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Biomedical subjects

Harold L Lazar

Publications and source records attributed to Harold L Lazar.

At least 19 recordsLinked to original sources
PubMed2006

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.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed2006

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.

Accidents, Traffic↗
PubMed2005

Role of angiotensin-converting enzyme inhibitors in the coronary artery bypass patient.

Angiotensin-converting enzyme inhibitors have been shown to prolong survival and decrease infarct size in patients after acute coronary syndromes. Now there is evidence to suggest that angiotensin-converting enzyme inhibition is beneficial in coronary artery bypass patients. This review will summarize the beneficial effects of angiotensin-converting enzyme inhibition in patients with ischemic heart disease and provide evidence to show that the routine use of angiotensin-converting enzyme inhibition in coronary artery bypass patients can improve clinical outcomes.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2005

The use of angiotensin-converting enzyme inhibitors in patients undergoing coronary artery bypass graft surgery.

Angiotensin-converting enzyme inhibitors have been shown to prolong survival, decrease infarct size, and improve ventricular function in patients who have congestive heart failure, and in those who have sustained a myocardial infarction. This review will summarize the evidence to show that angiotensin-converting enzyme inhibitors can also benefit patients undergoing coronary artery bypass graft surgery by minimizing perioperative ischemia, and reducing long-term cardiovascular events.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2004

Soluble human complement receptor 1 limits ischemic damage in cardiac surgery patients at high risk requiring cardiopulmonary bypass.

BACKGROUND: This study was undertaken to determine whether soluble human complement receptor type 1 (TP10), a potent inhibitor of complement activation, would reduce morbidity and mortality in high-risk patients undergoing cardiac surgery on cardiopulmonary bypass (CPB). METHODS: This was a randomized multicenter, prospective, placebo-controlled, double-blind study in which 564 high-risk patients undergoing cardiac surgery on CPB received an intravenous bolus of TP10 (1, 3, 5, 10 mg/kg) or placebo immediately before CPB. The primary endpoint was the composite events of death, myocardial infarction (MI), prolonged (> or =24 hours) intra-aortic balloon pump support (IABP), and prolonged intubation. RESULTS: TP10 significantly inhibited complement activity after 10 to 15 minutes of CPB and this inhibition persisted for 3 days postoperatively. However, there was no difference in the primary endpoint between the 2 groups (33.7% placebo versus 31.4% TP10; P=0.31). The primary composite endpoint was, however, reduced in all male TP10 patients by 30% (P=0.025). TP10 reduced the incidence of death or MI in males by 36% (P=0.026), the incidence of death or MI in CABG males by 43% (P=0.043) and the need for prolonged IABP support in male CABG and valve patients by 100% (P=0.019). There was, however, no improvement seen in female TP10 patients. There were no significant differences in adverse events between the groups. CONCLUSIONS: TP10 effectively inhibits complement activation during CPB; however, this was not associated with an improvement in the primary endpoint of the study. Nevertheless, TP10 did significantly decrease the incidence of mortality and MI in male patients.

Aged↗
PubMed2004

Tight glycemic control in diabetic coronary artery bypass graft patients improves perioperative outcomes and decreases recurrent ischemic events.

BACKGROUND: This study sought to determine whether tight glycemic control with a modified glucose-insulin-potassium (GIK) solution in diabetic coronary artery bypass graft (CABG) patients would improve perioperative outcomes. METHODS AND RESULTS: One hundred forty-one diabetic patients undergoing CABG were prospectively randomized to tight glycemic control (serum glucose, 125 to 200 mg/dL) with GIK or standard therapy (serum glucose <250 mg/dL) using intermittent subcutaneous insulin beginning before anesthesia and continuing for 12 hours after surgery. GIK patients had lower serum glucose levels (138+/-4 versus 260+/-6 mg/dL; P<0.0001), a lower incidence of atrial fibrillation (16.6% versus 42%; P=0.0017), and a shorter postoperative length of stay (6.5+/-0.1 versus 9.2+/-0.3 days; P=0.003). GIK patients also showed a survival advantage over the initial 2 years after surgery (P=0.04) and decreased episodes of recurrent ischemia (5% versus 19%; P=0.01) and developed fewer recurrent wound infections (1% versus 10%, P=0.03). CONCLUSIONS: Tight glycemic control with GIK in diabetic CABG patients improves perioperative outcomes, enhances survival, and decreases the incidence of ischemic events and wound complications.

Atrial Fibrillation↗
PubMed2004

Role of statin therapy in the coronary bypass patient.

Statins have been proven to prevent or delay ischemic events in patients at risk for atherosclerotic coronary disease. Increasing evidence suggests that statin therapy is also beneficial to patients undergoing coronary revascularization. In this review statin therapy will be shown to improve vein graft patency, minimize recurrent ischemic events, and decrease the need for repeat revascularization procedures in patients who have undergone coronary artery bypass grafting.

Acute Disease↗
PubMed2004

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.

Adult↗
PubMed2004

Cardiopulmonary bypass: it's not the size, it's how you use it! Review of a comprehensive blood-conservation strategy.

Several of the manufacturers of cardiopulmonary bypass equipment have recently introduced new miniature cardiopulmonary bypass systems. New advancements in cardiopulmonary bypass technology are almost always of interest to the perfusion community. However, the question arises, what advantages do these systems offer over our present technology? The manufacturers claim that these new systems will add to our perfusion armamentarium by offering us an opportunity to further reduce priming volume and the surface area to which the blood is exposed. Our group, in the Department of Cardiac Surgery at Boston Medical Center has been involved in the development of a comprehensive blood conservation strategy since 1994. Our published data clearly demonstrates improved clinical outcomes using coated circuit technology as part of a comprehensive blood conservation strategy. In an effort to clearly evaluate this new technology, in this article we review our current technique at Boston Medical Center.

Anticoagulants↗
PubMed2003

Pretreatment with statins enhances myocardial protection during coronary revascularization.

OBJECTIVE: This experimental study was undertaken to determine whether pretreatment with statins would enhance myocardial protection and minimize ischemic injury during revascularization of acutely ischemic myocardium. METHODS: In 20 pigs the second and third diagonal arteries were occluded for 90 minutes, followed by 45 minutes of blood cardioplegic arrest and 180 minutes of reperfusion. Ten pigs received atorvastatin (40 mg orally every day) for 21 days before surgical intervention; 10 others received no statins. Ischemic damage was assessed on the basis of the need for cardioversions for ventricular arrhythmias, regional wall-motion scores (4 = normal to -1 = dyskinesia) were determined by means of 2-dimensional echocardiography, endothelial function was assessed on the basis of bradykinin-induced coronary artery relaxation, and infarct size was calculated by determining the area of necrosis to the area of risk by means of histochemical staining. Results are given as means +/- SE. RESULTS: Statin-treated animals required fewer cardioversions (0.11 +/- 0.01 vs 2.87 +/- 0.20, P =.0001), had improved wall-motion scores (2.81 +/- 0.10 vs 1.52 +/- 0.08, P =.01), had lower infarct size (21% +/- 2% vs 41% +/- 2%, P =.0001), and had more complete coronary artery relaxation (34% +/- 5% vs 8% +/- 4%, P =.01). Total serum cholesterol levels were similar between the groups (62 +/- 5 mg/dL for statin-treated animals vs 68 +/- 5 mg/dL for non-statin-treated animals, P =.30). CONCLUSIONS: Pretreatment with statins enhances myocardial protection during revascularization by means of mechanisms that are independent of their cholesterol-lowering properties.

Animals↗
PubMed2003

U-clip anastomoses in coronary artery bypass grafting: initial clinical experience.

BACKGROUND: Recent studies suggest that the U-Clip interrupted coronary artery anastomosis is superior to continuous suture. However, clinical experience with this device is limited. AIM: To evaluate our initial clinical experience with the U-Clip technology. METHODS: Outcomes of 59 patients undergoing isolated coronary artery bypass grafting (CABG) using U-Clips (UCs) were compared to outcomes of 138 patients undergoing CABG using conventional sutures (Conv). RESULTS: The average number of distal anastomoses was similar in the groups (UC, 2.9; Conv, 3.2; P = .33). Also similar were the number of arterial grafts (1.6 versus 1.5, P = .4), percentage of sequential anastomoses (22% versus 12%, P = .058), and percentage performed off pump (27% versus 28%, P = .74). Cardiopulmonary bypass and aortic crossclamp times were longer in the UC group (98 +/- 27 versus 81 +/- 20 minutes, P = .001; 63 +/- 25 versus 54 +/- 24 minutes, P = .028). Rates of operative mortality (UC, 1.69%; Conv, 0.7%), postoperative myocardial infarction (0% each), stroke (0% each), renal failure (2% versus 1.4%), and blood transfusion (53% versus 58%) were not statistically different. Average follow-up in 36 (61%) of UC patients was 5 +/- 2 months (range, 1-7 months). One patient died from a non-cardiacrelated cause. At the time of follow-up 90% of patients were in angina class I-II. CONCLUSIONS: The U-Clip interrupted anastomosis technique is versatile and safe and is associated with excellent short-term outcomes.

Aged↗
PubMed2002

Antioxidant improves smooth muscle sarco/endoplasmic reticulum Ca(2+)-ATPase function and lowers tyrosine nitration in hypercholesterolemia and improves nitric oxide-induced relaxation.

Antioxidants improve endothelial function in hypercholesterolemia (HC); however, whether this includes improvement of the vascular smooth muscle response to NO is unknown. NO relaxes arteries, in part, by stimulating Ca(2+) uptake via sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA) in aortic smooth muscle, and HC impairs SERCA function and the response to NO. HC induces oxidative stress, which could impair SERCA function. To study the effect of antioxidants, which are known to improve endothelium-dependent relaxation in HC, smooth muscle SERCA activity and NO-induced relaxation were studied in rabbits fed normal chow or a 0.5% cholesterol diet for 13 weeks. The antioxidant t-butylhydroxytoluene (BHT, 1%) was mixed with the HC diet in the last 3 weeks. HC impaired acetylcholine- and NO-induced relaxation, and these were restored by BHT. After inhibiting SERCA with thapsigargin, no difference existed in NO-induced relaxation among the three groups. Reduced aortic SERCA activity in HC was restored by BHT without changing SERCA protein expression. 3-Nitrotyrosine was notably increased in the media of the HC aorta, where it colocalized with SERCA. Tyrosine-nitrated SERCA protein was immunoprecipitated in the aortas of HC rabbits, where it was decreased by BHT, and it was also detected in the aortas of atherosclerotic humans. Thus, the antioxidant reverses impaired smooth muscle SERCA function in HC, and this is correlated with the improved relaxation to NO. These beneficial effects may depend on reducing the direct effects on SERCA of reactive oxygen species that are augmented in HC.

Animals↗
PubMed2002

Pretreatment with angiotensin-converting enzyme inhibitors attenuates ischemia-reperfusion injury.

BACKGROUND: The Heart Outcomes Prevention Evaluation (HOPE) trial demonstrated that ischemic events are decreased in patients receiving angiotensin-converting enzyme (ACE) inhibitors. This study sought to determine whether pretreatment with ACE inhibitors would attentuate ischemic injury during surgical revascularization of ischemic myocardium. METHODS: In a porcine model, the second and third diagonal vessels were occluded for 90 minutes, followed by 45 minutes of cardioplegic arrest, and 180 minutes of reperfusion. Ten pigs received quinapril (20 mg p.o. q.d.) for 7 days prior to surgery; 10 others received no-ACE inhibitors. RESULTS: Quinapril-treated animals required less cardioversions for ventricular arrhythmias (1.58 +/- 0.40 vs 2.77 +/- 0.22; p < 0.05), had higher wall motion scores assessed by two-dimensional echocardiography (4 = normal to -1 = dyskinesia; 2.11 +/- 0.10 vs 1.50 +/- 0.07; p < 0.05), more complete coronary artery endothelial relaxation to bradykinin (45% +/- 3% vs 7% +/- 4%; p < 0.005), and lower infarct size (24.0% +/- 3.0% vs 40.0% +/- 1.7%; p < 0.0001). CONCLUSIONS: ACE inhibition prior to coronary revascularization enhances myocardial protection by decreasing ventricular irritability, improving regional wall motion, lowering infarct size, and preserving endothelial function.

Angiotensin-Converting Enzyme Inhibitors↗