Bone marrow-derived mesenchymal stromal cell treatment in patients with ischaemic heart failure: final 4-year follow-up of the MSC-HF trial.

AIMS: The study assessed 4-year outcomes of intramyocardial injections of autologous bone marrow-derived mesenchymal stromal cells (MSCs) in patients with ischaemic heart failure. METHODS AND RESULTS: The MSC-HF trial was a randomized, double-blind, placebo-controlled trial. Patients were randomized 2:1 to intramyocardial injections of MSCs or placebo. The primary endpoint was change in left ventricular end-systolic volume (LVESV), measured by magnetic resonance imaging or computed tomography. Sixty patients aged 30-80 years with ischaemic heart failure, New York Heart Association class II-III, left ventricular ejection fraction (LVEF) <45% and no further treatment options were randomized. Patients were followed clinically for 12 months and in addition 4-year data of hospitalizations and survival were retrieved. After 12 months, LVESV was significantly reduced in the MSC group and not in the placebo group, with difference between groups of 17.0 ± 16.2 mL (95% confidence interval 8.3-25.7, P = 0.0002). There were also significant improvements in LVEF of 6.2% (P < 0.0001), stroke volume of 16.1 mL (P < 0.0001) and myocardial mass (P = 0.009) between groups. A significant dose-response effect was also observed. Moreover, a significant reduction in the amount of scar tissue and quality of life score in the MSC group but not in the placebo group was observed. After 4 years, there were significantly fewer hospitalizations for angina in the MSC group and otherwise no differences in hospitalizations or survival. No side effects were identified. CONCLUSIONS: Intramyocardial injections of autologous bone marrow-derived MSCs improved myocardial function and myocardial mass in patients with ischaemic heart failure.

Overcoming the bottleneck of platelet lysate supply in large-scale clinical expansion of adipose-derived stem cells: A comparison of fresh versus three types of platelet lysates from outdated buffy coat-derived platelet concentrates.

BACKGROUND: Platelet lysates (PL) represent a promising replacement for xenogenic growth supplement for adipose-derived stem cell (ASC) expansions. However, fresh platelets from human blood donors are not clinically feasible for large-scale cell expansion based on their limited supply. Therefore, we tested PLs prepared via three methods from outdated buffy coat-derived platelet concentrates (PCs) to establish an efficient and feasible expansion of ASCs for clinical use. METHODS: PLs were prepared by the freeze-thaw method from freshly drawn platelets or from outdated buffy coat-derived PCs stored in the platelet additive solution, InterSol. Three types of PLs were prepared from outdated PCs with platelets suspended in either (1) InterSol (not manipulated), (2) InterSol + supplemented with plasma or (3) plasma alone (InterSol removed). Using these PLs, we compared ASC population doubling time, cell yield, differentiation potential and cell surface markers. Gene expression profiles were analyzed using microarray assays, and growth factor concentrations in the cell culture medium were measured using enzyme-linked immunosorbent assay (ELISA). RESULTS: Of the three PL compositions produced from outdated PCs, removal of Intersol and resuspension in plasma prior to the first freezing process was overall the best. This specific outdated PL induced ASC growth kinetics, surface markers, plastic adherence and differentiation potentials comparable with PL from fresh platelets. ASCs expanded in PL from fresh versus outdated PCs exhibited different expressions of 17 overlapping genes, of which 10 were involved in cellular proliferation, although not significantly reflected by cell growth. Only minor differences in growth factor turnover were observed. CONCLUSION: PLs from outdated platelets may be an efficient and reliable source of human growth supplement allowing for large-scale ASC expansion for clinical use.

Experimental myocardial stem cell therapy for ST-elevation myocardial infarction: rationale and level of evidence.

Ischemic heart disease (IHD) is one of the leading causes of death worldwide and is characterized by the formation of atherosclerotic plaques in the coronary arteries reducing the blood supply to the heart muscle causing ischemia. IHD can result in ST-elevation myocardial infarction (STEMI), chronic IHD and heart failure. The patients suffer from chest pain (angina), dyspnea and a reduced quality of life. Common for all these conditions is loss of functional cardiomyocytes and endothelial cells. Stem cell therapy to regenerate injured myocardium is a new treatment option which has gained much interest in the last 10-15 years especially after STEMI. Many preclinical and clinical studies have shown encouraging results but also very diverse clinical outcomes after stem cell treatment. This diversity in results may be explained by different factors, such as cell isolation technique, infarct location, timing and route of delivery, cell dosage, cell type etc. The present review will try to elaborate and clarify the present status for stem cell therapy in STEMI.

Quantification of myocardial perfusion using cardiac magnetic resonance imaging correlates significantly to rubidium-82 positron emission tomography in patients with severe coronary artery disease: a preliminary study.

INTRODUCTION: Aim was to compare absolute myocardial perfusion using cardiac magnetic resonance imaging (CMRI) based on Tikhonov's procedure of deconvolution and rubidium-82 positron emission tomography (Rb-82 PET). MATERIALS AND METHODS: Fourteen patients with coronary artery stenosis underwent rest and adenosine stress imaging by 1.5-Tesla MR Scanner and a mCT/PET 64-slice Scanner. CMRI were analyzed based on Tikhonov's procedure of deconvolution without specifying an explicit compartment model using our own software. PET images were analyzed using standard clinical software. CMRI and PET data was compared with Spearman's rho and Bland-Altman analysis. RESULTS: CMRI results were strongly and significantly correlated with PET results for the absolute global myocardial perfusion differences (r=0.805, p=0.001) and for global myocardial perfusion reserve (MPR) (r=0.886, p<0.001). At vessel territorial level, CMRI results were also significantly correlated with absolute PET myocardial perfusion differences (r=0.737, p<0.001) and MPR (r=0.818, p<0.001). Each vessel territory had similar strong correlation for absolute myocardial perfusion differences (right coronary artery (RCA): r=0.787, p=0.001; left anterior descending artery (LAD): r=0.796, p=0.001; left circumflex artery (LCX): r=0.880, p<0.001) and for MPR (RCA: r=0.895, p<0.001; LAD: r=0.886, p<0.001; LCX: r=0.886, p<0.001). CONCLUSION: On a global and vessel territorial basis, CMRI-measured absolute myocardial perfusion differences and MPR were strongly and significantly correlated with the Rb-82 PET findings.

Ultrastructural characterization of mesenchymal stromal cells labeled with ultrasmall superparamagnetic iron-oxide nanoparticles for clinical tracking studies.

INTRODUCTION: To evaluate survival and engraftment of mesenchymal stromal cells (MSCs) in vivo, it is necessary to track implanted cells non-invasively with a method, which does not influence cellular ultrastructure and functional characteristics. Iron-oxide particles have been applied for cell tracking for years, but knowledge regarding possible cytotoxic ultrastructural changes subsequent to iron-oxide particle labeling is limited. Hence, the purpose of this study was to label MSCs with dextran-coated ultrasmall super-paramagnetic iron-oxide (USPIO) particles conjugated with the transduction sequence of trans-activator of transcription (TAT) (IODEX-TAT) and evaluate the effect of labeling on ultrastructure, viability, phenotype and proliferative capacity of the cells. MATERIALS AND METHODS: MSCs were labeled with 5 and 10 µg IODEX-TAT/10(5) cells for 2, 6 and 21 hours. IODEX-TAT uptake and cellular ultrastructure were determined by electron microscopy. Cell viability was determined by propidium iodide staining and cell proliferation capacity by 5-bromo-2-deoxyuridine (BrdU) incorporation. Maintenance of stem cell surface markers was determined by flow cytometry. Results. IODEX-TAT labeling for 2, 6 and 21 h did not influence cellular ultrastructure or viability. Moreover, neither stem cell surface markers nor cell proliferation capacity was affected by labeling with IODEX-TAT. CONCLUSION: Our results demonstrate that labeling of MSCs for 21 h with a clinically relevant dose of 10 µg IODEX-TAT/10(5) cells is feasible and does not affect MSC ultrastructure, viability, phenotype or proliferation capacity.

Value of cardiac 320-multidetector computed tomography and cardiac magnetic resonance imaging for assessment of myocardial perfusion defects in patients with known chronic ischemic heart disease.

The challenge for therapies targeting perfusion abnormalities is to identify and evaluate the region of interest. The aim of this study was to compare rest and stress myocardial perfusion measured by cardiac multi-detector computed tomography (MDCT) and cardiac magnetic resonance (CMR) imaging in patients with invasive coronary angiography demonstrated occluded vessels. Twenty-four patients with refractory angina due to occluded coronary arteries underwent perfusion imaging obtained by 320-MDCT scanner and 1.5 T MR scanner. Rest and adenosine stress images were obtained and interpreted using the modified 17-segment American Heart Association model. For the qualitative analysis, each segment was graded according to the following scoring system: 0 = no defect, 1 = hypoperfusion transmural extent <1/3, 2 = 1/3-1/2, 3 = >1/2, and 4 = infarct stigmata. In the semiquantitative analysis the perfusion was either scored 0 (normal) or 1 (abnormal). The summed rest and stress scores were calculated. MDCT and CMR had a high probability to identify perfusion defects. An excellent correlation between MDCT and CMR summed rest (r = 0.916) and stress scores (r = 0.915) was found. The interobserver reproducibility was high for MDCT and CMR images. The qualitative and semiquantitative MDCT against CMR analysis of rest and stress images showed high concordance to detect perfusion defects per vascular territory and on a per myocardial segment basis. 320-MDCT and CMR perfusion imaging can be used clinically to identify myocardial perfusion defects and potentially evaluate the effect of therapy targeting perfusion abnormalities.

Left atrial volume and function in patients following ST elevation myocardial infarction and the association with clinical outcome: a cardiovascular magnetic resonance study.

AIMS: The left atrium (LA) transfers blood to the left ventricle in a complex manner. LA function is characterized by passive emptying (LA passive fraction), active emptying (LA ejection fraction), and total emptying (LA fractional change). Despite this complexity, the clinical relevance of the LA is based almost exclusively on LA maximal volume (LAmax), which may not glean the full prognostic potential. Cardiovascular magnetic resonance (CMR) is considered the most accurate method for studying LA function and size. The aim of the present study was to evaluate the prognostic importance of LA function in patients following ST elevation myocardial infarction (STEMI). METHODS AND RESULTS: In 199 patients, a CMR scan was performed within 1-3 days after STEMI to measure LAmax and minimal volume (LAmin) and LA function. The incidence of death, re-infarction, stroke, and admission for heart failure [major adverse cardiac event (MACE)] were registered during the follow-up period [2.3 years (inter-quartile range: 2.0-2.5)]. A total of 40 patients (20%) met the clinical endpoint of MACE during follow-up. In a Cox regression analysis adjusting for known risk factors, LA fractional change remained independently associated with MACE [adjusted hazard ratio: 0.66 (95% confidence interval: 0.46-0.95)]. LAmax, LAmin, or LA passive fraction was not independently associated with MACE. Furthermore, LA fractional change provided incremental prognostic value to LAmax and other known predictors (Wald χ(2) 31.0 vs. 39.9, P= 0.016). CONCLUSION: In STEMI patients, impaired LA fractional change is independently associated with outcome and provide incremental prognostic information to established predictors including LAmax.

Direct intramyocardial mesenchymal stromal cell injections in patients with severe refractory angina: one-year follow-up.

In patients with stable coronary artery disease (CAD) and refractory angina, we performed direct intramyocardial injections of autologous mesenchymal stromal cells (MSC) and followed the safety and efficacy of the treatment for 12 months. A total of 31 patients with stable CAD, moderate to severe angina, normal left ventricular ejection fraction, and no further revascularization options were included. Bone marrow MSCs were isolated and culture expanded for 6-8 weeks and then stimulated with vascular endothelial growth factor (VEGF) for 1 week. The 12-month follow-up demonstrated that it was safe to culture expand MSCs and use the cells for clinical treatment. The patients' maximal metabolic equivalent (MET) during exercise increased from 4.23 MET at baseline to 4.72 MET at 12-month follow-up (p < 0.001), Canadian Cardiovascular Society Class (CCS) was reduced from 3.0 to 0.8 (p < 0.001), angina attacks per week from 13.8 to 3.2 (p < 0.001), and nitroglycerin consumption from 10.7 to 3.4 per week (p < 0.001). In addition, Seattle Angina Questionnaire (SAQ) evaluations demonstrated highly significant improvements in physical limitation, angina stability, angina frequency, and quality of life (p < 0.001 for all). It is safe in the intermediate/long term to treat patients with stable CAD using autologous culture expanded MSCs. Previously reported, early and highly significant improvements in exercise capacity and clinical symptoms persist after 12 months. The results are encouraging, and a larger controlled study is warranted.

Angiographic features and cardiovascular risk factors in human immunodeficiency virus-infected patients with first-time acute coronary syndrome.

A matched cohort study was conducted comparing patients with first-time acute coronary syndromes infected with human immunodeficiency virus (HIV) to non-HIV-infected patients with and without diabetes matched for smoking, gender, and type of acute coronary syndrome who underwent first-time coronary angiography. A total of 48 HIV-infected patients were identified from a national database. Coronary angiography showed that the HIV-infected patients had significantly fewer lesions with classification B2/C than the 2 control groups (p <0.001) but the same extent of multivessel disease. The HIV-infected patients were a decade younger than the non-HIV-infected controls and had significantly higher concentrations of total cholesterol (6.3 vs 4.8 and 4.5 mmol/L, p <0.0001), low-density lipoprotein (4.0 vs 2.9 and 2.5 mmol/L, p <0.001), and triglycerides (2.8 vs 1.0 and 1.4 mmol/L, p <0.01) compared to the nondiabetic and diabetic non-HIV-infected groups, respectively. In conclusion, HIV-infected patients with first-time acute coronary syndromes have fewer complex lesions than non-HIV-infected patients. This finding supports the idea that the pathogenesis of atherosclerotic disease in HIV patients is different from that in the general population.

Myocardial area at risk after ST-elevation myocardial infarction measured with the late gadolinium enhancement after scar remodeling and T2-weighted cardiac magnetic resonance imaging.

To evaluate the myocardial area at risk (AAR) measured by the endocardial surface area (ESA) method on late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) when applied after scar remodeling (3 months after index infarction) compared to T2-weighted CMR imaging. One hundred and sixty nine patients with ST-elevation myocardial infarction, treated with primary percutaneous coronary intervention, underwent one CMR within 1 week after index treatment to determine the AAR with T2-weighted imaging and a second scan 3 months after to measure AAR with the ESA method. There was a moderate correlation between the two methods (r = 0.86; P < 0.001). The AAR was significantly higher measured with T2-weighted imaging than with the ESA methods (32 ± 11% of left ventricle (LV) vs. 26 ± 10%LV; P < 0.001). The mean difference was 6 ± 6%LV. Furthermore, the mean difference between the two methods was statistical higher in the patients with myocardial salvage index ≥0.90 than in the remaining patients (9 ± 8%LV vs. 6 ± 5%LV; P = 0.02). The ESA method performed after scar remodeling (3 months following STEMI) yields significantly lower AAR's and myocardial salvage indices compared to the T2-weighted method. Therefore, T2-weighted CMR plus LGE is the method of choice to assess AAR and myocardial salvage index using CMR. However, the ESA method is an easy and valid method for determining AAR, which can be used in settings where T2-weighted imaging has not been obtained in the acute phase.

Exenatide reduces reperfusion injury in patients with ST-segment elevation myocardial infarction.

AIMS: Exenatide, a glucagon-like-peptide-1 analogue, increases myocardial salvage in experimental settings with coronary occlusion and subsequent reperfusion. We evaluated the cardioprotective effect of exenatide at the time of reperfusion in patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI). METHODS AND RESULTS: A total of 172 patients with STEMI and Thrombolysis in Myocardial Infarction flow 0/1 were randomly assigned to exenatide or placebo (saline) intravenously. Study treatment was commenced 15 min before intervention and maintained for 6 h after the procedure. The primary endpoint was salvage index calculated from myocardial area at risk (AAR), measured in the acute phase, and final infarct size measured 90 ± 21 days after pPCI by cardiac magnetic resonance (CMR). In 105 patients evaluated with CMR, a significantly larger salvage index was found in the exenatide group than in the placebo group (0.71 ± 0.13 vs. 0.62 ± 0.16; P= 0.003). Infarct size in relation to AAR was also smaller in the exenatide group (0.30 ± 0.15 vs. 0.39 ± 0.15; P= 0.003). In a regression analysis, there was a significant correlation between the infarct size and the AAR for both treatment groups and an analysis of covariance showed that datapoints in the exenatide group lay significantly lower than for the placebo group (P= 0.011). There was a trend towards smaller absolute infarct size in the exenatide group (13 ± 9 vs. 17 ± 14 g; P= 0.11). No difference was observed in left ventricular function or 30-day clinical events. No adverse effects of exenatide were observed. CONCLUSION: In patients with STEMI undergoing pPCI, administration of exenatide at the time of reperfusion increases myocardial salvage.

Myocardial area at risk and salvage measured by T2-weighted cardiovascular magnetic resonance: reproducibility and comparison of two T2-weighted protocols.

BACKGROUND: Late gadolinium enhancement (LGE) and T2-weighted cardiovascular magnetic resonance (CMR) provides a means to measure myocardial area at risk (AAR) and salvage. Several T2-weighted CMR sequences are in use, but there is no consensus in terms of which sequence to be the preferred. Therefore, the aim of the present study was to: (1) Assess the reproducibility and (2) compare the two most frequently used T2-weighted CMR protocols for measuring AAR and salvage. METHODS: 91 patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention underwent a CMR scan 1-7 days after initial treatment. Two different T2-weighted protocols, varying in slice thickness and echo time (TE), were applied covering the entire left ventricle (LV) (protocol 1: TE 65 msec and slice thickness 15 mm; protocol 2: TE 100 msec and slice thickness of 8 mm). On a second scan performed 3 months later, infarct size was assessed with a standard LGE sequence. The two protocols were compared in terms of AAR and salvage index. Furthermore, intra- and interobserver reproducibility were assessed. RESULTS: Protocol 1 measures a larger AAR and salvage index than protocol 2 with a mean difference in AAR of 1±8%LV (p<0.01) and 6±12 g (p<0.01) and salvage index of 0.04±0.12 (p<0.01). Both protocols had a high intra- and interobserver reproducibility with acceptable limits of agreement (6-8%LV and 6-12 g in AAR and 0.06-0.08 in salvage index). CONCLUSIONS: We report acceptable reproducibility for AAR and salvage index measured by T2-weighted images. Thus CMR is a reliable tool for measuring AAR and salvage index. Protocol 2 (8 mm slice thickness and 100 msec TE) measures slightly smaller AAR than protocol 1 (15 mm slice thickness and 65 msec TE), but the present study does not allow for a clear recommendation of either of the protocols.

Plasma YKL-40 in relation to the degree of coronary artery disease in patients with stable ischemic heart disease.

BACKGROUND: YKL-40 is a glycoprotein secreted by macrophages and neutrophils in tissues with inflammation. Plasma YKL-40 is increased in patients with coronary artery disease (CAD) and associated with cardiovascular and all-cause mortality. Furthermore, plasma YKL-40 seems related to the number of diseased main vessels in patients with stable CAD. The aim was to further study the relation between YKL-40 and stenosis degree, stenosis type and actual ischemia in stable CAD patients. METHODS: Plasma YKL-40 and hsCRP levels were determined from 206 consecutive patients with stable angina pectoris admitted for coronary angiography. Plasma YKL-40 in 245 healthy subjects was used for comparison. In addition to one to three vessel stenosis scores, two new scores for evaluating coronary angiographies were established for discriminating between focal and diffuse CAD and the extent of myocardial ischemia. RESULTS: YKL-40 levels in CAD patients (median: 52 µg/L and quartiles: 37-85 µg/L) were significantly increased (p < 0.001) compared to the healthy controls. In univariate analyses plasma YKL-40 was significantly associated with ischemic myocardium score, age, hypertension, peripheral vascular disease and serum creatinine levels. In multivariate analyses YKL-40 was related to hsCRP, peripheral artery disease, hypertension, and statin treatment. CONCLUSIONS: Plasma YKL-40 was increased in patients with CAD compared to controls. YKL-40 was related to the ischemic myocardium, but not to degree of CAD using different scoring systems. Therefore, YKL-40 is not related to the extent of CAD, but to some other pathophysiological mechanisms of importance for the prognosis.

Mesenchymal stromal cell derived endothelial progenitor treatment in patients with refractory angina.

AIMS: We evaluated the feasibility, safety and efficacy of intra-myocardial injection of autologous mesenchymal stromal cells derived endothelial progenitor cell (MSC) in patients with stable coronary artery disease (CAD) and refractory angina in this first in man trial. METHODS AND RESULTS: A total of 31 patients with stable CAD, moderate to severe angina and no further revascularization options, were included. Bone marrow MSC were isolated and culture expanded for 6-8 weeks. It was feasible and safe to establish in-hospital culture expansion of autologous MSC and perform intra-myocardial injection of MSC. After six months follow-up myocardial perfusion was unaltered, but the patients increased exercise capacity (p < 0.001), reduction in CCS Class (p < 0.001), angina attacks (p < 0.001) and nitroglycerin consumption (p < 0.001), and improved Seattle Angina Questionnaire (SAQ) evaluations (p < 0.001). For all parameters there was a tendency towards improved outcome with increasing numbers of cells injected. In the MRI substudy: ejection fraction (p < 0.001), systolic wall thickness (p = 0.03) and wall thickening (p = 0.03) all improved. CONCLUSIONS: The study demonstrated that it was safe to treat patients with stable CAD with autologous culture expanded MSC. Moreover, MSC treated patients had significant improvement in left ventricular function and exercise capacity, in addition to an improvement in clinical symptoms and SAQ evaluations.

High-sensitivity C-reactive protein and N-terminal pro-B-type natriuretic peptide in patients with stable coronary artery disease: a prognostic study within the CLARICOR trial.

BACKGROUND: Patients with stable coronary artery disease (CAD) have a poor prognosis. The aim of the study was to evaluate the extent to which serum high-sensitivity C-reactive protein (hs-CRP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) measurement alone or together could be prognostic biomarkers in patients with stable CAD. MATERIALS AND METHODS: During the 2.6-year follow-up period 270 patients among the 4264 patients with stable CAD in the CLARICOR trial suffered myocardial infarction (MI) and 377 died (187 cardiovascular deaths (CVD)). RESULTS: Serum NT-proBNP was significantly associated with MI (hazard ratio (HR), 1. 65 (refers to a 2.72 fold increase in serum level, p = 0.0005), CVD (HR, 2.42, p < 0.0005) and non-CVD (HR, 1.79, p < 0.0005). When correcting for hs-CRP, NT-proBNP was still significantly associated with MI (HR, 1.63, p = 0.0005), CVD (HR, 2.36, p < 0.0005) and non-CVD (HR, 1.66, p < 0.0005). Serum hs-CRP was compared to NT-proBNP less associated with MI (HR, 1.20, p = 0.001), CVD (HR, 1.39, p < 0.0005) and non-CVD (HR, 1.67, p < 0.0005). When corrected for NT-proBNP, hs-CRP was only associated with non-CVD (HR, 1.51, p < 0.0005). When adjusting for cardiovascular risk factors hs-CRP predicted non-CVD (HR, 1.46) and all-cause death (HR, 1.24) and NT-proBNP predicted MI (HR, 1.50), CVD (HR, 1.98), non-CVD (HR, 1.39), and all-cause death (HR, 1.62)(p < 0.0005 for all). CONCLUSION: Increased serum NT-proBNP was a stronger predictor of MI, cardiovascular death and non-cardiovascular death than hs-CRP in patients with stable CAD. Once NT-proBNP was taken into account, hs-CRP did not improve predictions.