RESUMO
OBJECTIVES: Cardiac extracellular matrix structure is largely under the control of the matrix metalloproteinases (MMPs) whose activity maintains a balance between connective tissue synthesis and degradation. MMP gene polymorphisms, by modifying the level of gene expression, may affect atrial structural remodelling and atrial fibrillation recurrence rate. The aim of this study was to evaluate the association between MMP-1 and MMP-3 polymorphisms and arrhythmia recurrence. METHODS: We studied 74 persistent atrial fibrillation patients who underwent electrical cardioversion to restore sinus rhythm. In both patient and reference control groups, identification of MMP-1 and MMP-3 gene polymorphisms was performed by means of polymerase chain reaction according to standard techniques. RESULTS: Distribution of MMP-1 and MMP-3 genotypes and alleles were similar in atrial fibrillation patients and controls. During a 3-week follow-up period, 37 patients showed atrial fibrillation recurrences. Risk for atrial fibrillation recurrence significantly differed among groups (P = 0.0139) according to 5A and 1G allele presence. In particular, atrial fibrillation recurred in 62% of the patients carrying both 5A and 1G alleles (reference group) compared with no recurrence in patients carrying neither of them. CONCLUSIONS: We observed a significant relationship between MMP-1 and MMP-3 polymorphism and atrial fibrillation recurrences in patients with persistent atrial fibrillation. These findings suggest that genetic factors contribute to determine arrhythmic recurrence rate in persistent atrial fibrillation.
Assuntos
Arritmias Cardíacas/genética , Cardioversão Elétrica , Metaloproteinase 1 da Matriz/genética , Metaloproteinase 3 da Matriz/genética , Polimorfismo de Nucleotídeo Único , Idoso , Arritmias Cardíacas/enzimologia , Arritmias Cardíacas/terapia , Fibrilação Atrial/enzimologia , Fibrilação Atrial/genética , Fibrilação Atrial/terapia , Feminino , Frequência do Gene , Predisposição Genética para Doença , Humanos , Masculino , Metaloproteinase 1 da Matriz/metabolismo , Metaloproteinase 3 da Matriz/metabolismo , Pessoa de Meia-Idade , Razão de Chances , Reação em Cadeia da Polimerase , RecidivaRESUMO
In light-chain (AL) amyloidosis, prognosis is dictated by cardiac dysfunction. N-terminal natriuretic peptide type B (NT-proBNP) and cardiac troponins (cTn) are used to assess the severity of cardiac damage. We evaluated the prognostic relevance of a high-sensitivity (hs) cTnT assay, NT-proBNP, and cardiac troponin I in 171 consecutive patients with AL amyloidosis at presentation and 6 months after treatment. Response and progression of NT-proBNP were defined as more than 30% and more than 300 ng/L changes. All 3 markers predicted survival, but the best multivariable model included hs-cTnT. The hs-cTnT prognostic cutoff was 77 ng/L (median survival 10.6 months for patients with hs-cTnT above the cutoff). After treatment, response and progression of NT-proBNP and a more than 75% increase of hs-cTnT were independent prognostic determinant. In AL amyloidosis, hs-cTnT is the best baseline prognostic marker. Therapy should be aimed at preventing progression of cardiac biomarkers, whereas NT-proBNP response confers an additional survival benefit.