Blood group A: a risk factor for heart rupture after acute myocardial infarction.

INTRODUCTION: Studies have been performed to identify the association between ABO blood groups and coronary artery disease. However, data is scarce about the impact of ABO blood groups on heart rupture (HR) after acute myocardial infarction (AMI). METHODS: We conducted a retrospective case-control study that included 61 consecutive patients with HR after AMI during a period from 1 January 2012 to 1 December 2019. The controls included 600 patients who were selected randomly from 8143 AMI patients without HR in a ratio of 1:10. Univariate and multivariate logistic regression analysis were used to identify the association between ABO blood groups and HR. RESULTS: Patients with blood group A had a greater risk of HR after AMI than those with non-A blood groups (12.35% vs 7.42%, P < 0.001). After adjusting for age, gender, heart rate at admission, body mass index (BMI), and systolic blood pressure (SBP), blood group A was independently related to the increased risk of HR after AMI (OR = 2.781, 95% CI 1.174-7.198, P = 0.035), and remained as an independent risk factor of HR after AMI in different multivariate regression models. CONCLUSION: Blood group A is significantly associated with increased HR risk after AMI.

Risk of cardiac rupture after acute myocardial infarction is related to a risk of hemorrhage.

Although cardiac rupture (CR) is a fatal mechanical complication of acute myocardial infarction (AMI), to date no predictive model for CR has been described. CR has common pathological characteristics with major bleeding. We aimed to investigate the relationship between the risk factors of major bleeding and CR. A total of 10202 consecutive AMI patients were recruited, and mechanical complications occurred in 72 patients. AMI patients without CR were chosen as control group. Clinical characteristics including bleeding-related factors were compared between the groups. The incidences of free wall rupture (FWR), ventricular septal rupture (VSR), and papillary muscle rupture (PMR) were 0.39%, 0.21%, and 0.09%, respectively, and the hospital mortalities were 92.5%, 45.5%, and 10.0%, respectively. Female proportion and average age were significantly higher in the groups of FWR and VSR than in the control group (P<0.01); higher white blood cell count and lower hemoglobin were found in all CR groups (P<0.01). Compared to the control group, patients with CR were more likely to receive an administration of thrombolysis [26.39% vs. 13.19%, P<0.05], and were less likely to be treated with primary percutaneous coronary intervention (PCI) [41.67% vs. 81.60%, P<0.05]. The major bleeding scores (integer scores) of FWR, VSR, and PMR were (17.70±7.24), (21.91±8.33), and (18.60±7.88), respectively, and were significantly higher than that of the control group (11.72±7.71) (P<0.05). A regression analysis identified age, increased heart rate, anemia, higher white blood cell count, and thrombolysis as independent risk factors of CR, most of which were major bleeding-related factors. The patients with CR have a significantly higher risk of hemorrhage compared to the group without CR. Risk of CR after AMI is related to the risk of hemorrhage.

Novel role of platelets in mediating inflammatory responses and ventricular rupture or remodeling following myocardial infarction.

OBJECTIVE: The goal of this study was to investigate the role of platelets in systemic and cardiac inflammatory responses and the development of postinfarct ventricular complications, as well as the efficacy of antiplatelet interventions. METHODS AND RESULTS: Using a mouse myocardial infarction (MI) model, we determined platelet accumulation and severity of inflammation within the infarcted myocardium by immunohistochemistry and biochemical assays, analyzed peripheral blood platelet-leukocyte conjugation using flow cytometry, and tested antiplatelet interventions, including thienopyridines and platelet depletion. Platelets accumulated within the infarcted region early post-MI and colocalized with inflammatory cells. MI evoked early increase in circulating platelet-leukocyte conjugation mediated by P-selectin/P-selectin glycoprotein ligand-1. Antiplatelet interventions inhibited platelet-leukocyte conjugation in peripheral blood, inflammatory infiltration, content of matrix metalloproteinases or plasminogen activation, and expression of inflammatory mediators in the infarcted myocardium (all P<0.05) and lowered rupture incidence (P<0.01). Clopidogrel therapy alleviated the extent of chronic ventricular dilatation by serial echocardiography. CONCLUSIONS: Platelets play a pivotal role in promoting systemic and cardiac inflammatory responses post-MI. Platelets accumulate within the infarcted myocardium, contributing to regional inflammation, ventricular remodeling, and rupture. Antiplatelet therapy reduces the severity of inflammation and risk of post-MI complications, demonstrating a previously unrecognized protective action.

Critical role for white blood cell NAD(P)H oxidase-mediated plasminogen activator inhibitor-1 oxidation and ventricular rupture following acute myocardial infarction.

Plasminogen activator inhibitor-1 (PAI-1) is an oxidant-sensitive protease inhibitor that is inactivated by oxidation and has a critical role in ventricular remodeling post myocardial infarction (MI). PAI-1 knockout (KO) mice die within 7days of myocardial infarction post MI due to increased plasmin activity leading to ventricular rupture. The goal of this study was to assess the relevant pathways of leukocyte-derived oxidants post MI that alter PAI-1 activity. Transplantation of wild-type (WT) bone marrow into PAI-1 null mice prolonged survival after MI (WT marrow: 41.66% vs. PAI-1 KO marrow: 0% in PAI-1 KO mice at day 7 (p<0.02). To determine relevant enzyme systems, we transplanted marrow from mice with specific deletions relevant to leukocyte-derived oxidants (NAD(P)H oxidase, iNOS, myeloperoxidase (MPO)) to determine which deletion controls PAI-1 oxidative inactivation and prolongs survival. MI was induced by ligation of the left anterior descending artery (LAD) and the incidence of cardiac rupture was monitored. PAI-1 KO transplanted with MPO KO, or iNOS KO bone marrow died within 9 days after MI. PAI-1 KO mice transplanted with p47(phox) KO marrow exhibited prolonged survival 21 days after MI (30% survival, p<0.03, n=10) compared to WT marrow (8.3%, n=12). Three days after MI, PAI-1 KO mice transplanted with p47(phox) KO marrow had increased PAI-1 activity and decreased nitration of PAI-1 in myocardial tissue compared to PAI-1 KO mice transplanted with WT marrow. These data suggest that modulating O(2)(•-) generation by NAD(P)H oxidase appears to be a therapeutically relevant target for increasing myocardial PAI-1 levels after MI, whereas downstream enzymes like MPO and iNOS may not be.

Mechanical complications after myocardial infarction reliably predicted using C-reactive protein levels and lymphocytopenia.

We assessed the accuracy of C-reactive protein (CRP) levels and lymphocyte counts to predict a mechanical complication (MC) after myocardial infarction (MI). Within 10 years, we identified 36 patients with 39 echocardiographically confirmed MC within 30 days of MI: ventricular septal defect (17 cases), papillary muscle rupture (10 cases), and left ventricular free wall rupture (12 cases). They were compared to 41 controls with an uncomplicated hospital course after MI. Peak CRP levels and minimum relative lymphocyte counts obtained within 96 h of the acute MI (AMI) and before diagnosis of the complication were compared with clinical parameters. Prior to the MC, peak CRP levels were significantly higher (p < 0.001) and relative lymphocyte counts lower (p < 0.001) than in controls while creatine kinase levels did not differ (p = nonsignificant). Using multivariate logistic regression, the following score was identified to have excellent prognostic significance for MC: CRP (mg/l) - 10 x Lyc (%). The area under the receiver-operating characteristic curve was 0.90 +/- 0.05 (p < 0.001). Combined use of CRP levels and relative lymphocyte counts may be helpful in accurately predicting an MC after AMI and should therefore be routinely assessed.

Brain natriuretic peptide and cardiac rupture after acute myocardial infarction.

Cardiac rupture is a fatal complication in the acute stage of myocardial infarction (MI). However, no measures have yet been established to predict it. Herein we describe three MI patients with cardiac rupture in whom plasma brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) concentrations had been serially monitored from the onset of MI to cardiac rupture. In these cases, plasma BNP levels increased without symptomatic and hemodynamic changes and reached their highest level immediately before cardiac rupture, while plasma ANP levels remained unchanged. These cases suggest that the increased plasma BNP concentrations without symptomatic and hemodynamic changes may be a useful marker for predicting cardiac rupture after acute MI.

[The pathogenesis of heart rupture in myocardial infarct]. / O patogeneze razryva serdtsa pri infarkte miokarda.

Examination of 166 patients with primary transmural myocardial infarction (MI) of the anterior site has shown that the blood of MI patients (n = 34) complicated by cardiorrhexis manifests the maximal increase of the stress reaction components, lipid peroxidation products and an appreciable lowering of the content of adaptogens. It is emphasized that the development of the maladaptation syndrome underlies the pathogenesis of cardiorrhexis during MI as the result of the failure of the compensatory-adaptive potentialities of the body in response to the excessive stress reaction. It has been discovered that the high rise of the ST segment on the ECG and pronounced arterial hypoxemia are informative indicators mirroring the high probability of cardiorrhexis occurrence in MI patients. A scheme of cardiorrhexis pathogenesis in MI patients is offered.

[Biochemical blood indices of patients with a myocardial infarct complicated by heart rupture]. / Biokhimicheskie pokazateli krovi u bol'nykh infarktom miokarda, oslozhnennym razryvom serdtsa.

Adrenal function, blood kallikrein-kinin status and the levels of serotonin, histamine, electrolytes and enzymes were repeatedly assessed in 97 patients with myocardial infarction and external cardiorrhexis. Certain patterns were identified as common to the pre-rupture period and the time of the rupture proper that can have a pathogenetic, and sometimes also diagnostic and predictive, significance.