1. To understand the differential diagnosis of chest pain requiring cardiac surgical consultation. 2. To understand the physiology of and rationality for medical treatment of ischemic coronary artery disease. 3. To differentiate acute aortic dissection from myocardial infarction in the emergency setting. 4. To understand initial stabilization of the patient with aortic dissection. 5. To recognize the risk factors associated with openheart surgery.

Purpose: Our objective was to determine the association of pre-operative and post-operative coagulation testing abnormalities with the cause of post-operative bleeding requiring re-exploration following cardiac surgery. Methods: Retrospective chart review of post-operative bleeding and the incidence of re-exploration for hemorrhage in 2263 adult patients undergoing elective and emergency open heart surgery which included coronary artery bypass, valvular, and combined valve coronary procedures. Results: Eighty-two patients (3.6%) required re-exploration. Sixty-six percent had surgical bleeding; the remaining 34% were coagulopathic (no surgical site found). The pre-operative PT and ACT were significantly elevated in coagulopathic patients ( P<0.005). Post-operative ACT, PT, and APTT were increased and fibrinogen levels were decreased in coagulopathic patients ( P<0.05). Conclusions: Pre-operative testing (ACT, PT) weakly correlated with post-operative coagulopathy. Post-operative coagulation abnormalities were identified with high risk ratios and good diagnostic accuracy when using testing cut-off values to assist in surgical decision making.

Objective To examine systemic immune cell proinflammatory receptor expression and apoptosis in patients with congestive heart failure (CHF). Summary Background Data Prior studies have demonstrated that CHF is associated with a chronic myocardial inflammatory state, including increased plasma proinflammatory cytokine and soluble receptor expression. By contrast, it has also been shown that tumor necrosis factor (TNF) receptor protein expression is decreased in the failing myocardium. However, no studies to date have examined systemic immune cell proinflammatory receptor expression or function as disease markers in patients with heart failure. Methods Twenty-nine patients were studied prospectively over an 8-month period at a single institution. One group (n = 16) had a history of clinical symptoms of CHF and moderate to severe left ventricular dysfunction. The second group (n = 13) consisted of patients who had coronary artery disease without symptoms of CHF and documented preservation of left ventricular function. Blood samples were analyzed for polymorphonuclear cell (PMN) and monocyte TNF and CD95 membrane-associated receptor expression, spontaneous and CD95 (Fas)-mediated PMN apoptosis, and plasma cytokine and soluble TNF receptor levels. Isolated PMNs were incubated for 6 hours with or without CH 11, a CD95 agonist. Propidium iodide/RNAase staining and flow cytometry was used to assess apoptosis, defined as PMNs expressing hypodiploid DNA (<2 n DNA). Membrane-associated TNF receptor and CD95 were also measured by flow cytometry. Plasma levels of TNF, interleukin (IL)-6, IL-10, and soluble TNF receptors 1 and 2 were quantified using enzyme-linked immunosorbent assay. Results Compared to patients without CHF, circulating PMN and monocyte TNF receptor levels were significantly decreased in patients with CHF. By contrast, PMN and monocyte CD95 expression was not significantly changed in patients with CHF versus those without CHF. Patients with CHF had a 60% decrease in spontaneous PMN apoptosis compared to patients without CHF, whereas no significant difference in CD95-mediated apoptosis was observed between the two groups. Pearson-product movement correlation of monocyte TNF receptor expression and spontaneous PMN apoptosis rates versus patients’ ejection fraction was performed and was statistically significant. Plasma levels of soluble TNF receptor 2 (p75) were elevated in CHF patients versus patients without CHF, while there was no significant difference in soluble TNF receptor 1 (p55), TNF, IL-6, and IL-10 between the two groups. Conclusions These data demonstrate a systemic alteration in immune cell phenotype and apoptosis in patients with CHF. These findings provide support for the concept that inflammatory mediators either contribute to myocardial dysfunction or are elaborated systemically by left ventricular compromise. This present study suggests that immune cell TNF receptor expression and diminished PMN apoptosis may serve as biologic markers of myocardial failure.

OBJECTIVES:To differentiate surgical bleeding requiring re-exploration from postoperative coagulopathy and determine the differences in patient outcomes.METHODS:This was a retrospective chart review of 2,263 adult patients undergoing elective and emergency open heart procedures encompassing coronary artery bypass, valvular, and a combined procedure to determine the impact of source of bleeding leading to re-exploration.RESULTS:Eighty-two patients (3.6%) required re-exploration. Sixty-six percent had surgical bleeding; the remaining 34% were coagulopathic. Postoperative coagulopathy was associated with preoperative heparin use (37% vs. 19.9% for controls p<0.05). Re-operative procedures combined bypass/ valve (p<0.001) and prolonged cardiopulmonary bypass and aortic cross-clamp times (p<0.05) were more prevalent in the coagulopathy group. Postoperative inotrope use was increased in patients who were re-explored (p<0.001), as were cardiac, pulmonary, renal and abdominal complications (p<0.001), and in all cases those patients with medically related bleeding had worse acute outcomes than the group with surgical causes for re-exploration. The hospital stay was prolonged for both patients with surgical bleeding (23.5 days) and patients with coagulopathy (27.1 days) compared to patients not undergoing re-exploration for bleeding (12.0 days, p<0.001). Survival was 91.3% for patients with surgical bleeding, 87.5% for patients with coagulopathy, and 98.0% for all others (p<0.01).CONCLUSIONS:Severe postoperative hemorrhage is associated with significant morbidity and increased mortality. Postoperative hospital stay, morbidity, and mortality were significantly worse in patients suffering from coagulopathy when compared to those patients with hemorrhage from surgical causes.

OBJECTIVES:This study evaluated acute results as a function of the number of arterial conduits used to compare procedural differences and the subsequent effects on acute outcomes in selected patient populations.BACKGROUND:All arterial operations may provide better long-term results for younger patients undergoing coronary bypass surgery (CABG). However, concerns regarding additional morbidity when using multiple arterial conduits have inhibited their use.METHODS:The study comprised a retrospective review of patients (2,586) undergoing CABG. Group 1 consists of single artery vein graft (1,755). Group 2: two arteries were used in addition to vein grafts (209). Group 3: three or more arterial conduits were used, with or without vein grafts (116). Group 4: only vein grafts were used (506).RESULTS:Patients undergoing primarily arterial procedures, Group 2 and 3, were younger, had a better exercise profile, less history of myocardial infarction (MI), had less left ventricular dysfunction. There were also fewer emergencies, co-morbidities and associated procedures in this group. The cardiopulmonary bypass and cross clamp times were longer in those procedures with three or more arteries; however, this difference was only thirteen and fourteen minutes, respectively. Post-operative complications were higher in patients in the vein only group. The hospital stay and mortality was equivalent among groups in which an arterial bypass was used and better than those in which only vein grafts were used.CONCLUSIONS:For younger patients, "all arterial operations," require only minimal increases in ischemic and operative times, which do not affect acute outcomes.

HYPOTHESIS Delayed or reduced polymorphonuclear leukocyte (PMN) apoptosis may contribute to prolongation of systemic inflammation after cardiopulmonary bypass. BACKGROUND/OBJECTIVE Preoperative administration of glucocorticoids has been used ostensibly to attenuate the systemic inflammation associated with cardiopulmonary bypass. Therefore, this study evaluated, in patients undergoing cardiopulmonary bypass, the efficacy of glucocorticoids in restoring peripheral blood PMN apoptosis and modulating PMN surface receptors (CD95, tumor necrosis factor receptor [TNFR]) known to be involved in proapoptotic or antiapoptotic signal transduction. DESIGN Randomized control study. SETTING Medical school and affiliated tertiary care hospital. PATIENTS Thirteen patients undergoing coronary artery bypass grafting. INTERVENTION Patients were randomly assigned to the control group (n = 7) or to receive 1 g of methylprednisolone sodium succinate on anesthetic induction (n = 6). MAIN OUTCOME MEASURES Blood samples were drawn before induction, 20 minutes after sternotomy and bypass, immediately postoperatively, and on postoperative day 1. Isolated PMNs were incubated for 6 hours with or without the CD95 agonist CH 11. Polymorphonuclear leukocyte apoptosis was measured using propidium iodide-RNAase staining and flow cytometry. Levels of PMN cell-associated receptors (TNFR and CD95), cytokines (TNF-alpha, interleukin 6 [IL-6], IL-8, and IL-10), and soluble receptors (sTNFR1 and sTNFR2) were measured. RESULTS In all 13 patients, spontaneous and Fas-mediated PMN apoptosis decreased more than 80% from baseline (P<.001) by postoperative day 1. Polymorphonuclear leukocyte CD95 increased (P<.003) by postoperative day 1 compared with baseline, whereas PMN TNFR was unchanged. Methylprednisolone administration did not modulate PMN apoptosis or immunocyte receptor expression; however, such treatment did decrease postoperative IL-6 secretion (P<.001) and increase postoperative IL-10 secretion (P<.001). CONCLUSIONS The complications of major surgery include persistent inflammation, which can lead to multisystem organ failure. Polymorphonuclear leukocyte resistance to apoptosis may contribute to this process. A single preoperative dose of glucocorticoids did not effect PMN apoptosis or receptor phenotype.

BACKGROUND: As case-based methods replaced lectures in a surgical clerkship, the influences of case structure and prior experience on learning were investigated.METHODS: Early and late third-year students randomly received different cases. ''Structured'' cases had data presented and summarized. ''Unstructured'' cases required questions to faculty for information. Multiple choice tests and differential diagnosis activities were administered. An attitudinal questionnaire gauged student perceptions.RESULTS: In both multiple choice and differential diagnosis activities, the late rotation, ''unstructured'' group scored higher than the ''structured'' group. Conversely, the early rotation, ''unstructured'' group scored lower than the ''structured'' group. Combined, rotation, and structure significantly affected both multiple choice and differential diagnosis activities (ANOVA, P less than or equal to 0.02). Early rotation, ''unstructured'' students described a more enjoyable experience, despite lower evaluation scores.CONCLUSIONS: Surgical clerkship case-based learning is profoundly affected by case structure and prior clinical experience. Case-based curriculum should be tailored to accommodate these interactions.

In order to study the pharmacokinetics of famotidine in cardiac surgery patients, we administered famotidine 20mg by intravenous injection at the beginning of surgery and 12 hours after surgery in 8 patients undergoing elective cardiac surgery with cardiopulmonary bypass. Total body clearance, volume of distribution, and elimination half-life were calculated using noncompartmental analysis and compared with published normal parameters (control) using a 2-tailed, 1-sample t-test. Intra- and postoperative clearances were 2.93 ± 1.06 and 3.18 ± 1.06 ml/min/kg, respectively, which were more than 50% less than the control value (6.07 ml/min/kg; p<0.0005). The volume of distribution (1.0 L/kg) was unaltered during the study and did not differ from the control value (1.19 L/kg; p>0.08). Intra- and postoperative half-lives were 4.52 ± 2.21 hours and 4.27 ± 1.58 hours, respectively, which were more than 50% longer than control (2.92 hours; p<0.03). Famotidine pharmacokinetics are significantly altered during cardiac surgery with cardiopulmonary bypass, and these changes persist for up to 24 hours after surgery.

Antibiotic sterilized valves have been shown to function longer than those chemically sterilized; however, the reason remains obscure. Current hypotheses cite either retention of donor fibroblasts capable of repairing the grafted valve, or host fibroblast ingrowth into and onto the leaflet ground substance. A cryopreserved aortic homograft from a male donor was explanted from a female recipient after 10 months, and subjected to immunocyto-chemistry, tissue culture, and karyotyping. The leaflet bases exhibited normal morphology with an intact endothelium. The distal one-third of the leaflets was devoid of fibroblasts. Cytogenetic analysis of culture derived fibroblasts from the leaflet bases showed them to be of host origin. This homograft seems to have been implanted with an intact ground substance which allowed for host cell repopulation of the inner one-third of the leaflets. Perhaps donor cell viability in itself is not as important to durability as is preservation of the leaflet ground substance, but rather the presence of viable cells may be an index of the structural integrity of the collagen and elastic matrix.