Platelet function, coagulation and fibrinolysis in patients with previous coronary and cerebrovascular ischemic events

Abstract

OBJECTIVES:Ischemic stroke (IS) or transient ischemic attack (TIA) history is present in 4-17% of patients with coronary artery disease (CAD). This subgroup of patients is at high risk for both ischemic and bleeding events. The aim of this study was to determine the role of platelet aggregability, coagulation and endogenous fibrinolysis in patients with CAD and previous IS or TIA.METHODS:A prospective case-control study that included 140 stable CAD patients divided into two groups: the CASE group (those with a previous IS/TIA, n=70) and the CONTROL group (those without a previous IS/TIA, n=70). Platelet aggregability (VerifyNow Aspirin® and VerifyNow P2Y12®), coagulation (fibrinogen and thromboelastography by Reorox®) and endogenous fibrinolysis (D dimer and plasminogen activator inhibitor-1) were evaluated.RESULTS:Patients in the CASE group presented significantly higher systolic blood pressure levels (135.84±16.09 vs 123.68±16.11, p<0.01), significantly more previous CABG (25.71% vs 10%, p=0.015) and significantly higher calcium channel blocker usage (42.86% vs 24.29%, p=0.02) than those in the control group. In the adjusted models, low triglyceride values, low hemoglobin values and higher systolic blood pressure were significantly associated with previous IS/TIA (CASE group). Most importantly, platelet aggregability, coagulation and fibrinolysis tests were not independently associated with previous cerebrovascular ischemic events (CASE group).CONCLUSION:Platelet aggregability, coagulation and endogenous fibrinolysis showed similar results among CAD patients with and without previous IS/TIA. Therefore, it remains necessary to identify other targets to explain the higher bleeding risk presented by these patients.

Relation of High Lipoprotein (a) Concentrations to Platelet Reactivity in Individuals with and Without Coronary Artery Disease

“…Our main finding was that high Lp(a) concentration, defined as Lp(a) C 50 mg/dL [23][24][25][26]34], is unrelated to platelet reactivity as assessed by multiple established tests [31][32][33][34][35][36], and regardless of the presence or absence of CAD. To the best of our knowledge, the present study is the first to analyze the potential association between high concentrations of Lp(a) and platelet reactivity in individuals with and without CAD, which could contribute to a better understanding of the pathophysiology of atherosclerosis [2][3][4][5].…”

“…Since we had 396 individuals with samples available for both Lp( a ) and ADP-induced platelet reactivity, we performed a post-hoc power calculation assessing the difference in platelet reactivity that could be detected in individuals with Lp( a ) ≥ 50 mg/dL versus < 50 mg/dL. On the basis of a prior study from our group [ 33 ], individuals with CAD on aspirin had a mean reactivity of 251.74 ± 43.72 PRU. For a two-tailed α equal to 0.05, the study had 80% power to detect a mean difference of 12.4 PRU and 90% power to detect a mean difference of 14.4 PRU between both groups of interest (Supplementary Table 5).…”

Hypercoagulability as Measured by Thrombelastography May Be Associated with the Size of Acute Ischemic Infarct—A Pilot Study

“…Many studies have shown that high platelet reactivity, higher levels of fibrinogen or hyperactivated properties of the coagulation system may correspond to the increased incidence of recurrent vascular events [ 5 , 6 ]. Therefore, TEG ® is widely applicated in the evaluation of clot transformation and monitoring the coagulation properties of blood in different branches of medicine [ 7 , 8 , 9 , 10 , 11 ]. Recently, increasingly data supported the potential use of this tool in a clinical approach in stroke neurology [ 12 ].…”