The role of diabetes mellitus in the composition of coronary thrombi in patients presenting with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.

BACKGROUND: Although diabetes mellitus (DM) is a predictor of poor outcomes in patients with ST-segment elevation myocardial infarction (STEMI), few studies have analyzed the impact of DM on the constituency of coronary thrombi. OBJECTIVES: Comparing morphologic and histopathologic aspects of coronary thrombi in STEMI patients with and without DM who underwent primary percutaneous coronary intervention. METHODS: All consecutive patients with STEMI admitted to our institution between April 2010 and December 2012 (n = 1,548) were considered for inclusion. Thrombus material was obtained by aspiration thrombectomy; morphologic and histopathologic aspects were assessed by 3 independent pathologists blinded to clinical characteristics and outcomes. Patients with DM were compared with those without DM. A sensitivity analysis was performed using a propensity score. RESULTS: During the study period, coronary thrombi material from 259 patients was obtained, of whom 19% (n = 49) had diabetes. Diabetic patients were older (P = .10), had a higher frequency of hypertension (P < .01) and dyslipidemia (P = .03), and had a trend to a longer time from the onset of chest pain to hospital arrival (P = .08). The number of retrieved fragments, the size of the thrombi and its composition (leukocytes, fibrin, and erythrocytes percent), and thrombus age and color were similar between patients with or without DM. There were also no statistically significant differences in thrombus constituency of the propensity score-matched patients (n = 92). CONCLUSIONS: In this study, morphologic and histopathologic constituency of coronary thrombi in the setting of a ST-elevation myocardial infarction was not significantly different between patients with or without DM. This finding was intriguing and deserves further investigation.

Prevalência, etiologia e características dos pacientes com infarto agudo domiocárdio tipo 2 / Prevalence, etiology, and characteristics of patients with type-2 acute myocardial infarction

Introdução: Na prática clínica, os tipos 1 (trombose coronariana) e 2 (desequilíbrio entre a demanda e ofertade oxigênio) de infarto agudo do miocárdio (IAM) não são claramente distinguidos. O objetivo deste estudo foi avaliar a prevalência e a etiologia do IAM tipo 2, e comparar seu perfil com o do tipo 1. Métodos: Foram analisados pacientes admitidos com IAM com supradesnivelamento do segmento ST(IAMCST) com < 12 horas, encaminhados para coronariografia, no período de 2009 a 2013. Resultados: Foram incluídos 1.960 pacientes, sendo 1.817 analisados, dos quais 1.786 (98,3%) com IAM tipo 1 e 31 (1,7%) do tipo de 2. Todos os pacientes com IAM tipo 2 apresentaram coronárias sem lesões significativas e, em 36% dos casos, discinesia apical. Os pacientes com IAM tipo 2 apresentaram, em geral, perfil clínico e laboratorial semelhante aos do tipo 1, com exceção da idade mais jovem, menores níveis de marcadores de necrose miocárdica, maior probabilidade de apresentarem fluxo TIMI 3 pré e maior fração de ejeção do ventrículo esquerdo. Aos 30 dias, a mortalidade (3,2 vs. 9,0%; p = 0,23) e a ocorrência de morte, reinfarto ou necessidade de revascularização do vaso-alvo (3,2 vs. 13,0%; p = 0,09) foram numericamente menores no IAM tipo 2. Conclusões: Uma pequena fração de pacientes com IAMCST foi classificada como de tipo 2; exibiram anormalidades estruturais isoladas ou associadas à ausência de lesões significativas; mostraram poucas diferenças no perfil clínico e laboratorial, e desfechos clínicos semelhantes aos 30 dias, comparados aos pacientes com IAM tipo 1.

Background: In clinical practice, type-1 (coronary thrombosis) and type-2 (imbalance between oxygen demand and supply) acute myocardial infarction (AMI) are not clearly differentiated. The aim of this study was to evaluate the prevalence and etiology of type-2 AMI and compare its profile with that of type-1 AMI. Methods: Patients admitted with ST-segment elevation AMI (STEMI) < 12 hours of symptom onset, and referred for coronary angiography, from 2009 to 2013, were analyzed. Results: There were 1,960 patients included; 1,817 were analyzed, of whom 1,786 (98.3%) had type-1 AMI, and 31 (1.7%), type-2. All patients with type-2 AMI showed no significant coronary lesions, and 36% of the cases had apical dyskinesia. Type-2 AMI patients had, in general, a clinical and laboratory profile that was similar to those with type-1, except for the younger age, lower levels of myocardial necrosis markers, higher probability of having pre-TIMI 3 flow and higher left ventricular ejection fraction. At 30 days, mortality (3.2vs. 9.0%; p = 0.23) and the occurrence of death, reinfarction, or need for target-vessel revascularization (3.2vs. 13.0%; p = 0.09) were numerically lower in type-2 AMI. Conclusions: Few patients with STEMI were classified as type-2; they had structural abnormalities, isolatedor associated with the absence of significant lesions; showed little difference regarding the clinical and laboratory profile, and similar clinical outcomes at 30 days, when compared to patients with type-1 AMI.