ABSTRACT
The objective of this study was to compare the outcomes of angina, myocardial infarction (MI), cardiac death, and all-cause death following percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG). The study design was based on retrospective, nonrandomized analysis and was set in referral teaching hospitals and community hospitals. Eighty-four chronic dialysis patients with symptomatic coronary artery disease without prior revascularization were included in the study. Twenty-four patients underwent PTCA of one or more vessels, and 60 patients underwent CABG. Recurrence of angina, MI, cardiac death, and all-cause death following revascularization as well as the number of inpatient days preprocedure and postprocedure were recorded. The two patient groups were comparable in terms of age, sex, history of MI, left ventricular mass and function, and angina severity. Diabetes mellitus was more prevalent in the PTCA group. The CABG group had more severe coronary artery disease. The 2-year survival rate of the CABG patients (66%; 95% confidence interval = 53.79) did not differ from that of the PTCA patients (51%; 95% confidence interval = 27.65). Thirteen PTCA patients were restudied 106 +/- 108 days after recurrence of angina; nine (69%) of these patients were found to have angiographic restenosis. The postprocedure risk of angina and the combined endpoints of angina, MI, and cardiovascular death were significantly greater following PTCA than CABG. Percutaneous transluminal coronary angioplasty was the only consistent predictor of outcomes; the adjusted relative risks (compared with CABG) of postprocedure angina and combined endpoints were 16.4 and 10.2, respectively, and were several-fold higher than the unadjusted risks. We conclude that in chronic dialysis patients with symptomatic coronary disease, patients undergoing PTCA have a higher risk of subsequent angina and combined angina, MI, and cardiovascular death than those undergoing CABG. The optimal approach to coronary revascularization in this patient population remains to be determined.
Subject(s)
Angioplasty, Balloon, Coronary , Coronary Artery Bypass , Coronary Disease/therapy , Kidney Failure, Chronic/complications , Renal Replacement Therapy , Adult , Aged , Aged, 80 and over , Angina Pectoris/epidemiology , Angioplasty, Balloon, Coronary/adverse effects , Angioplasty, Balloon, Coronary/mortality , Cause of Death , Chi-Square Distribution , Cohort Studies , Coronary Artery Bypass/adverse effects , Coronary Artery Bypass/mortality , Coronary Disease/complications , Coronary Disease/mortality , Female , Follow-Up Studies , Humans , Incidence , Kidney Failure, Chronic/therapy , Life Tables , Male , Middle Aged , Myocardial Infarction/epidemiology , Prognosis , Proportional Hazards Models , Recurrence , Retrospective Studies , Risk , Survival AnalysisABSTRACT
The reduction potential of Fe3+ in transferrin was measured spectrophotometrically by equilibration with methyl viologen in the presence of sodium dithionite. For an ionic strength near 0.1 M at 25 degrees C and pH 7.3 under 0.048 atm. CO2, half of the iron is reduced at a potential near -0.40 V (vs. standard hydrogen electrode). At least one disulfide bond of the protein is partially reduced at a potential of -0.44 V, as evidenced by reaction with [14C]iodoacetate.
Subject(s)
Ferric Compounds , Iron , Transferrin , Disulfides , Dithionite , Iodoacetates , Iodoacetic Acid , Oxidation-Reduction , Paraquat , Solutions , SpectrophotometryABSTRACT
Fe2+ is oxidized and taken up by ferritin or ápoferritin in the presence of dioxygen. Iodate causes Fe2+ oxidation and uptake by ferritin, but not by apoferritin. Synthetic iron polymer facilitates Fe2+ oxidation by either dioxygen or iodate. Nitrilotriacetic acid or iminodiacetic acid facilitate oxidation of Fe2+ by oxygen but not by iodate. These results support the crystal growth model of ferritin iron uptake, with iron polymer serving as a model for the ferritin core and aminocarboxylic acids mimicking the metal-binding sites of apoferritin.
