Surgical revascularization and perioperative management in patients with non-ST-elevation acute coronary syndromes

PURPOSE

The management and surgical revascularization treatment of patients with acute coronary syndromes (ACS) have undergone great evolution over the past decade. The objective of the present study was therefore to analyze the outcome and predictors of survival in patients unresponsive to maximal non-surgical treatment referred to emergency coronary artery bypass grafting (CABG) with ACS.

MATERIAL AND METHODS

Between October 1999 and September 2004, a total of 3571 CABG patients underwent primary isolated CABG at our institution. Out of these, non-ACS (N-ACS) was present in 3124 patients (group 1), 386 patients (group 2) had non-ST-elevation ACS (NSTE-ACS), whereas 61 patients (group 3) had ST-elevation ACS (STE-ACS). Clinical data, in-hospital morbidity and mortality were prospectively recorded and studied retrospectively in the groups.

RESULTS

Left main stem stenosis was observed in 25%, 32%, and 41%, respectively (P<0.02). Previous myocardial infarction was found in 33%, 43%, and 73% (P<0.001). Overall in-hospital mortality was 1.5% in group 1, 4.2% in group 2, and 13.0% in group 3 (P< 0.001). Logistic regression and receiver operating characteristic analyses identified cTnI as the strongest preoperative predictor significantly related to in-hospital mortality. A preoperative cTnI level above 1.5 ng/ml was the best single predictor for in-hospital mortality amongst patients with ACS.

CONCLUSIONS

The present study clearly demonstrates a significant difference of in-hospital morbidity and mortality between patients with ACS undergoing CABG. A more precise patient's risk stratification on admission and improvements in the perioperative management with adjunctive pharmacological therapies and the use of intraaortic balloon counter pulsation may improve patients' outcome.

Deleterious effects of oxygen during extracorporeal circulation for the microcirculation in vivo*1

OBJECTIVE

Clinical complications arising from extracorporeal circulation (ECC) have been linked to disturbances in the microcirculation. Hyperoxia, a mainstay of supportive treatment, is clinically used for a variety of pathological states. In previous in vivo animal experiments we found increased leukocyte/endothelial (L/E) cell interaction following ECC due to oxygen derived free radicals. This study was carried out to investigate the link between arterial pO2 during ECC and the potential damage to the microcirculation, supposedly caused by oxygen derived radicals.

METHODS

Intravital fluorescence microscopy was used on the dorsal skinfold chamber preparation in syrian golden hamsters. ECC was introduced via a micro-rollerpump (0.7 ml/min) and a 60 cm silicon tube (1 mm inner diameter) shunted between the carotid artery and the jugular vein after application of 300 IE Heparin/kg/bw. Experiments were performed in chronically instrumented, awake animals (age: 10-14 weeks, weight: 65-75 g). Control inspired room air, experimental group 1 inspired 100% oxygen, group 2 received 100% oxygen and 2000 IE of Heparin i.v. (n=7/group), that releases endothelial bound superoxide dismutase, a natural scavenger of oxygen derived free radicals in the hamster.

RESULTS

Normobaric inhalation of 100% oxygen increased arterial pO2 from 64+/-8.1 mmHg to 512+/-124 mmHg (P<0.05 vs. baseline). ECC under 100% oxygen reduced functional capillary density (FCD) to 70% of baseline values 8 h after ECC (P<0.05). Adherent leukocytes in postcapillary venules and arterioles increased significantly (P<0.05). 2000 IE Heparin prevented the reduction in FCD and decreased the number of adherent leukocytes.

CONCLUSIONS

Reduction in FCD, increased leukocyte adherence to the microvascular endothelium of postcapillary venules and arterioles under hyperoxia compared to ECC under room air conditions, demonstrates harmful effects of oxygen during ECC in vivo. A high dose of Heparin enhances functional capillary density, thus attenuating the microvascular dysfunction/damage in the period after ECC.

Nodular pulmonary vasculitis in a twelve-year-old boy

A 12-year-old boy presented with left shoulder pain during physical exercise and complained of uncommon sweating and fatigue. Diagnostic evaluation revealed a solitary pulmonary nodule in the left upper lobe. All laboratory values were within normal limits, except for an elevated level of antineutrophil cytoplasmic antibodies directed against myeloperoxidase (p-ANCA). Surgery was performed, and pathological examination showed a localized granulomatous vasculitis. Antineutrophil cytoplasmic antibodies directed against affinity purified proteinase 3 (p-ANCA) concentrations returned to baseline within 6 months, and the patient has done well during a follow-up period of 2 years. While nodular vasculitis is known to occur in Wegener's granulomatosis, to the best of our knowledge, this case represents the first c-ANCA negative primary pulmonary vasculitis in childhood.