Metabolism of hibernating myocardium assessed by microdialysis during surgical revascularization: report of a case.

We present an 80-year-old woman with hibernating myocardium in the left anterior descending coronary artery (LAD) territory who underwent surgical revascularization and metabolic evaluation of the dysfunctioning segments by microdialysis (microD) technique. Myocardial lactate, pyruvate, and glucose did not show obvious changes throughout the procedure. Conversely, myocardial glycerol and glutamate concentrations markedly increased early after cardioplegic arrest and subsided after weaning from cardiopulmonary bypass (CPB) and recovery of myocardial function. Intraoperative myocardial microD may add relevant pathophysiologic information on hibernating myocardium undergoing coronary flow restoration and, eventually, improve patient care.

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 < or = 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.

Long-term outcome of survivors of prolonged intensive care treatment after cardiac surgery.

BACKGROUND: The relative impact of perioperative risk profile and postoperative complications on long-term outcome in cardiac surgical patients is currently unclear. The aim of this work was to assess the relative predictive value of the European System for Cardiac Operative Risk Evaluation (EuroSCORE) and Sequential Organ Failure Assessment (SOFA) on long-term event-free survival in this patient population. METHODS: Preoperative and postoperative variables, EuroSCORE and SOFA, 30-day mortality, and long-term mortality or hospital admission for cardiovascular events were assessed in 115 consecutive cardiac surgical patients in whom multiorgan dysfunction syndrome developed postoperatively. RESULTS: Mean age was 70 +/- 8 years, 41% were women, EuroSCORE averaged 7.87 +/- 3.99, and postoperative stay in the intensive care unit was 10.3 +/- 8.2 days. In-hospital 30-day mortality was 10.4% (n = 12). During 1998 person-months follow-up, 12 (11.6%) of 103 patients discharged alive died, and 46 (44.7%) met the combined end point of all-cause death or cardiovascular admission. By Cox multivariate analysis, maximum SOFA (hazard ratio [HR], 2.17; 95% confidence interval [CI], 1.34 to 3.51) and maximum cardiovascular score (HR, 2.35; 95% CI, 1.22 to 4.51) independently predicted all-cause mortality. EuroSCORE (HR, 1.33; 95% CI, 1.01 to 1.76), maximum cardiovascular score (HR 2.09; 95% CI 1.41 to 3.10), and maximum liver score (HR 2.67; 95% CI, 1.46 to 4.86) were independently associated with the combined end point. CONCLUSIONS: High-risk cardiac surgical patients with postoperative multiorgan dysfunction syndrome show excess mortality and cardiovascular morbidity after hospital discharge. Combined preoperative and postoperative risk stratification identifies patients with the highest likelihood of death or early readmission.

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

OBJECTIVE: To evaluate myocardial lactate metabolism as a marker of functional status after surgical coronary revascularization. DESIGN: Single-center, prospective, cohort study. SETTING: Tertiary care teaching hospital. PARTICIPANTS: Fifty patients with stable angina, ejection fraction >0.40, undergoing coronary artery bypass surgery for multiple-vessel disease. MEASUREMENTS AND MAIN RESULTS: Before (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. CONCLUSIONS: Myocardial 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.