.01) and to the content of DHA in subcutaneous adipose tissue (r=0.15; p<0.05) and granulocytes (r=0.17; p<0.05). After regression analysis EPA in platelets (p=0.017) and granulocytes (p=0.030) remained an independent correlate of adiponectin levels, while DHA was no longer an independent correlate. In conclusion, serum levels of adiponectin were lower in patients with angiographically documented coronary artery disease. Also, intake of EPA may increase serum adiponectin and through this exert a protective effect on CHD.

Instability of standard PCR reference genes in adipose-derived stem cells during propagation, differentiation and hypoxic exposure.

BACKGROUND: For the accurate determination of gene expression changes during growth and differentiation studies on adipose-derived stem cells (ASCs), quantitative real-time RT-PCR has become a method of choice. The technology is very sensitive, however, without a proper selection of reference genes, to which the genes of interest are normalized, erroneous results may be obtained. RESULTS: In this study, we have compared the gene expression levels of a panel of twelve widely used reference genes during hypoxic culture, osteogenic and chondrogenic differentiation, and passaging of primary human ASCs. We found that several of the commonly used reference genes including 18S rRNA, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and beta-actin were unsuitable for normalization in the conditions we tested, whereas tyrosine 3/tryptophan 5-monooxygenase activation protein (YMHAZ), TATAA-box binding protein (TBP), beta-glucuronidase (GUSB) were the most stable across all conditions. CONCLUSION: When determining gene expression levels in adipose-derived stem cells, we recommend normalizing transcription levels to the geometric mean of YMHAZ, TBP and GUSB.

Fish, marine n-3 polyunsaturated fatty acids and coronary heart disease: a minireview with focus on clinical trial data.

In this paper, we will briefly deal with the background for the possible effects of long-chain marine n-3 (also called omega-3) polyunsaturated fatty acids (PUFA) in coronary heart disease (CHD) and then focus on findings from clinical trials in humans. We will not deal with effects of alpha-linolenic acid, the non-marine type of n-3 PUFA derived from plant oils.