BMJ Heart Asia Latest Issue

Serum myeloperoxidase: a novel biomarker for evaluation of patients with acute coronary syndrome

Thu, 15 Oct 2009 15:06:05 PDT

Objectives: Myeloperoxidase, an abundant leucocyte enzyme, is elevated in culprit lesions that have ruptured in patients with sudden cardiac injury. Multiple lines of evidence suggest an association between myeloperoxidase and inflammation and acute coronary syndrome. Myeloperoxidase has been proposed as a potent risk marker and diagnostic tool in acute coronary syndrome (ACS). Recent studies have reported the potential use of myeloperoxidase in acute coronary syndrome, but limited reports are available on its utility in different groups of ACS in the emergency department. Therefore the circulating levels of serum myeloperoxidase in patients with acute coronary syndrome and control subjects were studied.

Design and setting: The levels of serum myeloperoxidase were measured by ELISA in 485 patients admitted to emergency care unit, of which 89 patients were diagnosed as non-cardiac chest pain (NCCP). The levels of myeloperoxidase were significantly increased in patients with ACS when compared with controls and NCCP. From the receiver operator characteristic (ROC) curve analysis, the optimum value above which myeloperoxidase can be considered positive was found to be 48.02 U/ml. The area under the curve was found to be 0.956 with 95% CI (0.934 to 0.973) (p<0.0001). A combination analysis of ROC curves of troponin, creatine kinase MB (CK-MB) and myeloperoxidase showed myeloperoxidase to be highly significant. Multivariate analysis revealed myeloperoxidase to be an independent diagnostic marker for early diagnosis of ACS.

Conclusion: Myeloperoxidase, in contrast to troponin and CK-MB, identified patients at risk of ischaemic events, even in the absence of myocardial necrosis, thus highlighting its potent usefulness for risk stratification among patients presenting with chest pain.

Practice viewpoints: AICD, who and when?

Sung, R J, Chan, N-Y — Thu, 15 Oct 2009 15:06:05 PDT

Automatic implantable cardioverter-defibrillator (AICD) is a costly but effective treatment modality for the prevention of sudden cardiac death (SCD). Causes of SCD are age-dependent, disease-specific and affected by racial/ethnic differences. Atherosclerotic heart disease (ASHD) is the most frequent underlying disease in individuals >=35 years old. Available information suggests that Asians have a lower rate of SCD compared with African black individuals and Caucasians. Whether it is for secondary or for primary prevention, physicians should be educated to perform a thorough diagnostic work-up and be able to identify transient and/or reversible causes of lethal ventricular tachyarrhythmias such as acute myocardial infarction, residual ischaemia, electrolyte imbalance, adverse effect of drugs, valvular heart diseases, etc before contemplating AICD implantation. Correction of these reversible causes may avoid the necessity of AICD implantation. The status of left ventricular function is not sufficiently specific for guiding AICD implantation in ASHD patients after acute myocardial infarction. The urgent need is to develop better biological or physiological markers for risk stratification so that patients who would actually benefit from AICD implantation can be readily identified. Such an approach will make the use of AICD more cost-effective. Based on molecular genetic data obtained from patients with inherited structural cardiovascular diseases and malignant arrhythmogenic disorders in which the risk of SCD appears to be gene- and/or mutant-specific, a continuous search for genetic markers for better risk stratification is warranted in patients suffering from ASHD.

Arrhythmogenic right ventricular dysplasia in emergency department

Rao, M, Prashanth, P, Mukhaini, M K — Thu, 15 Oct 2009 15:06:05 PDT