Identifying proteomic profiles as indicators of disease severity in arrhythmogenic cardiomyopathy

Introduction

Arrhythmogenic cardiomyopathy (ACM) is an inherited heart muscle disease characterized by progressive fibrofatty replacement of the myocardium and ventricular arrhythmias. Biventricular (BiV) involvement may lead to heart failure. This study aimed to investigate characteristic proteomic patterns in plasma of ACM patients, and correlated them with clinical outcome as well as physical exercise, to assess if key soluble molecules may serve as specific biomarkers for ACM, and whether mechanical stress induced by physical exercise may alter proteomic patterns in ACM patients.

Methods

In 38 ACM patients clinical parameters and major adverse cardiovascular events (MACE defined as presence of sustained ventricular tachycardia, ventricular fibrillation, appropriate therapy from implantable cardioverter defibrillator, sudden cardiac death, death related to end-stage heart failure or cardiac transplant) were obtained prospectively during a mean follow-up period of 36 months. All patients received genetic testing using next generation DNA sequencing. Plasma protein expression was analysed using the Proximity Extension Assay (PEA) technology, where a pair of oligonucleotide-labelled antibody probe binds to each targeted protein. In a subgroup of 11 patients blood was drawn immediately before and 3 hours after standardised bicycle exercise testing, and plasma protein expression was compared.

Results

12 patients had ACM with BiV involvement, and 26 patients had isolated right ventricular (RV) involvement. During the follow-up period, 34 patients had a MACE (30% with RV and 14% with BiV). Over 360 proteins were assessed in all ACM patients and compared to 24 healthy controls. The proteomic signature of ACM patients differed significantly compared to controls, and 32 proteins were upregulated in ACM (Figure 1). The proteomic profiles of patients with RV involvement also differed from those with BiV involvement. Most importantly, after exercise, over 40 proteins were upregulated specifically in ACM patients compared to controls, including key pro-inflammatory, adipogenic molecules and also markers of cardiac fibrosis.

Conclusion

Our study shows that ACM patients with RV and BiV involvement have different plasma proteomic profiles compared to healthy controls. Furthermore we were able to demonstrate that, specifically in ACM patients, several pro-inflammatory pathways are upregulated after exercise compared to healthy controls, further elucidating the molecular pathways associated with arrhythmogenicity and disease progression and highlighting the key role of physical stress. Our results may enable the identification of potential future biomarkers for diagnosis and risk stratification and may pave the way for personalized patient specific treatments.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Baugarten Foundation ZurichSwiss National Foundation

Outcomes of patients presenting with acute coronary syndromes on workdays vs. rest days (SPUM-ACS substudy)

Introduction

Conflicting data exist upon whether patients presenting with acute coronary syndromes (ACS) during on- or off-hours differ regarding outcomes. Moreover, definitions of on- and off-hours vary in literature. The notion of a weekend effect with increased mortality has been raised, mostly seen in relation to lesser use of invasive treatment.

Purpose

This multi-center study investigated the baseline characteristics and associated outcomes of patients presenting with ACS undergoing coronary angiography on weekdays compared to those presenting on weekends or holidays.

Methods

Data from the prospective SPUM-ACS (Special Program University Medicine Acute Coronary Syndromes and Inflammation) Cohort were examined, with patients recruited between 2009 and 2012. Patients were divided into two groups according to whether they presented for coronary angiography for ACS on workdays (Monday-Friday, 00:00–23:59) or on rest days (Saturday or Sunday, 00:00–23:59, and public holidays shared by all centers). Time of presentation was defined as time point of catheter sheath insertion.

Results

From a total of 2168 patients (21.4% females), 1828 (84.3%) presented on workdays, 340 (15.7%) on rest days without difference in female/male ratio. On rest days, patients more often showed signs of advanced heart failure (Killip Class III–IV 3.9% vs. 7.1%, p=0.009). Patients presented more frequently with ST-segment elevation ACS (STE-ACS) than non-ST-segment elevation ACS (STE-ACS on workdays vs. rest days: 50.4% vs. 65.0%, p<0.001).

In- and out-of-hospital time delay metrics did not differ between groups, apart from symptom onset-to-balloon time, which was shorter on rest days (598 vs. 520 min, p=0.040). There was a trend towards more frequent use of percutaneous (89.2% vs. 92.6%, p=0.053) or surgical (3.3% vs 5.0%, p=0.131) revascularization on rest days.

30-day all-cause mortality was higher on rest days for any ACS (1.75% vs 3.82%, p=0.007) and for STE-ACS only (2.39% vs 4.98%, p=0.019, Fig. 1). Notably, the same trend was seen when comparing only patients presenting with Killip Class III/IV, both for any ACS (11.27% vs. 20.83%, p=0.119) and for STE-ACS (14.00% vs. 26.32%, p=0.114). On rest days, female patients showed higher 30-day all-cause mortality than males for any ACS (7.46% vs 2.93%, p=0.042); the same trend was observed for STE-ACS (8.89% vs. 3.98%, p=0.088).

Conclusions

On rest days, patients more often presented with STE-ACS and more frequently showed signs of advanced heart failure, with similar use of invasive revascularization as for patients presenting on workdays. This might contribute to higher early mortality observed in ACS patients on rest days. These differences persisted within the subgroups STE-ACS and Killip Class III/IV. Interestingly, female patients showed increased early mortality on rest days compared to males. Thus, patients presenting with ACS on rest days warrant particular attention.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Swiss National Science Foundation (SNSF)

Prevalence and outcomes of peripheral artery disease in a real-world cohort of patients with acute coronary syndrome: insights from the prospective SPUM registry

Background

Despite substantial improvement in secondary preventive therapy, the burden of recurrent cardiovascular (CV) events remains high. Peripheral artery disease (PAD), is a potential marker of increased residual ischemic risk in acute coronary syndrome (ACS) patients suggesting greater net clinical benefit from intensified individualized therapy.

Purpose

We aimed to assess the prevalence and cardiovascular (CV) outcomes of peripheral arterial disease (PAD) in 4'787 patients with acute coronary syndromes (ACS) in the Swiss prospective multicenter SPUM study.

Methods

PAD was defined according to international guidelines. The composite primary endpoint was major adverse cardiac and cerebrovascular events (MACCE), i.e., stroke, myocardial infarction (MI) and death at 1 year. Adjusted Cox proportional hazards regression models were used to estimate the risk associated with PAD and outcomes.

Results

Out of 4'787 ACS patients, 285 patients (6.0%) had PAD. These patients were older (70.1±10.6 vs 63.3±12.4, p<0.001), presented all traditional CV risk factors (all p<0.001) and were more likely to have a complex history of CV disease, such as previous MI (24.3% vs 11.4%, p<0.001), prior percutaneous (32.3% vs 13.8%, p<0.001) or surgical (12.6% vs 3.5%, p<0.001) coronary revascularization. PAD-patients presented also higher levels of inflammatory biomarkers, such as hs-CRP, and GRACE 2.0 score (all p<0.001). At 1 year, patients with PAD had a higher rate of MACCE compared to those presenting without PAD. Rates of the individual components of the primary endpoint and CV-death were all significantly higher in patients with PAD (all p<0.001), except for a numerical increase in MI (5.3% vs 3.3%, p=0.060). This enhanced risk persisted after adjustment for differences in baseline characteristics, with a 53% (Adj. HR 1.53, CI95% 1.14–2.08, p=0.005) increase in MACCE. In spite of high-intensity anti-thrombotic therapy, PAD patients presented the same rate (Adj. HR 1.03, CI95% 0.68–1.54, p=0.901) of major bleeding events at 1 year.

Conclusions

Among a real-world cohort of ACS patients, the coexistence of PAD, a very-high CV risk phenotype, is associated with significantly increased rates of MACCE, but no difference in major bleeding events. These observations might help clinicians to further stratify this very-high risk population and to identify patients who may derive the greatest benefit from more intense secondary prevention therapies.

Funding Acknowledgement

Type of funding sources: None.

Heavy weekly alcohol consumption versus binge drinking after an acute coronary syndrome and risk of major adverse cardiovascular events at one year follow up

Background

The association between heavy weekly alcohol consumption or binge drinking and the risk of major adverse cardiovascular events (MACE) after acute coronary syndromes (ACS) is still unclear.

Purpose

To determine the risks of MACE at one year follow up according to baseline alcohol consumption, especially in patients with heavy weekly alcohol consumption or binge drinking.

Methods

We analyzed data of 6053 patients hospitalized in 4 Swiss centres for an ACS and followed over 12 months. Data on alcohol consumption were collected at baseline and at one year follow up after ACS. Binge drinking was defined as the consumption of ≥6 units of alcohol on one occasion, for the 12-months period preceding the one-year follow up. We defined MACE as a composite of cardiac death, myocardial infarction, stroke or clinically indicated target vessel coronary revascularization. We applied Cox regression to assess the risk of MACE associated with heavy alcohol weekly consumption (>14 standard units/week) compared to light consumption (<1 standard unit/week) or abstinence, as well as the risk with binge drinking, compared to no binge drinking, adjusting for baseline differences (age, sex, body-mass index, smoking, diabetes, peripheral artery disease, stroke, hypertension, use of aspirin, anticoagulation, statin, beta-blocker, ACE-inhibitor or ATII receptor blocker).

Results

At baseline, 817 (13.4%) patients reported heavy weekly alcohol consumption and 717 (11.8%) reported to have at least one episode of binge drinking per month. The risk for MACE at one year follow up was not increased in those with heavy weekly consumption compared to light consumption (8.7% vs. 8.5%, HR 0.96, 95% CI 0.69–1.33, P=0.80) or no consumption (8.7% vs. 10.3%, HR 1.26, 95% CI 0.88–1.80, P=0.21). However, the risk of MACE was higher in those reporting binge drinking with less than one episode a month (9.4% vs. 7.7%, HR 1.67, 95% CI 1.32–2.12, P<0.001), as well as in those with at least one episode of binge drinking per month (13.4% vs. 7.7%, HR 2.07, 95% CI 1.62–2.65, P<0.001), when compared to no binge drinking.

Conclusion

In contrast to regular heavy alcohol consumption, binge drinking behavior is associated with significant increased risk of MACE 12 months after ACS.

Funding Acknowledgement

Type of funding sources: None.

Statin therapy intensity and physical activity after acute coronary syndrome

Introduction/Purpose

High-intensity statin after acute coronary syndrome (ACS) may cause reduced physical activity because of statin-associated muscle symptoms. We aimed to assess the association between statin intensity and physical activity one year after ACS.

Methods

We studied patients from the Special Program University Medicine-Acute Coronary Syndromes (SPUM-ACS) study, a large multicenter prospective Swiss cohort. In a cross-sectional assessment one year after the index ACS, we identified high-intensity, low/moderate intensity, and no statin users. Physical activity was assessed with the International Physical Activity Questionnaire (IPAQ). Using a multivariable adjusted negative binomial hurdle model, metabolic equivalent-minutes per week (MET-min/week) were first stratified into sedentary and physically active categories, and then analyzed continuously among physically active patients. Models were adjusted for age, sex, education, body mass index, depression, type of ACS, pre-existing chronic disease, premature coronary heart disease, LDL-cholesterol, anti-hypertensive treatment, cardiac rehabilitation, and follow-up medical visits after hospital discharge.

Results

Among the 2274 patients included in the SPUM-ACS cohort, 1222 (53.7%) were on high intensity statin, 890 (39.1%) on low/moderate intensity statin, and 162 (7.1%) were not on statin. Compared to no statin users, low/moderate intensity statin users were more likely to be physically active than sedentary, with a fully adjusted odds ratio (OR) of 2.78, 95% confidence interval (CI) 1.11–6.93. A similar association was found when comparing non-users with high-intensity statin users, with a fully adjusted OR of 4.18, 95% CI 1.65–10.60. Among physically active patients, physical activity level median scores were 2792.5 MET-min/week in no statin category, 2712.0 and 2839.5 in moderate/low statin category and high statin category respectively (p=0.307), showing no statistically significant difference with median ratios of 1.02, 95% CI 0.84–1.22 and 1.06, 95% CI of 0.88–1.27 for low/moderate intensity and high-intensity statin use, respectively.

Conclusion

One year after an ACS, neither low/moderate nor high-intensity statin was associated with reduced physical activity compared to no statin use. These findings go against the belief that statin therapy may lead to reduced physical activity among ACS patients because of associated muscular symptoms.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Center for primary care and public health (Unisanté)

Systemic immune-inflammation index predicts major adverse cardiovascular events in patients with ST-elevation myocardial infarction

Background

ST-elevation myocardial infarction (STEMI) represents the life-threatening manifestation of atherosclerosis, a chronic inflammatory disease of arterial wall, and is associated with high rate of morbidity and mortality. Thus, inflammatory biomarkers may be useful in identifying high inflammatory burden patients who may benefit from tailored high-intensity secondary prevention therapy.

Purpose

We therefore assessed the relationship between the systemic immune-inflammation index (SII) and CV outcomesamong 1144 all-comers patients admitted to four Swiss University Hospital for STEMI and enrolled in the prospective multicenter SPUM registry cohort I (NCT 01000701).

Methods

SII was calculated as platelet counts x neutrophil counts / lymphocyte counts. Patients were subdivided into three groups according to SII tertiles. The composite primary endpoint was major adverse cardiac and cerebrovascular events (MACCE: stroke, myocardial infarction, CV death). Adjusted Cox proportional hazards regression models were implemented to determine the risk associated with SII and outcomes.

Results

Out of 1144 STEMI patients, 912 patients (79,7%) had available for SII. Patients within the highest tertile were slightly more frequently male (23.0 vs 22.0%, p=0.05), with higher plasma values of neutrophils (11.4±2.4 vs 6.5±3.7 G/l, p<0.001), platelets (275.3±97.5 vs 202.5±51.6 G/l, p<0.001) and lower levels of lymphocytes (1.0±0.6 vs 2.1±1.1 G/l, p<0.001) and LVEF (46.4±11.5% vs 50.4±10.3%, p<0.001) (Fig. 1A). At 1 year, these patients presented the highest rate of all-cause mortality (7.2% vs 2.6%, p=0.02) and MACCE (8.2% vs 3.3, p=0.03). This enhanced risk persisted for all-cause mortality and MACCE, after adjustment for age, sex, ace-inhibitors and statin therapy (Adj. HR 2.85, 95% CI 1.30–6.70, p=0.03 and Adj. HR 2.63, 95% CI 1.25–5.55, p=0.03, respectively, Fig. 1B).

Conclusions

Among a real-world cohort of STEMI-patients, SII highlights the highest inflammatory risk phenotype, being associated with significant increased rates of MACCE and all-cause of death. These observations might help clinicians to furtherly identify patients who may derive the greatest benefit from tailored more intense secondary prevention therapies including inflammatory modulation.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Location and impact of the infarct-related artery in acute coronary syndrome: insight from the Swiss SPUM- ACS cohort

Background

Identifying the infarct-related artery (IRA) in patients with acute coronary syndromes (ACS) has prognostic and therapeutic implications.

Purpose

We aimed to evaluate the distribution, clinical presentation and impact of the culprit lesion location on long-term outcomes in ACS patients treated with primary percutaneous coronary intervention, medication and secondary prevention according to Guidelines.

Methods

Patients referred for ACS to one of the participating centres of the observational SPUM-ACS study between 2009 and 2017 with one year outcomes and independent events adjudication were included. The distribution of IRA, clinical presentation (STEMI/NSTEMI) and impact of IRA location on major adverse cardiac events (cardiac death, myocardial infarction, stent thrombosis, target vessel revascularisation) at one year were investigated.

Results

4'546 patients were included with 55% presenting as STEMI (mean age 62-years; 20% women), 42% as NSTEMI and 3% as unstable angina. The left anterior descending (LAD) artery was involved in 44.3%, the right coronary artery (RCA) and left circumflex artery (LCX) in 32.9% and 20%, respectively. Proximal and middle segments of the 3 main vessels were more often the culprit location compared to distal segments and side branches (78% versus. 22%). Left main (LM) and bypass graft were rarely involved (1.6% and 1.2% respectively), but most often responsible to overall cardiac dysfunction (higher NT-proBNP and hs troponin levels). Patients with an occluded IRA at angiography usually presented as STEMI on ECG (100% for LM, 90.5% for LAD territory, 83.8% for RCA territory, 56.6% for LCX territory). However 43.1% of patients with occluded LCX presented as NSTEMI. These patients were prone to extensive cardiac damage and significantly higher hs troponin levels as compared to those with patent LCX or STEMI presentation (626 ng/l vs 310 ng/l and 626 ng/l vs 580 ng/l respectively, p<0.001). Overall, 1-year MACE occurred in 11.8%. In native coronaries, the location of IRA had no impact on outcomes (20% LM, 10.9% LAD, 11.8% RCA, 11.8% LCX, p=0.112). However, in NSTEMI-ACS there were twice as many events when the LM was the IRA (MACE 20%, p=0.023) and 3-times higher when a bypass-graft was the IRA (33.9%, p=0.0001).

Conclusions

ST elevations are highly suggestive of an occluded IRA. However more than 40% of patients presenting with ACS involving an occluded LCX did not demonstrate ST-elevation and were prone to extensive cardiac damage, urging the necessity for early invasive measures in these patients. In native coronaries the IRA location did not affect outcomes except in NSTEMI with LM involvement or ACS with bypass grafts as IRA that had much worse outcomes.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): - Swiss National Research Foundation - Zurich Heart House

Impact of smoking cessation on depression after acute coronary syndrome

Background

Smoking and depression are two risk factors for acute coronary syndrome (ACS) that often go hand-in-hand, as smokers are more likely to be depressed and people that are depressed are more likely to be smokers. Smoking cessation in depressed patients with ACS may worsen depressive symptoms, which could increase the risk of recurrence of cardiac events and decrease adherence to other cardiac risk-reducing lifestyle changes.

Purpose

We aimed to investigate the evolution of depression according to smoking cessation one-year after ACS. Furthermore, we investigated if there was a higher incidence of one-year depression among ACS smokers who quit in comparison to continuous smokers.

Method

Data from 1,822 patients with ACS of the Swiss multicenter SPUM-ACS cohort study were analysed over a one-year follow-up period. Participants were classified in three groups based on smoking status one-year post-ACS – continuous smokers, smokers who quit within the year post-ACS, and non-smokers. Depression status at baseline and at one-year after the index ACS event was assessed with the Center for Epidemiologic Studies Depression scale (CES-D) and antidepressant drug use. A multivariate adjusted logistic regression model was used to calculate the risk ratio (RR) between groups.

Results

In comparison to depressed smokers who continued to smoke one year post-ACS, depressed smokers who quit smoking had an adjusted RR of 2.02 (95% CI 1.04–3.92) of improving their depression. Among 543 non-depressed ACS smokers, new depression at one-year was found in 57/266 (21.4%) smokers who quit, and 68/277 (24.6%) continuous smokers, with an adjusted RR of 0.89 (95% CI 0.58–1.36) of incidence of new depression.

Conclusion

Smokers with depression at the time of ACS who quit smoking improved more frequently their depression compared to those who continued smoking. Although not statistically significant, there was a smaller incidence of new depression among smokers who quit after ACS in comparison to continuous smokers.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Swiss National Science Foundation

P1222Intensification of lipid lowering therapy before and after publication of the IMPROVE-IT trial: A temporal analysis from the SPUM-ACS cohort

Background

The gradual implementation of evidence-based treatment strategies has improved outcomes in patients with acute coronary syndromes (ACS). The Improved Reduction of Outcomes: Vytorin Efficacy International Trial (IMPROVE-IT) was published on June 3rd, 2015, but its relevance on real life practice has not been explored.

Methods

We analyzed a prospective Swiss cohort of 6266 patients hospitalized for ACS between 2009 and 2017. The primary endpoints were the ezetimibe use overall or in combination with high-intensity statin at discharge and at one year after ACS. Secondary endpoint was LDL-C target achievement at one year in a subsample of 2984 patients. Relative Ratios (RR) were used to assess changes in primary endpoints before and after the publication of IMPROVE-IT, adjusting for age, sex, pre-existing diabetes, history of myocardial infarction, baseline low-density lipoprotein cholesterol (LDL-C) and attendance to cardiac rehabilitation.

Results

The period following the publication of the IMPROVE-IT trial was associated with an overall increase in the use of ezetimibe at discharge (from 1.8% to 3.8%, P<0.001, adjusted RR 2.85, 95% CI 1.90–4.25) and at one year (from 5.0% to 13.8%, P<0.001, adjusted RR 3.00, 95% CI 2.40–3.75). Before IMPROVE-IT trial, ezetimibe use at one year was stable around 5%, then steadily increased after its publication until 20% for patients included in 2017. The combination of high-intensity statin and ezetimibe increased from 0.9% to 2.1% at discharge (P<0.001, adjusted RR 3.35, 95% CI 1.90–5.89) and from 2.1% to 7.8% at one year (P<0.001, adjusted RR 3.98, 95% CI 2.90–5.47). The period following the publication of the IMPROVE-IT trial was associated with an improvement of LDL-C target <1.8 mmol/L (adjusted RR 1.37, 95% CI 1.12–1.68).

Conclusion

After the publication of the IMPROVE-IT trial, the use of ezetimibe was increased by three-fold in a large contemporary cohort of ACS patients, concomitant with an improved LDL-C target achievement.

P6440The perils of polyvascular disease with concomitant type 2 diabetes in a real-world cohort of patients with acute coronary syndrome

Background

Despite substantial improvement in type 2 diabetes (DM2) care, the burden of recurrent cardiovascular (CV) events remains high. Polyvascular disease (PVD), has recently emerged as a potential marker of heightened residual ischemic risk in DM2 patients, that are likely to derive a greater absolute risk reduction from more intense, individualized therapy.

Purpose

We sought to assess the relationship between DM2, PVD and CV outcomes among 2,168 all-comers patients admitted to four Swiss University Hospital for acute coronary syndrome (ACS) and enrolled in the prospective multicenter SPUM registry (NCT 01000701).

Methods

PVD was defined as concomitant peripheral artery disease, stroke or transient ischemic attack, or both. The composite primary endpoint was major adverse cardiac and cerebrovascular events (MACCE: Stroke, myocardial infarction, CV death). Adjusted Cox proportional hazards regression models were implemented to determine the risk associated with PVD disease in DM2 and outcomes, and intention-to-treat analysis was performed.

Results

Out of 2,168 ACS patients, 396 patients (18.3%) had DM2; of these 62 (15%) had PVD. Despite compared with the general ACS population, those with PVD + DM2 were more likely to have a complex history of CV disease, such as previous MI (27.4% vs 14.7%, p=0.021), prior percutaneous (37.1% vs 17%, p<0.001) or surgical (24.2% vs 5.1%, p<0.001) coronary revascularization, one third was not on statin therapy. At 1 year, patients with PVD + DM2 had a higher rate of MACCE compared to those presenting with PVD or DM2 alone. Rates of the single components of the primary endpoint and all-cause of death were all significantly higher in patients with PVD + DM2 vs. PVD or DM2 alone (Fig. 1A, all p<0.001). This enhanced risk persisted after adjustment for significant baseline differences, with a 34% (Adj. HR 1.34, 95% CI 1.15–1.49, p=0.02) increase in MACCE and a 44% increment of all cause of death (Adj. HR 1.44, 95% CI 1.06–1.54, p=0.02, Fig. 1B).

Outcomes by PVD and DM2 status.

Conclusions

Among a real-world cohort of ACS-patients, the coexistence of PVD and DM2 highlights the highest CV risk phenotype, being associated with significant increased rates of MACCE and all-cause of death. These observations might help clinicians to furtherly stratify the very high risk population and to identify patients who may derive the greatest benefit from more intense secondary prevention therapies.

P715Deletion of fibroblast activation protein decreases experimental atherosclerotic plaque formation and vulnerability

Background

Fibroblast activation protein (FAP) is a serine protease that is upregulated in sites of tissue remodeling, including arthritis, tumors and atherosclerosis. We have reported that FAP degrades type I collagen in human thin-cap fibroatheromata; its expression is enhanced in advanced human plaques and induced by inflammation. However, the role of endogenous FAP in atherosclerosis remains unknown.

Purpose

To investigate the effects of constitutive Fap loss-of-function on atherosclerotic plaque formation and vulnerability.

Methods and results

Male 8-week-old Apoe−/− Fap+/+ and Apoe−/− Fap−/− mice were fed a high-cholesterol diet (1.25% chol) for 12 weeks. En face analyses of thoracoabdominal aortae using Oil Red O (ORO) revealed decreased plaques in Apoe−/− Fap−/− mice (5.7±0.5%; n=21) compared to Apoe−/− Fap+/+ mice (10.7±0.7%; n=24; p<0.0001). In parallel, ORO analyses of serial aortic root cross sections showed diminished plaques in Fap-deficient mice (18.4±3.4% vs 27.6±2.1%). As a surrogate of plaque vulnerability, fibrous cap thickness was increased in Apoe−/− Fap−/− mice (65±6 mm vs 35±3 mm; p<0.01), whereas necrotic core size, plaque macrophages (CD68) and T cells (CD3) accumulation, as well as VCAM1 expression did not differ. These changes were independent of plasma triglycerides, total and LDL-cholesterol levels. Plasma of Fap-deficient mice showed decreased FAP activity compared to Fap wildtype controls. Notably, second harmonics generation in cross sections of aortic root plaques showed that the deposition and density of fibrillar collagens was enhanced in Fap-deficient (25.5±4.4%) compared to control plaques (13.8±2.5%; p<0.05). Consistently, Fap deletion led to an accumulation of uncleaved pre-COL3A1, a proteolytic target of FAP.

Conclusions

Constitutive Fap deletion decreases experimental atherosclerosis and features of plaque vulnerability. Thus, inhibition of FAP expression or activity may be a promising therapeutic target in atherosclerosis.

Acknowledgement/Funding

Swiss National Science Foundation, Swiss Heart Foundation

2287Endothelial SIRT6 exerts a beneficial role in cerebral ischemia/reperfusion injury by preserving blood-brain barrier integrity

Introduction

Stroke is a major cause of mortality and morbidity worldwide. Yet, therapeutic strategies are limited to the early reperfusion which can, on the other hand, worsen the brain damage trough ischemia/reperfusion (I/R) injury. Post-stroke blood-brain barrier (BBB) impairment is associated with worsened outcome. Aging is a major risk factor for stroke and genes regulating lifespan also contribute to the determination of cerebral damage during I/R injury.

Purpose

Given the pivotal role of endothelial cells in BBB, we hypothesized that the endothelial-specific expression of the longevity gene SIRT6 may protect the BBB from ischemia/reperfusion damage thus having a beneficial role on stroke outcome.

Methods

Endothelial-specific SIRT6 knockout (eSIRT6−/−) mice and control littermates (CTRL) underwent transient middle cerebral artery occlusion (tMCAO) for 45 min followed by 48 hours of reperfusion. Immunohistochemistry (IHC) was used to investigate BBB permeability by IgG extravasation and molecular mechanisms. Primary human brain microvascular endothelial cells (HBMVECs) transfected with either SIRT6 (siSIRT6) or scrambled (siSCR) small interfering RNA were subjected to hypoxia/reoxygenation (H/R). An in vitro BBB model consisting of a monolayer of siRNA-treated HBMVECs was established and barrier function was assessed by 48 h-lasting transendothelial electrical resistance measurement. SIRT6 expression in monocytes from stroke patients was correlated with the short-term neurological outcome [ΔNIHSS% = (NIHSS discharge-NIHSS admission)/ NIHSS admission*100].

Results

eSIRT6−/− displayed higher infarct volumes and lower survival rate compared to WT mice 48 h after tMCAO. The increased infarct volume was functionally relevant as eSIRT6−/− also showed worse post-stroke neurological impairment. Analysis of brain sections revealed increased BBB damage and increased endothelial expression of cleaved caspase-3 in eSIRT6−/− as compared to control littermates. In vitro, H/R reduced SIRT6 expression in HBMVECs. Mirroring the animal results, SIRT6 silencing impaired the barrier function of HBMVECs 48 h after exposure to H/R. In line with this, SIRT6-silenced HBMVECs showed reduced viability, increased cleaved caspase-3 expression and reduced activation of the anti-apoptotic survival pathway Akt as compared to control cells after H/R. The direct interaction between SIRT6 and Akt was confirmed by co-immunoprecipitation. In ischemic stroke patients, SIRT6 expression was higher in those with short-term neurological improvement (ΔNIHSS% >0) and negatively correlated with ΔNIHSS%.

Conclusion

Endothelial SIRT6 exerts a beneficial role in ischemic stroke by blunting I/R-mediated BBB damage. Specifically, SIRT6 reduces endothelial I/R-induced apoptotic death through activation of the protective Akt pathway. The longevity gene SIRT6 may represent a novel therapeutic target for the treatment of ischemic stroke.

Acknowledgement/Funding

Swiss National Science Foundation

Long-term outcomes of elderly patients with CYP2C9 and VKORC1 variants treated with vitamin K antagonists

Essentials The long-term effects of VKORC1 and CYP2C9 variants on clinical outcomes remains unclear. We followed 774 patients ≥65 years with venous thromboembolism for a median duration of 30 months. Patients with CYP2C9 variants are at increased risk of death and non-major bleeding. Patients with genetic variants have a slightly lower anticoagulation quality only.

SUMMARY

Background The long-term effect of polymorphisms of the vitamin K-epoxide reductase (VKORC1) and the cytochrome P450 enzyme gene (CYP2C9) on clinical outcomes remains unclear. Objectives We examined the association between CYP2C9/VKORC1 variants and long-term clinical outcomes in a prospective cohort study of elderly patients treated with vitamin K antagonists for venous thromboembolism (VTE). Methods We followed 774 consecutive patients aged ≥ 65 years with acute VTE from nine Swiss hospitals for a median duration of 30 months. The median duration of initial anticoagulant treatment was 9.4 months. The primary outcome was the time to any clinical event (i.e. the composite endpoint of overall mortality, major and non-major bleeding, and recurrent VTE. Results Overall, 604 (78%) patients had a CYP2C9 or VKORC1 variant. Three hundred and thirty-four patients (43.2%) had any clinical event, 119 (15.4%) died, 100 (12.9%) had major and 167 (21.6%) non-major bleeding, and 100 had (12.9%) recurrent VTE. After adjustment, CYP2C9 (but not VKORC1) variants were associated with any clinical event (hazard ratio [HR], 1.34; 95% confidence interval [CI], 1.08-1.66), death (HR, 1.74; 95% CI, 1.19-2.52) and clinically relevant non-major bleeding (sub-hazard ratio [SHR], 1.39; 95% CI, 1.02-1.89), but not with major bleeding (SHR, 1.03; 95% CI, 0.69-1.55) or recurrent VTE (SHR, 0.95; 95% CI, 0.62-1.44). Patients with genetic variants had a slightly lower anticoagulation quality. Conclusions CYP2C9 was associated with long-term overall mortality and non-major bleeding. Although genetic variants were associated with a slightly lower anticoagulation quality, there was no relationship between genetic variants and major bleeding or VTE recurrence.

Association between thyroid dysfunction and venous thromboembolism in the elderly: a prospective cohort study

BACKGROUND

Venous thromboembolism (VTE) and subclinical thyroid dysfunction (SCTD) are both common in elderly patients. SCTD has been related to a hypercoagulable state and an increased thromboembolic risk. However, prospective data on the relationship between SCTD and VTE are lacking.

OBJECTIVES

To investigate the relationship between SCTD and recurrent VTE (rVTE), all-cause mortality, and thrombophilic biomarkers. Patients Elderly patients with VTE were studied.

METHODS

In a prospective multicenter cohort, thyroid hormones and thrombophilic biomarkers were measured 1 year after acute VTE, as both may be influenced by acute thrombosis. We defined subclinical hypothyroidism (SHypo) as elevated thyroid-stimulating hormone (TSH) levels (4.50-19.99 mIU L(-1) ), and subclinical hyperthyroidism (SHyper) as TSH levels of < 0.45 mIU L(-1) , both with normal free thyroxine levels. Outcomes were incidence of rVTE and overall mortality during follow-up starting after the 1-year blood sampling.

RESULTS

Of 561 participants (58% with anticoagulation), 6% had SHypo and 5% had SHyper. After 20.8 months of mean follow-up, 9% developed rVTE and 10% died. The rVTE incidence rate was 7.2 (95% confidence interval [CI] 2.7-19.2) per 100 patient-years in SHypo participants, 0.0 (95% CI 0.0-7.6) in SHyper participants, and 5.9 (95% CI 4.4-7.8) in euthyroid participants. In multivariate analyses, the sub-hazard ratio for rVTE was 0.00 (95% CI 0.00-0.58) in SHyper participants and 1.50 (95% CI 0.52-4.34) in SHypo participants as compared with euthyroid participants, without increased levels of thrombophilic biomarkers. SHyper (hazard ratio [HR] 0.80, 95% CI 0.23-2.81) and SHypo (HR 0.99, 95% CI 0.30-3.29) were not associated with mortality.

CONCLUSION

In elderly patients, SHyper may be associated with lower rVTE risks. SHypo showed a non-statistically significant pattern of an association with rVTE, without increased mortality or differences in thrombophilic biomarkers.

Physical activity and risk of bleeding in elderly patients taking anticoagulants

BACKGROUND

Although the possibility of bleeding during anticoagulant treatment may limit patients from taking part in physical activity, the association between physical activity and anticoagulation-related bleeding is uncertain.

OBJECTIVES

To determine whether physical activity is associated with bleeding in elderly patients taking anticoagulants.

PATIENTS/METHODS

In a prospective multicenter cohort study of 988 patients aged ≥ 65 years receiving anticoagulants for venous thromboembolism, we assessed patients' self-reported physical activity level. The primary outcome was the time to a first major bleeding, defined as fatal bleeding, symptomatic bleeding in a critical site, or bleeding causing a fall in hemoglobin or leading to transfusions. The secondary outcome was the time to a first clinically relevant non-major bleeding. We examined the association between physical activity level and time to a first bleeding by using competing risk regression, accounting for death as a competing event. We adjusted for known bleeding risk factors and anticoagulation as a time-varying covariate.

RESULTS

During a mean follow-up of 22 months, patients with a low, moderate, and high physical activity level had an incidence of major bleeding of 11.6, 6.3, and 3.1 events per 100 patient-years and an incidence of clinically relevant non-major bleeding of 14.0, 10.3, and 7.7 events per 100 patient-years, respectively. A high physical activity level was significantly associated with a lower risk of major bleeding (adjusted sub-hazard ratio 0.40, 95% confidence interval 0.22-0.72). There was no association between physical activity and non-major bleeding.

CONCLUSIONS

A high level of physical activity is associated with a decreased risk of major bleeding in elderly patients receiving anticoagulant therapy.

Risk of falls and bleeding in elderly patients with acute venous thromboembolism

OBJECTIVE

Whether or not a high risk of falls increases the risk of bleeding in patients receiving anticoagulants remains a matter of debate.

METHODS

We conducted a prospective cohort study involving 991 patients ≥ 65 years of age who received anticoagulants for acute venous thromboembolism (VTE) at nine Swiss hospitals between September 2009 and September 2012. The study outcomes were as follows: the time to a first major episode of bleeding; and clinically relevant nonmajor bleeding. We determined the associations between the risk of falls and the time to a first episode of bleeding using competing risk regression, accounting for death as a competing event. We adjusted for known bleeding risk factors and anticoagulation as a time-varying covariate.

RESULTS

Four hundred fifty-eight of 991 patients (46%) were at high risk of falls. The mean duration of follow-up was 16.7 months. Patients at high risk of falls had a higher incidence of major bleeding (9.6 vs. 6.6 events/100 patient-years; P = 0.05) and a significantly higher incidence of clinically relevant nonmajor bleeding (16.7 vs. 8.3 events/100 patient-years; P < 0.001) than patients at low risk of falls. After adjustment, a high risk of falls was associated with clinically relevant nonmajor bleeding [subhazard ratio (SHR) = 1.74, 95% confidence interval (CI) = 1.23-2.46], but not with major bleeding (SHR = 1.24, 95% CI = 0.83-1.86).

CONCLUSION

In elderly patients who receive anticoagulants because of VTE, a high risk of falls is significantly associated with clinically relevant nonmajor bleeding, but not with major bleeding. Whether or not a high risk of falls is a reason against providing anticoagulation beyond 3 months should be based on patient preferences and the risk of VTE recurrence.

Prospective, multicenter validation of prediction scores for major bleeding in elderly patients with venous thromboembolism

BACKGROUND

The Outpatient Bleeding Risk Index (OBRI) and the Kuijer, RIETE and Kearon scores are clinical prognostic scores for bleeding in patients receiving oral anticoagulants for venous thromboembolism (VTE). We prospectively compared the performance of these scores in elderly patients with VTE.

METHODS

In a prospective multicenter Swiss cohort study, we studied 663 patients aged ≥ 65 years with acute VTE. The outcome was a first major bleeding at 90 days. We classified patients into three categories of bleeding risk (low, intermediate and high) according to each score and dichotomized patients as high vs. low or intermediate risk. We calculated the area under the receiver-operating characteristic (ROC) curve, positive predictive values and likelihood ratios for each score.

RESULTS

Overall, 28 out of 663 patients (4.2%, 95% confidence interval [CI] 2.8-6.0%) had a first major bleeding within 90 days. According to different scores, the rate of major bleeding varied from 1.9% to 2.1% in low-risk, from 4.2% to 5.0% in intermediate-risk and from 3.1% to 6.6% in high-risk patients. The discriminative power of the scores was poor to moderate, with areas under the ROC curve ranging from 0.49 to 0.60 (P = 0.21). The positive predictive values and positive likelihood ratios were low and varied from 3.1% to 6.6% and from 0.72 to 1.59, respectively.

CONCLUSION

In elderly patients with VTE, existing bleeding risk scores do not have sufficient accuracy and power to discriminate between patients with VTE who are at a high risk of short-term major bleeding and those who are not.

Prospective comparison of clinical prognostic scores in elder patients with a pulmonary embolism

BACKGROUND

The Geneva Prognostic Score (GPS), the Pulmonary Embolism Severity Index (PESI) and its simplified version (sPESI) are well-known clinical prognostic scores for a pulmonary embolism (PE).

OBJECTIVES

To compare the prognostic performance of these scores in elderly patients with a PE.

PATIENTS AND METHODS

In a multicenter Swiss cohort of elderly patients with venous thromboembolism, we prospectively studied 449 patients aged ≥ 65 years with a symptomatic PE. The outcome was 30-day overall mortality. We dichotomized patients as low vs. higher risk in all three scores using the following thresholds: GPS scores ≤ 2 vs. > 2, PESI risk classes I-II vs. III-V and sPESI scores 0 vs. ≥ 1. We compared 30-day mortality in low- vs. higher-risk patients and the areas under the receiver-operating characteristic curve (ROC).

RESULTS

Overall, 3.8% of patients (17/449) died within 30 days. The GPS classified a greater proportion of patients as low risk (92% [413/449]) than the PESI (36.3% [163/449]) and the sPESI (39.6% [178/449]) (P < 0.001 for each comparison). Low-risk patients based on the sPESI had a mortality of 0% (95% confidence interval [CI] 0-2.1%) compared with 0.6% (95% CI 0-3.4%) for low-risk patients based on the PESI and 3.4% (95% CI 1.9-5.6%) for low-risk patients based on the GPS. The areas under the ROC curves were 0.77 (95% CI 0.72-0.81), 0.76 (95% CI 0.72-0.80) and 0.71 (95% CI 0.66-0.75), respectively (P = 0.47).

CONCLUSIONS

In this cohort of elderly patients with PE, the GPS identified a higher proportion of patients as low risk but the PESI and sPESI were more accurate in predicting mortality.

Hyperglycemia inhibits vascular smooth muscle cell apoptosis through a protein kinase C-dependent pathway

We hypothesized that the pathogenesis of diabetic vasculopathy involves the abnormal regulation of vascular smooth muscle cell (VSMC) apoptosis. In nondiabetic mice, a reduction in carotid artery blood flow resulted in a significant loss of medial VSMCs via apoptosis (normal flow 84+/-1 viable VSMCs, reduced flow 70+/-5 viable VSMCs; n=12, P:<0.01). In contrast, flow-induced VSMC apoptosis was markedly attenuated in streptozotocin-induced diabetic mice (normal flow 85+/-2 viable VSMC, reduced flow 82+/-4 viable VSMC; n=13, NS). In accord with our in vivo findings, the exposure of cultured rat and human VSMCs to high glucose (17.5 mmol/L) significantly attenuated the induction of apoptosis in response to serum withdrawal (rat VSMCs in normal [5.5 mmol/L] glucose 28+/-1%, high D-glucose 19+/-2%; P:<0.0001). High glucose also inhibited apoptosis induced by Fas ligand (100 ng/mL) (normal 23+/-2%, high D-glucose 13+/-2%; P:<0.006). Supplementation with the nonmetabolized enantiomer L-glucose had no effect. We confirmed reports that high glucose activates protein kinase C (PKC) and demonstrated that PKC blockade with long-term phorbol ester treatment or calphostin C prevented the antiapoptotic effect (P:<0. 001). Moreover, the upregulation of either PKCalpha or PKCbetaII expression was sufficient to inhibit serum withdrawal-induced apoptosis (control 25+/-2%, PKCalpha 11+/-2%, PKCbetaII 8+/-2%; P:<0. 0001), whereas the upregulation of PKCdelta had no significant effect. Taken together, these findings demonstrate that hyperglycemia inhibits VSMC apoptosis via a PKC-dependent pathway.

Effect of NO donors on LV diastolic function in patients with severe pressure-overload hypertrophy

BACKGROUND

Previous experimental studies have shown that nitric oxide (NO) modulates cardiac function by an abbreviation of systolic contraction and an enhancement of diastolic relaxation. However, the response to NO donors of patients with severe pressure-overload hypertrophy and diastolic dysfunction is unknown.

METHODS AND RESULTS

Intracoronary NO donors were given to 17 patients with severe aortic stenosis. A dose-response curve was obtained with nitroglycerin (30, 90, and 150 microg) in 11 patients and sodium nitroprusside (1, 2, and 4 microg/min) in 6. Left ventricular (LV) high-fidelity pressure measurements with simultaneous LV angiograms were performed at baseline and after the maximal dose of NO. The dose-response curve for intracoronary NO donors showed a marked fall in LV end-diastolic pressure, from 23 to 14 mm Hg (-39%; P<0.0001), whereas LV peak systolic pressure fell only slightly, from 206 to 196 mm Hg (-4%; P<0.01). End-diastolic chamber stiffness decreased from 0.12 to 0.07 mm Hg/mL (P<0.0001) and end-systolic stiffness from 1.6 to 1.3 mm Hg/mL (P<0.01). Heart rate, right atrial pressure, LV ejection fraction, the time constant of isovolumic pressure decay (tau), and LV filling rates remained unchanged.

CONCLUSIONS

In patients with severe pressure-overload hypertrophy, intracoronary NO donors exert a marked decrease in LV end-diastolic pressure without affecting LV systolic pump function. Thus, the hypertrophied myocardium appears to be particularly susceptible to NO donors, with a marked improvement in diastolic function.