Platelet-fibrin clot strength and platelet reactivity predicting cardiovascular events after percutaneous coronary interventions.

BACKGROUND AND AIMS: Platelet-fibrin clot strength (PFCS) is linked to major adverse cardiovascular event (MACE) risk. However, the association between PFCS and platelet reactivity and their prognostic implication remains uncertain in patients undergoing percutaneous coronary intervention (PCI). METHODS: In PCI-treated patients (n = 2512) from registry data from January 2010 to November 2018 in South Korea, PFCS using thromboelastography and platelet reactivity using VerifyNow were measured. High PFCS (PFCSHigh) was defined as thromboelastography maximal amplitude ≥ 68 mm, and high platelet reactivity (HPR) was defined as >208 P2Y12 reaction units. Patients were stratified into four groups according to maximal amplitude and P2Y12 reaction unit levels: (i) normal platelet reactivity (NPR)-PFCSNormal (31.8%), (ii) HPR-PFCSNormal (29.0%), (iii) NPR-PFCSHigh (18.1%), and (iv) HPR-PFCSHigh (21.1%). Major adverse cardiovascular event (all-cause death, myocardial infarction, or stroke) and major bleeding were followed up to 4 years. RESULTS: High platelet reactivity and PFCSHigh showed an additive effect for clinical outcomes (log-rank test, P < .001). Individuals with NPR-PFCSNormal, NPR-PFCSHigh, HPR-PFCSNormal, and HPR-PFCSHigh demonstrated MACE incidences of 7.5%, 12.6%, 13.4%, and 19.3%, respectively. The HPR-PFCSHigh group showed significantly higher risks of MACE compared with the NPR-PFCSNormal group [adjusted hazard ratio (HRadj) 1.89; 95% confidence interval (CI) 1.23-2.91; P = .004] and the HPR-PFCSNormal group (HRadj 1.60; 95% CI 1.12-2.27; P = .009). Similar results were observed for all-cause death. Compared with HPR-PFCSNormal phenotype, NPR-PFCSNormal phenotype was associated with a higher risk of major bleeding (HRadj 3.12; 95% CI 1.30-7.69; P = .010). CONCLUSIONS: In PCI patients, PFCS and platelet reactivity demonstrated important relationships in predicting clinical prognosis. Their combined assessment may enhance post-PCI risk stratification for personalized antithrombotic therapy.

Early assessment of the pharmacokinetic and pharmacodynamic effects following acetylsalicylic acid loading: toward a definition for acute therapeutic response.

Despite decades of investigations, the optimal assessment of the "therapeutic response" to early after loading dose of acetylsalicylic acid (ASA) remains unclear. Limited information is available on the relation between pharmacodynamic (PD) and pharmacokinetic (PK) measurements assessed immediately after ASA administration. Serial PD and PK analyses were performed immediately after a single 162 or 650 mg dose of chewed and swallowed ASA in ten healthy adults. ASA response was defined as > 95% inhibition of serum thromboxane (Tx)B2, < 550 aspirin reaction units (ARU) by VerifyNow Aspirin (VN) test, and ≤ 20% arachidonic acid (AA)-induced platelet aggregation (PA). Correlation analyses between PK and PD measurements and receiver operating characteristic (ROC) curve analyses were performed. ASA response measured by VN test and AA-induced PA was achieved within 30 min of ASA administration. A correlation was observed between ARU and AA-induced maximum PA (r = 0.69, p < 0.001), serum TxB2 (r = 0.74 and p < 0.001), and serum TxB2 inhibition (r = 0.79, p < 0.001). In ROC curve analyses, ≤ 558 ARU and ≤ 7% AA-induced PA were associated with > 95% inhibition of TxB2. 686 ng/ml plasma ASA cut-off point was associated with > 95% inhibition of serum TxB2, ≤ 7% 1 mM AA-induced PA, and ≤ 585 ARU. A modest ~ 50% inhibition of TxB2 inhibition was associated with marked inhibition of 1 mM AA-induced platelet aggregation by LTA. Our analyses demonstrated important relationships between pharmacodynamic, and pharmacokinetic parameters measured immediately following oral ASA and cutoff values for ARU and AA-induced PA that is associated with > 95% inhibition of serum TxB2.

Development of a routine bedside CYP2C19 genotype assessment program for antiplatelet therapy guidance in a community hospital catheterization laboratory.

Genotype based personalized antiplatelet therapy in the setting of percutaneous coronary intervention (PCI) has been studied in clinical trials. Despite the demonstrated risk associated with CYP2C19 loss-of-function (LoF) carriage in clopidogrel-treated PCI patients, real-world implementation of genotyping for PCI has been low. The goal of the current study was to provide CYP2C19 genotype information to the interventionalist prior to the completion of the catheterization to facilitate immediate personalized antiplatelet therapy. Routine personalization of P2Y12 inhibitor therapy for PCI in a community hospital cardiac catheterization laboratory by POC genotyping with the SpartanRx system was first offered in February 2017. A best practice advisory (BPA) based on the Clinical Pharmacogenetics Implementation Consortium Guideline for CYP2C19 genotype and clopidogrel therapy was placed in the electronic health record prescription medication ordering system. By December 2019, 1,052 patients had CYP2C19 genotype testing, 429 patients underwent PCI with genotype guided antiplatelet therapy, and 250 patients underwent PCI without genotype testing and received antiplatelet therapy at the discretion of the treating physician. BPA compliance was 93. 87% of LoF allele carriers were prescribed ticagrelor or prasugrel whereas 96% of non-LoF allele carriers were prescribed clopidogrel. The genotyping results were available within 1 h and made immediately available for decision making by the interventional cardiologist. POC CYP2C19 genotyping is feasible in a community hospital catheterization laboratory and is associated with high rate of best practice compliance.Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT03040622.

Utility of VerifyNow to assess the immediate pharmacodynamic response of chewed and swallowed aspirin: comparison with aggregometry.

VerifyNow (VN) test is a less laborious method to assess pharmacodynamics (PD) compared to light transmittance aggregometry (LTA). VN assay has not been used to study the immediate PD effects of acetylsalicylic acid (ASA). Ten healthy volunteers were randomly assigned to a single 162 or 650 mg dose of chewed and swallowed ASA. Pharmacodynamic and pharmacokinetic measurements were performed at baseline and serially up to 60 min after ASA administration. Onset by VN was 20 ± 7 min with 162 mg and 13 ± 7 min with 650 mg ASA (p = .07). Onset by 1 mM AA-induced PA was 13 ± 12 min with 162 mg and 7 ± 3 min with 650 mg ASA (p=NS). VN correlated with AA-induced PA (r = 0.80, p < .001) and serum TxB2 levels (r = 0.76, p < .001). 95% inhibition of serum TxB2 was achieved at 38 ± 22 min and 22 ± 8 min with the 162 and 650 mg ASA, respectively (p = .08). The onset and extent of the antiplatelet effect of 650 mg ASA is numerically faster and greater than the 162 mg dose. VN identifies the onset, extent, and dose response to ASA therapy. The ease of using VN should facilitate multicenter PD investigations of ASA.

Aspirin (acetylsalicylic acid) is an important drug widely used to prevent adverse ischemic events in patients with cardiovascular disease. Platelet aggregation and thromboxane B₂ levels in blood samples by complex laboratory methods are used to assess platelet response to aspirin. VerifyNow assay is a simple laboratory test that has not been used to assess the immediate effect of aspirin. In this study, conducted in 10 healthy volunteers, we compared the immediate platelet response to aspirin by serially assessing platelet aggregation by aggregometry and VerifyNow assay, and thromboxane B₂ levels. We also measured plasma levels of acetylsalicylic acid and salicylic acid. Our study demonstrated that the VerifyNow Aspirin test identifies the onset, extent, and dose-response to aspirin therapy. The ease of using the VerifyNow test should facilitate multicenter pharmacodynamic investigations of aspirin.

Prognostic impact of hypercoagulability and impaired fibrinolysis in acute myocardial infarction.

AIMS: Atherothrombotic events are influenced by systemic hypercoagulability and fibrinolytic activity. The present study evaluated thrombogenicity indices and their prognostic implications according to disease acuity. METHODS AND RESULTS: From the consecutive patients undergoing percutaneous coronary intervention (PCI), those with thrombogenicity indices (n = 2705) were grouped according to disease acuity [acute myocardial infarction (AMI) vs. non-AMI]. Thrombogenicity indices were measured by thromboelastography (TEG). Blood samples for TEG were obtained immediately after insertion of the PCI sheath, and TEG tracing was performed within 4 h post-sampling. Major adverse cardiovascular events (MACE, a composite of cardiovascular death, non-fatal myocardial infarction, and non-fatal stroke) were evaluated for up to 4 years. Compared with non-AMI patients, AMI patients had higher platelet-fibrin clot strength [maximal amplitude (MA): 66.5 ± 7.8 vs. 65.3 ± 7.2 mm, P < 0.001] and lower fibrinolytic activity [clot lysis at 30 min (LY30): 0.9 ± 1.8% vs. 1.1 ± 1.9%, P < 0.001]. Index AMI presentation was associated with MA [per one-mm increase: odds ratio (OR): 1.024; 95% confidence interval (CI): 1.013-1.036; P < 0.001] and LY30 (per one% increase: OR: 0.934; 95% CI: 0.893-0.978; P = 0.004). The presence of high platelet-fibrin clot strength (MA ≥68 mm) and low fibrinolytic activity (LY30 < 0.2%) was synergistically associated with MACE occurrence. In the multivariable analysis, the combined phenotype of 'MA ≥ 68 mm' and 'LY30 < 0.2%' was a major predictor of post-PCI MACE in the AMI group [adjusted hazard ratio (HR): 1.744; 95% CI: 1.135-2.679; P = 0.011], but not in the non-AMI group (adjusted HR: 1.031; 95% CI: 0.499-2.129; P = 0.935). CONCLUSION: AMI occurrence is significantly associated with hypercoagulability and impaired fibrinolysis. Their combined phenotype increases the risk of post-PCI atherothrombotic event only in AMI patients. These observations may support individualized therapy that targets thrombogenicity for better outcomes in patients with AMI. CLINICAL TRIAL REGISTRATION: Gyeongsang National University Hospital (G-NUH) Registry, NCT04650529.

Oxygen Targets After Cardiac Arrest: A Meta-analysis of Randomized Controlled Trials.

BACKGROUND: Optimal oxygen saturation target in patients resuscitated after cardiac arrest is unknown. Previous randomized controlled trials (RCTs) comparing restrictive oxygen therapy with liberal therapy have shown conflicting results. STUDY QUESTION: We performed a meta-analysis of available RCTs to consolidate the contrasting findings regarding the oxygen targets after cardiac arrest. DATA SOURCES: We searched electronic databases for RCTs comparing restrictive versus liberal oxygen targets in patients resuscitated after cardiac arrest. STUDY DESIGN: End points of interest were mortality, unfavorable neurological outcomes, and rearrests. Random-effects meta-analysis was performed to estimate the risk ratio (RR) with a 95% confidence interval (CI). RESULTS: Eight RCTs with 1641 patients (restrictive n = 833, liberal n = 808) were included in the analysis. The oxygen targets were defined by either saturation, partial pressure (PaO2), or supplementation rates. The mean age and male percentage were 63 years and 80%, respectively. There was no significant difference observed in the 2 groups for overall mortality (RR = 0.91, 95% CI = 0.75-1.10, P = 0.33), unfavorable neurological outcomes (RR = 0.93, 95% CI = 0.74-1.18, P = 0.56), and rearrests (RR = 0.67, 95% CI = 0.22-1.98, P = 0.47). CONCLUSIONS: Overall, this meta-analysis shows no significant difference in mortality, unfavorable neurological outcomes, and rearrests when using restrictive or liberal oxygen targets in patients after cardiac arrest. The limitations in the newer trials should be kept in mind while interpreting the overall results.

Metformin use in patients hospitalized with COVID-19: lower inflammation, oxidative stress, and thrombotic risk markers and better clinical outcomes.

Diabetes mellitus (DM) is associated with a greater risk of COVID-19 and an increased mortality when the disease is contracted. Metformin use in patients with DM is associated with less COVID-19-related mortality, but the underlying mechanism behind this association remains unclear. Our aim was to explore the effects of metformin on markers of inflammation, oxidative stress, and hypercoagulability, and on clinical outcomes. Patients with DM on metformin (n = 34) and metformin naïve (n = 41), and patients without DM (n = 73) were enrolled within 48 h of hospital admission for COVID-19. Patients on metformin compared to naïve patients had a lower white blood cell count (p = 0.02), d-dimer (p = 0.04), urinary 11-dehydro thromboxane B2 (p = 0.01) and urinary liver-type fatty acid binding protein (p = 0.03) levels and had lower sequential organ failure assessment score (p = 0.002), and intubation rate (p = 0.03), fewer hospitalized days (p = 0.13), lower in-hospital mortality (p = 0.12) and lower mortality plus nonfatal thrombotic event occurrences (p = 0.10). Patients on metformin had similar clinical outcomes compared to patients without DM. In a multiple regression analysis, metformin use was associated with less days in hospital and lower intubation rate. In conclusion, metformin treatment in COVID-19 patients with DM was associated with lower markers of inflammation, renal ischemia, and thrombosis, and fewer hospitalized days and intubation requirement. Further focused studies are required to support these findings.

Pharmacosimulation of delays and interruptions during administration of tirofiban: a systematic comparison between EU and US dosage regimens.

Tirofiban is a glycoproteine (GP) IIb/IIIa receptor antagonist, which inhibits platelet-platelet aggregation and is a potential adjunctive antithrombotic treatment in patients with acute coronary syndromes (ACS) or high-risk percutaneous coronary interventions (PCI). It is administered intravenously as a bolus followed by continuous infusion. However, the dosage recommendations in the United States (US) and European Union (EU) differ considerably. Furthermore, in routine clinical practice, deviations from the recommendations may occur. The objective of the present study was to investigate the impact of different alterations on tirofiban plasma concentrations in US and EU administration regimens and to give suggestions for delay management in clinical practice. We therefore mathematically simulated the effects of different bolus-infusion delays and infusion interruptions in different scenarios according to the renal function. Here, we provide a systematic assessment of concentration patterns of tirofiban in the US versus EU dosage regimens. We show that differences between the two regimens have important effects on plasma drug levels. Furthermore, we demonstrate that deviations from the proper administration mode affect the concentration of tirofiban. Additionally, we calculated the optimal dosage of a second bolus to rapidly restore the initial concentration without causing overdosage. In conclusion, differences in tirofiban dosing regimens between the U.S and EU and potential infusion interruptions have important effects on drug levels that may impact on degrees of platelet inhibition and thus antithrombotic effects. Thus, the findings of our modelling studies may help to explain differences in clinical outcomes observed in previous clinical trials on tirofiban.

Serial assessment of thrombogenicity and hemodynamics in patients with type II diabetes in a clinical research unit: Evidence for circadian variations in clot formation.

BACKGROUND: Circadian fluctuations in thrombogenicity and hemostasis play a role in acute cardiovascular thrombotic events occurring in the early morning hours. There is a lack of data assessing thrombogenicity, platelet function, and hemodynamics to investigate diurnal variations in a high cardiovascular risk population. METHODS: This was an exploratory, single-center study conducted in aspirin-treated patients with Type II Diabetes Mellitus (T2DM) (n = 37) with documented vascular disease and/or multiple cardiovascular risk factors. Hemodynamic monitoring and blood sample collection for thromboelastography (TEG) and platelet function testing were done serially at 7-9 AM (morning), 7-9 PM (evening), 11 PM-1 AM (night), and at 5-7 AM (awakening). RESULTS: R-value measured by TEG was shorter during awakening hours than during the night and day hours (p < 0.05). There were no changes in platelet reactivity in response to arachidonic acid, adenosine diphosphate, and collagen between time points. Pulse pressure (PP) was highest during awakening hours (p < 0.05). CONCLUSION: Study findings provide a mechanistic explanation for increased thrombotic events observed in the early waking hours among diabetics with multiple cardiovascular risk factors. The role of chronotherapy in reducing coagulability and PP to improve clinical outcomes should be explored.

The role of viscoelastic testing in assessing peri-interventional platelet function and coagulation.

We carried out a literature search in MEDLINE (PubMed) and EMBASE literature databases to provide a concise review of the role of viscoelastic testing in assessing peri-interventional platelet function and coagulation. The search identified 130 articles that were relevant for the review, covering the basic science of VHA and VHA in clinical settings including cardiac surgery, cardiology, neurology, trauma, non-cardiac surgery, obstetrics, liver disease, and COVID-19. Evidence from these articles is used to describe the important role of VHAs and platelet function testing in various peri-interventional setups. VHAs can help us to comprehensively assess the contribution of platelets and coagulation dynamics to clotting at the site-of-care much faster than standard laboratory measures. In addition to standard coagulation tests, VHAs are beneficial in reducing allogeneic transfusion requirements and bleeding, in predicting ischemic events, and improving outcomes in several peri-interventional care settings. Further focused studies are needed to confirm their utility in the peri-interventional case.

Defining platelet response to acetylsalicylic acid: the relation between inhibition of serum thromboxane B2 and agonist-induced platelet aggregation.

Arachidonic acid (AA)-induced platelet aggregation (PA) and serum thromboxane B2 (TxB2) inhibition are widely used to indicate cyclooxygenase-1 activity and the antiplatelet effect of acetylsalicylic acid (ASA). Despite decades of investigations, the relation between these measurements remains unclear. We sought to evaluate the relation between AA-PA and serum TxB2 inhibition. We serially measured AA-PA (conventional aggregation), serum TxB2, plasma ASA and salicylic acid (SA) (liquid chromatography-mass spectrometry), and urinary 11-dehydro thromboxane B2 (u11-dh TxB2) (enzyme-linked immunosorbent assay) levels at 10 times over 24 hours in seventeen healthy volunteers receiving a single dose of 162 mg chewed and swallowed ASA (n = 6), 50 mg inhaled ASA (n = 6), or 100 mg inhaled ASA (n = 5) (ClinicalTrials.gov Identifier: NCT04328883, April 1, 2020). Baseline variability was more pronounced with serum TxB2 (31-680 ng/mL) as compared to maximal AA-PA (65-81%) and u11-dh TxB2 (1556-4440 pg/mg creatinine). The relation between serum TxB2 inhibition and AA-PA was stepwise; after 30-40% inhibition of serum TxB2, AA-PA fell to < 5%. By receiver operating characteristic curve analysis using AA-PA < 5% to define aspirin responsiveness, serum TxB2 inhibition > 49% and u11-dh TxB2 < 1520 pg/mg creatinine met the definition. Our study demonstrates a non-linear relation between serum TxB2 inhibition and AA-PA. Aggregation was nil once TxB2 inhibition reached > 49%. Moreover, these results suggest that the definition of > 95% inhibition of serum TxB2 to indicate the level of platelet COX-1 inhibition needed for clinical efficacy may be overestimated and should be re-considered in future translational research investigations that attempt to link the clinical efficacy of ASA with a laboratory measurement cutoff.

Clinical validation of AggreGuide A-100 ADP, a novel assay for assessing the antiplatelet effect of oral P2Y12 antagonists.

In this prospective, 3-arm, repeated-measure multicenter investigation in 280 patients with cardiovascular risk factors, platelet aggregation was measured with the novel AggreGuide A-100 ADP (A-100 ADP) and VerifyNow (VN)-PRU assays at baseline, and after United States Food and Drug Administration approved loading and 7 days maintenance doses of clopidogrel (n = 94), prasugrel (n = 43) or ticagrelor, (n = 143). Based on the predetermined cutoff values of < 4.7 platelet activity index with A-100 ADP assay to indicate antiplatelet response, more than 91% of patients met the criteria following loading and maintenance doses of prasugrel and more than 84% patients met the criteria following loading and maintenance doses of ticagrelor whereas only 32% and 51% of patients met the criteria following loading and maintenance doses of clopidogrel, respectively. The total percent agreement between the A-100 ADP and VN-PRU assays was 89%. The A-100 ADP assay, which includes whole blood in motion, performs comparably to the VN-PRU assay in a study of patients with cardiovascular risk factors treated with P2Y12 inhibitors possessing known differences in antiplatelet potencies. Trial registration ClinicalTrials.gov Identifier: NCT3111420.

Viscoelastic properties of clot formation and their clinical impact in East Asian versus Caucasian patients with stable coronary artery disease: a COMPARE-RACE analysis.

Compared with Caucasian patients, East Asian patients with coronary artery disease (CAD) have demonstrated better clinical outcomes. We sought to compare the viscoelastic properties of clot formation and their impact on clinical outcomes in East Asian vs. Caucasian patients. We analyzed age- and sex-matched East Asian and Caucasian patients with stable CAD (n = 249 each). Viscoelastic properties of clot formation were assessed with thromboelastography (TEG), and 3-year clinical outcomes were recorded. Major adverse cardiovascular events (MACE) were defined as a composite of cardiovascular death, myocardial infarction, or stroke. Compared with Caucasians, East Asians showed lower platelet-fibrin clot strength (PFCS) (maximum amplitude [MA]: 61.8 ± 7.9 vs. 65.4 ± 5.0 mm, p < 0.001). In a multivariate analysis, high PFCS (defined as MA ≥ 68 mm) was significantly associated with MACE occurrence (odds ratio 6.27, 95% CI 2.41 to 16.30, p < 0.001). East Asians vs. Caucasians had lower prevalence of high PFCS (odds ratio 0.50, 95% CI 0.27 to 0.93, p = 0.028). In conclusion, this is the first study to demonstrate different viscoelastic properties of clot between East Asian and Caucasian patients with stable CAD. The platelet-fibrin clot strength was significantly associated with MACE in these patients and was significantly lower in East Asians. Future studies are warranted to further explore the mechanistic explanation and clinical importance of these findings.

Combination Antiplatelet and Oral Anticoagulant Therapy in Patients With Coronary and Peripheral Artery Disease.

Antiplatelet therapy is the mainstay for the treatment of acute and chronic arterial disease involving the coronary and peripheral beds. However, questions remain about optimal antithrombotic therapy for long-term treatment of chronic vascular disease. The observation that dual antiplatelet therapy with acetylsalicylic acid and clopidogrel was associated with lower thrombotic event rates than acetylsalicylic acid monotherapy in patients with acute coronary syndromes and those undergoing percutaneous coronary intervention changed the treatment paradigm. Moreover, the demonstration that more pharmacodynamically potent P2Y12 inhibitors than clopidogrel were associated with fewer thrombotic event occurrences further solidified the dual antiplatelet therapy approach. However, recurrent thrombotic events occur in ≈1 in 10 patients in the first year following an acute coronary syndrome event, despite treatment with the most potent P2Y12 inhibitors, a limitation that has stimulated interest in exploring the efficacy and safety of approaches using anticoagulants on top of antiplatelet therapy. These investigations have included treatment with very-low-dose oral anticoagulation, and even its replacement of acetylsalicylic acid in the presence of a P2Y12 inhibitor, in patients stabilized after an acute coronary syndrome event. Recent basic and translational studies have suggested noncanonical effects of coagulation factor inhibition that may further modulate clinical benefits. This in-depth review will discuss developments in our understanding of the roles that platelets and coagulation factors play in atherothrombosis and review the rationale and clinical evidence for combining antiplatelet and oral anticoagulant therapy in patients with coronary and peripheral artery disease.

Direct oral anticoagulants: a review on the current role and scope of reversal agents.

New guideline recommendations prefer direct oral anticoagulants (DOACs) over warfarin in DOAC-eligible patients with atrial fibrillation and patients with venous thromboembolism. As expected with all antithrombotic agents, there is an associated increased risk of bleeding complications in patients receiving DOACs that can be attributed to the DOAC itself, or other issues such as acute trauma, invasive procedures, or underlying comorbidities. For the majority of severe bleeding events, the widespread approach is to withdraw the DOAC, then provide supportive measures and "watchful waiting" with the expectation that the bleeding event will resolve with time. However, urgent reversal of anticoagulation may be advantageous in patients with serious or life-threatening bleeding or in those requiring urgent surgery or procedures. Until recently, the lack of specific reversal agents, has affected the uptake of these agents in clinical practice despite a safer profile compared to warfarin in clinical trials. In cases of life-threatening or uncontrolled bleeding or when patients require emergency surgery or urgent procedures, idarucizumab has been recently approved for reversal of anticoagulation in dabigatran-treated patients and andexanet alfa for factor Xa inhibitor-treated treated patients. The current review summarizes the current clinical evidence and scope of these agents with the potential impact on DOAC use in clinical practice.

The Impact of platelet-fibrin clot strength on occurrence and clinical outcomes of peripheral artery disease in patients with significant coronary artery disease.

Patients with peripheral artery disease (PAD) have shown the increased risk of cardiovascular (CV) morbidity and mortality. This study sought to evaluate the impact of clot strength on prevalence and major adverse CV events (MACE) of PAD in high-risk patients. We enrolled patients undergoing percutaneous coronary intervention (PCI) (n = 1667) with available platelet-fibrin clot strength [thrombin-induced maximal amplitude (MAthrombin) measured by thromboelastography] and inflammation [high sensitivity C-reactive protein (hs-CRP)]. PAD was defined with abnormal ankle-brachial index (≤ 0.9 or > 1.4). MACE was defined as a composite of CV death, myocardial infarction or stroke. PAD was observed in 201 patients (12.1%). In the multivariate analysis, high clot strength [MAthrombin ≥ 68 mm: odds ratio (OR) 1.70, 95% confidence interval (CI) 1.20 to 2.41, p = 0.003] and enhanced inflammation (hs-CRP ≥ 3.0 mg/L: OR 2.30, 95% CI 1.56 to 3.41, p < 0.001) were associated with PAD occurrence. During the follow-up post-PCI (median, 25 months), MACE was more frequently occurred in patients with vs. without PAD (18.7% vs. 6.4% at 3 years; hazard ratio 1.72, 95% CI 1.03 to 2.87, p = 0.039). Furthermore, combined presence of PAD and high clot strength significantly increased the risk of MACE. In conclusion, this study is the first to show the impact of clot strength on prevalence and clinical outcomes of PAD in coronary artery disease patients undergoing PCI. Whether antithrombotic strategy according to level of this biomarker can improve clinical outcomes in PAD patients deserves the further study.

Detailed thrombogenicity phenotyping and 1 year outcomes in patients undergoing WATCHMAN implantation: (TARGET-WATCHMAN) a case-control study.

The relation of device related thrombosis (DRT) and major bleeding after left atrial appendage closure (LAAC) to laboratory thrombosis and hemostasis markers has not been studied. We performed a prospective case control study to identify clinical characteristics and laboratory markers in patients who developed DRT and major bleeding following WATCHMAN LAAC. Thromboelastography, platelet aggregation (PA), urinary 11-dehydrothromboxane B2 (UTX), fibrinogen, D-dimer, thrombin time and von Willebrand factor activity were determined at baseline, immediately following, and at 45 and 180 days post-LAAC (n = 32) and outcomes were followed for 1 year. Baseline characteristics and thrombogenic profiles of patients with and without DRT and/or BARC bleeding were compared. Mean age was 76 ± 8 years and CHADS2 VASc score was 4.4 ± 1.4. There were 3 DRTs (2 within 6 months, and 1 at 12 months), 4 Type 3A BARC bleeds, and 2 non-cardiac deaths. Patients with DRT had higher baseline thrombin-induced platelet-fibrin clot strength (68.0 ± 1.8 vs. 62.7 ± 4.7 mm, p = 0.06); FCS (35.6 ± 6.0 vs. 24.4 ± 6.6 mm, p = 0.009); and D-dimer (1712 ± 2330 vs. 283 ± 213 ng/mL, p = 0.001). At baseline, 5 patients had all 3 factors associated with high thrombotic risk and 2 experienced a DRT within 6 months. Patients with Type 3A BARC bleeding had lower baseline collagen-induced and 45-day ADP-induced PA (p < 0.01 for both). DRT following LAAC was associated with a baseline prothrombogenic profile whereas bleeding was associated with low platelet reactivity. These preliminary findings warrant further validation and have future implications on patient selection and adjunctive antithrombotic therapy following LAAC.Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT03040622 .

Is There a Role for Preoperative Platelet Function Testing in Patients Undergoing Cardiac Surgery During Antiplatelet Therapy?

Up to 11% of patients presenting with acute coronary syndromes undergo coronary artery bypass grafting. Guidelines largely recommend a one-size-fits-all preoperative discontinuation period for P2Y12 receptor blockers to avoid bleeding. These recommendations do not account for highly variable pharmacodynamic responsiveness and for variable recovery of platelet reactivity following discontinuation of P2Y12 receptor blockers. Several observational studies have demonstrated that an objective measurement of platelet function among these patients may reduce the waiting period while mitigating the risk of bleeding. Based on these findings, 2 recent guidelines included a Class IIa and IIb recommendation for platelet function testing in patients undergoing cardiac surgery. The following review article describes the rationale for discontinuation of dual antiplatelet therapy before cardiac surgery and the limitations with this approach, available platelet function assays to assess pharmacodynamic effects, and the association between platelet inhibition and other clinical factors with surgery-related bleeding. The information will assist the reader in determining which patients undergoing cardiac surgery might benefit from preoperative platelet function monitoring.

A narrative review of the cardiovascular risks associated with concomitant aspirin and NSAID use.

The concomitant use of low-dose aspirin for cardioprotection and non-steroidal anti-inflammatory agents for pain relief is prevalent, particularly in the elderly for whom cardiovascular disease and pain are common co-morbidities. Non-selective non-steroidal anti-inflammatory drugs (NSAIDs) are known to interfere with the antiplatelet effect of aspirin through competitive binding with COX-1. While the clinical significance of this interference is still unclear, this review sought to assess the body of literature which has evaluated the potential attenuation of the anti-platelet effect of aspirin when dosed concomitantly with an NSAID. This review supports that the pharmacodynamic interaction between aspirin and non-selective NSAIDs occurs, but finds that the interaction varies amongst agents, and is highly dependent on numerous factors including: dose timing, dose of aspirin, and dose of the NSAID in question. Recent findings suggest that patient factors, such as body weight may also be indicators of aspirin's cardiovascular effectiveness. Ultimately, the clinical decision making for concomitant NSAID and low-dose aspirin regimens remains at the patient level.