Beneficial effects of complement inhibition with soluble complement receptor 1 (TP10) during cardiac surgery: is there a gender difference?

BACKGROUND: TP10, a potent inhibitor of complement activation during cardiopulmonary bypass (CPB) has been shown to significantly reduce the incidence of death and myocardial infarction (MI) in high-risk male patients undergoing cardiac surgery. However, the effect of TP10 in females was undefined because of the limited number of females studied. To examine the possibility of a gender effect, this phase 2 multi-center trial was undertaken to determine whether TP10 would also limit ischemic damage in a larger sample size of high-risk females undergoing cardiac surgery on cardiopulmonary bypass (CPB). METHODS AND RESULTS: This prospective, double-blind, placebo-controlled, multi-center trial involved 297 high-risk (urgent surgery, CABG + Valve, reoperations, ejection fraction <30%) female patients randomized to receive a 5 mg/kg dose of TP10 (n=150) or placebo (n=147) as a 30-minute intravenous infusion before surgery. The primary end point was the incidence of death or MI at 28 days after surgery. Complement activation was assessed by levels of CH50 and SC5b-9 during and after CPB. TP10 was well tolerated and there were no differences in the safety profiles of the 2 groups. Although TP10 effectively suppressed complement activation (at 2 hours after CPB CH50 (mean+SD % change from baseline) 50+/-17% placebo versus 4+/-14% TP10; P=0.0001; SC5b-9 (ng/mL) 917+/-1067 placebo versus 204+/-79 TP10; P=0.0001), there was no difference in the primary end point between the groups (17% placebo versus 21% TP10; P=0.2550). CONCLUSIONS: The benefits of TP10 appear to be gender-related. and mechanisms other than complement activation may be responsible for myocardial injury in high-risk female patients during cardiac surgery on CPB.

Endoscopic versus conventional radial artery harvest--is smaller better?

BACKGROUND: We sought to assess our initial experience with the recently introduced technique of endoscopic radial artery harvest (ERH) for coronary artery bypass grafting (CABG). METHODS: Data were prospectively collected on 108 consecutive patients undergoing isolated CABG with ERH, and compared to 120 patients having conventional harvest (CH). Follow-up was achieved in 227 patients (99%). At the time of follow-up the severity of motor and sensory symptoms, as well as cosmetic result in the harvest forearm, were subjectively graded using a 5-point scale. Grade 1-- high intensity deficits, poor cosmetic result. Grade 5 -- no deficits, excellent cosmetic result. RESULTS: Hospital mortality, myocardial infarction, and stroke rates were similar between the groups. Follow-up mortality, reintervention rate, and average angina class were also similar. Harvest time was longer in the ERH group (61 +/- 24 min vs. 45 +/- 11 min, p < 0.001). Three patients in the ERH group were converted to CH and one radial artery was discarded. There were no vascular complications of the hand in either group. Average score of motor (ERH 4.4 +/- 0.9, CH 4.2 +/- 1.0) or sensory symptoms (ERH 3.7 +/- 1.1, CH 3.8 +/- 1.2) were similar. In the CH group sensory deficits were observed in the distribution of both the lateral antebrachial cutaneous and the superficial radial nerves (SRN). In contrast, sensory deficits in the ERH group were limited to the distribution of the SRN. Cosmetic result score was higher in the ERH group (ERH 4.2 +/- 1.0, CH 3.1 +/- 1.4, p < 0.0001). CONCLUSIONS: ERH is safe. It is technically demanding with a significant learning curve. Motor and sensory symptoms are not completely eliminated by using a smaller incision, but cosmetic results are clearly superior.

OPCAB for acute LAD dissection due to blunt chest trauma.

A 40-year-old male pedestrian was hit by a truck and was admitted with multiple injuries including blunt chest trauma. Electrocardiogram revealed acute anterior ST-segment elevation and myocardial infarction. Coronary angiography demonstrated acute ostial left anterior descending coronary artery dissection. Due to extent and location, the lesion was not amenable for angioplasty. Multiple associated injuries and severely impaired coagulation studies directed us to perform emergency off-pump coronary artery bypass grafting.

Coronary artery bypass grafting in patients with severe left ventricular dysfunction--early and mid-term outcomes.

BACKGROUND: The prevalence of patients with severe left ventricular dysfunction (LVD) referred for coronary artery bypass grafting (CABG) is increasing. The aim of the present study was to assess the outcomes of patients with severe LVD undergoing CABG. METHODS: Outcomes of 115 consecutive patients with severe LVD (left ventricular ejection fraction [LVEF]30% (HEF). To further evaluate the LVD patients, they were divided into three subgroups base on LVEF: 0% to 10%, 11% to 20%, and 21% to 30%. Data were collected prospectively and entered into the departmental database of the Society of Thoracic Surgeons. RESULTS: Patients in the LVD group had increased incidence of diabetes, chronic obstructive pulmonary disease (COPD), peripheral vascular disease, prior myocardial infarction (MI), congestive heart failure, and less elective procedures compared to the HEF group. Despite this greater risk profile, operative mortality (LVD 2.6% vs. HEF 1.2%, p = 0.19), the incidence of stroke (2.6% vs. 1.0%, p = 0.13), and perioperative MI (0.9% vs. 0.7%) were not statistically different between the groups. The incidence of respiratory (14.8% vs. 1.9%, p < 0.001), renal (5.2% vs. 1.0%, p < 0.001), and vascular (5.2% vs. 0.5%, p < 0.001) complications was significantly higher in the LVD group, resulting in a longer hospital length of stay (8 +/- 8 vs. 6 +/- 4 days, p < 0.0001). In a multivariate analysis, advanced age was as an independent predictor of hospital mortality. Average follow-up in 108 (94%) LVD patients was 36 +/- 22 months (range 2 to 78 months). Twenty-one patients expired during the follow-up, for nine the causes were cardiac-related. Three- and 5-year survival rates were 91 +/- 3% and 76 +/- 6%, respectively. Independent predictors of mid-term mortality in the LVD group by a multivariate analysis included female gender, renal failure, respiratory complications, and grade I/II mitral regurgitation (MR). At the time of follow-up, 72% of LVD patients were in functional class I/II. There were no statistically significant differences in short- and mid-term outcomes among the LVD subgroups. CONCLUSION: CABG in patients with severe LVD can be performed with a low mortality, albeit with higher morbidity and longer length of hospital stay, than patients with LVEF >30%. Low ejection fraction per se was not a predictor of hospital mortality. CABG should be considered a safe and effective therapy for low ejection fraction patients with ischemic heart disease. Mitral valve repair/replacement in the presence of moderate degree of MR should be considered at the time of the initial operation.

Endoscopic versus conventional radial artery harvest for coronary artery bypass grafting: functional and histologic assessment of the conduit.

BACKGROUND: The radial artery's propensity for vasospasm and vulnerability to surgical trauma are well known. A less invasive endoscopic method to harvest the radial artery was recently introduced, but its effect on radial artery integrity is unknown. METHODS: To compare the effects of harvest method on radial artery function, we prospectively randomized 54 patients undergoing coronary artery bypass grafting with the radial artery into 3 groups on the basis of harvest techniques: endoscopic, conventional with cautery, and conventional with harmonic scalpel. We assessed endothelium-dependent and endothelium-independent relaxation of radial artery segments to sequential doses of acetylcholine and nitroglycerin, respectively, using standard organ-chamber methodology. Vasospasm was assessed as the vasoconstrictor response to the thromboxane analog U46619. We assessed endothelial integrity using light and electron microscopy and by rating intercellular adhesion molecule 1, vascular cell adhesion molecule 1, and P-selectin expression by means of immunohistochemistry on a semiquantitative 0- to 3-point scale. Harvest procedures were performed by a single surgeon, and data analyses were blinded to the harvesting method. RESULTS: Maximal relaxation-contraction responses to acetylcholine, nitroglycerin, and U46619 and effective drug concentration yielding 50% response were similar in the 3 groups. Adhesion molecule expression and histologic changes, as assessed by means of light and electron microscopy, were similar in the 3 groups. CONCLUSIONS: Endoscopic harvest does not alter radial artery vasoreactivity or endothelial integrity compared with conventional harvest techniques. Because the endoscopic technique is less invasive, it might prove to be the technique of choice to harvest the radial artery.

Dual-beam ultrasound versus transit-time flow meter for intraoperative graft flow measurement during coronary artery bypass grafting.

OBJECTIVE: : Assessment of graft flow during coronary artery bypass grafting (CABG) is increasingly practiced as a quality measure, particularly in patients undergoing minimally invasive or "off-pump" revascularization. Transit-time flow meters such as Transonic system (TS) are currently the most frequently used technology. The QuantixOR flow probe (QOR) is a novel technology comprised of dual-beam ultrasound transducer and a digital pulse-wave Doppler, allowing immediate, quantitative blood flow measurements. Excellent correlation between QOR and TS was observed in phantom and animal models. This study evaluated the QOR in patients undergoing CABG. METHODS: : Graft flow was measured in 75 patients undergoing CABG (203 grafts). Intraobserver (n = 169) and interobserver (n = 33) variability was assessed and the QOR was compared with the TS (n = 155). RESULTS: : An average of 2 probe sizes per case and "skeletonization" of a short segment of the vessel were required to measure flow in arterial conduits using TS. In contrast, measurements of flow with the QOR were achieved using a single probe without special vessel preparation for all types of conduits. Average intraobserver and interobserver variability using the QOR were 5 ± 41% and 4 ± 40%, respectively. Correlation was observed between 2 sets of measurements by the same observer (R = 0.746, P < 0.0001) and between 2 different observers (R = 0.667, P < 0.0001). Correlation was also observed between the QOR and TS (R = 0.542, P < 0.0001) with a variance of 12 ± 21%. CONCLUSIONS: : The QOR technology provides a reliable quantitative graft flow assessment that is simpler to obtain compared with TS. Correlation between the QOR and TS is excellent.

Endoscopic radial artery harvest for coronary artery bypass grafting: initial clinical experience.

BACKGROUND: Recently, an endoscopic technique was developed to harvest the radial artery (RA) via a 3-cm wrist incision in patients undergoing coronary artery bypass graft (CABG). The aim of this study was to evaluate our initial clinical experience with this technology. METHODS: Data were prospectively collected on 75 consecutive patients undergoing CABG with endoscopic RA harvest using the Ultra-Retractor (CardioVations, Somerville, NJ, USA) and the harmonic scalpel (Ethicon Endo-Surgery, Cincinnati, OH, USA). RESULTS: There were 66 men (88%) and 9 women (12%) with a mean age of 60 years (range, 31-77 years). Forty-eight (64%) of cases had non-elective surgery. Thirty-one (41%) of patients had diabetes. Sixty seven percent of the operations were performed on pump and 33% off pump. Average RA harvest time was 66 minutes (range, 25-120 minutes) with a significant learning curve (75 minutes for the first 20 cases and 63 minutes for the last 50 cases). Two (2.6 %) radial arteries were discarded, one because of extensive calcifications and the other because of damage to the conduit. No patients suffered death, perioperative myocardial infarction, or stroke. There was one reexploration of the forearm for a tunnel hematoma. Follow-up was achieved in 100% of patients and averaged 3.6 months (range, 0.5-13 months). Two patients died during the follow-up. There were no myocardial infarctions or reinterventions, with 96% of patients in functional class I /II. There were no motor deficits. There were no sensory deficits in the distribution of the lateral antebrachial cutaneous nerve, but transient mild dorsal thenar numbness or paresthesias were observed in 86% of patients. Cosmetic results were defined as good to excellent in 82% of patients. CONCLUSIONS: Short-term results of endoscopic RA harvest are excellent. There is a significant learning curve. Longterm follow-up as well as structural and functional assessments of the conduit are indicated.