Comparison of N-acetylcysteine and fenoldopam for preventing contrast-induced nephropathy (CAFCIN).

BACKGROUND: N-acetylcysteine and fenoldopam are commonly prescribed for prevention of contrast mediated nephropathy, however, comparative superiority of either agent is unknown. METHODS: In a prospective, randomized, parallel-group trial, adult cardiac catheterization patients at the university and veterans' hospitals with pre-existing stable renal insufficiency were randomized to N-acetylcysteine 600 mg orally twice daily for 4 doses or fenoldopam 0.1 mcg/kg/min intravenously for a minimum of 8 h. All patients received intravenous hydration with normal saline (5% dextrose in normal saline for diabetics on insulin). Randomization was stratified for diabetes. The primary endpoint was mean change in Scr at 72 h. Secondary endpoint was the incidence of contrast-induced nephropathy (25% increase above baseline Scr or absolute increase of 0.5 mg/dL). RESULTS: Study termination occurred after ninety-five patients (mean age 68+/-10 years, female 25%, diabetic 42%, mean baseline Scr 1.5+/-0.4 mg/dL) were randomized, with 84 completing follow-up (44 N-acetylcysteine, 40 fenoldopam). Overall, there were no significant differences in mean change in Scr at 72 h (N-acetylcysteine 0.20+/-0.72 vs. fenoldopam 0.08+/-0.48 mg/dL, p=0.4) or incidence of contrast-induced nephropathy (N-acetylcysteine 5 vs fenoldopam 8, p=0.4). No differences were detected in subgroup analyses for diabetes, baseline Scr >1.7 or 2.0 mg/dL, gender, age >70 years, or contrast volume >150 mL. Results were similar after multivariate adjustment for diabetes, contrast volume, heart failure and gender. CONCLUSIONS: Our randomized comparison failed to demonstrate a significant difference in the abilities of N-acetylcysteine and fenoldopam to prevent the decline in renal function or the incidence of contrast-induced nephropathy during cardiac catheterization.

Effects of subclinical hypothyroidism and its treatment on serum lipids.

OBJECTIVE: To determine whether the literature supports an effect of subclinical hypothyroidism on serum lipids and, if so, what are the effects of thyroxine replacement therapy. DATA SOURCES: Articles were identified on MEDLINE using the MeSH terms hypothyroidism, lipids, or cholesterol. DATA SYNTHESIS: The majority of studies that determined the prevalence of lipid abnormalities in subclinical hypothyroidism and studies that evaluated the effects of thyroxine replacement on lipids were small, uncontrolled, and varied in inclusion criteria. Six randomized, placebo-controlled trials were identified that evaluated the effect of levothyroxine on lipids in subclinically hypothyroid patients. CONCLUSIONS: Subclinical hypothyroidism can potentially contribute to a pro-atherogenic lipid profile, with effects being greater at higher thyroid-stimulating hormone levels. Thyroxine replacement reduces total cholesterol and low-density lipoprotein cholesterol, with no effect on triglycerides. Effects on high-density lipoprotein, lipoprotein (a), and apolipoproteins A1 and B require further study. Larger prospective studies are needed to clarify many issues.