Association of serum MMP9 with adverse features of plaque progression in patients with chronic coronary syndrome (CCS)

Background

Previous studies have demonstrated that MMP-9 may be a predictor of atherosclerotic plaque instability and future adverse cardiovascular events, but longitudinal data on the association between MMP9 and coronary disease progression are lacking.

Purpose

This study is aimed at investigating whether MMP9 is associated with atherosclerotic plaque progression.

Methods

MMP9 serum levels were measured in stable patients with chronic coronary syndrome (CCS) undergoing coronary computed tomography angiography at baseline and after a period of 6.5±1.1 years of follow up to assess progression of Total, Fibrous, Fibro-fatty, Necrotic Core, and Dense Calcium plaque volume (PV). The relationship of serum MMP9 with plaque progression was assessed using linear regression analysis, adjusting for clinical variables including, age, sex, risk factors, medical therapy, LDL-C, TG/HDL-C ratio, hs-CRP, and the presence of obstructive CAD (>50% coronary stenosis in at least one major coronary vessels).

Results

A total of 157 patients (58±8 years of age; 66% males) were included in the analysis, with median MMP9 values of 135±186 mg/dL (mean ± SD). Annual changes of Total, Fibrous-Fatty and Necrotic Core PV were significantly different across MMP9 tertiles (Figure 1). Multivariable linear regression analysis demonstrated a positive association between serum levels of MMP9 and annual change of Total and Necrotic Core PV (Figure 1).

Conclusion

Among patients with CCS, MMP9 serum levels were an independent predictor of progression of coronary plaque burden and, in particular, of adverse plaque features, such as Necrotic Core PV. This association was robust and independent from baseline traditional cardiovascular risk factors and medications, supporting for MMP9 a role as a novel marker of residual coronary risk.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Horizon 2020 - Project “Simulation Modeling of coronary ARTery disease: a tool for clinical decision support–SMARTool”

Association of eNOS Glu298Asp polymorphism with cardiometabolic risk and inducible myocardial ischemia in patients with stable coronary artery disease

Background

The endothelial nitric oxide synthase (eNOS) gene deficiency is known to cause insulin resistance, hypertension, hypertriglyceridemia and impaired coronary vasodilating capability in animal models. In the general clinical population, the eNOS gene polymorphism (Glu298Asp, G894T), able to reduce eNOS activity, was associated either with features of the metabolic syndrome or prevalence of coronary artery disease (CAD).

Purpose

To investigate the possible association of Glu298Asp polymorphism with cardiometabolic risk [insulin resistance, increased triglycerides (TG) and low HDL-cholesterol (HDL-C)], obstructive CAD and inducible myocardial ischemia in stable patients with suspected coronary disease.

Methods

Six cardiology units enrolled a total of 506 consecutive patients (314 males; mean age 62±9 years) referred for suspected CAD within the BIOGEN-CARE Tuscan Region Italian Study. Among these, 325 patients underwent stress ECG or cardiac imaging to assess the presence of inducible ischemia and 436 patients underwent non invasive computerized tomography or invasive coronary angiography to assess the presence of obstructive CAD (>50% stenosis in at least one major coronary vessel). Blood samples were collected from each patient for genotyping and measurements of lipid and glucose parameters. The TG/HDL-C ratio and the TyG-index [ln(TG × Fasting plasma glucose/2)] were used as synthetic markers of atherogenic dyslipidemia and insulin resistance, main components of the cardiometabolic risk.

Results

In the whole population, 49.6% of patients were homozygous for the G894allele, 40.9% heterozygotes, and 9.5% homozygous for T894. Myocardial ischemia was documented in 160/325 (49.2%) patients undergoing stress testing and obstructive CAD in 178/436 (40.8%) patients undergoing coronary angiography. Patients carrying the T allele (dominant model TT+GT vs GG) had higher TG/HDL ratio (2.7±1.8 vs 2.5±1.9, P=0.03) (Figure) without differences in other lipid and glucose markers. Independent predictors of obstructive CAD were age, gender, obesity, diabetes and TG/HDL-C ratio but not the the T allele (OR 0.80; CI 0.51–1.25; ns). Independent predictors of inducible ischemia were age, gender, obesity and the T allele (OR 1.91; CI 01.19–3.08; P=0.007). Stratifying the population for both obstructive CAD and ischemia, the T allele was associated with increased risk of ischemia (OR 1.96; CI 1.11–3.44; P=0.02) even after adjustment for the presence of obstructive CAD (OR 3.09; CI 1.85–5.78; P<0.001) (Figure 1).

Conclusions

In stable patients with suspected CAD, the eNOS Glu298Asp gene polymorphism is an independent risk factor for inducible myocardial ischemia and is significantly associated with the specific cardiometabolic risk expressed by high TG and low HDL-C which independently predicts obstructive CAD.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): “BIOhumoral and GENetic predictors of CARdiac Evolving phenotype in Ischemic Heart Disease (BIOGENCARE-IHD)”; funded by Toscan Region-Programma per la ricerca regionale in materia di Salute 2009

A common plasma lipidomics signature of cardiometabolic and coronary risk in statin users

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Commission in the H2020 program: Project SMARTool, “Simulation

Modeling of coronary ARTery disease: a tool for clinical decision support—SMARTool”

Background and aims

The coexistence of elevated plasma triglycerides (TG) and low high-density lipoprotein cholesterol (HDL-C) may contribute to the residual cardiometabolic risk of coronary artery disease (CAD) independently of total cholesterol and low-density lipoprotein cholesterol (LDL-C) absolute plasma levels [1]. Aim of this study is to assess whether a high TG/HDL-C ratio is characterized by a specific lipidomics signature in statin users and its relationship with the coronary risk score defined by coronary computed tomography angiography (CTA).

Methods

TG/HDL-C ratio was calculated in 132 patients (68.8±7.7 years, 85 males) with suspected or known CAD referred to coronary CTA and receiving statins treatment in the last 6.3 ± 1.4 years before enrolment. Patients were grouped according to TG/HDL-C ratio quartiles: IQ (≤1.694), IIQ (1.695-2.399), IIIQ (2.400-3.281), and IVQ (>3.282). Coronary CTA exams were analysed according to the modified 17-segment American Heart Association classification [2] and interpretable segments were visually assessed for degree of stenosis and plaque composition. A comprehensive coronary risk score (CTA score) [3], previously validated as predictor of adverse outcome, was calculated in each patient. Except for subjects with normal arteries (CTA score = 0), all patients were classified into 3 groups of CTA score severity:  low (score < 5), intermediate (score 5-20) and high (score > 20) risk [4]. Patient-specific plasma targeted lipidomics was performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). This approach allowed to quantify 69 circulating lipids encompassing six lipid classes (triacylglycerol [TG], phosphatidylcholine [PC], phosphatidylethanolamine [PE], ceramide [Cer], sphingomyelin [SM], cholesterol ester [CE]). Differential analysis was performed using TG/HDL-C and CTA score annotation.

Results

18 altered lipid species in the group with higher TG/HDL-C ratio were also altered in the group with higher CTA risk score. This common set of lipids is composed of CE(16:0), CE(18:0), PC(38:2), 8 SM [SM(34:2), SM(38:2), SM(41:2), SM(41:1), SM(42:4), SM(42:3), SM(42:1), SM(43:3)], TG(52:1) and 6 PE [PE(34:0), PE(34:1), PE(34:2), PE(36:1), PE(36:2), PE(36:3)], and represents the lipidomics signature associating elevated plasma TG/HDL-C ratio with high CTA risk score in statin users.

Conclusion

In patients with stable CAD under statin treatment, a specific pattern of altered lipids, characterized by reduced plasma levels of cholesterol esters and sphingomyelins and increased levels of triacylglicerols and phosphatidylethanolamines, is associated with high TG/HDL-C ratio and high CTA score. This specific lipidomic signature identifies patients with higher residual cardiometabolic and coronary risk, not tackled by current lipid lowering therapy, unveiling possible new molecular targets of treatment.

P32 SELF–LEARN IMPLEMENTATION OF ULTRASOUND FOR THE STUDY AND ULTRASOUND–GUIDED PUNCTURE OF VASCULAR ACCESSES IN THE IMPLANTATION OF PACEMAKERS AND IMPLANTABLE DEFIBRILLATORS

Background

The vascular access represents a crucial phase in the management of complications related to the implantation of devices. After the use of the axillary vein, which allows the elimination of intrathoracic complications as well as the subclavian crush of the catheters, the ultrasound–guided approach could represent the next step for the reduction of vascular complications.

Experience

All implants performed (n = 86) by an independent operator who implemented ultrasound to minimize complications related to central access were reviewed. During the first phase, the ultrasound–guided approach involved the study of vascular accesses before the start of the implant. The assessment took place before the preparation of the sterile field, for the localization of the axillary approach and for the study of the anatomical variants. It was immediately followed by the use of skin marks. The use of markers made it possible to attempt surgical isolation of the cephalic vein as a first approach. In case of failure, or the need for multiple accesses, the transition to central access could be facilitated by the presence of skin markers. This approach have not significantly modified the probability of successful axillary vein puncture without the use of venography (75% vs 71%, p NS). In the last phase all implants were performed with ultrasound–guided puncture with sterile technique before skin incision (n = 26). The procedures involved dual chamber (61%), single chamber (19%), CRTD (11%), dual chamber ICD. Ultrasound showed all cases of hypoplastic cephalic vein (15%). In the first three months of implementation, the success rate was 71.4% with 1 self–healing case of apical pneumothorax. In the following months the success rate rapidly increased to 94.1% (p < 0.05) with no pneumo or hemothorax. The median time to effective puncture was 28 seconds (8–450sec) in the second phase. It was possible to isolate the cephalic vein in 40% of cases for two or three chamber implants.

Conclusions

The ultrasound study of the accesses performed before the incision allows to identify the anatomy and to define the course of the axillary vascular system and its relationships. When performed with a sterile approach, it allows direct ultrasound–guided puncture before the surgical incision, with a high success rate from the early stages of implementation.

Sex differences in the natural history of plaque progression by serial coronary computed tomography angiography

Background

Sex related differences exist for coronary artery disease (CAD). Women tend to be older when presenting with CAD and have lower rates of obstructive disease. Invasive intravascular ultrasound studies have shown differences in plaque composition between males and females. However, these studies were performed in a high risk population needing invasive imaging. Coronary computed tomography angiography (CTA) allows for a fast and non-invasive quantification of CAD in low risk patients. Sex differences and quantitative analysis of plaque progression and changes in plaque composition have not been studied intensively.

Purpose

To evaluate the role of sex on long term plaque progression and on the change of plaque composition in a population with low-intermediate risk.

Methods

Patients that received a coronary CTA were prospectively included in the SMARTool study to receive a follow-up coronary CTA. In total, 275 patients from 5 European countries were recruited in 7 centers. Baseline and follow-up coronary CTA were quantitative analyzed on a per-lesion basis using dedicated software package. Patients without coronary plaques at follow-up or with uninterpretable coronary CTA results were excluded. Total plaque volume and compositional volumes, calcified or non-calcified (defined as fibrous, fibro-fatty or necrotic core), were normalized using the vessel volume to calculate a percentage atheroma volume (PAV). Lesions between males and females were compared using linear mixed models. We further classified patients into age groups <55 and ≥55 years to evaluate the influence of menopause on plaque progression.

Results

In total, 211 patients were included in this analysis, 146 (69%) were male and 65 (31%) were female. Mean interscan period was 6.2±1.4 years. Females were older (64±7 vs 61±8 years; p<0.001), had higher HDL levels (56±15 vs 49±15 mg/dL; p=0.003) and presented more often with atypical chest pain (62 vs 38%; p=0.017). Males had 434 plaque sites and females 156. On a per-lesion analysis females had less fibro-fatty PAV compared to males (β −1.3±0.4%; p<0.001), no other differences were seen (p>0.05). When stratifying the patients in above and below 55 years old, females still had less fibro-fatty PAV compared to males in both age groups (p<0.05). However, females in the age group <55 years showed more regression of fibrous PAV compared to males (β −0.8±0.3% per year; p=0.002) and non-calcified plaque PAV (β −0.7±0.3% per year; p=0.027) (Figure).

Conclusions

Males have larger fibro-fatty PAV compared to females, however the rate of change did not differ. Younger women showed more regression of fibrous PAV and non-calcified PAV compared to males. No differences in the rate of plaque progression or plaque composition changes were seen between males and females in the older age group.

Figure plaque progression and sex diff

Funding Acknowledgement

Type of funding source: Public grant(s) – EU funding. Main funding source(s): EU H2020 research and innovation program

P6167Low leptin plasma levels are associated with progression of coronary atherosclerosis in patients with stable coronary artery disease from the SMARTool Study

Background

Leptin is an adipokine involved in energy homeostasis and has been related with established vascular risk factors. However, studies on the association of leptin plasma levels with coronary artery disease (CAD) have yielded conflicting results.

Purpose

Aim of the present study was to evaluate the association between leptin plasma levels and presence, severity and progression of coronary atherosclerosis in patients with suspected stable CAD.

Methods

In a cohort of 257 patients with symptoms of stable CAD enrolled in the SMARTool study, coronary computed tomography angiography (CTA), plasma leptin levels and clinical and bio-humoral CAD risk profile (including glucose, lipid and inflammation variables) were obtained at enrolment and after 6±1yrs of follow-up. Sixty-four patients were revascularized and the remaining 193 represent the population for the present study. CTA findings were categorised as no-minimal CAD (<30% stenosis), non-obstructive CAD (30%-50% stenosis) and obstructive CAD (≥50% stenosis in at least one major coronary vessel). A CTA risk score (based on plaque extent, severity, composition, and location) was calculated at baseline and at follow-up to assess coronary atherosclerotic burden and its progression (Δ CTA score≥5).

Results

CTA findings showed obstructive CAD in 11% of patients at baseline and in 15% at follow-up (p<0.0001). CTA risk score, was 8.03±7.80 at baseline and increased to 10.33±8.17 at follow-up (p<0.0001) with CAD progression in 20% of patients. Leptin plasma levels were inversely related with CTA findings both at baseline and follow-up (Figure). In a Cox model, baseline plasma leptin was an independent predictor of CAD progression, after adjustment for clinical risk factors, biomarkers, and treatment (HR 0.572, 95% CI 0.393–0.834, P=0.0037).

Figure 1

Conclusion

Plasma leptin is inversely associated with coronary atherosclerotic burden and disease progression in patients with stable CAD. This association is independent of known factors affecting leptin levels. These results could prompt further investigations on the pathophysiological mechanisms of this association.

Acknowledgement/Funding

EU H2020 research and innovation program under grant agreement No 689068

Cancer incidence and mortality in patients with heart disease. Effect of oral anticoagulant therapy

Cancer incidence and mortality were reviewed in patients (683) who, during the period 1969-1988, had been attending the Cardiological Center of Pisa University for more than 1 year for valvular (494), ischemic (183), or myocardial (6) disease. Oral anticoagulant therapy (tromexan, acenocoumarol or warfarin) was administered to 312 of these 693 patients and regulated to prolong prothrombin time to a value between 20% and 40% of normal controls. The duration of treatment ranged from 1 to 14 years, with a mean of 4 years. As clinical and radiological controls were performed on all the patients at regular intervals (2-12 months), cancer incidence and mortality were recorded. Cancer incidence and mortality in the 312 patients treated with anticoagulants were compared with that of the 381 patients who did not receive this therapy. Furthermore, cancer mortality in the patients on anticoagulants was compared to that expected on the basis of national tumor registry rates. The age of the patients varied from 20 or under to 80 or over in both groups. The total observation period was 1415 patient-years (555 for males and 860 for females) in the former and 1617 patient-years (735 males and 882 females) in the latter. The proportion of the patient-years of the men over 45 (with the highest risk of cancer mortality) was higher in the group treated with anticoagulants (83%) than in the controls (72%) (p < .001). The proportion of the patient-years of the women over 45 was also higher in the former (84% vs 62%; p < .001). Six cancers were observed in the patients treated with oral anticoagulants (3 men, 3 women), while 12 cancers occurred in the control group (9 men, 3 women). There were 3 deaths in the former (1 man, 2 women) and 6 in the latter (5 men, 1 woman). On the basis of the national tumor registry rates, deaths expected in men and women on oral anticoagulants were 3 and 2. These data are compatible with the hypothesis that oral anticoagulants might reduce cancer incidence and mortality in humans.

Purine release from isolated rat heart: a new approach to the study of energy metabolism

The rate of release of purines (adenosine, inosine, hypoxanthine, xanthine and uric acid) from isolated working rat hearts was measured and compared to tissue concentrations of high energy phosphate compounds. Hearts were subjected to different workloads, and perfusions were performed: with normal oxygen supply (group 1); with the addition of insulin to the standard perfusion buffer, which contained glucose as energy source (group 2); in hypoxic conditions (group 3). In each group purine release increased (P less than 0.01) at higher workload and was closely related to indices of mechanical performance such as cardiac output or minute work (r = 0.902 and 0.858 in group 1, r = 0.902 and 0.851 in group 2, r = 0.851 and 0.881 in group 3, P less than 0.001 in each case). Work had no effect on adenine nucleotides but produced a significant (P less than 0.01) reduction in phosphocreatine/creatine ratio. The comparison of different groups showed that at any level of heart performance purine release was higher (P less than 0.001) in group 3 vs. group 1, and lower (P less than 0.001) in group 2 vs. group 1. High energy phosphates were reduced in group 3 vs. group 1 but were unchanged in group 2 vs. group 1. We conclude that in the isolated heart purine release is directly related to the rate of energy consumption, and inversely related to the rate of energy production. Purine release provides a sensitive method to evaluate myocardial energy metabolism, which is more sensitive than measurement of high energy phosphates.

The adenosine hypothesis revisited: relationship between purine release and coronary flow in isolated rat heart

We evaluated the adenosine hypothesis through a new approach, based on the study of the relationship between coronary flow or resistance and purine release, which is an accurate index of myocardial adenosine release. Isolated rat hearts were perfused at different work loads, in hypoxic conditions and after a short period of global ischaemia. When the results of all experiments were considered together, purine release was significantly but weakly related to coronary flow and coronary resistance (r = 0.416 v coronary flow, r = 0.378 v the reciprocal of coronary resistance, p less than 0.01). Closer relationships were obtained within the three subgroups: the correlation coefficients increased to 0.819 and 0.835 (p less than 0.001) in the hearts perfused at different work loads with normal oxygen supply, to 0.701 and 0.757 (p less than 0.02 and p less than 0.01) in the hypoxic hearts, and to 0.897 and 0.978 (p less than 0.02 and p less than 0.01) in the hearts recovering from ischaemia. The relationships between purine release and coronary flow or resistance were significantly different in the three subgroups (p less than 0.001): at any value of purine release coronary resistance was highest during hypoxia and lowest after ischaemia, while the opposite was true for coronary flow. We suggest that the adenosine hypothesis is converted into a "weaker" statement: adenosine is involved in the adjustment between heart performance and coronary resistance but other factors contribute to the regulation of coronary flow, and/or affect the response to adenosine.

Protection of isolated rat heart from oxidative stress by exogenous creatine phosphate

The influence of exogenous creatine phosphate (CP) on peroxidative heart injury was investigated in two experimental models: isolated working rat hearts and myocardial membrane preparations. In the first model the addition of 190 microM hydrogen peroxide to the perfusion buffer caused a marked decrease of aortic flow, minute work and peak aortic pressure, and leakage of intracellular enzymes. In the presence of 10 mM CP the hemodynamic damage produced by the same concentration of hydrogen peroxide was significantly lower and enzyme release was also remarkably reduced. The protection was concentration-dependent and the whole structure of the molecule was required since creatine was found to be ineffective. In the absence of hydrogen peroxide, CP and creatine did not affect heart performance. In microsomal membrane preparations CP decreased the formation of thiobarbituric acid-reactive material (malonaldehyde) induced by hydrogen peroxide in the presence of ferrous ions. This protection was concentration-dependent and occurred at physiological concentrations of CP. Also in this experimental model creatine had no effect and creatine plus inorganic phosphate was much less active than CP. The influence of CP on oxidative heart stress could account for the beneficial effect of this substance in different models of ischemic injury.