Ticagrelor vs Clopidogrel in Clopidogrel-Naive Patients With Chronic Coronary Syndrome.

BACKGROUND: Whether ticagrelor may reduce periprocedural myocardial necrosis after elective percutaneous coronary intervention (PCI) in patients with and without chronic clopidogrel therapy is unclear. OBJECTIVES: This study sought to compare ticagrelor vs clopidogrel in patients with and without chronic clopidogrel therapy before undergoing elective PCI. METHODS: In this prespecified analysis of the ALPHEUS (Assessment of Loading With the P2Y12 Inhibitor Ticagrelor or Clopidogrel to Halt Ischemic Events in Patients Undergoing Elective Coronary Stenting) trial, patients were defined as clopidogrel(+) and clopidogrel(-) according to the presence and absence of clopidogrel treatment for ≥7 days before PCI, respectively. The primary endpoint was the composite of PCI-related myocardial infarction and major injury as defined by the third and fourth universal definition 48 hours after PCI. RESULTS: A total of 1,882 patients were included, 805 (42.7%) of whom were clopidogrel(+). These patients were older, had more comorbidities, and had more frequent features of complex PCI. The primary endpoint was less frequently present in clopidogrel(-) compared to clopidogrel(+) patients (32.8% vs 40.0%; OR: 0.73; 95% CI: 0.60-0.88), but no significant differences were reported for the risk of death, myocardial infarction, stroke, or transient ischemic attack at 48 hours or 30 days. Ticagrelor did not reduce periprocedural myocardial necrosis or the risk of adverse outcomes, and there was no significant interaction regarding the presence of chronic clopidogrel treatment. CONCLUSIONS: Clopidogrel-naive patients presented less periprocedural complications compared to clopidogrel(+) patients, a difference related to a lower risk profile and less complex PCI. The absence of clopidogrel at baseline did not affect the absence of a difference between ticagrelor and clopidogrel in terms of PCI-related complications supporting the use of clopidogrel as the standard of care in elective PCI in patients with or without chronic clopidogrel treatment.

P2Y12 Inhibitor Loading Time Before Elective PCI and the Prevention of Myocardial Necrosis.

BACKGROUND: There are dated and conflicting data about the optimal timing of initiation of P2Y12 inhibitors in elective percutaneous coronary intervention (PCI). Peri-PCI myocardial necrosis is associated with poor outcomes. We aimed to assess the impact of the P2Y12 inhibitor loading time on periprocedural myocardial necrosis in the population of the randomized Assessment of Loading With the P2Y12 Inhibitor Ticagrelor or Clopidogrel to Halt Ischemic Events in Patients Undergoing Elective Coronary Stenting (ALPHEUS) trial, which compared ticagrelor with clopidogrel in high-risk patients who received elective PCI. METHODS: The ALPHEUS trial divided 1809 patients into quartiles of loading time. The ALPHEUS primary outcome was used (type 4 [a or b] myocardial infarction or major myocardial injury) as well as the main secondary outcome (type 4 [a or b] myocardial infarction or any type of myocardial injury). RESULTS: Patients in the first quartile group (Q1) presented higher rates of the primary outcome (P = 0.01). When compared with Q1, incidences of the primary outcome decreased in patients with longer loading times (adjusted odds ratio [adjOR], 0.70 [0.52.-0.95]; P = 0.02 for Q2; adjOR 0.65 [0.48-0.88]; P < 0.01 for Q3; adjOR 0.66 [0.49-0.89]; P < 0.01 for Q4). Concordant results were found for the main secondary outcome. There was no interaction with the study drug allocated by randomization (clopidogrel or ticagrelor). Bleeding complications (any bleeding ranging between 4.9% and 7.3% and only 1 major bleeding at 48 hours) and clinical ischemic events were rare and did not differ among groups. CONCLUSIONS: In elective PCI, administration of the oral P2Y12 inhibitor at the time of PCI could be associated with more frequent periprocedural myocardial necrosis than an earlier administration. The long-term clinical consequences remain unknown.

Is plasma concentration of coenzyme Q10 a predictive marker for left ventricular remodelling after revascularization for ST-segment elevation myocardial infarction?

BACKGROUND: Left ventricular remodelling that frequently occurs after acute myocardial infarction is associated with an increased risk of heart failure and cardiovascular death. Although several risk factors have been identified, there is still no marker in clinical use to predict left ventricular remodelling. Plasma concentration of coenzyme Q10, which plays a key role in mitochondrial energy production and as an antioxidant, seems to be negatively correlated with left ventricular function after acute myocardial infarction. OBJECTIVE: The goal of our study was to determine whether the plasma coenzyme Q10 baseline concentrations at time of the ST-elevation myocardial infarction (STEMI) could predict left ventricular remodelling at six months' follow-up. METHODS: Sixty-eight patients who were admitted to hospital for STEMI and successfully revascularized with primary percutaneous coronary intervention were recruited. All patients underwent a 3D-echocardiography examination within the first four days after percutaneous coronary intervention and six months later then divided into two groups based on the presence or not of left ventricular remodelling. Plasma coenzyme Q10 concentration at the time of percutaneous coronary intervention was determined using high-performance liquid chromatography-tandem mass spectrometry. RESULTS: While we found similar plasma coenzyme Q10 concentrations compared with other studies, no association was evidenced between coenzyme Q10 concentrations and left ventricular remodelling (P = 0.89). CONCLUSION: We found no evidence for using plasma coenzyme Q10 concentration as an early prediction marker of left ventricular remodelling after STEMI.

Impaired left atrial function in adults and adolescents with corrected aortic coarctation.

This study examined the left atrial (LA) function using two-dimensional (2D) strain analysis after aortic coarctation (CoA) repair, as well as relationships between LA function and patient characteristics, especially aortic arch anatomy. 56 patients (34 males, age: 31 ± 16 years) with CoA repair (46 post 'end-to-end anastomosis/subclavian flap') and 56 controls were studied. 2D strain imaging was performed to assess left ventricular (LV) and LA functions including peak-positive LA strain, early and late diastolic LA strains, and global longitudinal (LV-GLS) and circumferential (LV-GCS) strains. LA dysfunction (LAD) was defined as a peak-positive LA strain value lower than the mean value of the control group minus 2 SDs. Peak-positive LA strain, early and late diastolic LA strains, and LV-GLS were significantly lower in the CoA group while LV-GCS did not differ. No significant correlation was found between LA strain and either current age, age at initial repair, or blood pressure; Ea and LV-GLS were moderately correlated to peak-positive LA strain (r = 0.49, p < 0.001 and r = - 0.55, p < 0.001, respectively). 23 CoA patients (41%) presented LAD (abnormal peak-positive LA strain < 25%). Among patients who underwent end-to-end anastomosis/subclavian flap, those with a non-romanesque aortic arch anatomy exhibited a significantly lower peak-positive LA strain. Ischemic stroke and atrial arrhythmia were more frequent in CoA patients with LAD. Our findings suggest that LAD may be prevalent late after CoA repair. Postoperative aortic arch anatomy may impact peak-positive LA strain.

Impaired left atrial stiffness in patients with corrected congenital left ventricular outflow obstructions.

OBJECTIVE: We examined the left atrial stiffness index (LA Stiff) on echocardiography and its determinants in adults and adolescents with repaired congenital left ventricular outflow obstructions (c-LVOOs), including isolated subaortic stenosis (SAS), stenotic bicuspid aortic valve (BAV), and aortic coarctation (CoA). METHODS: Seventy-two patients (43 males, age: 31 ± 15 years) with repaired c-LVOOs (SAS: n = 12; BAV: n = 27; CoA: n = 33) were compared to 72 age- and sex-matched controls. 2D strain imaging was performed to assess left ventricular (LV) and LA function, including peak positive longitudinal LA strain (LAS), late diastolic LA strain (LDS), and LV global longitudinal strain (GLS). The (E/Ea)/LAS ratio was used to calculate LA Stiff. RESULTS: LA Stiff was significantly higher in the c-LVOO group than in the control group. Among the c-LVOO patients, the CoA group had the lowest GLS and the highest LA Stiff; no significant differences were found with respect to sex, hypertension history, smoking status, or repeated repair among c-LVOO subtypes. Multivariable regression analysis with the variables "BMI" and "c-LVOO subtype" revealed that BMI and c-LVOO subtypes were independently associated with LA Stiff (b = 0.290, P = .009 and b = 0.353, P = .002, respectively). CONCLUSIONS: We documented abnormal LA Stiff values in adults and adolescents after c-LVOO repair. Patients with CoA demonstrated the most impaired LA Stiff values. Overweight may contribute to worse LA Stiff values. Further studies are required to determine the prognostic implications of LA Stiff in patients with repaired c-LVOOs.

Ticagrelor versus clopidogrel in elective percutaneous coronary intervention (ALPHEUS): a randomised, open-label, phase 3b trial.

BACKGROUND: Percutaneous coronary intervention (PCI)-related myonecrosis is frequent and can affect the long-term prognosis of patients. To our knowledge, ticagrelor has not been evaluated in elective PCI and could reduce periprocedural ischaemic complications compared with clopidogrel, the currently recommended treatment. The aim of the ALPHEUS study was to examine if ticagrelor was superior to clopidogrel in reducing periprocedural myocardial necrosis in stable coronary patients undergoing high-risk elective PCI. METHODS: The ALPHEUS study, a phase 3b, randomised, open-label trial, was done at 49 hospitals in France and Czech Republic. Patients with stable coronary artery disease were eligible for the study if they had an indication for PCI and at least one high-risk characteristic. Eligible patients were randomly assigned (1:1) to either ticagrelor (180 mg loading dose, 90 mg twice daily thereafter for 30 days) or clopidogrel (300-600 mg loading dose, 75 mg daily thereafter for 30 days) by use of an interactive web response system, and stratified by centre. The primary outcome was a composite of PCI-related type 4 (a or b) myocardial infarction or major myocardial injury and the primary safety outcome was major bleeding, both of which were evaluated within 48 h of PCI (or at hospital discharge if earlier). The primary analysis was based on all events that occurred in the intention-to-treat population. The trial was registered with ClinicalTrials.gov, NCT02617290. FINDINGS: Between Jan 9, 2017, and May 28, 2020, 1910 patients were randomly assigned at 49 sites, 956 to the ticagrelor group and 954 to the clopidogrel group. 15 patients were excluded from the ticagrelor group and 12 from the clopidogrel group. At 48 h, the primary outcome was observed in 334 (35%) of 941 patients in the ticagrelor group and 341 (36%) of 942 patients in the clopidogrel group (odds ratio [OR] 0·97, 95% CI 0·80-1·17; p=0·75). The primary safety outcome did not differ between the two groups, but minor bleeding events were more frequently observed with ticagrelor than clopidogrel at 30 days (105 [11%] of 941 patients in the ticagrelor group vs 71 [8%] of 942 patients in the clopidogrel group; OR 1·54, 95% CI 1·12-2·11; p=0·0070). INTERPRETATION: Ticagrelor was not superior to clopidogrel in reducing periprocedural myocardial necrosis after elective PCI and did not cause an increase in major bleeding, but did increase the rate of minor bleeding at 30 days. These results support the use of clopidogrel as the standard of care for elective PCI. FUNDING: ACTION Study Group and AstraZeneca.

Serum neprilysin levels are associated with myocardial stunning after ST-elevation myocardial infarction.

BACKGROUND: Left ventricular remodeling following ST-elevation myocardial infarction (STEMI) is associated with poor outcome, including heart failure (HF). Neprilysin inhibition leads to improved outcome in patients with altered left ventricular ejection fraction (LVEF). METHODS: We aimed to assess the association between serum levels of neprilysin and left ventricular (LV) volumes, function and remodeling in STEMI patients with successful myocardial reperfusion and no clinical sign of HF. Sixty-eight patients were admitted for STEMI and had both plasma neprilysin measurement at baseline and 3D transthoracic echocardiogram at baseline and after a median follow-up of 7 months. We compared 3 groups: a group with a low-level of plasma neprilysin (< 125 pg/mL, i.e. the lower limit of detection of the assay) and the two other groups were defined as being below or above the median value of the remaining samples. RESULTS: Median age was 58.5 ± 12.8 years and 56 (82.4%) were men. Median LVEF was 45.0 ± 8.5%. Baseline characteristics were comparable between groups (low-level of neprilysin group [≤125 pg/mL, n = 38], medium-level of neprilysin group [126-450 pg/mL, n = 15] and a high-level group [> 450 pg/mL, n = 15]). At baseline there was a non-significant trend towards lower end-diastolic volume (p = 0.07) but significantly lower LVEF in the high neprilysin group (46.4 ± 8.3%, 47.1 ± 8.1% and 39.1 ± 6.9%, p < 0.01). At follow-up, the magnitude of LVEF increase was significantly more important in the high neprilysin group compared to the other groups (p = 0.022 for relative change in LVEF and 6.6 ± 7.3%, 3.6 ± 9.0% and 11.3 ± 8.4%, p = 0.031 for absolute change in LVEF) resulting in similar LVEF levels at follow-up between all groups (53.0 ± 8.9%, 50.6 ± 9.7% and 50.4 ± 9.9%, p = 0.55). CONCLUSIONS: Initial high neprilysin levels may identify patients with stunned myocardium early after STEMI, with a recovery of contractility leading to improved LVEF at follow-up. Future studies will have to assess the role of neprilysin in the setting of STEMI and the potential benefit of its blockade.

Blunting periprocedural myocardial necrosis: Rationale and design of the randomized ALPHEUS study.

BACKGROUND: Clopidogrel associated with aspirin is the recommended treatment for patients undergoing elective percutaneous coronary intervention (PCI). Although severe PCI-related events are rare, evidence suggests that PCI-related myocardial infarction and myocardial injury are frequent complications that can impact the clinical prognosis of the patients. Antiplatelet therapy with a potent P2Y12 receptor inhibitor such as ticagrelor may reduce periprocedural ischemic complications while maintaining a similar safety profile as compared with conventional dual antiplatelet therapy by aspirin and clopidogrel in this setting. METHODS: Assessment of Loading with the P2Y12 inhibitor ticagrelor or clopidogrel to Halt ischemic Events in patients Undergoing elective coronary Stenting (ALPHEUS) (NCT02617290) is an international, multicenter, randomized, parallel-group, open-label study in patients with stable coronary artery disease who are planned for an elective PCI. In total, 1,900 patients will be randomized before a planned PCI to a loading dose of ticagrelor 180 mg or a loading dose of clopidogrel (300 or 600 mg) in addition to aspirin. Patients will then receive a dual antiplatelet therapy with aspirin and ticagrelor 90 mg twice daily or clopidogrel 75 mg once daily for 30 days. The primary ischemic end point is PCI-related myocardial infarction (myocardial infarction type 4a or 4b) or major myocardial injury within 48 hours (or at hospital discharge if earlier) after elective PCI/stent. Safety will be evaluated by major bleeding events (Bleeding Academic Research Consortium type 3 or 5) at 48 hours (or discharge if it occurs earlier). CONCLUSION: ALPHEUS is the first properly sized trial comparing ticagrelor to clopidogrel in the setting of elective PCI and is especially designed to show a reduction in periprocedural events, a surrogate end point for mortality.

Residual platelet reactivity, thrombus burden and myocardial reperfusion in patients treated by PCI after successful pre-hospital fibrinolysis compared to primary PCI.

We compared residual platelet reactivity and post PCI atherothrombotic burden using OFDI in patients successfully treated by primary PCI versus pharmacoinvasive approach (PI) defined as PCI after successful pre-hospital fibrinolysis. Despite pre-hospital P2Y12-inhibitor loading dose, high rates of high on-treatment platelet reactivity were found at the time of PCI in both groups. Primary PCI patients had higher post stenting thrombus burden and lower rates of final normal myocardial blush grade compared to PI. These findings support the use of a pharmacoinvasive reperfusion strategy especially when primary PCI cannot be timely performed.

Systematic review and meta-analysis of the prognostic impact of cancer among patients with acute coronary syndrome and/or percutaneous coronary intervention.

BACKGROUND: Patients with cancer admitted for an acute coronary syndrome (ACS) and/or percutaneous coronary intervention (PCI) represent a growing and high-risk population. The influence of co-existing cancer on mortality remains unclear in such patients. We aimed to assess the impact of cancer on early and late, all-cause and cardiac mortality in the setting of ACS and/or PCI. METHODS: We performed a systematic review and meta-analysis of studies comparing outcomes of patients with and without a history of cancer admitted for ACS and/or PCI. RESULTS: Six studies including 294,528 ACS patients and three studies including 39,973 PCI patients were selected for our meta-analysis. Patients with cancer had increased rates of in-hospital all-cause death (RR 1.74 [1.22; 2.47]), cardiac death (RR 2.44 [1.73; 3.44]) and bleeding (RR 1.64 [1.35; 1.98]) as well as one-year all-cause death (RR 2.62 [1.2; 5.73]) and cardiac death (RR 1.89 [1.25; 2.86]) in ACS studies. Rates of long term all-cause (RR 1.96 [1.52; 2.53]) but not cardiac death were higher in cancer patients admitted for PCI. CONCLUSION: Cancer patients represent a high-risk population both in the acute phase and at long-term after an ACS or PCI. The magnitude of the risk of mortality should however be tempered by the heterogeneity among studies. Early and long term optimal management of such patients should be promoted in clinical practice.

Spironolactone and perioperative atrial fibrillation occurrence in cardiac surgery patients: Rationale and design of the ALDOCURE trial.

BACKGROUND: After artery bypass grafting (CABG), the presence of perioperative AF (POAF) is associated with greater short- and long-term cardiovascular morbidity. Underlying POAF mechanisms are complex and include the presence of an arrhythmogenic substrate, cardiac fibrosis and electrical remodeling. Aldosterone is a key component in this process. We hypothesize that perioperative mineralocorticoid receptor (MR) blockade may decrease the POAF incidence in patients with a left ventricular ejection fraction (LVEF) ≥50% who are referred for CABG with or without aortic valve replacement (AVR). STUDY DESIGN: The ALDOCURE trial (NCT03551548) will be a multicenter, randomized, double-blind, placebo-controlled trial testing the superiority of a low-cost MR antagonist (MRA, spironolactone) on POAF in 1500 adults referred for on-pump elective CABG surgery with or without AVR, without any history of heart failure or atrial arrhythmia. The primary efficacy end point is the occurrence of POAF from randomization to within 5 days after surgery, assessed in a standardized manner. The main secondary efficacy end points include the following: postoperative AF occurring within 5 days after cardiac surgery, perioperative myocardial injury, major cardiovascular events and death occurring within 30 days of surgery, hospital and intensive care unit length of stay, need for readmission, LVEF at discharge and significant ventricular arrhythmias within 5 days after surgery. Safety end points, including blood pressure, serum potassium levels and renal function, will be monitored regularly throughout the trial duration. CONCLUSION: The ALDOCURE trial will assess the effectiveness of spironolactone in addition to standard therapy for reducing POAF in patients undergoing CABG. CLINICAL TRIAL REGISTRATION: NCT03551548.

Safety and efficacy of IIb/IIIa inhibitors in combination with highly active oral antiplatelet regimens in acute coronary syndromes: A meta-analysis of pivotal trials.

The risk and benefit of GP-IIb/IIIa Inhibition (GPI) in combination with recent antiplatelet regimens in acute coronary syndromes (ACS) remain unassessed. The advent of fast-acting highly active oral P2Y12 inhibitors questions the additional value and risk of their association with GPI. We studied the effect of GPI in combination with prasugrel and ticagrelor, compared to clopidogrel on major bleeding in pivotal randomized controlled trials in the setting of ACS, using a meta-analytic approach. A similar analysis, further including the comparison of a double versus standard dose clopidogrel regimen, was performed for the risk of the primary efficacy endpoint. The combination of GPI and recent P2Y12 inhibitors was associated with a similar risk of bleeding as compared with GPI and the standard clopidogrel regimen (RR 0.92 [0.74; 1.13]). The benefit of recent regimens, including double dose clopidogrel, in reducing the primary ischemic endpoint (RR 0.86 [0.78; 0.94]) persisted in those treated with GPI. Although GPI use was associated with a consistent increase in the risk of bleeding in both recent (RR 1.27 [1.05-1.55]) and standard regimens (RR 2.01 [1.64-2.47]), the relative magnitude of such an increase was lower in association with prasugrel or ticagrelor as compared with clopidogrel. The risk of bleeding using a combination of GPI and oral antiplatelet regimens is mainly related to the use of GPI and not the oral antiplatelet regimen. Considering the absence of increased risk of bleeding and the persistence of the benefit of recent P2Y12 regimens in combination with GPI as compared with the standard clopidogrel regimen, the use of such a combination within the guidelines is supported by our findings.

Prasugrel but not high dose clopidogrel overcomes the lansoprazole neutralizing effect of P2Y12 inhibition: Results of the randomized DOSAPI study.

AIMS: The potential negative metabolic interaction between proton pump inhibitors and clopidogrel is an unsolved issue. We hypothesized that doubling the clopidogrel maintenance dose (150 mg) would be less effective than switching to prasugrel 10 mg maintenance dose (MD) to overcome this negative interaction. METHOD AND RESULTS: In a randomized study with a factorial design, 82 stable coronary artery disease patients treated with 75 mg clopidogrel MD and aspirin were assigned to receive in a double blind fashion lansoprazole (30 mg/day) or placebo and to receive in an open fashion 150 mg clopidogrel MD or 10 mg prasugrel MD. The primary endpoint was the relative change in residual platelet reactivity over the 14-day study period [(RPA14day-RPAbaseline)/RPAbaseline]. The effect of doubling the clopidogrel MD on relative change in RPA was neutralized by lansoprazole (-53.6±48.4% versus +0.8±53.7% without and with lansoprazole, respectively, p = 0.02) whereas 10 mg of prasugrel MD dramatically reduced RPA irrespective of lansoprazole co-administration (-81.8 %±24.8% vs. -72.9%±32.9% without and with lansoprazole, respectively, p = NS). Lansoprazole exposure was the only parameter with a significant interaction with RPA among subgroups. CONCLUSION: The higher platelet inhibitory effect obtained by doubling the clopidogrel MD was totally neutralized by the co-administration of lansoprazole. This drug interaction was not observed with prasugrel 10 mg.

Switching acute coronary syndrome patients from prasugrel to clopidogrel.

OBJECTIVES: This study sought to assess the consequences of switching prasugrel to clopidogrel on platelet inhibition and clinical outcomes after an acute coronary syndrome (ACS). BACKGROUND: Many ACS patients are switched from prasugrel to clopidogrel within the recommended 1-year duration of treatment. METHODS: Platelet reactivity was measured with the VerifyNow P2Y(12) assay (Accumetrics, San Diego, California) in 300 ACS patients treated for 15 days with prasugrel 10 mg. Patients displaying low on-treatment platelet reactivity (LPR) and/or at high risk of bleeding were switched to clopidogrel 75 mg and tested again 15 days later. The rate of patients with high on-treatment platelet reactivity (HPR), P2Y(12) reaction units (PRU) >208, and LPR (PRU <0) were evaluated before and after the switch. Bleeding and ischemic events were also recorded. RESULTS: On a regimen of prasugrel 10 mg, the rate of patients with LPR was 45.6% (n = 137), whereas 4.3% (n = 13) had HPR. A group of 31 patients (10.3%) was switched to clopidogrel 75 mg, of whom 29 had LPR (93.5%) on a regimen of prasugrel. On-treatment platelet reactivity (PRU) increased from 14 ± 4 on a regimen of prasugrel to 155 ±15 on a regimen of clopidogrel (p = 0.0001), resulting in a much lower rate of patients with LPR (9.7%). The rate of patients with HPR increased from 0% with prasugrel to 29% (n = 9) with clopidogrel. The rate of minor bleeding decreased after the switch from 32.2% to 9.7%; p = 0.03. CONCLUSIONS: An LPR is frequent in patients treated with prasugrel 10 mg. Early switching from prasugrel 10 mg to clopidogrel 75 mg reduces the number of patients with LPR and minor bleeding events but unmasks a group of nonresponders to clopidogrel with unknown consequences on clinical outcomes.

High doses of clopidogrel to overcome genetic resistance: the randomized crossover CLOVIS-2 (Clopidogrel and Response Variability Investigation Study 2).

OBJECTIVES: This study sought to determine whether the pharmacokinetic (PK) and pharmacodynamic (PD) responses to high or standard clopidogrel loading doses (LDs) differ according to CYP2C19*2 allele. BACKGROUND: CYP2C19 loss-of-function alleles are associated with reduced responsiveness to standard clopidogrel doses. METHODS: Young post-myocardial infarction patients heterozygous (wild type [wt]/*2, n = 43) or homozygous (*2/*2, n = 8) for the CYP2C19*2 genetic variant were matched with patients not carrying the variant (wt/wt, n = 58). All patients were randomized to a 300- or 900-mg clopidogrel LD. The relative reduction in residual platelet aggregation (RR-RPA, %) and the area under the plasma concentration time curve of active metabolite from baseline to 6 h after loading (AUC(0-6)) were compared according to both LD and CYP2C19*2 carriage. RESULTS: The 300-mg LD led to a gene-dose effect for RR-RPA (-65.7% ± 35.9% in wt/wt vs. -48.0% ± 38.4% in wt/*2 vs. -14.6% ± 32.4% in *2/*2; overall p value = 0.003, p = 0.03 for wt/wt versus wt/*2, p = 0.04 for wt/*2 versus *2/*2) with minor effect in *2/*2 carriers. After the 900-mg LD, the effect of the CYP2C19*2 variant on platelet inhibition was fully compensated in wt/*2 carriers but not in *2/*2 carriers (-83.6% ± 25.8% in wt/wt vs.-77.2% ± 26.9% in wt/*2 vs. -29.5% ± 26.8% in *2/*2; overall p value = 0.0003, p = 0.20 for wt/wt versus wt/*2, p < 0.001 for wt/*2 versus *2/*2). A similar pattern was observed for the active metabolite AUC(0-6) according to carriage of CYP2C19*2 for both LDs. There was a significant correlation between PK and PD responses irrespective of the LD. CONCLUSIONS: Carriers of CYP2C19*2 display significantly lower responses to clopidogrel with a gene-dose effect. Clopidogrel resistance can be overcome by increasing the dose in heterozygous carriers but not in homozygous carriers. (Clopidogrel and Response Variability Investigation Study 2 [CLOVIS-2]; NCT00822666).

Composition of coronary thrombus in acute myocardial infarction.

OBJECTIVES: We sought to analyze the composition of coronary thrombus in vivo in ST-segment elevation myocardial infarction (STEMI) patients. BACKGROUND: The dynamic process of intracoronary thrombus formation in STEMI patients is poorly understood. METHODS: Intracoronary thrombi (n = 45) were obtained by thromboaspiration in 288 consecutive STEMI patients presenting for primary percutaneous intervention, and analyzed using high-definition pictures taken with a scanning electron microscope. Plasma biomarkers (TnI, CRPus, IL-6, PAI-1, sCD40 ligand, and TNF-α) and plasma fibrin clot viscoelastic properties were measured simultaneously on peripheral blood. RESULTS: Thrombi were mainly composed of fibrin (55.9 ± 18%) with platelets (16.8 ± 18%), erythrocytes (11.5 ± 9%), cholesterol crystals (5.2 ± 8.4%), and leukocytes (1.3 ± 2.0%). The median ischemic time was 175 min (interquartile range: 140 to 297). Ischemic time impacted thrombi composition, resulting in a positive correlation with intracoronary thrombus fibrin content, r = 0.38, p = 0.01, and a negative correlation with platelet content, r = -0.34, p = 0.02. Thus, fibrin content increased with ischemic time, ranging from 48.4 ± 21% (<3 h) up to 66.9 ± 9% (>6 h) (p = 0.02), whereas platelet content decreased from 24.9 ± 23% (<3 h) to 9.1 ± 6% (>6 h) (p = 0.07). Soluble CD40 ligand was positively correlated to platelet content in the thrombus (r = 0.40, p = 0.02) and negatively correlated with fibrin content (r = -0.36; p = 0.04). Multivariate analysis indicated that ischemic time was the only predictor of thrombus composition, with a 2-fold increase of fibrin content per ischemic hour (adjusted odds ratio: 2.00 [95% confidence interval: 1.03 to 3.7]; p = 0.01). CONCLUSIONS: In acute STEMI, platelet and fibrin contents of the occlusive thrombus are highly dependent on ischemia time, which may have a direct impact on the efficacy of drugs or devices used for coronary reperfusion.