Elevated Plasma Fibrinogen Rather Than Residual Platelet Reactivity After Clopidogrel Pre-Treatment Is Associated With an Increased Ischemic Risk During Elective Percutaneous Coronary Intervention

Fibrinogen-to-Albumin Ratio and Glucose Metabolic States in Patients With Coronary Heart Disease

This study investigated the relationship between fibrinogen-to-albumin ratio (FAR) and glucose metabolic state in patients with coronary heart disease (CHD). A total of 52,062 patients were enrolled in this study. Patients were classified according to FAR tertiles (T1: FAR < 0.0073; T2: 0.0073 ≤ FAR ≤ 0.0886; T3: FAR ≥ 0.0887). Patients were also classified into the normal glucose regulation (NGR) and elevated blood glucose (EBG) groups. The relationship between FAR and EBG was analyzed using logistic regression, and the association was evaluated according to sex and age. Among the participants, 32,471 (62.4%) had EBG, which was positively associated with FAR (odds ratio [OR], 1.19; 95% confidence interval [CI] 1.15-1.23). The OR of the FAR for EBG in males was higher than that in females (1.25; 95% CI 1.18-1.33 vs 1.15; 95% CI 1.10-1.20). Moreover, the OR of FAR for EBG was greater in patients aged 60 or younger (OR: 1.25; 95% CI 1.18-1.33) than in the elderly patients (over 60 years of age) (OR: 1.15; 95% CI 1.10-1.20). The results indicated a significant relationship between FAR and EBG and this association was higher in males and middle-aged patients.

Fibrinogen is Associated with Clinical Adverse Events in Patients with Psoriasis and Coronary Artery Disease

Purpose

The presence of elevated fibrinogen levels is associated with cardiovascular disease. However, whether fibrinogen level is associated with adverse clinical events in patients with psoriasis and coronary artery disease (CAD) is unknown. This study aimed to investigate the relationship between fibrinogen levels and cardiovascular adverse events in these patients.

Patients and Methods

This retrospective cohort study collected consecutive patients with psoriasis and CAD between January 2017 and May 2022 in our hospital. The clinical records were collected, and comparisons were made between groups. The Cox regression analysis and Kaplan-Meier survival analysis were used to evaluate the association between variables.

Results

Of the 267 participants, one hundred and forty-seven patients (55.1%) had elevated fibrinogen levels. Compared with patients in low fibrinogen group, white blood cell and platelet counts and high-sensitivity C-reactive protein levels were higher, whereas the left ventricular ejection fraction was lower in patients in high fibrinogen group. After a median follow-up of 35.5 months, the incidence of major adverse cardiovascular events (MACEs) was higher in patients in high fibrinogen group compared with patients in low fibrinogen group (31.4% vs 16.4%, p = 0.013). The Kaplan-Meier survival curves showed the same trend (log rank p = 0.020). Subgroup analysis revealed a positive association between elevated fibrinogen levels and MACEs in patients aged <60 years (log-rank p = 0.013), those with diabetes (log-rank p = 0.027), and those who were not admitted for acute cardiovascular syndrome (log-rank p = 0.015).

Conclusion

Elevated fibrinogen levels were associated with adverse clinical events in patients with psoriasis and CAD, especially among patients aged <60 years, those with diabetes, and those not admitted for acute cardiovascular syndrome.

Synergistic role of circulating CD14++CD16+ monocytes and fibrinogen in predicting the cardiovascular events after myocardial infarction

BACKGROUND

Monocytes and fibrinogen (FIB) play important roles in driving acute and reparative inflammatory pathways after myocardial infarction (MI). In humans, there are three subsets of monocytes, namely, CD14++CD16- (Mon1), CD14++CD16+ (Mon2), and CD14+CD16++ (Mon3). During the inflammatory response, monocyte subsets express high levels of integrin α_M β₂ and protease-activated receptors 1 and 3 to interact with FIB.

HYPOTHESIS

However, whether there is a synergistic role of FIB combined with Mon2 counts in prioritizing patients at high risk of future major adverse cardiovascular events (MACEs) after MI remains unknown.

METHODS

The MI patients who treated with primary percutaneous coronary intervention were enrolled. MI patients were categorized into four groups, that is, low FIB/low Mon2, low FIB/high Mon2, high FIB/low Mon2, and high FIB/high Mon2, according to cutoff values of 3.28 g/L for FIB and 32.20 cells/μL for Mon2. Kaplan-Meier survival analysis and Cox proportional hazards models were used to estimate the risk of MACEs of MI patients during a median follow-up of 2.7 years. Mediating effects of high FIB levels and MACEs associated with high monocyte subsets were calculated by mediation analysis.

RESULTS

High FIB/high Mon2 group had the highest risk of MACEs during a median follow-up of 2.7 years. Moreover, mediation analysis showed that a high FIB level could explain 24.9% (p < .05) of the increased risk of MACEs associated with Mon2.

CONCLUSION

This work provides evidence indicating the translational potential of a synergistic role of FIB combined with Mon2 in prioritizing patients at high risk of future MACEs after MI.

The impact of high on-treatment platelet reactivity and fibrinogen levels on ischemic events in patients with ST elevation myocardial infarction: a prospective observational study

BACKGROUND

After treatment, high residual platelet reactivity (HRPR) is considered as an essential risk factor for recurrent ischemic events.

AIM

To evaluate the impact of fibrinogen on HRPR after implantation of emergency drug-eluting stents (DES) in patients treated with aspirin and clopidogrel or ticagrelor due to ST-elevation myocardial infarction (STEMI) and to explore the predictive values of HRPR and fibrinogen for adverse ischemic events at 12 months.

METHOD

This single-center prospective observational study analyzed patients with STEMI who underwent primary percutaneous coronary intervention (PCI) with second-generation DES implantation from January 2017 to December 2018. Platelet reactivity was measured by thromboelastography (TEG) at 60-72 h after primary PCI. HRPR was defined as the adenosine diphosphate-induced maximum amplitude (MA_ADP) > 47 mm.

RESULTS

A total of 919 patients were analyzed, of which 512 (55.8%) received aspirin and clopidogrel and 406 (44.2%) received aspirin and ticagrelor. Elevated fibrinogen levels were associated with an increased prevalence of HRPR (P < 0.001). High fibrinogen (quartile IV, ≥ 410 mg/dL) was an independent risk factor for HRPR after multivariate regression (odds ratio 6.556, 95% confidence interval [CI]: 3.200-13.431, P < 0.001). When analyzed by Kaplan-Meier survival curves, the combination of high fibrinogen and HRPR was strongly predictive for ischemic major adverse cardiac events at 12 months compared to the group without HRPR and with low fibrinogen (hazard ratio 9.681, 95% CI: 4.467-20.98, log-rank P < 0.001). Similar results were confirmed in subgroups according to different dual antiplatelet therapies.

CONCLUSION

A combination of high fibrinogen and HRPR may identify recurrent adverse ischemic events over 12 months. Ticagrelor exhibited more potent platelet inhibition and a better prognosis than clopidogrel.

Association Between Preoperative Fibrinogen-to-Albumin Ratio and All-Cause Mortality After Off-Pump Coronary Artery Bypass Grafting: A Retrospective Observational Study

BACKGROUND

The fibrinogen-to-albumin ratio (FAR) is a recently introduced prognostic marker for patients with coronary artery disease. The present study investigated whether the FAR is associated with clinical outcome after off-pump coronary artery bypass grafting (OPCAB).

METHODS

We retrospectively reviewed 1759 patients who underwent OPCAB (median duration of follow-up, 46 months). To evaluate the association between FAR and mortality in OPCAB patients, time-dependent coefficient Cox regression analyses were used to assess the association between FAR and all-cause mortality.

RESULTS

In multivariable time-dependent coefficient Cox regression analyses, preoperative FAR was an independent risk factor for all-cause mortality after OPCAB (adjusted hazard ratio, 1.051; 95% confidence interval, 1.021-1.082). In the restricted cubic spline function curve of the multivariable-adjusted relationship between the preoperative FARs, a linear increase in the relative hazard for all-cause mortality was observed as the FAR increased (P = .001).

CONCLUSIONS

A higher FAR is associated with increased all-cause mortality after OPCAB. The preoperative FAR could be a prognostic factor for predicting higher mortality after OPCAB.

Ethnic Difference of Thrombogenicity in Patients with Cardiovascular Disease: a Pandora Box to Explain Prognostic Differences

Arterial and venous atherothrombotic events are finely regulated processes involving a complex interplay between vulnerable blood, vulnerable vessel, and blood stasis. Vulnerable blood ('thrombogenicity') comprises complex interactions between cellular components and plasma factors (inflammatory, procoagulant, anticoagulant, and fibrinolytic factors). The extent of thrombogenicity may determine the progression of atheroma and the clinical manifestation of atherothrombotic events, with the highest thrombogenicity in African Americans and lowest in East Asians. Inherent thrombogenicity may influence clinical efficacy and safety of specific antithrombotic treatments in high-risk patients, which may in part explain the observation that East Asian patients have reduced anti-ischemic benefits and elevated bleeding risk with antithrombotic therapy compared to Caucasian patients. In this review, we discuss available evidence regarding the racial differences in thrombogenicity and its impact on clinical outcomes among patients with atherosclerotic cardiovascular disease.

Association Between Residual Platelet Reactivity on Clopidogrel Treatment and Severity of Coronary Atherosclerosis: Intrinsic Hypercoagulability as a Mediator

INTRODUCTION

High on-treatment residual platelet reactivity (HRPR) was associated with greater atherosclerosis burden. We examined whether intrinsic hypercoagulability (IHC) could be attributed to that association in patients treated by drug-eluting stents.

METHODS

This retrospective observation enrolled a total of 891 coronary artery disease (CAD) subjects. Platelet and coagulant reactivity was measured by thrombelastography. At least 24 h after a 300-mg dose of clopidogrel, adenosine diphosphate (ADP)-induced maximum amplitude of clot strength (MA_adp) > 47 mm represented HRPR. Thrombin-induced platelet-fibrin clot strength (MA_thrombin) and blood fibrinogen surrogated intrinsic coagulability. Using mediation analysis to evaluate the effect of IHC on the relationship between the number of narrowed coronaries and HRPR on clopidogrel.

RESULTS

More HRPR on clopidogrel and higher intrinsic coagulability were observed in more severe coronary atherosclerosis, especially in the three-vessel disease. After adjustment for confounding factors, the number of narrowed coronaries (OR_adj = 1.343, 95% CI 1.063-1.695, p = 0.013), MA_thrombin (OR_adj = 1.106, 95% CI 1.058-1.157, p < 0.001), and fibrinogen (OR_adj = 1.003, 95% CI 1.001-1.005, p = 0.012) were all independent positive predictors for HRPR. MA_thrombin and fibrinogen were meaningful mediators for the significant positive association of the number of narrowed vessels and HRPR on clopidogrel, which were enhanced by around 30% and 43%, respectively, for this effect.

CONCLUSIONS

This is the first study to demonstrate that the positive correlation between the number of stenotic coronaries and HRPR on clopidogrel may be partly attributed to IHC, which may enhance the risk stratification, guide more precise coagulation in multi-vessel disease after drug-eluting stents, and therefore deserve further study.

Ticagrelor for Secondary Prevention of Atherothrombotic Events in Patients With Multivessel Coronary Disease

BACKGROUND

Patients with prior myocardial infarction (MI) and multivessel coronary disease (MVD) are at high risk for recurrent coronary events.

OBJECTIVES

The authors investigated the efficacy and safety of ticagrelor versus placebo in patients with MVD in the PEGASUS-TIMI 54 (Prevention of Cardiovascular Events in Patients With Prior Heart Attack Using Ticagrelor Compared to Placebo on a Background of Aspirin-Thrombolysis In Myocardial Infarction 54) trial.

METHODS

Patients with a history of MI 1 to 3 years before inclusion in the PEGASUS-TIMI 54 trial were stratified in a pre-specified analysis based on the presence of MVD. The effect of ticagrelor (60 mg and 90 mg) on the composite of cardiovascular death, MI, or stroke (major adverse cardiovascular events [MACE]), as well as the composite of coronary death, MI, or stent thrombosis (coronary events), and on TIMI major bleeding, intracranial hemorrhage (ICH), and fatal bleeding were evaluated over a median of 33 months.

RESULTS

A total of 12,558 patients (59.4%) had MVD. In the placebo arm, compared with patients without MVD, those with MVD were at higher risk for MACE (9.37% vs. 8.57%, adjusted hazard ratio [HR_adj]: 1.24; p = 0.026) and for coronary events (7.67% vs. 5.34%, HR_adj: 1.49; p = 0.0005). In patients with MVD, ticagrelor reduced the risk of MACE (7.94% vs. 9.37%, HR: 0.82; p = 0.004) and coronary events (6.02% vs. 7.67%, HR: 0.76; p < 0.0001), including a 36% reduction in coronary death (HR: 0.64; 95% confidence interval: 0.48 to 0.85; p = 0.002). In this subgroup, ticagrelor increased the risk of TIMI major bleeding (2.52% vs. 1.08%, HR: 2.67; p < 0.0001), but not ICH or fatal bleeds.

CONCLUSIONS

Patients with prior MI and MVD are at increased risk of MACE and coronary events, and experience substantial relative and absolute risk reductions in both outcomes with long-term ticagrelor treatment relative to those without MVD. Ticagrelor increases the risk of TIMI major bleeding, but not ICH or fatal bleeding. For patients with prior MI and MVD, ticagrelor is an effective option for long-term antiplatelet therapy. (Prevention of Cardiovascular Events [e.g., Death From Heart or Vascular Disease, Heart Attack, or Stroke] in Patients With Prior Heart Attack Using Ticagrelor Compared to Placebo on a Background of Aspirin [PEGASUS]; NCT01225562).

Haemotherapy with Fibrinogen for Perioperative Bleeding Prevention-A View on Arterial Thrombogenesis and Myocardial Infarction in the Rat In Vivo

Major blood loss during cardiac surgery is associated with increased morbidity and mortality. Clinical pilot studies indicated that preoperative fibrinogen supplementation reduces postoperative blood loss without increasing thrombotic complications. However, an increase in fibrinogen concentration might rather aggravate pre-existing thrombosis than increase the incidence of thrombotic events. Therefore, we investigated, in the present study, whether fibrinogen supplementation influences (1) arterial thrombus formation, (2) the extent of myocardial infarction and (3) the cardioprotective effect of ischaemic preconditioning. Arterial thrombogenesis of the femoral artery was induced by topic FeCl₃ treatment in anaesthetised Wistar rats after pretreatment with 60 mg/kg (Fib_low), 120 mg/kg (Fib_high) or vehicle (Con). Vessel blood flow was monitored, and time to vessel occlusion was analysed as a marker for arterial thrombogenesis. In addition, regional myocardial I/R injury was induced by temporary left coronary artery occlusion in rats pretreated with or without fibrinogen supplementation. In additional groups, ischaemic preconditioning (IPC) was induced by 3 cycles of 5 min of ischaemia/reperfusion. In all groups, myocardial infarct size was determined by triphenyltetrazoliumchlorid staining. Arterial thrombogenesis was not affected by fibrinogen pretreatment. No differences in time until vessel occlusion between Con, Fib_low and Fib_high groups were observed. In addition, fibrinogen supplementation in low and high concentrations had no effect on infarct size after regional myocardial ischaemia and reperfusion (Fib_low: 66 ± 10%, Fib_high: 62 ± 9%; each ns vs. Con). IPC reduced infarct size from 62 ± 14% to 34 ± 12% (p < 0.05 vs. Con). Furthermore, both fibrinogen concentrations did not affect cardioprotection by ischaemic preconditioning (Fib_low + IPC: 34 ± 11%, Fib_high + IPC: 31 ± 13%; each ns vs. IPC). Haemotherapy with fibrinogen did not affect arterial thrombogenesis, myocardial infarction and the cardioprotective effect of ischaemic preconditioning.

Increased level of fibrinogen chains in the proteome of blood platelets in secondary progressive multiple sclerosis patients

Epidemiological studies indicate a high risk of stroke, heart failure and myocardial infarction in patients with multiple sclerosis, especially in its secondary progressive (SPMS) phase. Some ischaemic events are directly associated with abnormal platelet functions and their prothrombotic activity. Recent reports, including this study, confirm the increased activation of circulating platelets in SPMS, and also show increased platelet reactivity, among other responses, as well as strong aggregation. In this current study, we conducted a comparative analysis of the platelet proteome in SPMS patients and in healthy controls, to demonstrate the quantitative and qualitative differences likely to affect functional changes observed in SPMS. During densitometry evaluation of 2-D fluorescence difference gel electrophoresis, we observed differences between the electrophoretic patterns of SPMS platelets and the control samples. To determine a detailed characterisation of the proteome changes in the SPMS patients' blood platelets, in the next stage, we performed mass spectrometry of selected spots and indicated the increased presence of four proteins (fibrinogen, α-2 macroglobulin, septin-14 and tubulin β-1 chain). The most important of these is the increased amount of prothrombotic protein, fibrinogen, which seems to confirm the accuracy of the imaging and potentially explains the increased risk of platelet-origin thrombotic events. This study provides new knowledge of the potential existence of the molecular mechanisms responsible for the acceleration of the platelet pro-coagulant function in SPMS. This can help to identify new targets for therapy, which can then be used not only in the second stage of the disease.

Elevated Baseline Serum Fibrinogen: Effect on 2-Year Major Adverse Cardiovascular Events Following Percutaneous Coronary Intervention

Background

Elevated fibrinogen is associated with short‐term major adverse cardiovascular events (MACE) after percutaneous coronary intervention, but the relation with late MACE is unknown.

Methods and Results

Baseline demographics and 2‐year MACE were recorded among subjects undergoing nonemergent percutaneous coronary intervention. A total of 332 subjects (66.6±19.5 years, 69.9% male, 25.3% acute coronary syndrome) were enrolled. Two‐year MACE (periprocedural myocardial infarction 9.0%, rehospitalization 6.3%, revascularization 12.7%, non–periprocedural myocardial infarction 4.5%, stent thrombosis 0.9%, stroke 1.8%, and death 0.6%) were associated with higher fibrinogen (352.8±123.4 mg/dL versus 301.6±110.8 mg/dL; P<0.001), longer total stent length (40.1±25.3 mm versus 32.1±19.3 mm; P=0.004), acute coronary syndrome indication (38.7% versus 17.8%; P<0.001), number of bare‐metal stents (0.5±1.1 versus 0.2±0.5; P=0.002), and stent diameter ≤2.5 mm (55.8% versus 38.4%, P=0.003). No relation between platelet reactivity and 2‐year MACE was observed. Fibrinogen ≥280 mg/dL (odds ratio [OR] 3.0, confidence interval [CI], 1.6–5.4, P<0.001), total stent length ≥32 mm (OR 2.2, CI, 1.3–3.8, P<0.001), acute coronary syndrome indication (OR 4.1, CI, 2.3–7.5, P<0.001), any bare‐metal stents (OR 3.2, CI, 1.6–6.1, P<0.001), and stent diameter ≤2.5 mm (OR 2.0, CI, 1.2–3.5, P=0.010) were independently associated with 2‐year MACE. Following a landmark analysis excluding periprocedural myocardial infarction, fibrinogen ≥280 mg/dL remained strongly associated with 2‐year MACE (37.0% versus 17.4%, log‐rank P<0.001).

Conclusions

Elevated baseline fibrinogen level is associated with 2‐year MACE after percutaneous coronary intervention. Acute coronary syndrome indication for percutaneous coronary intervention, total stent length implanted, and use of bare‐metal stents or smaller‐diameter stents are also independently associated with 2‐year MACE, while measures of on‐thienopyridine platelet reactivity are not.

[Involvement of thrombophilia in coronary thrombosis]

This review of thrombophilia and coronary thrombosis takes into account the "classical" thrombophilia commonly found in venous pathology and the conditions under which their research may be useful in certain forms of arterial thrombosis especially coronary thrombosis. In addition to the classical thrombophilia, exceptional thrombophilia are evoked, which are both factors of venous thrombosis but also arterial thrombosis. There are also thrombophilia that are more specific to the arterial system such as - homocystein which is potentially both a thrombosis factor but also an agent of arterial parietal lesion or - serotonin which is a factor of arterial spasm and especially coronary spasm. Finally, under the term thrombophilia, it is possible to include thrombophilic conditions, in particular cancers and inflammatory conditions.

Fibrin clot strength measured by thrombelastography and outcomes after percutaneous coronary intervention

Supplementary Material to this article is available online at www.thrombosis-online.com.

Effect of Fibrinogen on Platelet Reactivity Measured by the VerifyNow P2Y12 Assay

The VerifyNow assay is based upon the ability of activated platelets to cross-link beads coated with fibrinogen. However, fibrinogen is an abundant protein of blood, and therefore it may affect test results by competing with fibrinogen of beads for binding to platelets. To test this assumption, we assessed the influence of artificial alteration of fibrinogen level in blood samples obtained from donors (n = 9) and patients on clopidogrel therapy (n = 8) on the results of the VerifyNow P2Y12 assay. Fibrinogen level was altered by adding to blood samples 1/10 volume of fibrinogen solution (10.56 g/liter) or corresponding buffer. Relative to baseline, addition of buffer significantly increased platelet reactivity, whereas addition of fibrinogen decreased it. Analysis of the relationship between change in platelet reactivity values (dBase and dPRU) and change in fibrinogen concentration (dFg) revealed strong negative correlations: dBase = -63.3 × dFg - 27.1 (r = -0.924, p < 0.0005) and dPRU = -54.4 × dFg - 21.8 (r = -0.764, p < 0.0005). Thus, the results of our experiments suggest that: (i) blood fibrinogen strongly influences results of the VerifyNow P2Y12 assay, and (ii) correcting for fibrinogen effect may be needed to improve the accuracy of the test in the measuring of antiplatelet effect of clopidogrel therapy.

Effect of Serum Fibrinogen, Total Stent Length, and Type of Acute Coronary Syndrome on 6-Month Major Adverse Cardiovascular Events and Bleeding After Percutaneous Coronary Intervention

This study evaluated the relation between baseline fibrinogen and 6-month major adverse cardiovascular events (MACE) and bleeding after percutaneous coronary intervention (PCI). Three hundred eighty-seven subjects (65.6 ± 16.1 years, 69.5% men, 26.9% acute coronary syndrome [ACS]) who underwent PCI with baseline fibrinogen and platelet reactivity (VerifyNow P2Y12 assay, Accumetrics, San Diego, California) measured were enrolled. Fibrinogen (368.8 ± 144.1 vs 316.8 ± 114.3 mg/dl; p = 0.001), total stent length (TSL; 44.5 ± 25.0 vs 32.2 ± 20.1 mm; p <0.001), and ACS presentation (40.6% vs 23.9%; p = 0.005) were independently associated with 6-month MACE rates (17.8%: myocardial infarction 9.8%, rehospitalization for ACS 3.6%, urgent revascularization 3.6%, stroke 0.5%, and death 0.3%). Measures of platelet reactivity were not associated with 6-month MACE. After multivariate analysis, fibrinogen ≥280 mg/dl (odds ratio [OR] 2.60, 95% CI 1.33 to 5.11, p = 0.005), TSL ≥32 mm (OR 3.21, 95% CI 1.82 to 5.64, p <0.001), and ACS presentation (OR 2.58, 95% CI 1.45 to 4.61, p = 0.001) were associated with higher 6-month MACE. In 271 subjects receiving chronic P2Y12 inhibitor therapy, 6-month Thrombolysis In Myocardial Infarction bleeding after PCI was 7.0%, but no difference in fibrinogen level (338.3 ± 109.7 vs 324.3 ± 113.8 mg/dl, p = 0.60) stratified by Thrombolysis In Myocardial Infarction bleeding was observed. In conclusion, elevated serum fibrinogen, ACS presentation, and longer TSL are independently associated with higher 6-month MACE after PCI, whereas no association with on-thienopyridine platelet reactivity and 6-month MACE was observed. Post-PCI bleeding was not associated with lower fibrinogen level.

Comparison of functional fibrinogen (FF/CFF) and FIBTEM in surgical patients – a retrospective study

Fibrinogen-based clot firmness is reported as the maximum amplitude (MA) when using the citrated functional fibrinogen (CFF) assay in thrombelastography (TEG), and as the maximum clot firmness (MCF) together with several clot amplitude parameters when using the FIBTEM assay in thromboelastometry (ROTEM). Concern is currently being raised that these two tests have different platelet inhibiting performance and consequently provide different values. This is relevant for the clinical setting of fibrinogen replacement. We aim herein to compare the parameters of these two fibrinogen-based clot quality tests and their correlation with the plasma fibrinogen level as determined by the Clauss method.

In total 261 whole blood samples taken from 163 clinical routine surgical patients were analyzed with TEG 5000 and ROTEM tests, and correlation with Clauss fibrinogen level was assessed.

: Using TEG, the overall fibrin-based clot firmness measured in the CFF assay was significantly higher than the MCF measured by FIBTEM assay. Both assays showed significantly positive correlations with the fibrinogen levels measured using the Clauss method. However, individual values of Clauss fibrinogen concentration corresponded with different values for the two viscoelastometric tests; e.g. within the range of 1.9–2.1 g/L Clauss fibrinogen the median of CFF MA was 16.3 mm whereas FIBTEM MCF was 12.0 mm.

: We showed herein by measurements of citrated whole blood samples from surgical patients that CFF MA values were different from FIBTEM MCF values measured in the same sample. Awareness that these whole blood assays provide different clot amplitude results is mandatory, particularly if they are being considered as tools for guiding fibrinogen supplementation. Thromboembolic side effects caused by a potentially too high fibrinogen substitution must also kept in mind in this context.

Association of fibrinogen with severity of stable coronary artery disease in patients with type 2 diabetic mellitus

BACKGROUND

Some studies have suggested a relation of plasma fibrinogen to the severity of coronary artery disease (CAD). However, whether plasma fibrinogen can predict the presence and severity of CAD in patients with diabetes mellitus has not been determined.

METHODS

A total of consecutive 373 diabetic patients with typical angina pectoris who received coronary angiography were enrolled and classified into three groups by tertiles of Gensini score (GS, low group <8; intermediate group 8~28; high group >28). The relationship between fibrinogen and GS was evaluated.

RESULTS

There were correlations of fibrinogen with hemoglobin A1c, C-reactive protein, and GS (r = 0.17, r = 0.52, and r = 0.21, resp.; all P < 0.001). Area under the receivers operating characteristic curve of fibrinogen was 0.62 (95% CI 0.56-0.68, P < 0.001) for predicting a high GS. Multivariate analysis suggested that plasma fibrinogen was an independent predictor of a high GS for diabetic patients (OR = 1.40, 95% CI 1.04-1.88, and P = 0.026) after adjusting for traditional risk factors of CAD.

CONCLUSIONS

The present data indicated that plasma fibrinogen, a readily measurable systematic inflammatory marker, appeared to be an independent predictor for the severity of CAD in diabetic patients.

Point-of-care assessment of platelet reactivity in the emergency department may facilitate rapid rule-out of acute coronary syndromes: a prospective cohort pilot feasibility study

OBJECTIVE

Accurate, efficient and cost-effective disposition of patients presenting to emergency departments (EDs) with symptoms suggestive of acute coronary syndromes (ACS) is a growing priority. Platelet activation is an early feature in the pathogenesis of ACS; thus, we sought to obtain an insight into whether point-of-care testing of platelet function: (1) may assist in the rule-out of ACS; (2) may provide additional predictive value in identifying patients with non-cardiac symptoms versus ACS-positive patients and (3) is logistically feasible in the ED.

DESIGN

Prospective cohort feasibility study.

SETTING

Two urban tertiary care sites, one located in the USA and the second in Argentina.

PARTICIPANTS

509 adult patients presenting with symptoms of ACS.

MAIN OUTCOME MEASURES

Platelet reactivity was quantified using the Platelet Function Analyzer-100, with closure time (seconds required for blood, aspirated under high shear, to occlude a 150 µm aperture) serving as the primary endpoint. Closure times were categorised as 'normal' or 'prolonged', defined objectively as the 90th centile of the distribution for all participants enrolled in the study. Diagnosis of ACS was made using the standard criteria. The use of antiplatelet agents was not an exclusion criterion.

RESULTS

Closure times for the study population ranged from 47 to 300 s, with a 90th centile value of 138 s. The proportion of patients with closure times ≥138 s was significantly higher in patients with non-cardiac symptoms (41/330; 12.4%) versus the ACS-positive cohort (2/105 (1.9%); p=0.0006). The specificity of 'prolonged' closure times (≥138 s) for a diagnosis of non-cardiac symptoms was 98.1%, with a positive predictive value of 95.4%. Multivariate analysis revealed that the closure time provided incremental, independent predictive value in the rule-out of ACS.

CONCLUSIONS

Point-of-care assessment of platelet reactivity is feasible in the ED and may facilitate the rapid rule-out of ACS in patients with prolonged closure times.

Comparison of On-Treatment Platelet Reactivity Between Triple Antiplatelet Therapy With Cilostazol and Standard Dual Antiplatelet Therapy in Patients Undergoing Coronary Interventions

Background:

The recent literature has shown that triple antiplatelet therapy with cilostazol in addition to the standard dual antiplatelet therapy with aspirin and clopidogrel may reduce platelet reactivity and improve clinical outcomes following percutaneous coronary intervention. The purpose of this meta-analysis is to compare the efficacy of triple antiplatelet therapy and dual antiplatelet therapy in regard to on-treatment platelet reactivity.

Methods:

Nine studies (n = 2179) comparing on-treatment platelet reactivity between dual antiplatelet therapy (n = 1193) and triple antiplatelet therapy (n = 986) in patients undergoing percutaneous coronary intervention were included. Primary end points were P2Y12 reaction unit (PRU) and platelet reactivity index (PRI). Secondary end points were platelet aggregation with adenosine diphosphate (ADP) 5 and 20 µmol/L and P2Y12% inhibition. Mean difference (MD) and 95% confidence intervals (CI) were computed and 2-sided α error <.05 was considered as a level of significance.

Results:

Compared to dual antiplatelet therapy, triple antiplatelet therapy had significantly lower maximum platelet aggregation with ADP 5 µmol/L (MD: −14.4, CI: −21.6 to −7.2, P < .001) and 20 µmol/L (MD: −14.9, CI: −22.9 to −6.8, P < .001), significantly lower PRUs (MD: −45, CI: −59.4 to −30.6, P < .001) and PRI (MD: −26, CI: −36.8 to −15.2, P < .001), and significantly higher P2Y12% inhibition (MD: 18.5, CI: 2.3 to 34.6, P = .025).

Conclusion:

Addition of cilostazol to conventional dual antiplatelet therapy significantly lowers platelet reactivity and may explain a decrease in thromboembolic events following coronary intervention; however, additional studies evaluating clinical outcomes will be helpful to determine the benefit of triple antiplatelet therapy.

Aspirin, Platelet P2Y12 Receptor Inhibitors, and Other Oral Antiplatelets: Comparative Pharmacology and Role in Elective PCI

Angina pectoris accounts for a large burden of disease worldwide. Antiplatelet agents play a crucial role in inhibiting the platelet response to vascular injury after percutaneous coronary intervention (PCI) for the management of coronary artery disease. Antiplatelet agents are also essential in the longer term, because the metallic structure of stents is inherently thrombogenic. This article examines the use of aspirin, P2Y12 inhibitors, and other oral antiplatelets in the setting of elective PCI. Dual antiplatelet therapy in elective PCI is now standard therapy. The clinical use of novel antiplatelet therapy in the setting requires further evaluation.