Bénédicte Gaborit

Comparison of omeprazole and pantoprazole influence on a high 150-mg clopidogrel maintenance dose the PACA (Proton Pump Inhibitors And Clopidogrel Association) prospective randomized study.

OBJECTIVES This study sought to compare the effect of 2 proton pump inhibitors (PPIs) on platelet response to clopidogrel after coronary stenting for non-ST-segment elevation acute coronary syndrome (NSTE ACS). BACKGROUND Use of omeprazole has been reported to significantly decrease the clopidogrel antiplatelet effect because of cytochrome P450 interaction. Because all PPIs are metabolized by CYP2C19, but to a varying degree, we hypothesized that the reported negative omeprazole-clopidogrel drug interaction may not be caused by a class effect. METHODS A total of 104 patients undergoing coronary stenting for NSTE ACS were prospectively included and randomized to omeprazole or pantoprazole 20 mg. They received at discharge 75-mg aspirin and 150-mg clopidogrel. Platelet reactivity index (PRI) vasoactive stimulated phosphoprotein (VASP) was used to assess clopidogrel response and adenosine diphosphate (ADP)-induced aggregation for platelet reactivity (ADP-Ag). RESULTS After 1 month, patients receiving pantoprazole had a significantly better platelet response to clopidogrel as assessed with the PRI VASP: 36 +/- 20% versus 48 +/- 17% (p = 0.007). We identified more clopidogrel nonresponders in the omeprazole group than in the pantoprazole group: 44% versus 23% (p = 0.04), odds ratio: 2.6 (95% confidence interval: 1.2 to 6.2). Conversely, we did not observe any significant difference in platelet reactivity with ADP-Ag between the omeprazole and pantoprazole groups: 52 +/- 15% and 50 +/- 18%, respectively (p = 0.29). CONCLUSIONS The present findings suggest the preferential use of pantoprazole compared with omeprazole in patients receiving clopidogrel to avoid any potential negative interaction with CYP2C19.

Human epicardial adipose tissue induces fibrosis of the atrial myocardium through the secretion of adipo-fibrokines

AIMS Recent studies have reported a relationship between the abundance of epicardial adipose tissue (EAT) and the risk of cardiovascular diseases including atrial fibrillation (AF). However, the underlying mechanisms are unknown. The aim of this study was to examine the effects of the secretome of human EAT on the histological properties of the myocardium. METHODS AND RESULTS Samples of EAT and subcutaneous adipose (SAT), obtained from 39 patients undergoing coronary bypass surgery, were analysed and tested in an organo-culture model of rat atria to evaluate the fibrotic properties of human fat depots. The EAT secretome induced global fibrosis (interstitial and peripheral) of rat atria in organo-culture conditions. Activin A was highly expressed in EAT compared with SAT and promoted atrial fibrosis, an effect blocked using neutralizing antibody. In addition, Activin A levels were enhanced in patients with low left-ventricular function. In sections of human atrial and ventricular myocardium, adipose and myocardial tissues were in close contact, together with fibrosis. CONCLUSION This study provides the first evidence that the secretome from EAT promotes myocardial fibrosis through the secretion of adipo-fibrokines such as Activin A.

Predictive value of post-treatment platelet reactivity for occurrence of post-discharge bleeding after non-ST elevation acute coronary syndrome. Shifting from antiplatelet resistance to bleeding risk assessment?

AIMS We assessed prospectively the association between occurrence of post-discharge non-CABG-related TIMI major and minor bleeding and post-treatment platelet reactivity in patients with non-ST elevation acute coronary syndrome (NSTE ACS). METHODS AND RESULTS Five hundred and ninety-seven consecutive patients admitted with NSTE ACS were prospectively included. Between hospital discharge and one month follow-up, we observed 16 (2.7%) non-CABG-related TIMI haemorrhagic complications including five (0.84%) major and 11 (1.8%) minor bleeds. Patients with bleeding had significantly lower post-treatment values of ADP-induced aggregation (43+/-14% versus. 56+/-19%, p=0.002) and platelet reactivity index VASP (43+/-14% versus 54+/-23%; p=0.04) and a trend for lower values of arachidonic acid-induced aggregation (2.4+/-5.4 versus 13+/-21; p=0.27). After stratification by quartiles based on post-treatment ADP-induced platelet aggregation, we identified patients in the first quartile as hyper-responders with very low post-treatment platelet reactivity, below <40%. The risk of TIMI major and minor bleeding was significantly higher in the first quartile of hyper-responders than in the others quartiles: 10 (6.6%) versus six (1.4%), p=0.001. CONCLUSIONS Our results suggest that assessment of post-treatment platelet reactivity might be used to detect hyper-responders to antiplatelet therapy with higher risk of non-CABG related bleeding and tailor antiplatelet therapy according to both ischaemic and bleeding risk.

The CYP2C19*17 allele is associated with better platelet response to clopidogrel in patients admitted for non-ST acute coronary syndrome.

Clopidogrel is a thienopyridine derivative that inhibits ADPinduced platelet aggregation. It is an inactive pro-drug that requires several biotransformation steps before it acquires its antiplatelet effect [1,2]. After intestinal absorption, clopidogrel requires oxidation by hepatic cytochrome P450 (CYP) to generate an active metabolite. This active metabolite inhibits platelet activation through irreversible binding to the platelet ADP receptor, P2Y12. Numerous studies have reported inter-individual variability in platelet response to clopidogrel, which is of clinical relevance with regard to patient treatment [3]. However, the mechanisms underlying this variability remain unclear. Putative explanations for variable clopidogrel response include genetic variations that influence the liver metabolism of clopidogrel. Several functional polymorphisms in genes encoding CYP have already been evaluated. Previous studies reported that the CYP3A4*1B and CYP3A5*3 polymorphisms could not explain the variability in the platelet inhibitory effects of clopidogrel [4,5]. In contrast, recent data have shown that the CYP2C19*2 loss-of-function allele is associated with a marked decrease in platelet response to clopidogrel in young healthy male volunteers [6] and in patients with coronary artery disease [7,8]. Moreover, this polymorphism has recently been associated with a poor clinical prognosis [9–11] and with an increased risk of thrombosis after coronary stent placement [12]. Recently, novel allelic variants of the CYP2C19 have been described including the CYP2C19*17 which is associated with ultrarapid enzyme activity and increased medication metabolism including omeprazole [13]. The aim of the present study was to evaluate the impact of these novel allelic variants of the CYP2C19 on platelet response to clopidogrel in patients suffering from non-ST elevation acute coronary syndrome (NSTE ACS). We therefore retrospectively evaluated 598 patients with NSTE ACS after the administration of a 600-mg clopidogrel loading dose, and the impact of CYP2C19*4 CYP2C19*5, CYP2C19*6 and CYP2C19*17 on platelet response to clopidogrel, as assessed using the maximal intensity of 10 lMADPinduced platelet aggregation (ADP-Ag) and by the platelet reactivity index vasodilator stimulated phosphoprotein assay (PRI VASP). All subjects analyzed in this retrospective study participated in a larger study conducted by the same organization to examine the effects of genetic polymorphisms involved in clopidogrel metabolism in NSTE ACS patients [7]. The baseline characteristics of the patients were: age 64.7 ± 12 years, 453 (76%) males, 169 (28%) had diabetes, 332 (56%) suffered from hypertension, 321 (54%) were dyslipidemic, 263 (44%) were current smokers, 336 (45%) were receiving statins, 271 (45%) were treated with betablockers and the body mass index (BMI) was 26.9 ± 4.3 kg.m. All patients were genotyped for CYP2C19*4, CYP2C19*5, CYP2C19*6 and CYP2C19*17. No significant deviations from Hardy–Weinberg equilibrium were observed for any of the genetic variants. Table 1 summarizes the observed frequencies of the CYP variants evaluated in the studied population. CYP2C19*4, CYP2C19*5 and CYP2C19*6 were very rare variants, whereas CYP2C19*17 was relatively common. The baseline characteristics of the patients did not differ between the different groups of genotypes. None of the polymorphisms (CYP2C19*4, CYP2C19*5 or CYP2C19*6) influenced platelet response to clopidogrel (C. Frere, T. Cuisset, B. Gaborit, M.-C. Alessi, J.-S. Hulot, unpublished data). In contrast, the CYP2C19*17 genotype was significantly associated with PRI VASP values, both in recessive (P = 0.02) and codominant (P = 0.0073) models (Table 2). After adjustment for factors that influence platelet reactivity (i.e. age, gender, BMI, diabetes and smoking status), this association remained Correspondence: Corinne Frere, Inserm, U626, 27 Boulevard Jean Moulin, 13385 Marseille cedex 05, France. Tel.: +33 491324504; fax: +33 491254336. E-mail: corinne.frere@mail.ap-hm.fr

Effects of bariatric surgery on cardiac ectopic fat: lesser decrease in epicardial fat compared to visceral fat loss and no change in myocardial triglyceride content.

OBJECTIVES This study investigated the effect of bariatric surgery (BS)-induced weight loss on cardiac ectopic fat using 3T magnetic resonance imaging in morbid obesity. BACKGROUND Heart disease is one of the leading causes of mortality and morbidity in obese patients. Deposition of cardiac ectopic fat has been related to increased heart risk. Whether sustained weight loss can modulate epicardial fat or myocardial fat is unknown. METHODS Twenty-three morbidly obese patients underwent 1H-magnetic resonance spectroscopy to determine myocardial triglyceride content (MTGC), magnetic resonance imaging to assess epicardial fat volume (EFV), cardiac function, and computed tomography visceral abdominal fat (VAF) measurements at baseline and 6 months after BS. RESULTS The BS reduced body mass index significantly, from 43.1±4.5 kg/m2 to 32.3±4.0 kg/m2, subcutaneous fat from 649±162 cm2 to 442±127 cm2, VAF from 190±83 cm2 to 107±44 cm2, and EFV from 137±37 ml to 98±25 ml (all p<0.0001). There was no significant change in MTGC: 1.03±0.2% versus 1.1±0.2% (p=0.85). A significant reduction in left ventricular mass (118±24 g vs. 101±18 g) and cardiac output (7.1±1.6 l/min vs. 5.4±1.0 l/min) was observed and was statistically associated with weight loss (p<0.05). The loss in EFV was limited (-27±11%) compared to VAF diminution (-40±19%). The EFV variation was not correlated with percentage of body mass index or VAF loss (p=0.007). The ratio of %EFV to %VAF loss decreased with sleep apnea syndrome (1.34±0.3 vs. 0.52±0.08, p<0.05). CONCLUSIONS Six-month BS modulates differently cardiac ectopic fat deposition, with a significant decrease in epicardial fat and no change in myocardial fat. Epicardial fat volume loss was limited in patients with sleep apnea. (Impact of Bariatric Surgery on Epicardial Adipose Tissue and on Myocardial Function; NCT01284816).

CYP2C19*2 and *17 Alleles Have a Significant Impact on Platelet Response and Bleeding Risk in Patients Treated With Prasugrel After Acute Coronary Syndrome.

OBJECTIVES The present study was designed to assess the effect of genetic variants on chronic biological response to prasugrel and bleeding complications. BACKGROUND CYP2C19*2 loss-of-function allele and CYP2C19*17 gain-of-function allele have been linked with response to clopidogrel, but preliminary data did not show any significant influence of these alleles on prasugrel effect. METHODS A total of 213 patients undergoing successful coronary stenting for acute coronary syndrome and discharged with prasugrel 10 mg daily were included. Prasugrel response was assessed at 1 month with the platelet reactivity index (PRI) vasodilator-stimulated phosphoprotein (VASP) and high on-treatment platelet reactivity (HTPR) defined as PRI VASP > 50% and hyper-response as PRI VASP <75th percentile (PRI VASP < 17%). CYP2C19*2 and CYP2C19*17 genotyping were performed. RESULTS Carriers of loss-of-function *2 allele had significantly higher PRI VASP than noncarriers (33 ± 15% vs. 27 ± 14%, p = 0.03) and higher rate of HTPR (16% vs. 4%, p = 0.01). Conversely, carriers of *17 gain-of-function allele had significantly lower PRI VASP than noncarriers (25 ± 13% vs. 31 ± 15%, p = 0.03, p = 0.03), lower rate of HTPR (1% vs. 10%, p = 0.02), higher rate of hyper-response (34% vs. 21%, p = 0.02), and higher rate of bleeding complications than noncarriers: 23% versus 11%, (odds ratio [95% confidence interval]: 2.5 [1.2 to 5.4]; p = 0.02). No significant influence of genotypes on platelet reactivity assessed by adenosine diphosphate-induced platelet aggregation was observed. CONCLUSIONS The present study shows a significant influence of CYP2C19*2 and *17 alleles on response to chronic treatment by prasugrel 10 mg daily and occurrence of bleeding complications.

Assessment of epicardial fat volume and myocardial triglyceride content in severely obese subjects: relationship to metabolic profile, cardiac function and visceral fat

Objective:To assess epicardial fat volume (EFV), myocardial TG content (MTGC) and metabolic profile in severely obese patients, and to determine whether ectopic fat depots are linked to metabolic disorders or myocardial function.Research design and methods:Sixty-three subjects with normal LV function and no coronary artery disease, including 33 lean (BMI: 21.4±2.0 kg m−2) and 30 obese (BMI: 41.8±6 kg m−2) patients, underwent 3-T cardiovascular MRI, and anthropometric, biological and visceral abdominal fat (VAT) assessments. EFV was measured by short-axis slice imaging and myocardial (intra-myocellular) TG content was measured by proton magnetic resonance spectroscopy.Results:EFV and MTGC were positively correlated (r=0.52, P<0.0001), and were both strongly correlated with age, BMI, waist circumference and VAT, but not with severity of obesity. EFV and MTGC were significantly higher in obese patients than in lean controls (141±18 versus 79±7 ml, P=0.0001; 1.0±0.1 versus 0.6±0.1%, P=0.01, respectively), but some differences were found between the two cardiac depots: EFV was higher in diabetic obese subjects as compared with that in non-diabetic obese subjects (213±34 versus 141±18 ml, P=0.03), and was correlated with parameters of glucose tolerance (fasting plasma glucose, insulin and HOMA-IR), whereas MTGC was not. EFV and MTGC were both associated with parameters of lipid profile or inflammation (TGs, CRP). Remarkably, this was VAT-dependent, as only VAT remained independently associated with metabolic parameters (P<0.01). Concerning myocardial function, MTGC was the only parameter independently associated with stroke volume (β=−0.38, P=0.01), suggesting an impact of cardiac steatosis in cardiac function.Conclusions:These data show that VAT dominates the relationship between EFV, MTGC and metabolic measures, and uncover specific partitioning of cardiac ectopic lipid deposition.

Predictive Values of Post-Treatment Adenosine Diphosphate–Induced Aggregation and Vasodilator-Stimulated Phosphoprotein Index for Stent Thrombosis After Acute Coronary Syndrome in Clopidogrel-Treated Patients

A low response to clopidogrel has been associated with an increased risk of stent thrombosis. However, the definition of a nonresponse to clopidogrel remains controversial, and different tests have been used to assess the clopidogrel response. The present study was designed to assess the predictive value of adenosine diphosphate (ADP)-induced platelet aggregation (ADP-Ag) and the Platelet Reactivity Index of vasodilator-stimulated phosphoprotein for the occurrence of stent thrombosis in patients admitted for non-ST-elevation acute coronary syndrome undergoing percutaneous coronary intervention. A total of 598 consecutive patients with non-ST-elevation acute coronary syndrome undergoing coronary stenting were prospectively included. They received 600 mg of clopidogrel >or=12 hours before percutaneous coronary intervention. Acute or subacute definite or probable stent thrombosis occurred in 11 patients (1.8%). These patients had significantly greater ADP-Ag compared to patients free of stent thrombosis (68 +/- 14% vs 56 +/- 19%, p = 0.002) but only a trend toward a greater Platelet Reactivity Index of vasodilator-stimulated phosphoprotein (62 +/- 14% vs 53 +/- 23%, p = 0.19). The construction of receiver operating characteristic curves to examine the most predictive value of ADP-Ag for stent thrombosis gave a threshold of ADP-Ag of >67% to identify low responders. These patients were at a greater risk of stent thrombosis than the clopidogrel responders (4.3% vs 0.8%, odds ratio 5.8, 95% confidence interval 1.9 to 24.6, p = 0.003). In conclusion, in patients with non-ST-elevation acute coronary syndrome undergoing percutaneous coronary intervention, ADP-Ag is a good parameter to identify clopidogrel nonresponders who are at increased risk of stent thrombosis, with a cutoff value of ADP-Ag of >67%.

Secretory Type II Phospholipase A2 Is Produced and Secreted by Epicardial Adipose Tissue and Overexpressed in Patients with Coronary Artery Disease

CONTEXT Epicardial adipose tissue (EAT) is a visceral adipose tissue in close contact with coronary vessels, the excess of which is associated with coronary artery disease (CAD). OBJECTIVE Our goal was to identify candidate molecule(s) characterizing EAT that could intervene in the pathogenesis of CAD. DESIGN An approach combining microarrays and bioinformatic sequence analysis tools for predicting secreted proteins (TargetP) was applied to paired biopsies of sc adipose tissue (SAT) and EAT, obtained from patients with or without CAD (NCAD). RESULTS were validated in three independent groups of subjects by quantitative RT-PCR, Western blot, immunohistochemistry, and explant secretion. RESULTS Secretory type II phospholipase A2 (sPLA2-IIA) ranked as the highest gene coding for potentially secreted proteins with the highest overexpression in EAT in both CAD and NCAD. Quantitative RT-PCR confirmed its increased expression in EAT (P < 0.01) as well as EAT from CAD as compared with NCAD (49.3 +/- 13 vs. 17.4 +/- 9.7 P < 0.01). sPLA2-IIA protein levels were higher in EAT than SAT (P < 0.001). EAT explants also showed significantly higher sPLA2-IIA secretion levels than SAT ones (4.37 +/- 2.7 vs. 0.67 +/- 0.28 ng/ml to 1 per gram tissue per 24 h, P < 0.03). sPLA2-IIA labeling was seen in the stroma vascular fraction between adipocytes and in connective capsules in EAT, with no immunostaining of the adipocytes. SAT was weakly labeled following the same process. CONCLUSION We have shown for the first time an increased expression of sPLA2-IIA in EAT in patients with CAD. sPLA2-IIA is a phospholipase, which has been shown to be an independent risk factor for CAD. These findings suggest that EAT has a potentially pathophysiological role in CAD.

Human epicardial adipose tissue has a specific transcriptomic signature depending on its anatomical peri-atrial, peri-ventricular, or peri-coronary location

AIMS Human epicardial adipose tissue (EAT) is a visceral and perivascular fat that has been shown to act locally on myocardium, atria, and coronary arteries. Its abundance has been linked to coronary artery disease (CAD) and atrial fibrillation. However, its physiological function remains highly debated. The aim of this study was to determine a specific EAT transcriptomic signature, depending on its anatomical peri-atrial (PA), peri-ventricular (PV), or peri-coronary location. METHODS AND RESULTS Samples of EAT and thoracic subcutaneous fat, obtained from 41 patients paired for cardiovascular risk factors, CAD, and atrial fibrillation were analysed using a pangenomic approach. We found 2728 significantly up-regulated genes in the EAT vs. subcutaneous fat with 400 genes being common between PA, PV, and peri-coronary EAT. These common genes were related to extracellular matrix remodelling, inflammation, infection, and thrombosis pathways. Omentin (ITLN1) was the most up-regulated gene and secreted adipokine in EAT (fold-change >12, P < 0.0001). Among EAT-enriched genes, we observed different patterns depending on adipose tissue location. A beige expression phenotype was found in EAT but PV EAT highly expressed uncoupled protein 1 (P = 0.01). Genes overexpressed in peri-coronary EAT were implicated in proliferation, O-N glycan biosynthesis, and sphingolipid metabolism. PA EAT displayed an atypical pattern with genes implicated in cardiac muscle contraction and intracellular calcium signalling pathway. CONCLUSION This study opens new perspectives in understanding the physiology of human EAT and its local interaction with neighbouring structures.