A meta-analysis of N-acetylcysteine in contrast-induced nephrotoxicity: unsupervised clustering to resolve heterogeneity

<p>Abstract</p> <p>Background</p> <p>Meta-analyses of N-acetylcysteine (NAC) for preventing contrast-induced nephrotoxicity (CIN) have led to disparate conclusions. Here we examine and attempt to resolve the heterogeneity evident among these trials.</p> <p>Methods</p> <p>Two reviewers independently extracted and graded the data. Limiting studies to randomized, controlled trials with adequate outcome data yielded 22 reports with 2746 patients.</p> <p>Results</p> <p>Significant heterogeneity was detected among these trials (<it>I</it>²= 37%; <it>p </it>= 0.04). Meta-regression analysis failed to identify significant sources of heterogeneity. A modified L'Abbé plot that substituted groupwise changes in serum creatinine for nephrotoxicity rates, followed by model-based, unsupervised clustering resolved trials into two distinct, significantly different (<it>p </it>< 0.0001) and homogeneous populations (<it>I</it>²= 0 and <it>p </it>> 0.5, for both). Cluster 1 studies (<it>n </it>= 18; 2445 patients) showed no benefit (relative risk (RR) = 0.87; 95% confidence interval (CI) 0.68–1.12, <it>p </it>= 0.28), while cluster 2 studies (<it>n </it>= 4; 301 patients) indicated that NAC was highly beneficial (RR = 0.15; 95% CI 0.07–0.33, <it>p </it>< 0.0001). Benefit in cluster 2 was unexpectedly associated with NAC-induced decreases in creatinine from baseline (<it>p </it>= 0.07). Cluster 2 studies were relatively early, small and of lower quality compared with cluster 1 studies (<it>p </it>= 0.01 for the three factors combined). Dialysis use across all studies (five control, eight treatment; <it>p </it>= 0.42) did not suggest that NAC is beneficial.</p> <p>Conclusion</p> <p>This meta-analysis does not support the efficacy of NAC to prevent CIN.</p

Prevention of acute kidney injury and protection of renal function in the intensive care unit

Acute renal failure on the intensive care unit is associated with significant mortality and morbidity. To determine recommendations for the prevention of acute kidney injury (AKI), focusing on the role of potential preventative maneuvers including volume expansion, diuretics, use of inotropes, vasopressors/vasodilators, hormonal interventions, nutrition, and extracorporeal techniques. A systematic search of the literature was performed for studies using these potential protective agents in adult patients at risk for acute renal failure/kidney injury between 1966 and 2009. The following clinical conditions were considered: major surgery, critical illness, sepsis, shock, and use of potentially nephrotoxic drugs and radiocontrast media. Where possible the following endpoints were extracted: creatinine clearance, glomerular filtration rate, increase in serum creatinine, urine output, and markers of tubular injury. Clinical endpoints included the need for renal replacement therapy, length of stay, and mortality. Studies are graded according to the international Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) group system Several measures are recommended, though none carries grade 1A. We recommend prompt resuscitation of the circulation with special attention to providing adequate hydration whilst avoiding high-molecular-weight hydroxy-ethyl starch (HES) preparations, maintaining adequate blood pressure using vasopressors in vasodilatory shock. We suggest using vasopressors in vasodilatory hypotension, specific vasodilators under strict hemodynamic control, sodium bicarbonate for emergency procedures administering contrast media, and periprocedural hemofiltration in severe chronic renal insufficiency undergoing coronary intervention

Triglycerides and risk factors for heart disease: their relationship with coronary artery saphenous vein bypass graft occlusion

Background/significance: Coronary artery disease prevention is achieved by controlling risk factors for atherosclerosis. Purpose: Our objective was to test the impact of these risk factors on saphenous vein graft (SVG) occlusion in patients post coronary artery bypass graft (CABG) surgery. Methods: We retrospectively studied 1,000 consecutive patients (mean age 66 years, 66% men) who underwent CABG surgery from January 2000 to August 2004 for the presence of SVG occlusion on coronary angiogram. Risk factors including smoking history, dyslipidemia, obesity, hypertension and diabetes mellitus were recorded. Follow-up data were available through October 2011. Wilcoxon rank-sum and chi-square tests were used to analyze data. Results: Univariate analysis showed statistical difference in SVG occlusion for triglycerides \u3e150 mg/dL, total cholesterol \u3e200 mg/ dL, and high-density lipoprotein (HDL) \u3c40 mg/dL (men) or \u3c50 mg/dL (women). Logistic regression used for multivariate analysis showed SVG occlusion was strongly associated with triglycerides (odds ratio [OR] 2.2, 95% confidence interval [CI], 1.6-3.0, p\u3c0.0001), and HDL (OR 2.3, CI, 1.7-3.1, p\u3c0.0001). Strict control of triglycerides \u3c70 mg/dL resulted in less SVG occlusion. Conclusion: Uncontrolled triglycerides and high-density lipoprotein levels are the driving variables behind saphenous vein graft occlusion in patients who have undergone surgical myocardial revascularization. Maintaining triglycerides level \u3c70 mg/dL helps to prevent occlusion

Coronary-bronchial fistula: Coil the steal

Coronary artery fistula is a rare coronary anomaly with communication between the coronary artery and either the cardiac chamber or other vessels. We present a case of coronary-to-bronchial artery fistula that resulted in likely coronary artery steal and was treated with coil embolization. ()