Mitochondrial haplogroups H and J: risk and protective factors for ischemic cardiomyopathy.

BACKGROUND: Since mitochondria are the principal source of reactive oxygen species (ROS), these organelles may play an important role in ischemic cardiomyopathy (IC) development. The mitochondrial genome may influence this disease. The aim of the present study was to test the relationship between IC development and the impact of single nucleotide polymorphisms (SNPs) in mitochondrial DNA (mtDNA) defining the mitochondrial haplogroups in a population study. METHODOLOGY AND PRINCIPAL FINDINGS: Ten major European haplogroups were identified by using the single base extension technique and by polymerase chain reaction-restriction fragment length polymorphism. Frequencies and Odds Ratios for the association between IC patients (n = 358) and healthy controls (n = 423) were calculated. No convincing associations between classical risk factors for ischemic cardiomyopathy development and haplogroups were found. However, compared to healthy controls, the prevalence of haplogroup H was significantly higher in IC patients (40.0% vs 50.0%, p-value = 0.039) while the frequency of haplogroup J was significantly lower (11.1% vs 5.6%, p-value = 0.048). The analysis of the SNPs characterizing the European mtDNA haplogroups showed that the m.7028C allele (40.0% vs 50.0%, p-value = 0.005) and m.14766C allele (43.0% vs 54.2%, p-value = 0.002) were overrepresented in IC patients, meanwhile the m.10398G allele (19.8% vs 13.1%, p-value = 0.015) and m.4216C allele (22.2% vs 16.5%, p-value = 0.044) were found as protective factors against IC. CONCLUSIONS AND SIGNIFICANCE: Our results showed that the haplogroups H and J were found as a risk and protective factors for ischemic cardiomyopathy development, respectively.

[Chronic anemia in heart transplant patients: prevalence, predisposing factors and prognostic significance]. / Anemia crónica en el trasplante cardiaco. Prevalencia, factores predisponentes y significado pronóstico.

INTRODUCTION AND OBJECTIVES: Data on chronic anemia following heart transplantation (HT) are scarce and contradictory. Our aims were to determine the prevalence of chronic anemia after HT, to identify predisposing factors for the condition at 12 months, and to evaluate its influence on medium-term and long-term survival. METHODS: Retrospective analysis of patients who underwent HT between 1991 and 2005 (n=457). Chronic anemia was defined as a hemoglobin level <12 g/dL. RESULTS: The prevalence of post-HT chronic anemia was 75.5% at 1 month, 31% at 12 months, and 26.2% at 120 months. The condition was significantly more prevalent among women than men. Predisposing factors for chronic anemia 1 year post-HT were mild-to-moderate chronic renal failure (i.e., creatinine level >1.5 mg/dL; odds ratio [OR]=2.8; 95% confidence interval [CI], 1.5-5.0), female sex (OR=6.4; 95% CI, 3.1-13.2), and immunosuppression with mycophenolate mofetil compared with azathioprine (OR=2.6;, 95% CI, 1.4-4.8). The prevalence of chronic anemia 12 months after HT was independent of the donor's sex, the recipient's age, the etiology of the recipient's heart failure, diabetes mellitus, mild-to-moderate graft rejection, cytomegalovirus infection, and angiotensin-converting enzyme inhibitor treatment. The presence of chronic anemia 12 months after HT did not influence either long-term survival (mean, 11.5 years with chronic anemia vs. 13.0 years without) or actuarial survival. CONCLUSIONS: Post-HT chronic anemia is common, but improves with time and treatment. Predisposing factors for the condition 1 year post-HT include chronic renal failure, female sex, and immunosuppression with mycophenolate mofetil. The presence of chronic anemia does not appear to influence long-term survival.