Prognostic Impact of Iron Metabolism Changes in Patients with Acute Coronary Syndrome

Abstract

BackgroundIron metabolism disorders have been associated with an increased risk of cardiovascular events. However, the prognostic impact on patients (pts) with acute coronary syndrome (ACS) has yet to be clarified.ObjectiveTo determine the prognostic value of serum iron and ferritin levels in pts with ACS in the short and long-term.MethodsConsecutive pts admitted to a coronary care unit with a diagnosis of ACS, for a period of 2 years, were evaluated. The population was divided into tertiles of serum iron and ferritin distribution. The primary adverse events were the occurrence of in-hospital death or heart failure (HF) and death or HF at 1 year of follow-up.ResultsWe studied 280 pts (73% males; mean age 68 ± 13 years). The mean levels of serum iron and ferritin were 59 ± 34 mcg/dL and 205 ± 185 ng/mL, respectively. Patients included in the 1st tertile of serum iron (≤ 40 mcg/dL) had a higher rate of adverse events, in-hospital and after 1 year. Lower and higher levels of ferritin (1st and 3rd tertiles, ≤ 110; >219 ng/ml, respectively) were associated with a higher incidence of HF during hospitalization and death at 1 year. A ferritin value >316 ng /mL was an independent risk factor for death at 1 year (adjusted OR: 14; 95%CI: 2.6 to 75.9).ConclusionIn this population, iron metabolism alterations were associated with a higher rate of adverse events and higher ferritin levels constituted an independent mortality predictor in the long-term.

Relation of Iron Status to Prognosis After Acute Coronary Syndrome

“…The utility of serum iron itself for the assessment of iron status is limited because of diurnal variation in level, especially in nonfasting samples. 18 Duarte et al 19 showed that in patients admitted with ACS and in the lower tertile of serum iron level had a higher rate of mortality and HF at 1 year but not reinfarction. Likewise, Steen et al 20 failed to demonstrate an association between catalytic iron and risk of MI in 1,701 patients with ACS.…”

“…Some studies even suggest a cytoprotective effect of ferritin, 22 whereas a prospective study in healthy Finnish men actually showed that elevated serum ferritin >200 mg/L was associated with a 2.2-fold greater risk of MI. 23 Duarte et al 19 showed that both low (<111) and high (>219) serum ferritin levels were associated with higher incidence of HF during hospitalization and mortality in patients with ACS. Moreover, a high serum ferritin level of 316 mg/L was an independent predictor of 1-year mortality.…”

Insuficiência cardíaca associada à anemia: Uso de ferro endovenoso comparado ao placebo

“…O grau de anemia também é associado à severidade da insuficiência cardíaca, uma vez que a elevação do peptídeo natriurético atrial (BNP), a dilatação do ventrículo esquerdo, as disfunções nos processos de sístole e/ou diástole, o aumento progressivo da pressão na artéria pulmonar, e a redução do consumo de oxigênio durante esforço ou repouso estão correlacionados com a diminuição da qualidade de vida (Pereira et al,2012) Sabendo-se que o aumento nos níveis de citocinas, sendo diretamente envolvidas a IL6 e TNF alfa, tem ação não somente no estresse oxidativo, que provoca o extravasamento do BNP, como também na apoptose das células musculares, causando, assim, perda considerável e progressiva da massa esquelética (Duarte et al, 2018).…”

“…A anemia foi marcador independente de mau prognóstico na análise multivariada (mortalidade 47% vs 24,6%, p = 0,016, risco relativo 2,54). Duarte et al (2018) Níveis mais baixos e mais elevados de ferritina (1o e 3o tercil, respetivamente, ≤ 110; > 219 ng/ml) estiveram associados a uma maior ocorrência de IC em internamento e de morte a 1 ano. Um valor de ferritina> 316 ng/mL constituiu fator de risco independente de morte a 1 ano (OR ajustado 14 IC 95% 2,6-75,9).…”

“…Essa deficiência de ferro é uma comorbidade comum e clinicamente relevante da insuficiência cardíaca, estando associado ao pior prognóstico. Alguns estudos (CONFIRM-HF) têm evidenciado o benefício na correção do ferro em termos de qualidade vida e tolerância ao esforço em doentes com insuficiência cardíaca com função sistólica deprimida (Duarte et al, 2018) A disponibilidade de ferro é regulada por 2 proteínas reguladoras de ferro: os elementos reguladores de ferro IRP1 e IRP2. Quando há deficiência de ferro, os IRPs interagem com elementos responsivos ao ferro, aumentando a estabilidade do mRNA do receptor da transferrina e inibindo a tradução da ferroportina e das cadeias L e H da ferritina, portanto favorecem o aumento do ferro intracelular.…”