S100A9 blockade ameliorates cardiac dysfunction and reduces myocardial immune infiltration in experimental autoimmune myocarditis

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Swedish Heart and Lung Foundation and Swedish Research Council

Background/Introduction

Autoimmune myocarditis is characterized by non-ischemic inflammatory heart injury, leading to myocardial damage and impaired cardiac function. S100A9 is an inflammatory alarmin present in large amounts in neutrophils. The role of S100A9 as a potential treatment target in myocarditis has not been fully explored.

Aim

We sought to investigate the impact of S100A9 blockade in experimental autoimmune myocarditis and assess the effects of treatment on cardiac function and immune infiltration.

Methods

BALB/C mice were immunized with αMHC peptide emulsified in Complete Freunds Adjuvant at day 0 and day 7 to induce the disease. The water-soluble small-molecule S100A9 blocker ABR-238901 was given continuously in drinking water starting on day 7. Echocardiography was performed weekly from day 21 to day 42 (n=11/group). For flow cytometry analysis, mice were sacrificed at day 21 (n=10/group).

Results

S100A9 blockade improved left ventricular ejection fraction [52.33% vs 44.87% on day 42 (p<0.001)]. Cardiac output was significantly improved on day 21 (12.69 vs 11.05 mL/min, p<0.05). We found a significant reduction of inflammatory cardiac infiltrates at day 21, characterized by reduced number of macrophages (p<0.05), neutrophils (p<0.01) and CD4+ T cells (p<0.05). The cardiac draining lymph nodes contained fewer dendritic cells (p<0.01), T cells (p<0.05), as well as reduced numbers of inflammatory CD4+ cells producing IL-17 (p<0.05).

Conclusion

Therapeutic S100A9 blockade inhibits inflammatory cardiac infiltration and improves cardiac function in experimental autoimmune myocarditis. Our findings highlight the important role of S100A9 in the pathogenesis of myocarditis and identify S100A9 blockade as a possible novel therapeutic avenue.

Systemic inflammation in the acute myocardial infarction can predict early negative left ventricular remodeling assessed by myocardial work analysis

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): UEFISCDI

Background. Left ventricular (LV) remodeling after acute myocardial infarction (AMI) is an important predictor of heart failure (HF). Systemic inflammatory response in the acute phase of AMI is of particular interest, while the relation to the remodeling process is still under debate. New imaging techniques derived from speckle tracking echocardiography (STE), such as myocardial work (MW), are attractive tools since they can detect myocardial remodeling before decrease of global LVEF. However, there is insufficient data regarding MW in AMI patients, and its relation to the inflammatory process.

Methods. We assessed 57 patients (53 ± 9 years, 45 men, 64% smokers, 59% hypertensive, 54% with type 2 diabetes) with AMI, by clinical, 2D echo, and STE. Biomarkers panel was evaluated within the first 24 hours from admission: hsTpI and CRP. A second visit with clinical and echo assessment was performed at 6-8 weeks from the baseline visit. Exclusion criteria were unstable patients, non-sinus rhythm, significant valvular disease (>grade 2), other significant pathologies leading to decreased life expectancy, and low quality 2DE. At both visits, global longitudinal stain (GLS) and MW by 2DSTE were measured, on top of conventional echo parameters: global work index (GWI), global constructive work (GCW), global wasted work (GWW), global work efficiency (GWE) (Figure 1: upper panel - an example of a patient with increase of GWE from baseline to visit 2 ; lower panel - an example of a patient with decrease of the GWE from baseline to visit 2).

Results. At baseline, myocardial necrosis by hsTpI significantly corelated with GLS (r = 0.44, p = 0.001) and MW (GWI: r=-0.44, p = 0.001; GCW: r=-0.40, p = 0.002), but not with LVEF. However, systemic inflammation by CRP did not correlate with LVEF or any of the STE parameters.  Interestingly, systemic inflammation by CRP significantly correlated with changes of MW between the two visits: for GWE r=-0.53, p < 0.001; and for GWW r = 0.48, p < 0.001 (Figure 2). A CRP level >28 mg/l was able to predict decrease of GWE from baseline to visit 2.

Conclusions. Magnitude of necrosis, expressed by hsTpI, corelates only with GLS and MW parameters, but not with LVEF. CRP level in the acute phase of AMI correlates with myocardial work changes, as an early marker of negative LV remodeling. Abstract Figure 1  Abstract Figure 2

Elevated soluble lectin-like oxidised low-density lipoprotein receptor-1 (sLOX-1) associated with increased risk for heart failure and MACE after an acute coronary event

Background/Introduction

The lectin-like oxidised low-density lipoprotein receptor (LOX-1) is involved in atherosclerotic plaque inflammation and vulnerability. Plasma levels of soluble LOX-1 (sLOX-1) have previously been associated with increased risk for recurrent coronary events and mortality in patients with acute coronary syndrome (ACS).

Purpose

To assess the association of sLOX-1 with the development of heart failure (HF) post-ACS.

Methods

We measured sLOX-1 in 524 patients with ACS within 24 hours after the acute event. A subgroup of 97 of these patients completed a follow-up echocardiogram after one year. The incidence of HF-related hospitalisation and recurrent major adverse cardiovascular events (MACE), defined as recurrent ACS or cardiovascular death, was followed for a mean period of two years. In a separate cohort of 363 patients with ACS and percutaneous coronary intervention (PCI), we studied the correlations between sLOX-1, coronary flow reserve, left ventricular systolic function and systemic inflammation at two follow-up visits within four weeks and 16 weeks post-ACS, respectively.

Results

Baseline sLOX-1 was positively associated with the risk of HF and MACE, independently of traditional cardiovascular risk factors, revascularisation and medication. The hazard ratios and 95% confidence intervals were 1.57 (1.10–2.23), p=0.012 for HF and 1.36 (1.08–1.71), p=0.009 for MACE per standard deviation baseline sLOX-1 increase. Elevated sLOX-1 was also negatively associated with lower-left ventricular ejection fraction at one year (r=−0.263, p=0.009). In the second ACS cohort, we found that plasma sLOX-1 measured at the two follow-up visits was negatively associated with coronary flow reserve and left ventricular systolic function, and positively correlated with biomarkers of systemic inflammation and cardiac overload.

Conclusion

Elevated sLOX-1 is associated with the development of HF and recurrent cardiovascular events in patients with ACS. Although this association study cannot confirm causality, the results suggest LOX-1 as a potential biomarker and treatment target in patients with ACS.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): • Swedish Research Council • The Swedish Heart and Lung foundation• Swedish Foundation for Strategic Research Dnr IRC15-0067 • Marianne and Marcus Wallenberg Foundation • Bundy Academy at Lund University

Organizational and patient-level predictors for reaching key risk factor targets in cardiac rehabilitation after myocardial infarction – the perfect-CR study

Background

The benefits of specific cardiac rehabilitation (CR) programme components on patient outcomes after myocardial infarction (MI) remain unclear, as does their relative predictive strength compared to patient-level predictors.

Purpose

To identify CR organizational and patient-level predictors for reaching risk factor targets at one-year post-MI.

Methods

This was an observational survey- and registry-based study. Data on CR organization at all 78 CR centres in Sweden was collected in 2016 and merged with individual patient data from nationwide registries (n=7549, median age 64 years, 24% females). Cross-validation resampled orthogonal partial least squares discriminant analysis identified predictors for reaching treatment targets for low-density lipoprotein-cholesterol (LDL-C<1.8 mmol/L), blood pressure (BP<140/90 mmHg) and smoking abstinence (yes/no). Predictors with Variables of Importance for the Projection (VIP) value >0.8 and 95% confidence intervals (CI) excluding zero, were considered meaningful.

Results

Of the 71 analysed organizational variables, 36 were identified as meaningful predictors for reaching LDL-C and 35 for BP targets (Figure 1). The strongest predictors (VIP [95% CI]) for LDL-C and BP were: offering psychosocial management at initial CR assessment 2.09 [1.70–2.49]; 2.34 [1.90–2.78], having a CR team psychologist 1.59 [1.28–1.91]; 2.00 [1.46–2.55], having extended CR centre opening hours 2.17 [1.95–2.40]; 1.51 [1.03–2.00], staff reporting satisfaction with CR centre facilities 1.55 [1.07–2.04]; 1.96 [1.64–2.28], having a medical director 1.71 [1.45–1.97]; 1.47 [1.07–1.87], nurses using protocols for antihypertensive and/or lipid lowering medication adjustment 1.58 [1.35–1.81]; 1.56 [1.03–2.08], having operational team meetings 1.36 [1.08–1.64]; 1.34 [0.99–1.70], and using audit data for quality improvement 1.00 [0.79–1.20]; 1.27 [0.99–1.56]. Offering pre-exercise-based CR (exCR) assessment and different modes of exCR were predictors for reaching both targets. The strongest patient-level predictor of reaching LDL-C target was low baseline LDL-C 3.90 [3.25–4.56], and for BP it was having no history of hypertension 2.93 [2.74–3.12]. Second, participation in exCR was the strongest predictor for both outcomes 1.60 [0.83–2.37]; 1.50 [1.15–1.86]. For smoking abstinence, 5 organizational variables were identified as meaningful predictors, the strongest being prescription of varenicline by the centre physicians 1.98 [0.13–3.84] (Figure 2). The strongest patient-level predictors were exCR participation 2.51 [2.24–2.79] and socioeconomic status variables e.g., income 1.67 [1.28–2.06], living with partner 1.47 [0.84–2.09] and education 0.80 [0.48–1.12].

Conclusion

The study identified multiple CR organizational and patient-level predictors for reaching key risk factor targets one-year post-MI. The results might contribute to defining the optimal composition of comprehensive CR programmes.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): 1) The Swedish Research Council for Health, Working Life and Welfare (FORTE)2) The Swedish Heart and Lung Foundation (Hjärt Lung Fonden)

Collagen remodeling markers show differentiated expression in patients with ST- and non-ST elevation myocardial infarction

Background

Following acute myocardial infarction (MI), the left ventricle undergoes molecular and extracellular matrix (ECM) changes. The ECM is a dynamic structure with a potential role in cardiac remodeling post-MI. Collagens are the major components of both cardiac and arterial ECM.

Purpose

We evaluated circulating levels of type I, IV and VI collagen fragments in two cohorts of patients with acute MI to investigate collagen turnover post-MI. The cohorts were Malmö AMI in elderly (MAMI-Y) and Assessing Platelet Activity in Coronary Heart Disease (APACHE).

Methods

Serum was collected from 190 patients from the discovery cohort (MAMI-Y: mean age 74, SD 10.8) at four timepoints: admission when MI, after 3–6 days, 6 weeks, 12 months; citrate plasma was collected from 142 patients from the validation cohort (APACHE: mean age 65, SD 11.6) at four timepoints: hospitalization, 3 days, 7–9 days, 6 months. The biomarkers of matrix metalloproteinase (MMP)-mediated degradation of type I collagen (C1M), MMP-mediated degradation of type IV collagen (C4M) and formation of type VI collagen (PRO-C6) were measured at all timepoints (immunosorbent assays). Differences in the markers at the different timepoints were calculated using repeated measures ANOVA.

Results

Circulating levels of the formation biomarker PRO-C6 significantly increased from baseline and remained high at all three following timepoints in both MAMI-Y and APACHE studies (all p<0.001). In contrast, the degradation biomarkers C1M and C4M showed a similar pattern of an initial increase 3 days post-MI followed by a decrease over time, with C1M in MAMI-Y and both C1M and C4M in APACHE having returned to baseline level by the final timepoint. Circulating baseline levels of PRO-C6 correlated with age (r=0.397, p<0.0001 in MAMI-Y, r=0.427, p<0.0001 in APACHE). Categorizing the subjects into ST elevation MI (STEMI; MAMI-Y: N=67, APACHE: N=71) or non-ST elevation MI (NSTEMI; MAMI-Y: N=130, APACHE: N=52) revealed that a correlation with age remained in both subgroups (r=0.443, p<0.0001 and r=0.325, p<0.0001, respectively, in MAMI-Y, and r=0.516, p<0.0001 and r=0.316, p=0.023, respectively, in APACHE). Moreover, PRO-C6 was elevated in STEMI patients that had previously experienced an MI in both cohorts (MAMI-Y: p=0.017, APACHE: p=0.016). C1M and C4M levels were not different in patients with prior MI in any of the cohorts. No association was found between any biomarker and gender or diabetes. Echocardiography showed a correlation between baseline levels of C1M and ejection fraction (r=0.228, p=0.023) in the whole MAMI-Y cohort and among NSTEMI, but not among STEMI, subjects (r=0.337, p=0.004).

Conclusions

We observed changes in circulating fragments reflecting collagen turnover in the acute phase post-MI, more pronounced in STEMI patients. This may indicate that STEMI patients have more active collagen remodeling than NSTEMI patients and may have more altered left ventricle function and remodeling.

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): This work was supported by the Danish Research Foundation “den danske forskningsfond”, the Innovation foundation (Innovationsfonden), Swedish Research Council, Swedish Heart and Lung Foundation, Swedish Society for Medical Research, Swedish Society of Medicine, the Crafoord Foundation, the Åke Wiberg foundation and the Stroke foundation.

Effect of a lifestyle-focused electronic patient support application on risk factor management in post-myocardial infarction patients – a randomized controlled trial

Background

Cardiac rehabilitation (CR) is central in reducing morbidity and mortality after myocardial infarction (MI). However, the fulfillment of guideline recommended CR targets is unsatisfactory. eHealth offers new possibilities to improve clinical care.

Purpose

The aim of this study was to assess the efficacy of a mobile device application to support adherence to lifestyle advice and self-control of risk factors as a complement to traditional CR after MI.

Method

This unblinded multi-centre randomized controlled trial included 150 patients with MI (81% men, 60.4±8.8 years). All patients in the intervention (INT) and control (CON) groups participated in a 1-year CR program. Additionally, INT patients (n=101) received access to the mobile device application for 25 weeks post-MI where information about lifestyle (i.e., diet, physical activity, smoking), modifiable risk factors (i.e., weight, blood pressure (BP)), and symptoms could be registered. The software provided direct positive feedback and lifestyle advice. Data was reviewed twice weekly by the CR nurse. The primary outcome was change in sub-maximal exercise capacity (W) between an exercise test 2-weeks post MI and at follow-up 4 month later. Secondary outcomes included changes in lifestyle and modifiable risk factors including body mass index, waist circumference, blood-lipids, fasting glucose and HbA1c, between baseline and 2-week, 2-month and 1-year follow-up visits. Regression analysis was used, adjusting for relevant baseline variables.

Results

Participation in CR was high, with 96% of INT patients and 98% of the CON patients attending the 1-year follow-up visit. Forty-six percent of the INT patients and 57% of the CON patients attended centre-based exercise training (p=0.1). In the INT group 86% logged data in the application at least once. Adherence, defined as logging data at least twice per week, was 92% in week 1 and 57% in week 25. There was a numerical trend toward better exercise capacity improvement in the INT group (INT +14.4±19.0 vs. CON +10.3±16.1 W, p=0.2) although differences were non-significant. INT patients achieved larger BP reduction at 2-weeks (systolic) and 2-months (systolic and diastolic) (Figure). At 2-months 70% vs. 46% of smokers in the INT vs CON groups had quit smoking, and at 1-year the respective percentages were 57% vs. 36%. The number of smokers in the study was however low (n=33) and the differences non-significant. For other secondary endpoints no differences were observed.

Conclusion

Complementing CR with a mobile device application improved BP during the first months after MI, and non-significant trends towards better exercise capacity and higher smoking cessation rates were observed. Even though the differences were non-significant in our small study sample, they indicate that using eHealth in the form of a mobile device application could clinically benefit post-MI patients participating in CR.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Governmental funding of clinical research within the National Health Services in Sweden.

The Gly82Ser polymorphism in the receptor for advanced glycation end products is associated with increased risk for coronary events in the general population

Background/Introduction

Activation of the receptor for advanced glycation end products (RAGE) by AGEs and various immune mediators has pro-inflammatory and pro-atherogenic effects. RAGE also exists in a soluble form, sRAGE, that acts as a decoy receptor for RAGE ligands. Low plasma sRAGE has previously been found to be associated with a higher risk for major adverse coronary events (MACE) in the population.

Purpose

The purpose of our study was to examine the causality of the association, by exploring whether genetic variants that influence sRAGE are associated with atherosclerosis progression and incident MACE and mortality in the population.

Methods

We performed a genome-wide association study (GWAS) in 4192 individuals from a randomly selected subgroup of a population-based cohort. Subsequently, we explored the associations between the identified single nucleotide polymorphims (SNPs) associated with plasma sRAGE levels, baseline intima media thickness (IMT) and IMT progression in the common carotid artery during a median follow-up of 16.5 years. Further, we analyzed the prospective relationships between the sRAGE-associated SNPs, incident MACE and mortality in the entire population-based cohort of 29245 individuals. The median follow-up time from baseline was 21.2 years for MACE and 21.6 years for total mortality (time to event or end of follow-up).

Results

We found the minor alleles of two single nucleotide polymorphisms (SNPs), rs2070600 and rs204993, to be independently associated with lower plasma sRAGE. While rs204993 is a silent intronic mutation, rs2070600 is known to cause a Gly82Ser polymorphism in the ligand binding domain, enhancing RAGE propensity for activation. In Cox regression analyses, we found an association between the minor T (vs. C) allele of rs2070600 and increased risk for first-time MACE [HR 1.12 (1.02–1.23); P=0.023]. The association was independent of traditional cardiovascular risk factors, blood pressure-lowering medication and lipid-lowering medication at baseline. rs204993 was not associated with MACE. Neither SNP was associated with carotid IMT at baseline or with IMT progression. We did not identify any relationships with total mortality.

Conclusions

We demonstrate for the first time an independent link between a genetic RAGE determinant and the risk for MACE in the population. Despite both identified SNPs being associated with lower sRAGE levels, only the functional rs2070600 mutation was associated with MACE, suggesting that the link is probably due to the enhancement of RAGE function rather than to the sRAGE lowering effect.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): This study was supported by grants from the Swedish Research Council and the Swedish Heart and Lung foundation.

P2684Blood pressure lowering by using a self-care focused smartphone application for patients after myocardial infarction

Background

We have previously shown that complementing traditional cardiac rehabilitation (CR) with a web-based smartphone application designed to support self-control of risk factors can improve secondary prevention outcomes, including lower blood pressure (BP).

Purpose

To explore possible explanations for better BP control among patients with myocardial infarction (MI) receiving access to a smartphone application as a complement to traditional CR, compared to patients receiving traditional CR alone.

Methods

Data from a multi-centre randomized controlled trial that included 150 patients with MI (81% men, 60.4±8.8 years) was used. All patients participated in traditional CR. In addition, patients in the intervention group (APP, n=101) had access to the application. Patients received automated positive feedback on normal values and all registered data was viewed by CR nurses twice weekly. As previously reported, APP patients achieved a 9 mmHg larger reduction in systolic BP than usual care (UC) patients at 2-months follow-up (p=0.02). In the current analysis we assessed differences between APP and UC patients in the number of visits and telephone contacts with the CR clinic, number of reported BP measurements and number and type of interventions on account of out-of-range BP during the first 6 months of follow-up, using Mann-Whitney and chi-square tests.

Results

There was no difference in the median (IQR) number of visits to a CR nurse or physician (APP 2 (2–3) vs UC 2 (2–3), p=0.8) or telephone contacts ((APP 2 (1–4) vs UC 2 (1–4), p=0.8) between the groups. Approximately one in ten telephone contacts were initiated because of BP, with no difference between the groups (p=0.8). Out of 101 APP patients 75 reported BP values through the application, ranging from 1–175 BP values/patient (median 6 (IQR 0–34)). Most measurements (90%) were normal. Grouping clinic visits, telephone contacts due to BP and BP reports through the application as a composite for the number of BP measurements the CR personnel were exposed to during follow-up, there was a significant difference between the groups (APP 9 (4–36) vs UC 3 (2–3), p<0.0001). There was a small non-significant difference between the groups in the proportion of patients where an intervention was performed by the CR nurse on account of out-of-range BP (i.e. medication adjustments, new measurement scheduled) (APP 22% vs UC 12%, p=0.1).

Conclusion

While CR personnel were exposed to significantly more BP measurements from patients using a self-care focused smartphone application as a complement to traditional CR, most BP measurements reported through the application were normal and there was no difference in the number of interventions performed on account of out-of-range BP values. Automated positive feedback on in-range BP measurements, increased patient responsibility with better adherence to BP lowering medication could be possible explanations to improved BP control.

Acknowledgement/Funding

The faculty of Medicine, Lund University, Lund, Sweden

P5510High plasma sRAGE is associated with slower carotid intima media thickness progression and lower risk for first-time coronary events and mortality

Background/Introduction

The receptor for advanced glycation end products (RAGE) and the extracellular matrix metalloproteinase inducer (EMMPRIN) are immune receptors for pro-inflammatory mediators. These receptors can also be found in a soluble form in the circulation. Soluble RAGE (sRAGE) has shown atheroprotective properties in animal studies, by acting as a decoy receptor for its ligands. Whether sEMMPRIN has similar roles is unknown.

Purpose

The purpose of our study was to investigate the associations between sRAGE and sEMMPRIN in plasma and the progression of vascular disease, incident coronary events and mortality in the general population.

Methods

We measured baseline sRAGE and sEMMPRIN in 4612 cardiovascular disease-free middle aged individuals from a population-based cohort. Measurements of intima media thickness (IMT) in the common carotid artery were performed at inclusion and after a median of 16.5 years. Incident major adverse coronary events (MACE) and mortality were recorded during a follow-up period of 21 years.

Results

sRAGE was negatively correlated with the progression of carotid IMT, independently of traditional cardiovascular risk factors, kidney function and hsCRP. Additionally, sRAGE was associated with decreased risk for MACE [HR=0.91 (0.83–0.99); p=0.031] and total mortality [HR=0.92 (0.87–0.99); p=0.017] in multivariate Cox regression analyses. We found no correlations between EMMPRIN, IMT progression or prognosis.

Conclusion

We show that individuals with high levels of circulating sRAGE have a slower rate of carotid artery disease progression, and a lower risk for coronary events and mortality. These findings support further research into the potential atheroprotective properties of sRAGE.

Acknowledgement/Funding

This study was supported by grants from the Swedish Research Council, Marianne and Marcus Wallenberg Foundation, Swedish Heart and Lung Foundation

Anti-ApoA-I IgG antibodies are not associated with carotid artery disease progression and first-time cardiovascular events in middle-aged individuals

OBJECTIVE

IgG antibodies against apolipoprotein A-I (ApoA-I) have been found to be elevated in subjects from the general population with clinically manifest cardiovascular disease and in myocardial infarction patients with an adverse prognosis. Here, we investigated whether these antibodies are prospectively associated with carotid artery disease progression and with the risk for first-time cardiovascular events in individuals with no previous history of cardiovascular disease.

APPROACH AND RESULTS

We selected 383 subjects from the cardiovascular cohort of Malmö Diet and Cancer study who suffered a coronary event during a median follow-up period of 15.4 (10.3-16.4) years and 395 age- and sex-matched controls. None of the study participants had a previous history of coronary artery disease or stroke. Anti-ApoA-I IgG were measured by ELISA in serum samples collected at baseline. Intima-media thickness (IMT) was measured in the common carotid artery and in the carotid bifurcation at baseline and after 15.9 (±1.5) years. We found no associations between anti-ApoA-I IgG and carotid artery IMT at baseline or with IMT progression during follow-up. In Cox proportional hazards analyses adjusted for traditional cardiovascular risk factors, the hazard ratio (HR 95%CI) for the primary outcome, incident coronary events, was 0.97 (0.75-1.25), P = 0.782, in subjects with anti-ApoA-I IgG within the highest tertile compared with the lowest tertile. Similarly, we did not find any associations with the secondary outcome, incident first-time stroke.

CONCLUSIONS

Serum autoantibodies against ApoA-I do not correlate with disease progression and adverse events in cardiovascular disease-free individuals from the general population.

Plasma procalcitonin and the risk of cardiovascular events and death: a prospective population-based study

OBJECTIVES

A number of inflammatory biomarkers such as C-reactive protein (CRP) are independent predictors of cardiovascular risk. The inflammatory biomarker procalcitonin (PCT) has previously been shown to be associated with coronary atherosclerosis and the metabolic syndrome. We evaluated the ability of PCT to predict future cardiovascular events in a population of apparently healthy individuals.

DESIGN

We measured plasma PCT levels in 3713 subjects with no previous history of cardiovascular disease, randomly selected from the Malmö Diet and Cancer cohort. The correlation between PCT concentration and the incidence of coronary events, stroke and cardiovascular death over a median follow-up period of 13.7 years was studied using a Cox regression analysis corrected for age, sex, CRP level, traditional risk factors and renal function.

RESULTS

Age and sex were strong determinants of PCT; the concentration of PCT was significantly higher in men than in women. PCT was associated with several of the established cardiovascular risk factors (CRP, hypertension, diabetes and renal function) as determined by multivariate linear regression. Of note, PCT was inversely correlated with HDL and smoking. We found significant correlations between PCT levels, coronary events and cardiovascular death. However, these relationships lost statistical significance when the analysis was corrected for CRP and the traditional risk factors.

CONCLUSIONS

This is the largest population-based prospective study to demonstrate a positive association between plasma PCT levels and cardiovascular risk in subjects with no previous history of acute cardiovascular events. However, the high degree of covariation between PCT and other cardiovascular risk factors limits the value of PCT as an independent cardiovascular risk predictor.

Low-dose rapamycin treatment increases the ability of human regulatory T cells to inhibit transplant arteriosclerosis in vivo

Regulatory T cells (T(reg)) are currently being tested in clinical trials as a potential therapy in cell and solid organ transplantation. The immunosuppressive drug rapamycin has been shown to preferentially promote T(reg) expansion. Here, we hypothesized that adjunctive rapamycin therapy might potentiate the ability of ex vivo expanded human T(reg) to inhibit vascular allograft rejection in a humanized mouse model of arterial transplantation. We studied the influence of combined treatment with low-dose rapamycin and subtherapeutic T(reg) numbers on the development of transplant arteriosclerosis (TA) in human arterial grafts transplanted into immunodeficient BALB/cRag2(-/-) Il2rg(-/-) mice reconstituted with allogeneic human peripheral blood mononuclear cell. In addition, we assessed the effects of the treatment on the proliferation and apoptosis of naïve/effector T cells. The combined therapy efficiently suppressed T-cell proliferation in vivo and in vitro. Neointima formation in the human arterial allografts was potently inhibited compared with each treatment alone. Interestingly, CD4(+) but not CD8(+) T lymphocytes were sensitive to T(reg) and rapamycin-induced apoptosis in vitro. Our data support the concept that rapamycin can be used as an adjunctive therapy to improve efficacy of T(reg)-based immunosuppressive protocols in clinical practice. By inhibiting TA, T(reg) and rapamycin may prevent chronic transplant dysfunction and improve long-term allograft survival.

Low-dose rapamycin treatment increases the ability of human regulatory T cells to inhibit transplant arteriosclerosis in vivo

Regulatory T cells (T(reg)) are currently being tested in clinical trials as a potential therapy in cell and solid organ transplantation. The immunosuppressive drug rapamycin has been shown to preferentially promote T(reg) expansion. Here, we hypothesized that adjunctive rapamycin therapy might potentiate the ability of ex vivo expanded human T(reg) to inhibit vascular allograft rejection in a humanized mouse model of arterial transplantation. We studied the influence of combined treatment with low-dose rapamycin and subtherapeutic T(reg) numbers on the development of transplant arteriosclerosis (TA) in human arterial grafts transplanted into immunodeficient BALB/cRag2(-/-) Il2rg(-/-) mice reconstituted with allogeneic human peripheral blood mononuclear cell. In addition, we assessed the effects of the treatment on the proliferation and apoptosis of naïve/effector T cells. The combined therapy efficiently suppressed T-cell proliferation in vivo and in vitro. Neointima formation in the human arterial allografts was potently inhibited compared with each treatment alone. Interestingly, CD4(+) but not CD8(+) T lymphocytes were sensitive to T(reg) and rapamycin-induced apoptosis in vitro. Our data support the concept that rapamycin can be used as an adjunctive therapy to improve efficacy of T(reg)-based immunosuppressive protocols in clinical practice. By inhibiting TA, T(reg) and rapamycin may prevent chronic transplant dysfunction and improve long-term allograft survival.