Off-pump coronary artery bypass grafting provides complete revascularization with reduced myocardial injury, transfusion requirements, and length of stay: a prospective randomized comparison of two hundred unselected patients undergoing off-pump versus conventional coronary artery bypass grafting.

OBJECTIVE: Retrospective comparisons of selected patients undergoing off-pump versus conventional on-pump coronary artery bypass grafting have yielded inconsistent results and raised concerns about completeness of revascularization in off-pump coronary artery bypass grafting. METHODS: Two hundred unselected patients referred for elective primary coronary artery bypass grafting were randomly assigned to undergo off-pump coronary artery bypass grafting with an Octopus tissue stabilizer (Medtronic, Inc, Minneapolis, Minn) or conventional coronary artery bypass grafting with cardiopulmonary bypass by a single surgeon. Revascularization intent determined before random assignment was compared with the revascularization performed. All management followed strict, unbiased, criteria-driven protocols. Patients and nonoperative care providers were blinded to surgical group. RESULTS: Baseline characteristics were similar. The number of grafts performed per patient (mean +/- SD 3.39 +/- 1.04 for off-pump coronary artery bypass grafting, 3.40 +/- 1.08 for conventional coronary artery bypass grafting) and the index of completeness of revascularization (number of grafts performed/number of grafts intended, 1.00 +/- 0.18 for off-pump coronary artery bypass grafting, 1.01 +/- 0.09 for conventional coronary artery bypass grafting) were similar. Likewise, the index of completeness of revascularization was similar between groups for the lateral wall. Combined hospital and 30-day mortalities and stroke rates were similar. Postoperative myocardial serum enzyme measures were significantly lower after off-pump coronary artery bypass grafting, suggesting less myocardial injury. Adjusted postoperative thromboelastogram indices, fibrinogen, international normalized ratio, and platelet levels all showed significantly less coagulopathy after off-pump coronary artery bypass grafting. Patients undergoing off-pump coronary artery bypass grafting received fewer units of blood, were more likely to avoid transfusion altogether, and had a higher hematocrit at discharge. Cardiopulmonary bypass was an independent predictor of transfusion (odds ratio 2.42, P =.0073) by multivariate analysis. More patients undergoing off-pump coronary artery bypass grafting were extubated in the operating room and within 4 hours. Postoperative length of stay (in days) was shorter for off-pump coronary artery bypass grafting (5.1 +/- 6.5 for off-pump coronary artery bypass grafting, 6.1 +/- 8.2 for conventional coronary artery bypass grafting, P =.005 by Wilcoxon test). One patient (in the conventional coronary artery bypass grafting group) required angioplasty for graft closure within 30 days. CONCLUSIONS: When compared with conventional coronary artery bypass grafting with cardiopulmonary bypass, off-pump coronary artery bypass grafting achieved similar completeness of revascularization, similar in-hospital and 30-day outcomes, shorter length of stay, reduced transfusion requirement, and less myocardial injury.

Episodic corticosterone secretion in the female rat.

Studies conducted in several laboratories have shown primate glucocorticoid secretion to occur episodically. In light of the methodological, as well as physiological importance of this finding, the present study was undertaken to determine whether the rat corticosteroid secretion also occurs episodically. Female rats were outfitted with chronic intravenous cannulas, and 1 week later 200 units of heparin were injected through the implanted cannula and blood samples (0.3-0.4 ml) were collected from each rat every 10 min for 3 h during the morning (06.00-10.00 h) or during the afternoon (16.00-19.00 h) (lights on from 05.00 to 19.00 h). Plasma corticosterone levels in cannulated rats showed fluctuations indicative of episodic secretion. The pattern of plasma corticosterone levels was characterized by periodic rapid increases in hormone concentration during both the morning and afternoon sampling periods; the occurrence of these hormonal fluctuations did not have a characteristic frequency. When the data were grouped to obtain single morning and afternoon values, the AM-PM difference was significant (p < 0.005). Collectively, these data suggest that in the rat, adrenal corticosteroids are secreted episodically.