Mojgan Hossein-Nia

Comparison of two strategies for myocardial management during coronary artery operations

Despite the current trend for using blood cardioplegia, ventricular fibrillation with intermittent ischemia is still used as a strategy to manage the myocardium with impressive results. These two methods of myocardial management were compared in 40 patients undergoing elective coronary artery operations using creatine kinase MB isoforms and troponin T assays. Each patient was randomized to have either cold blood cardioplegia (n = 20) or ventricular fibrillation with intermittent ischemia (n = 20) for myocardial management during the construction of distal anastomoses. Until recently, the comparison of different methods of myocardial management has been hindered by the lack of a specific and sensitive marker of myocardial damage. Analysis of creatine kinase MB isoforms (MB2, cardiac tissue form; MB1, plasma-modified form) and cardiac-specific troponin T (a structural protein) has been shown to improve the sensitivity for the detection of myocardial damage. There were no significant differences between the two groups in age, sex ratio, extent of disease, or left ventricular function. Blood samples for analysis were collected before cross-clamp application and at time intervals up to 48 hours after. Median peak creatine kinase MB2 activity was found to be significantly higher in the blood cardioplegia group compared with ventricular fibrillation (26.5 U/L versus 19.5 U/L, respectively, p = 0.04). Although median peak troponin T concentration was higher in the blood cardioplegia group, the difference failed to reach significance (2.2 ng/mL versus 1.6 ng/mL, p = 0.15).(ABSTRACT TRUNCATED AT 250 WORDS)

Myocardial Injury Induced by Radiofrequency and Low Energy Ablation: A Quantitative Study of CK Isoforms, CK‐MB, and Troponin‐T Concentrations

We conducted a prospective, controlled study to investigate the use of CK‐MB concentration and newer methods such as troponin‐T concentration and CK isoforms, in the assessment of myocardial damage caused by radiofrequency current or low energy DC catheter ablation. The study population consisted of 3 consecutive patients who underwent low energy catheter ablation, 28 consecutive patients subjected to radiofrequency ablation, and 4 patients wbo were subjected to radiofrequency energy ablation but also bad external DC shocks for cardioversion of atrial fibrillation that occurred during the procedure. The control group comprised eight subjects undergoing electrophysiological study. Prior to ablation and at 30 minutes, 1,2,6, and 12 hours following the procedure, serial blood samples were taken for measurement of troponin‐T and CK‐MB concentrations, and calculation of the MM3/MM1 and MB2/MB1 ratios.

Serum sialic acid concentration is not associated with the extent or severity of coronary artery disease in patients with stable angina pectoris

BACKGROUND Total serum sialic acid concentration has been reported to predict death from cardiovascular disease. This study was performed to assess the relation between serum sialic acid concentration and the angiographic extent and severity of coronary atheroma in patients with stable angina. METHODS Quantitative coronary angiography was performed in 40 patients with stable angina with either triple-vessel disease (23 patients) or normal/nearly normal coronary arteries (17 patients). A colorimetric assay for the enzymatic determination of serum sialic acid was used. RESULTS Serum sialic acid concentration was not significantly different in patients with normal or nearly normal coronary angiograms compared with those with triple-vessel disease (68+/-10 mg/100 mL and 68+/-11 mg/100 mL, respectively). Neither was there any association between the extent or severity of coronary disease and serum sialic acid levels. CONCLUSIONS Serum sialic acid concentration does not appear to be associated with the extent or severity of coronary artery disease in patients with stable angina pectoris. Thus the previously described association between serum sialic acid and cardiovascular death may reflect the role of mechanisms other than the severity of coronary artery narrowings.

Radioimmunoassays for Spirapril and Its Active Metabolite Spiraprilate: Performance and Application

Radioimmunoassays for a nonsulfhydryl angiotensin converting enzyme inhibitor prodrug–spirapril–and its active metabolite–spiraprilate–are described. Nonextraction equilibrium assays using antibodies with a high specificity for spirapril or spiraprilate were used, with charcoal separation of bound and free tracer. Within-assay reproducibility (CV%) was <20% in the concentration range 0.5–40 μg/L for both analytes and the comparable value for between-assay reproducibility was <25%. Results for external quality control samples were in good agreement with the expected values of 0–250 μg/L (spirapril, r = 0.997) and 0–300 μg/L (spiraprilate, r = 0.999). Overall, samples circulated to four laboratories gave good agreement for measured values, including one center using gas chromatography-mass spectrometry analysis for the two compounds. Data are presented to show the suitability of these two assays to the measurement of spirapril and spiraprilate in clinical samples from dose-ranging and bioequivalence studies. Results are also shown relating drug plasma concentration data to a measurement of the pharmacodynamic effects of spiraprilate, namely inhibition of angiotensin converting enzyme activity. It is concluded that these assays have the sensitivity for use in studies to model the relationship between the pharmacokinetics and pharmacodynamics of the two compounds.

Creatine kinase isoforms as circulating markers of deterioration in idiopathic dilated cardiomyopathy.

BACKGROUND A proportion of patients with dilated cardiomyopathy (DCM) may have ongoing myocardial damage secondary to viral or immune mediated myocardial inflammation. HYPOTHESIS The prognostic determinants identify patients with decreased survival but do not provide a measure of myocardial damage. To obtain an objective assessment of myocardial damage in DCM, we measured plasma levels of creatine kinase (CK), its isoenzymes (CK-MM and CK-MB), and separated the isoforms of CK-MM and CK-MB. METHODS The cohort consisted of 77 consecutive patients (61 men, 16 women) with DCM (World Health Organization criteria), aged 49 +/- 14 years (range 19-60). Patients had been symptomatic for 29 +/- 38 months (range 0.5-200 months) with 48 in New York Heart Association class I/II and 29 in class III/IV at the time of diagnosis. During median follow-up of 27 months from diagnosis (range 0.6-165), 50 patients remained clinically stable and 27 had deteriorated. RESULTS A significantly higher proportion of patients with DCM had abnormal MB2/MB1 ratio compared with normal volunteers (11, 14% vs. 1,1%, p = 0.003). Patients who deteriorated had higher MB2/MB1 ratio, (1.22 +/- 0.62 vs. 0.85 +/- 0.56; p = 0.01), and more frequently had abnormal MB2/ MB1 ratio (8, 30% vs. 3, 6%; p = 0.004) and CK and CK-MM activities (5, 19% vs. 2, 4%; p = 0.03) than those who remained stable. Patients with DCM with high CK-MB activity had 3.13-fold increased odds of sudden death or need for cardiac transplantation (95% confidence interval 1.53-6.40, p = 0.008). Thus, CK measurements, in particular CK-MB isoforms, are markers of myocardial damage in a subset of patients with DCM and could be useful in investigating the possibility of persistent myocardial damage in these patients.

Urinary Protein Excretion and the Diagnosis of Graft Rejection or Renal Dysfunction in Renal Transplant Patients

Urinary proteins have been found to be a sensitive marker of renal damage caused by nephrotoxic agents. An electrophoretic method was used to investigate the potential value of the pattern of urinary protein excretion in 14 cyclosporin-treated renal transplant patients, to differentiate between graft rejection episodes and other causes of renal dysfunction. Urinary protein excretion consistent with renal damage was observed in all of the patients studied, with no marked differences between those with signs of graft rejection, those with renal dysfunction, or those with stable renal function.