Evidence of prolonged disturbances in the haemostatic, hemorheologic and inflammatory profiles in transmural myocardial infarction survivors

Usefulness of whole blood viscosity estimated by de Simeone's formula to predict left ventricular thrombus formation within one year following acute anterior myocardial infarction

BACKGROUND

Despite improvements in treatment of ST-segment myocardial infarction (STEMI), thrombus formation in the left ventricle is still a concerning complication that may lead to systemic thromboembolism and stroke.

OBJECTIVES

To evaluate the predictive value of estimated whole blood viscosity (WBV) for left ventricular thrombus development in patients surviving an acute anterior myocardial infarction (AAMI).MATERIALS \& METHODS:Seven hundred eighty AAMI patients who were treated percutaneously were enrolled consecutively. Serial echocardiographic examinations were performed within 24h of admission, before hospital discharge, and at 1, 3, 6 and 12 months following hospital discharge. WBV was calculated according to de Simones formula.

RESULTS

One hundred patients (12.8%) developed thrombus formation within one year following AAMI. Patients with left ventricular thrombus (LVT) had significantly higher WBV values. Supramedian values of WBV at both low (0.5 sec-1) and high (208 sec-1) shear rates were found to be an independent predictor of LVT development.

CONCLUSION

As an easily accessible parameter, WBV might be a useful predictor of LVT formation within one year following acute anterior myocardial infarction.

Plasminogen activator inhibitor 1 in acute coronary syndromes

Plasminogen activator inhibitor 1 (PAI-1) is the main regulator of endogenous fibrinolysis, overriding the impact of other constituents of fibrinolysis. In plasma, it can be found in three forms: active, latent and inactive. There are numerous commercially available tests, analysing the activity of PAI-1 or the antigen level, with variable correlations between the two. PAI-1 has been extensively studied regarding incidence and outcomes of acute coronary syndromes, and showed positive association with both in numerous studies. Higher PAI-1 has been associated with worse short- and long-term outcomes. Studies are more consistent in the primary percutaneous coronary intervention era. Higher rise of PAI-1 within the first 24 h of acute myocardial infarction has been linked to some of its high-risk features. The circadian pattern of PAI-1 kinetics has been previously described, and the mechanisms behind this phenomenon and its impact on the incidence of acute coronary syndromes are well known. Further investigations are needed to test the safety and efficacy of PAI-1 as a pharmacological target in cardiovascular diseases.

Quantitative Measurement of Erythrocyte Aggregation as a Systemic Inflammatory Marker by Ultrasound Imaging: A Systematic Review

This systematic review is aimed at answering two questions: (i) Is erythrocyte aggregation a useful biomarker in assessing systemic inflammation? (ii) Does quantitative ultrasound imaging provide the non-invasive option to measure erythrocyte aggregation in real time? The search was executed through bibliographic electronic databases CINAHL, EMB Review, EMBASE, MEDLINE, PubMed and the grey literature. The majority of studies correlated elevated erythrocyte aggregation with inflammatory blood markers for several pathologic states. Some studies used "erythrocyte aggregation" as an established marker of systemic inflammation. There were limited but promising articles regarding the use of quantitative ultrasound spectroscopy to monitor erythrocyte aggregation. Similarly, there were limited studies that used other ultrasound techniques to measure systemic inflammation. The quantitative measurement of erythrocyte aggregation has the potential to be a routine clinical marker of inflammation as it can reflect the cumulative inflammatory dynamics in vivo, is relatively simple to measure, is cost-effective and has a rapid turnaround time. Technologies like quantitative ultrasound spectroscopy that can measure erythrocyte aggregation non-invasively and in real time may offer the advantage of continuous monitoring of the inflammation state and, thus, may help in rapid decision making in a critical care setup.

Association between plasminogen activator inhibitor-1 and cardiovascular events: a systematic review and meta-analysis

Background

Small studies have implicated plasminogen activator inhibitor-1 (PAI-1) as a predictor of cardiovascular events; however, these findings have been inconsistent.

We sought out to examine the potential role of PAI-1 as a marker for major adverse cardiovascular events (MACE).

Methods

We systematically reviewed all indexed studies examining the association between PAI-1 and MACE (defined as death, myocardial infarction, or cerebrovascular accident) or restenosis. EMBASE, Web of Science, Medline, and the Cochrane Library were searched through October 2016 to identify relevant studies, supplemented by letters to authors and review of citations. Studies reporting the results of PAI-1 antigen and/or activity levels in association with MACE in human subjects were included.

Results

Of 5961 articles screened, we identified 38 articles published between 1991 to 2016 that reported PAI-1 levels in 11,557 patients. In studies that examined PAI-1 antigen and activity levels, 15.1% and 29.6% of patients experienced MACE, respectively. Patients with MACE had higher PAI-1 antigen levels with a mean difference of 6.11 ng/mL (95% CI, 3.27-8.96). This finding was similar among patients with and without known coronary artery disease. Comparatively, studies that stratified by PAI-1 activity levels were not associated with MACE. In contrast, studies of coronary restenosis suggest PAI-1 antigen and activity levels are negatively associated with MACE.

Conclusions

Elevated plasma PAI-1 antigen levels are associated with MACE. Definitive studies are needed to ascertain if PAI-1 acts simply as a marker of risk or if it is indeed a bona fide therapeutic target.

Electronic supplementary material

The online version of this article (10.1186/s12959-018-0166-4) contains supplementary material, which is available to authorized users.

Analysis of the Blood Viscosity Behavior in the Sicilian Study on Juvenile Myocardial Infarction

Considering the role of hemorheology in coronary circulation, we studied blood viscosity in patients with juvenile myocardial infarction. We examined whole blood viscosity at high shear rate using the cone-on-plate viscosimeter Wells-Brookfield ½ LVT and at low shear rate employing a viscometer Contraves LS30 in 120 patients (aged <46 years) with myocardial infarction, at the initial stage and subsequently 3 and 12 months after. At the initial stage, patients had an increased whole blood viscosity in comparison to normal controls. This hemorheological profile was not influenced by the cardiovascular risk factors, nor by the extent of coronary lesions, even if some differences were evident between patients with ST-segment elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI). The blood viscosity pattern at the initial stage did not influence recurring ischemic events or the onset of heart failure during an 18 months’ follow-up. The neutrophil to lymphocyte ratio did not affect the blood viscosity pattern. We reevaluated 83 patients 3 months after and 70 patients 12 months after the acute coronary syndrome, and we found that the hemorheological parameters were still altered in comparison to normal controls at both times. We observed an impairment of the hemorheological pattern in young patients with myocardial infarction, partially influenced by the infarction type (STEMI and NSTEMI) and persisting in the long term.

PAI-1 levels are related to insulin resistance and carotid atherosclerosis in subjects with familial combined hyperlipidemia

Familial combined hyperlipidemia (FCH) is a primary atherogenic dyslipidemia with insulin resistance and increased cardiovascular risk. Plasminogen activator inhibitor type 1 (PAI-1) and myeloperoxidase (MPO) activity are associated with proinflammatory and atherothrombotic risk. Our aim was to study the role played by PAI-1 and MPO activity in the carotid atherosclerosis prevalence in FCH subjects. 36 FCH unrelated subjects (17 women) were matched by age and body weight with 36 healthy normolipidemic subjects (19 female). Blood lipids, glucose, insulin, insulin resistance (homeostasis model assessment (HOMA)), MPO, and PAI-1 were determined in both groups. Carotid intima media thickness (IMT) was measured by the same investigator by standardized protocol. No differences in age, body mass index (BMI) or waist circumference were observed between the two groups. HOMA and PAI-1 values were higher in the FCH group, reaching statistical significance in those subjects with insulin resistance. In addition, PAI-1 values correlated significantly with metabolic syndrome components and carotid IMT. It is known that the elevated cardiovascular risk that characterizes FCH is frequently associated with insulin resistance. We have detected that two known proinflammatory and proatherothrombotic factors (MPO and PAI-1) are significantly elevated in FCH subjects with insulin resistance. These results could partly explain the high cardiovascular risk present in FCH subjects.

Fibrinolytic status in acute coronary syndromes: evidence of differences in relation to clinical features and pathophysiological pathways

Limited data are available on the role of innate fibrinolysis in acute coronary syndromes (ACS). In the present study we evaluated the dynamic alterations of fibrinolytic markers in patients presenting with ACS. Tissue-type-(tPA) and urokinase type-(uPA) plasminogen activators, plasminogen activator inhibitor (PAI-1) antigen and activity and thrombin activatable fibrinolysis inhibitor (TAFI) were analysed in 50 patients with ST elevation myocardial infarction (STEMI), 47 non-STEMI patients (NSTEMI), 40 patients with stable coronary artery disease (CAD) and 39 controls. The parameters were measured on day 1 and days 3, 7 and 30. Counts of monocyte subsets, monocyte-platelet aggregates and plasma inflammatory cytokines were assessed on admission. On day 1, TAFI was higher in NSTEMI vs. STEMI (p<0.001) while PAI-1 activity was higher in STEMI (p<0.001). In STEMI, uPA activity levels was low on day 1 but significantly increased on day 30 (p<0.001). TAFI levels were increased in NSTEMI on day 1 and gradually reduced by day 30 (p<0.05). In STEMI, TAFI levels peaked at day 7 (p<0.05) and dropped significantly by day 30 (p<0.05). CD14++CD16+ monocytes were independently associated with PAI-1 activity in ACS (p=0.03). Monocyte-platelet aggregates rather than platelet-free monocytes were an independent determinant of tPA, PAI-1 antigen and TAFI on a multivariate analysis (p<0.05). There are significant differences in fibrinolytic activity between patients with STEMI and NSTEMI. These changes could reflect the role of these factors in post-MI myocardial healing. Monocyte-platelet interactions are independently associated with the regulation of the fibrinolytic status in ACS.

Comparison of hemorheological variables in ST-elevation myocardial infarction versus those in non-ST-elevation myocardial infarction or unstable angina pectoris

The aim of this study was to evaluate hemorheologic variables in patients with acute coronary syndromes in relation to the occurrence of ST-segment elevation myocardial infarction (STEMI). In 370 consecutive patients with acute coronary syndromes, 215 with STEMIs and 155 with non-ST-segment elevation myocardial infarctions or unstable angina pectoris, who underwent percutaneous coronary intervention, hemorheologic studies were performed by assessing whole-blood viscosity (at shear rates of 0.512 and 94.5 s(-1)), plasma viscosity, and erythrocyte deformability index. A significant difference in hematocrit and in whole-blood viscosity at 0.512 s(-1) was found between the 2 groups of patients. Hematocrit at admission in the highest tertile compared with the lowest tertile remained independently associated with the occurrence of STEMI on multivariate analysis adjusted for traditional cardiovascular risk factors, previous coronary artery disease, multivessel disease, bleeding complications, and leukocyte count. In conclusion, erythrocyte concentration seems to play a role per se in the occurrence of STEMI and complete coronary artery occlusion and might be considered in stratifying high-risk cardiovascular patients and as a possible therapeutic target in patients presenting with acute coronary syndromes.

Increased deformability of red blood cells is associated with a deletion polymorphism of the angiotensin-converting enzyme gene

Angiotensin-converting enzyme (ACE) plays important roles in the renin-angiotensin system. ACE converts angiotensin I to angiotensin II and also inactivates bradykinin, thereby modulating the vascular tone. A polymorphism of the ACE gene, located on chromosome 17, has been found in intron 16, and is characterized by the presence (insertion [I]) or absence (deletion [D]) of a 287-base-pair Alu repeat. Individuals with the D allele of the ACE gene have higher ACE levels and are at higher risk of cardiovascular events. We aimed to investigate the possible relationship between the I/D polymorphism of the ACE gene and hemorheological parameters, including red blood cell (RBC) deformability. The study was performed on 28 healthy young volunteers (13 women and 15 men, mean age 24 +/- 2). The prevalence of the I and D alleles was 30.4% and 69.6%, respectively. The I/I genotype (II) was found in 21.4%, I/D genotype (ID) in 17.9%, and D/D genotype (DD) in 60.7% of the subjects tested. No significant relationship between ACE I/D polymorphism and RBC aggregation or whole blood and plasma viscosity was observed. In contrast, RBC deformability was significantly increased in the subjects with the DD genotype compared with the II (p < 0.05) or the ID (p < 0.01) genotype, and in the subjects with the D allele compared with the I allele (p < 0.01). We suggest that RBC deformability of individuals with the D allele, who have higher risk for cardiovascular pathologies, may have been increased by a compensatory mechanism.

Low normal level of protein C or of antithrombin increases risk for recurrent cardiovascular events

The relationship between haemostatic factors and recurrent cardiovascular events was investigated in patients enrolled with acute coronary syndrome (acute non-Q myocardial infarction or unstable angina pectoris). One hundred and fifteen patients, aged 64 +/- 10 years, were included in the study. Haemostatic parameters [prothrombin time, activities of factor VII, factor VIII, factor X, antithrombin (AT) and protein C (PC), and concentrations of free protein S, fibrinogen, D-dimer, prothrombin fragment 1+2, and thrombin-antithrombin complex] were measured four times: within 48 h of hospitalization, at discharge (days 5-8), at 3 months and after 1 year. Screening for factor V Leiden mutation was also performed. Patients were followed for cardiovascular endpoints (new or refractory unstable angina pectoris, non-fatal myocardial infarction, stroke, or death) for an average of 555 days. Of all patients, 35 had an endpoint during the follow-up ("endpoint" group) and 80 patients did not ("no endpoint" group). Analysing the whole follow-up period, PC (P < 0.01) and AT (P < 0.01) were lower in the "endpoint" than in the "no endpoint" group. With 50% percentiles at enrollment, the odds ratio for getting an endpoint in the low (cut-off value < 100%) versus high PC group was 2.72 (95% confidence interval, 1.18-6.29; P < 0.05). Lower levels of AT (P < 0.05) and PC (P < 0.05) during the whole follow-up were associated with a shorter event-free time. In conclusion, lower PC and AT values, even within the normal range, seem to be associated with elevated risk for recurrent cardiovascular events and shorter event-free time in acute coronary syndrome patients.