Roberto Ceriani

N-acetylcysteine for prevention of acute renal failure in patients with chronic renal insufficiency undergoing cardiac surgery: a prospective, randomized, clinical trial.

Objective:To assess the preventive effect of the antioxidant N-acetylcysteine on postoperative acute renal failure in patients with renal insufficiency undergoing cardiac surgery. Design:Randomized, placebo-controlled, prospective study. Setting:University cardiology center. Patients:Two hundred fifty-four consecutive patients with chronic renal insufficiency (estimated creatinine clearance ≤60 mL/min) undergoing elective cardiac surgery. Interventions:Patients were randomized to receive N-acetylcysteine (n = 129) or placebo (n = 125). Patients of the N-acetylcysteine group received four boluses of intravenous N-acetylcysteine (1200 mg every 12 hrs, starting immediately before cardiac surgery). Measurements and Main Results:The incidence of postoperative acute renal failure (>25% increase in serum creatinine from baseline) and the in-hospital clinical course were evaluated. Acute renal failure occurred in 46% of patients and was associated with increased in-hospital mortality (7% vs. 0.7%; p = .024). It occurred in 52% of control patients and 40% of N-acetylcysteine-treated patients (p = .06). In-hospital mortality and need for renal replacement therapy were not affected by N-acetylcysteine, but a lower percentage of N-acetylcysteine-treated patients required mechanical ventilation prolonged for >48 hrs (3% vs. 18%; p < .001) and had an intensive care unit stay >4 days (13% vs. 33%; p < .001). Conclusions:Intravenous administration of N-acetylcysteine does not clearly prevent postoperative acute renal failure in patients with renal insufficiency undergoing cardiac surgery.

Myocardial lactate metabolism in relation to preoperative regional wall motion and to early functional recovery after coronary revascularization

OBJECTIVEnTo evaluate myocardial lactate metabolism as a marker of functional status after surgical coronary revascularization.nnnDESIGNnSingle-center, prospective, cohort study.nnnSETTINGnTertiary care teaching hospital.nnnPARTICIPANTSnFifty patients with stable angina, ejection fraction >0.40, undergoing coronary artery bypass surgery for multiple-vessel disease.nnnMEASUREMENTS AND MAIN RESULTSnBefore (T1) and 30 minutes (T2) after coronary artery bypass grafting, the authors simultaneously sampled blood from artery and coronary sinus to determine myocardial lactate dynamics and performed transesophageal echocardiography (TEE) to assess segmental wall motion. Wall motion score index (WMSI) was calculated with an online/offline comparison. At T2, WMSI improved from 1.40 +/- 0.31 to 1.17 +/- 0.23 (p = 0.0001). Preoperatively, 2 patterns of lactate balance were found: 39 patients were lactate extractors (17% +/- 10%) and 11 were lactate producers (-11% +/- 11%). At T2, lactate metabolism was shifted towards a pattern opposite to the baseline: delta lactate extraction was -8% +/- 16% in extractors at T1 versus 7% +/- 9% in producers at T1 (p = 0.003). Changes in WMSI were not correlated with changes in lactate utilization. No single preoperative variable predicted postoperative WMSI or its changes from baseline. Cardiopulmonary bypass (CPB) time was the only significant predictor of postoperative lactate extraction by multivariate regression (r = -0.46, p = 0.001): at T2, patients in the highest CPB time quartile showed frank lactate production (-6% +/- 13%) when compared with those in the lowest quartile (15% +/- 11%, p = 0.005). However, postoperative WMSI was similar in different CPB time groups.nnnCONCLUSIONSnMyocardial lactate metabolism pattern is not associated with functional status before and early after successful coronary revascularization. CPB time was the only significant predictor of postoperative lactate extraction. Measurement of lactate does not appear to be a valuable tool to assess the coupling of myocardial regional function and metabolism in the setting of coronary artery surgery and mild-to-moderate functional impairment.

Diagnostic pitfalls with the combination of a hypertrophic cardiomyopathy and aortic valvular stenosis

T HE DIFFERENTIAL diagnosis of primary or secondary hypertrophy may be complicated by the combination of aortic valve stenosis (AVS) and left ventricle (LV) myocardial thickening. This association has important surgical implications, because the presence of combined AVS and a primary hypertrophic cardiomyopathy (HCM) make aortic valve replacement together with a myomectomy mandatory. This report describes a case of a severe aortic valve stenosis that masked the obstructive character of LV hypertrophy due to a HCM.

Acute Kidney Injury in Diabetic Patients With Acute Myocardial Infarction: Role of Acute and Chronic Glycemia

Background In acute myocardial infarction, acute hyperglycemia is a predictor of acute kidney injury (AKI), particularly in patients without diabetes mellitus. This emphasizes the importance of an acute glycemic rise rather than glycemia level at admission. We investigated whether, in diabetic patients with acute myocardial infarction, the combined evaluation of acute and chronic glycemic levels may have better prognostic value for AKI than admission glycemia. Methods and Results At admission, we prospectively measured glycemia and estimated average chronic glucose levels (mg/dL) using glycosylated hemoglobin (HbA1c), according to the following formula: 28.7×HbA1c (%)−46.7. We evaluated the association with AKI of the acute/chronic glycemic ratio and of the difference between acute and chronic glycemia (ΔA−C). We enrolled 474 diabetic patients with acute myocardial infarction. Of them, 77 (16%) experienced AKI. The incidence of AKI increased in parallel with the acute/chronic glycemic ratio (12%, 14%, 22%; P=0.02 for trend) and ΔA−C (13%, 13%, 23%; P=0.01) but not with admission glycemic tertiles (P=0.22). At receiver operating characteristic analysis, the acute/chronic glycemic ratio (area under the curve: 0.62 [95% confidence interval, 0.55–0.69]; P=0.001) and ΔA−C (area under the curve: 0.62 [95% confidence interval, 0.54–0.69]; P=0.002) accurately predicted AKI, without difference in the area under the curve between them (P=0.53). At reclassification analysis, the addition of the acute/chronic glycemic ratio and ΔA−C to acute glycemia allowed proper AKI risk prediction in 16% of patients. Conclusions In diabetic patients with acute myocardial infarction, AKI is better predicted by the combined evaluation of acute and chronic glycemic values than by assessment of admission glycemia alone.