A comparison of ON-PUMP vs OFF-PUMP coronary artery bypass surgery among low, intermediate, and high-risk patients: the Hartford Hospital experience.

BACKGROUND: Off-pump coronary artery bypass (OP-CAB) graft surgery is being used with increasing frequency. This study was designed to compare OP-CAB outcomes with conventional surgical revascularization using cardiopulmonary bypass (CPB) in patients with varying risk categories at a high-volume center. METHODS AND RESULTS: Between 1/1/1999 and 1/31/2001, bypass surgery was performed on 1,312 patients, including 348 OP-CAB cases and 964 CPB cases. Compared to CPB cases, OP-CAB patients were more likely to be female and had a lower incidence of three vessel coronary artery disease, prior percutaneous intervention, and prior bypass surgery. Postoperatively, OP-CAB patients had a lower incidence of renal failure and prolonged ventilatory support, as well as a lower composite endpoint of inhospital mortality, perioperative myocardial infarction, cerebrovascular accident, and/or renal failure. In addition, OP-CAB patients required fewer transfusions and had a shorter total length of hospital stay. In general, morbidity and mortality increased in both OP-CAB and CPB groups with increasing Parsonnet score. CONCLUSIONS: OP-CAB surgery is a safe and effective alternative to conventional coronary artery bypass graft (CABG) surgery, with a lower incidence of major in-hospital adverse clinical events and a decreased requirement for medical resources. Adverse OP-CAB outcomes correlate well with pre-operative Parsonnet Score.

Synergy between intracoronary stenting and abciximab in improving angiographic and clinical outcomes of primary angioplasty in acute myocardial infarction.

This study examined 650 consecutive patients who presented with an acute myocardial infarction and were treated with primary angioplasty within 12 hours of symptom onset between August 1995 and December 1998. Patients were placed into 4 treatment groups depending on the adjunctive therapy they received: group 1, percutaneous transluminal coronary angioplasty (PTCA) ("balloon PTCA alone"; n = 220); group 2, PTCA plus intracoronary stent placement ("stent"; n = 128); group 3, PTCA plus abciximab therapy ("abciximab"; n = 104); and group 4, PTCA plus intracoronary stent placement plus abciximab therapy ("stent/abciximab"; n = 198). The patients' clinical characteristics, severity of disease, and total ischemia time on presentation were similar. At baseline, abciximab and stent/abciximab groups had a higher incidence of thrombus on coronary angiography. Postprocedural quantitative coronary analysis showed a significantly larger minimum luminal diameter in the stent and stent/abciximab groups than PTCA alone. Overall, stents were most efficacious in reducing target vessel revascularization rate, whereas abciximab was associated with a higher postprocedural Thrombolysis In Myocardial Infarction-3 trial flow and less "no reflow." The best angiographic result was achieved in the stent/abciximab group. Similarly, the primary combined end point of death, myocardial infarction, and target vessel revascularization at 30 days was the lowest (6.1%) in the stent/abciximab group. The combination of abciximab and stenting in primary angioplasty for acute myocardial infarction is thus synergistic and is associated with improved angiographic and clinical results at 30-day follow-up.

Influence of temperature on substrate and energy conversion in Pseudomonas fluorescens.

The influence of temperature on yield, maintenance rate, growth rate, and conversion of calories to biomass was studied with Pseudomonas fluorescens grown in a chemostat. Maintenance and growth rate are influenced linearly with temperature. Both rates increased with increasing temperature and gave linear Arrhenius plots over a limited range. Cells harvested during the steady-state at each temperature were burned in a microcalorimeter. The number of kilocalories per gram (dry weight) of organism was not influenced significantly by the temperature during growth, indicating that the conversion of substrate calories into biomass is apparently regulated in the range of temperature studied.