Is early anticoagulation with warfarin necessary after bioprosthetic aortic valve replacement?

OBJECTIVES: Freedom from anticoagulation is the principal advantage of bioprosthesis; however, the American Heart Association/American College of Cardiology and the American College of Chest Physicians guidelines recommend early anticoagulation with heparin, followed by warfarin for 3 months after bioprosthetic aortic valve replacement. We examined neurologic events within 90 days of bioprosthetic aortic valve replacement at our institution. METHODS: Between 1993 and 2000, 1151 patients underwent bioprosthetic aortic valve replacement with (641) or without (510) associated coronary artery bypass. By surgeon preference, 624 had early postoperative anticoagulation (AC+) and 527 did not (AC-). In the AC- group, 410 patients (78%) received antiplatelet therapy. Groups were similar with respect to gender (female, 36% AC+ vs 40% AC-, P = .21), hypertension (64% AC+ vs 61%, P = .27), and prior stroke (7.6% AC+ vs 8.5% AC-, P = .54). The AC+ group was slightly younger than the AC- group (median, 76 years vs 78 years, P = .006). RESULTS: Operative mortality was 4.1% with 43 (3.7%) cerebrovascular events within 90 days. Excluding 18 deficits apparent upon emergence from anesthesia, we found that postoperative cerebrovascular accident occurred in 2.4% of AC+ and 1.9% AC- patients. By multivariable analysis, the only predictor of operative mortality was hypertension ( P < .0001). Postoperative cerebrovascular accident was unrelated to warfarin use ( P = .32). The incidence of mediastinal bleeding requiring reexploration was similar (5.0% vs 7.4%), as were other bleeding complications in the first 90 days (1.1% vs 0.8%). No variables were predictive of bleeding by multivariate analysis. CONCLUSIONS: Although these data do not address the role of antiplatelet agents, early anticoagulation with warfarin after bioprosthetic aortic valve replacement did not appear to protect against neurologic events.

Effectiveness of the Cobra aortic catheter for dual-temperature management during adult cardiac surgery.

OBJECTIVES: In animals the Cardeon Cobra catheter (Cardeon Corp, Cupertino, Calif) allows independent control of aortic arch and descending aortic temperatures and profoundly reduces cerebral embolization during bypass. This investigation describes the first clinical use of the device during adult cardiac surgery. The purpose of the study was to confirm that the Cobra catheter delivers adequate cerebral and systemic perfusion while providing simultaneous cerebral hypothermia and systemic normothermia during cardiopulmonary bypass. METHODS: In a prospective multicenter study the Cobra aortic catheter was placed in 20 adults undergoing cardiopulmonary bypass. Arch and corporeal temperatures, bypass flows, and arterial blood pressures were recorded intraoperatively. Jugular bulb and mixed venous oxygen saturation was used to assess the adequacy of cerebral and systemic perfusion. RESULTS: Surgeons at 3 institutions placed the Cobra catheter in patients undergoing coronary artery bypass grafting (n = 13), valve (n = 3), and combined valve-bypass (n = 4) operations. Mean total bypass flows of 2.1 +/- 0.2 L x min(-1) x m(-2) maintained mean arterial pressures in arch and descending aortic circulations of greater than 55 mm Hg. A mean differential of 4.3 degrees C between arch and descending aortic temperatures was established before crossclamp application, and a mean maximum temperature differential of 7 degrees C was established during bypass. A 2.4 degrees C temperature differential was maintained at crossclamp removal. Cerebral and systemic venous oxygen saturation remained greater than 65% during bypass. CONCLUSIONS: The Cobra device met all expectations for an arterial cannula with adequate perfusion to the arch and corporeal circulations. Dual perfusion with the Cobra catheter allows for independent temperature control during cardiopulmonary bypass with simultaneous cerebral hypothermia and systemic normothermia.

Biocompatibility of Trillium Biopassive Surface-coated oxygenator versus uncoated oxygenator during cardiopulmonary bypass.

OBJECTIVE: To determine if the Trillium Biopassive Surface (Medtronic Cardiopulmonary, Minneapolis, MN) coating added to the cardiopulmonary bypass oxygenator reduces inflammatory mediators, blood loss, and transfusion requirements. DESIGN: Prospective, randomized, and blinded human trial. SETTING: Tertiary care academic medical center. PARTICIPANTS: Thirty adult patients undergoing elective coronary artery bypass graft surgery. INTERVENTIONS: Patients received visually identical coated or uncoated oxygenators. MEASUREMENTS AND MAIN RESULTS: Hemoglobin, hematocrit, leukocyte count, platelet count, terminal complement complex, complement activation, myeloperoxidase, beta-thromboglobulin, prothrombin fragment 1.2, plasmin-antiplasmin, heparin concentration, activated coagulation time, and fibrinogen concentration were measured. Blood loss and blood product usage were recorded. In both groups, there were significant inflammatory alterations with the initiation of cardiopulmonary bypass. In the postprotamine samples, the coated oxygenator group had small but significant increases in hemoglobin, hematocrit, and leukocyte count. There were no differences in inflammatory mediators, blood loss, or transfusion requirements between the coated and uncoated groups. CONCLUSION: This human trial of Trillium Biopassive Surface-coated oxygenators did not show clinical benefits or clinically important biochemical results.

Operation for anorexigen-associated valvular heart disease.

OBJECTIVES: Recently, valvular regurgitation has been observed in patients who have taken fenfluramine or dexfenfluramine with or without phentermine. This study describes the clinical, echocardiographic, and pathologic findings of anorexigen-associated valvular heart disease and the surgical interventions required to treat it. METHODS: We reviewed clinical information on 14 patients with severe anorexigen-associated valvular disease who underwent cardiac operations. RESULTS: Thirteen women (mean age 44.2 +/- 5.3 years) received fenfluramine, 58.5 +/- 22.3 mg/day, and phentermine, 32.1 +/- 11.4 mg/day, for an average of 12.1 +/- 7.3 months before presentation. One woman received dexfenfluramine, 30 mg/day for 13 months, and phentermine, 60 mg/day, concomitantly for 6 months. Presenting symptoms included dyspnea (12 cases), palpitations (3), and atypical chest pain (3). Six patients had heart failure, and 4 had a new murmur. Echocardiography demonstrated severe mitral valve regurgitation in all patients. Seven also had aortic regurgitation, and 4 had significant tricuspid regurgitation. Four patients had successful mitral valve repair, 1 with concomitant aortic valve repair. Ten additional patients eventually required mitral valve replacement, 5 with concomitant aortic valve replacement. Excised valves demonstrated a glistening white appearance with plaque-like encasement of leaflets and chordae. Focal surface proliferation and fibrosis with a "stuck-on" appearance was consistently found. CONCLUSIONS: Anorexigen use may lead to severe multivalvular regurgitation with characteristic echocardiographic and pathologic findings. Recognition of drug-induced valvulopathy is important because of widespread use of these medications and the uncertain natural history of the disease. Early surgical experience suggests that valve repair is possible in these young patients.

Carbon dioxide management and the cerebral response to hemodilution during hypothermic cardiopulmonary bypass in dogs.

BACKGROUND: Increases in blood flow support oxygen (O2) delivery with hemodilution. However, with alpha-stat management, the cerebral response to hemodilution is blunted. We tested the hypothesis that carbon dioxide (CO2) management is a primary determinant of the cerebral blood flow (CBF) response to hemodilution during hypothermic bypass. METHODS: Following Animal Care Committee approval, 15 dogs underwent bypass at 18 degrees C (pH-stat, n = 7 or alpha-stat, n = 8). Measurements were obtained after progressive hemodilution, and cerebral blood flow was determined by sagittal sinus outflow. Arterial pressure was maintained at 60 to 70 mm Hg. The CBF response to hemodilution and cerebral metabolic rate were compared in the two groups of animals. RESULTS: In both groups, hemodilution increased CBF. At every hematocrit, CBF and O2 delivery in the pH-stat group exceeded that of alpha-stat group, although O2 demand did not differ between groups. While absolute CBF in the pH-stat group was greater at every hematocrit, the relative change in CBF from control and the slope of the CBF-Hct relationship did not differ between groups. CONCLUSIONS: pH-stat management is associated with a greater absolute CBF and a greater ratio of cerebral O2 supply to demand for any degree of hemodilution. However, over the range of hematocrits common in practice, CO2 management per se does not determine the cerebral response to hemodilution.

Posterior pericardial ascending-to-descending aortic bypass: an alternative surgical approach for complex coarctation of the aorta.

BACKGROUND: Coarctation of the aorta is commonly associated with recoarctation or additional cardiovascular disorders that require intervention. The best surgical approach in such patients is uncertain. Ascending-to-descending aortic bypass graft via the posterior pericardium (CoA bypass) allows simultaneous intracardiac repair or an alternative approach for the patient with complex coarctation. METHODS AND RESULTS: Between 1985 and 2000, 18 patients (13 males and 5 females, mean age 43+/-13 years) with coarctation of the aorta underwent CoA bypass through median sternotomy. Before operation, average New York Heart Association class was II (range I to IV), and 15 patients (83%) had systemic hypertension. One or more previous cardiovascular operations had been performed in 12 patients (67%); 10 patients had >/=1 prior coarctation repair. Two patients had prior noncoarctation cardiovascular surgery. Concomitant procedures performed in 14 patients (78%) included the following: aortic valve replacement in 9; coronary artery bypass surgery in 3; mitral valve repair in 2; and septal myectomy, mitral valve replacement, aortoplasty, subaortic stenosis resection, ventricular septal defect closure, and ascending aorta replacement in 1 patient each. All patients survived the operation and were alive with patent CoA bypass at a mean follow-up of 45 months. No graft-related complications occurred, and there were no instances of stroke or paraplegia. Systolic blood pressure fell from 159 mm Hg before surgery to 125 mm Hg after surgery. CONCLUSIONS: CoA bypass via median sternotomy can be performed with low morbidity and mortality. Although management must be individualized, extra-anatomic CoA bypass via the posterior pericardium is an excellent single-stage approach for patients with complex coarctation or recoarctation and concomitant cardiovascular disorders.

Very long-term survival and durability of mitral valve repair for mitral valve prolapse.

BACKGROUND: Mitral regurgitation (MR) due to mitral valve prolapse (MVP) is often treatable by surgical repair. However, the very long-term (>10-year) durability of repair in both anterior leaflet prolapse (AL-MVP) and posterior leaflet prolapse (PL-MVP) is unknown. METHODS AND RESULTS: In 917 patients (aged 65+/-13 years, 68% male), surgical correction of severe isolated MR due to MVP (679 repairs and 238 replacements [MVRs]) was performed between 1980 and 1995. Survival after repair was better than survival after MVR for both PL-MVP (at 15 years, 41+/-5% versus 31+/-6%, respectively; P=0.0003) and AL-MVP (at 14 years, 42+/-8% versus 31+/-5%, respectively; P=0.003). In multivariate analysis adjusting for predictors of survival, repair was independently associated with lower mortality in PL-MVP (adjusted risk ratio [RR] 0.61, 95% CI 0.44 to 0.85; P=0.0034) and in AL-MVP (adjusted RR 0.67, 95% CI 0.47 to 0.96; P=0.028). The reoperation rate was not different after repair or MVR overall (at 19 years, 20+/-5% for repair versus 23+/-5% for MVR; P=0.4) or separately in PL-MVP (P=0.3) or AL-MVP (P=0.3). However, the reoperation rate was higher after repair of AL-MVP than after repair of PL-MVP (at 15 years, 28+/-7% versus 11+/-3%, respectively; P=0.0006). From the 1980s to the 1990s, the RR of reoperation after repair of AL-MVP versus PL-MVP did not change (RR 2.5 versus 2.7, respectively; P=0.58), but the absolute rate of reoperation decreased similarly in PL-MVP and AL-MVP (at 10 years, from 10+/-3% to 5+/-2% and from 24+/-6% to 10+/-2%, respectively; P=0.04). CONCLUSIONS: In severe MR due to MVP, mitral valve repair compared with MVR provides improved very long-term survival after surgery for both AL-MVP and PL-MVP. Reoperation is similarly required after repair or replacement but is more frequent after repair of AL-MVP. Recent improvement in long-term durability of repair suggests that it should be the preferred mode of surgical correction of MVP whether it affects anterior or posterior leaflets and is an additional incentive for early surgery of severe MR due to MVP.

Distribution and hierarchy of regional blood flow during hypothermic cardiopulmonary bypass.

BACKGROUND: Cardiopulmonary bypass (CPB) may decrease oxygen delivery relative to the nonbypass state. We predicted that a hierarchy of regional blood flow could be characterized under hypothermic (27 degrees C) CPB. METHODS: Ten pigs underwent bypass at 27 degrees C. Fluorescent microspheres were administered before and during CPB at four randomized flows: 1.9, 1.6, 1.3, and 1.0 L x min(-1) x m(-2). At completion, tissue samples were obtained from brain, renal cortex and medulla, pancreas, small bowel, and limb muscle for regional blood flow determination. RESULTS: Cerebral blood flow remained unchanged between CPB flows of 1.9 and 1.3 L x min(-1) x m(-2). Renal perfusion was stable between flows of 1.9 and 1.6 L x min(-1) x m(-2), whereas perfusion of small bowel decreased linearly with pump flow. Pancreatic perfusion was unchanged over the range of flows studied; muscle blood flow was profoundly reduced at the highest CPB flow and further decreased if pump flow was reduced below 1.6 L x min(-1) x m(-2). CONCLUSIONS: This study characterizes the organ-specific hierarchy of blood flow and oxygen distribution during hypothermic CPB. These dynamics are relevant to clinical decisions for perfusion management.

Valvular heart operation in patients with previous mediastinal radiation therapy.

BACKGROUND: The outcome of valvular heart operations in patients with previous mediastinal radiation therapy was studied. METHODS: This is a single center retrospective study of 60 patients (37 females, 23 males) with a mean age of 62 +/- 15 years (28 to 88 years old) operated on from January 1976 to December 1998. Valvular heart operations performed included aortic valve replacements (n = 26), mitral valve procedures (n = 16), tricuspid valve procedures (n = 6), and multiple valve procedures (n = 12). A total of 264 clinical, hemodynamic, electrocardiographic and echocardiographic variables were analyzed. RESULTS: Total follow-up was 199 patient-years with a mean of 3.3 +/- 3.1 years and a range of 0 to 12.4 years old. Early mortality was 7 patients (12%). Early mortality in patients with constrictive pericarditis was 40% (4 of 10) compared with 6% (3 of 50) in patients without constrictive pericarditis. By univariate analysis, early mortality was associated with constrictive pericarditis (p = 0.011), reduced preoperative ejection fraction (p = 0.015), and longer cardiopulmonary bypass times (p = 0.037). A total of 14 patients (23%) required permanent pacemaker placement before (n = 7), during (n = 1), or early (n = 6) after valvular heart operations. There were 19 late deaths (malignancies, 7; heart failures, 5; other cardiac, 4; and other noncardiac, 3). Overall survival and freedom from late cardiac death and cardiac reoperation at 5 years for hospital survivors were 66% +/- 8%, 82% +/- 7%, and 93% +/- 4%, respectively. By univariate analysis, late cardiac death was associated with low ejection fraction (p = 0.002), New York Heart Association (NYHA) functional class IV (p = 0.004), preoperative congestive heart failure (p = 0.02), and preoperative atrial fibrillation (p = 0.038). Eighty-five percent of the discharged patients were in NYHA functional class I or II at follow-up. CONCLUSIONS: Early results of valve replacement after mediastinal radiation therapy were good except in the presence of constrictive pericarditis. Long-term outcome was limited by malignancy and heart failure. Early surgical intervention is recommended before the development of risk factors for late death, namely, severe symptoms, left ventricular dysfunction, and atrial fibrillation.

Complicated mitral valve repairs.

The standard of care for mitral regurgitation secondary to degenerative valvular disease is mitral valve repair whenever possible. Mitral valve repair is associated with better left ventricular function preservation, fewer complications, and improved survival as compared with mitral valve replacement. Most of the mitral valve pathology involves the posterior leaflet or annulus and usually can be repaired by using standard valve repair techniques. Difficulties may arise when trying to repair the somewhat uncommon anterior leaflet prolapse or calcified mitral annulus. This article reviews these more complex mitral valve repair techniques and their outcomes.

Hierarchy of regional oxygen delivery during cardiopulmonary bypass.

BACKGROUND: Relative to the nonbypass state, cardiopulmonary bypass may decrease whole-body oxygen (O2) delivery. We predicted that during cardiopulmonary bypass, a hierarchy of regional blood flow and O2 delivery could be characterized. METHODS: In 8 46.5 +/- 1.2-kg pigs, fluorescent microspheres were used to determine blood flow and O2 delivery to five organ beds before and during 37 degrees C cardiopulmonary bypass at four randomized bypass flows (1.4, 1.7, 2.0, and 2.3 L/min/m2). At completion, 18 tissue samples were obtained from the cerebral cortex (n = 4), renal cortex (n = 2), renal medulla (n = 2), pancreas (n = 3), small bowel (n = 3), and limb muscle (n = 4) for regional blood flow determination. RESULTS: At conventional cardiopulmonary bypass flow (2.3 L/min/m2), whole-body O2 delivery was reduced by 44 +/- 6% relative to the pre-cardiopulmonary bypass state (p < 0.05). Over a range of cardiopulmonary bypass flows (2.3 to 1.7 L/min/m2), brain and kidney maintained their perfusion. Blood flow and O2 delivery to both regions were reduced when the cardiopulmonary bypass flow was reduced to 1.4 L/min/m2. However, perfusion and O2 delivery to other visceral organs (pancreas, small bowel) and skeletal muscle showed pump flow dependency over the range of flows tested. CONCLUSIONS: This study characterizes the organ-specific hierarchy of blood flow and O2 distribution during cardiopulmonary bypass. These dynamics are relevant to clinical decisions for perfusion management.

Reoperation for prosthetic aortic valve obstruction in the era of echocardiography: trends in diagnostic testing and comparison with surgical findings.

OBJECTIVES: We sought to: 1) identify trends in the diagnostic testing of patients with prosthetic aortic valve (AVR) obstruction who undergo reoperation and 2) compare diagnostic test results with pathologic findings at surgery. BACKGROUND: It is unclear whether Doppler transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) have reduced hemodynamic catheterization rates. METHODS: We reviewed 92 consecutive cases ofAVR reoperation at a single center from 1989 to 1998, comparing 49 cases of mechanical AVR obstruction (group A) to 43 cases of bioprosthetic obstruction (group B). Preoperative Doppler TTE was performed in all cases. RESULTS: In group A cases, there was a marginally significant trend towards lower catheterization rates for the Gorlin AVR area, from 36% in 1989 to 1990 to 10% in 1997 to 1998 (p = 0.07), but diagnostic TEE utilization (47% of cases) did not vary. The cause of mechanical AVR obstruction was pannus in 26 cases (53%), mismatch (P-PM) in 19 (39%) and thrombosis in 4 (8%). The mechanism (pannus/thrombus vs. mismatch) was identified in 10% by TTE and 49% by TEE (p < 0.001). In group B cases, hemodynamic catheterization rates (21%) and diagnostic TEE utilization (21%) did not vary with time. Obstruction was caused by structural degeneration in 37 cases (86%), thrombosis in 3 (7%), mismatch in 2 (5%) and pannus in 1 (2%). The mechanism was correctly identified in 63% by TTE and in 81% by TEE (p = 0.18). CONCLUSIONS: Doppler TTE is the primary means to diagnose AVR obstruction; hemodynamic catheterization is not routinely needed. In unselected patients with mechanical AVR obstruction, TEE differentiation of pannus or thrombus from mismatch is challenging.

Outcome of reoperation for aortic valve prosthesis-patient mismatch.

We report a single center's 10-year experience with 21 consecutive cases of repeat aortic valve replacement for prosthesis-patient mismatch (P-PM) in which there was no hospital mortality among 12 patients treated for isolated P-PM. With an overall survival of 92% at a median follow-up of 4.5 years and functional class I symptoms in most survivors (73%), we conclude that repeat surgery for isolated P-PM has a relatively low mortality and a good intermediate-term clinical outcome.

Cell proliferation in carcinoid valve disease: a mechanism for serotonin effects.

BACKGROUND AND AIM OF THE STUDY: Elevated serum serotonin is associated with carcinoid heart disease, the hallmark of which is valvular thickening. Yet, the mechanistic role of serotonin in carcinoid heart disease is poorly understood. We postulated that serotonin has a direct mitogenic effect on cardiac valvular subendocardial cells, and that this effect is mediated by serotonin receptors. METHODS: The dose-dependent proliferative effects of serotonin (10(-8) to 10(-4)M) on cultured porcine aortic valve cells via a [3H]thymidine assay were determined in vitro. Serotonin receptor antagonist studies in culture were also performed using methiotepin, a 5HT1b antagonist, and ketanserin, a 5HT2 receptor antagonist, to determine the mechanism of serotonin action. The ex-vivo proliferation level in human carcinoid (n = 26) and normal valves (n = 10) was compared using proliferating cell nuclear antigen (PCNA) staining, a marker for proliferation. Identification and localization of specific 5HT receptor was assessed by immunostaining for serotonin receptors in the valves. RESULTS: Serotonin increased valvular proliferation in vitro in a dose-dependent manner (10-fold increase) (p <0.001), and this mitogenic effect was inhibited by methiotepin but not ketanserin. In human carcinoid heart valves the level of proliferation was 35-fold higher than in normal human valves (p <0.001). 5HT1b receptors were found only in the carcinoid valves, and not in the normal valves. CONCLUSION: Serotonin is a powerful mitogen for valvular subendocardial cells. The mitogenic effect is at least partly mediated via 5HT1b receptors. Subendothelial cell proliferation is significantly elevated in human carcinoid valves in vivo. The data suggest a mechanism whereby serotonin may contribute to valvular proliferation in carcinoid heart disease.

Surgical treatment of valvular heart disease in patients with acromegaly.

BACKGROUND AND AIM OF THE STUDY: Acromegaly is associated with heart disease in one-third of patients, and diastolic dysfunction may precede global systolic dysfunction. Patients with acromegalic heart disease may have valvular disease, but the role of surgery in such patients has not been established. The purpose of this study was to document the outcome of surgery in a series of these patients from one institution. METHODS: Among 951 patients with the diagnosis of acromegaly seen at our institution since 1972, 10 (eight men, two women) have undergone operation for valvular heart disease. Average patient age was 62.2 +/- 11.5 years; average body weight was 84 +/- 13 kg; average height was 178 +/- 12 cm. The mean duration of acromegaly was 15.2 +/- 12.7 years. At the time of heart surgery, seven patients had active disease, defined by elevation of growth hormone levels, while three had inactive disease. Treatment of pituitary adenomas before valvular surgery included surgical resection in three patients and external-beam radiation treatment in four. The preoperative ejection fraction was 42 +/- 19% (range: 20% to 66%). Valve lesions included aortic stenosis in four patients, aortic regurgitation in four, and mitral regurgitation in three (one patient had double valve disease). RESULTS: Valve replacement was performed in all patients with aortic disease (two bioprostheses, six mechanical), and three patients with mitral regurgitation had repair. Concomitant procedures performed in seven patients included coronary bypass (two), left ventricular aneurysmectomy (two), and ligation of the left atrial appendage, septal myectomy and defibrillator insertion (one each). Early complications included endocarditis, low cardiac output and arrhythmia in one patient each. There were no perioperative deaths. One patient underwent reoperation ten years later for a perivalvular leak. CONCLUSION: Valvular surgery can be performed safely in acromegalic patients, even those with active endocrinopathy.

Posterior pericardial approach for ascending aorta-to-descending aorta bypass through a median sternotomy.

BACKGROUND: Bypass grafting for repeat operation or complex forms of descending aortic disease is an alternative approach to decrease potential complications of anatomic repair. METHODS: Between December 1985 and February 1998, 17 patients (13 men, 4 women; mean age, 47.6 +/- 18.5 years) underwent ascending aorta-to-descending aorta bypass through a median sternotomy and posterior pericardial approach. Indications for operation were coarctation or recoarctation of aorta in 8 patients, Takayasu's aortitis in 2, prosthetic aortic valve stenosis associated with coarctation of aorta, complex descending aortic arch aneurysm, reoperation for chronic descending aortic dissection, long-segment stenosis of descending aorta, acquired coarctation after repair of traumatic transection of descending aorta, severe aortic atherosclerosis, and false aneurysm of descending aorta after repair of coarctation in 1 patient each. Concomitant procedures were performed in 12 patients. RESULTS: No early or late mortality has occurred. Follow-up was 100% complete and extended to 12 years (mean, 2.7 +/- 3.3 years). No late graft-related complications have occurred; 1 patient had successful repair of perivalvular leak after mitral valve replacement, and 1 patient had replacement of lower descending and abdominal aorta. CONCLUSIONS: Exposure of the descending aorta through the posterior pericardium for ascending aorta-descending aorta bypass is a safe alternative and particularly useful when simultaneous intracardiac repair is necessary.

Predictors of mortality and mortality from cardiac causes in the bypass angioplasty revascularization investigation (BARI) randomized trial and registry. For the BARI Investigators.

BACKGROUND: The impact of percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG) on long-term mortality rates in the presence of various demographic, clinical, and angiographic factors is uncertain in the population of patients suitable for both procedures. METHODS AND RESULTS: In the Bypass Angioplasty Revascularization Investigation (BARI) randomized trial and registry, 3610 patients who were eligible to receive PTCA and CABG were revascularized between 1989 and 1992. Multivariate Cox models were used to identify factors associated with 5-year mortality and cardiac mortality, with particular attention to factors that interact with treatment. Diabetic patients receiving insulin had higher mortality and cardiac mortality rates with PTCA compared with CABG (relative risk [RR] 1.78 and 2.63, respectively, P<0.001), and patients with ST elevation had higher cardiac mortality rates with CABG than with PTCA (RR 4.08, P<0.001). Factors most strongly associated with high overall mortality rates were insulin-treated diabetes, congestive heart failure, kidney failure, and older age. Black race was also associated with higher mortality rates (RR 1.49, P=0.019). CONCLUSIONS: A set of variables was identified that could be used to help select a revascularization procedure and to evaluate risk of long-term mortality in the population of patients considering revascularization.

Blood loss from coronary angiography increases transfusion requirements for coronary artery bypass graft surgery.

OBJECTIVE: To determine the blood loss associated with coronary angiography and its impact on hemoglobin and transfusion requirements for subsequent coronary artery bypass graft (CABG) surgery. DESIGN: Retrospective chart review. SETTING: Tertiary-care, academic medical center. PARTICIPANTS: A total of 506 adult patients undergoing coronary angiography and CABG surgery. INTERVENTIONS: None (observational study). MEASUREMENTS AND MAIN RESULTS: Coronary angiography was associated with a reduction in hemoglobin of 1.8 g/dL. This reduction in hemoglobin was a significant predictor of allogeneic red blood cell transfusion. CONCLUSION: Coronary angiography contributes to a 1.8 g/dL reduction in hemoglobin concentration before CABG surgery and was associated with increased transfusion of allogeneic blood products. Measures aimed at maintaining red cell volume during coronary angiography, increasing erythropoiesis, or delaying surgery beyond 2 weeks may result in a decrease in transfusion requirements for patients undergoing CABG surgery.

Effect of cerebral embolization on regional autoregulation during cardiopulmonary bypass in dogs.

BACKGROUND: Embolization during cardiopulmonary bypass probably alters cerebral autoregulation. Therefore, using laser Doppler flowmetry we investigated the cerebral blood flow velocity changes in response to changes in arterial pressure, before and after embolization in a canine bypass model. METHODS: After Institutional Animal Care and Use Committee approval, 8 anesthetized dogs had a laser Doppler flow probe positioned over the temporoparietal dura. During 37 degrees C cardiopulmonary bypass, the cerebral blood flow velocity response to changing mean arterial pressure (40 to 85 mm Hg in random order) was assessed before and after systemic embolization of 100 mg of 97-microm latex microspheres. RESULTS: Before embolization, cerebral blood flow velocity increased 39% as mean arterial pressure increased from 40 to 85 mm Hg. Following embolization, a 94% increase in cerebral blood flow velocity was demonstrated over the same mean arterial pressure range. The slopes of the curves relating cerebral blood flow velocity to mean arterial pressure were 0.21+/-0.74 and 1.31+/-0.87, before and after embolization (p = 0.016) respectively. CONCLUSIONS: Regional cerebral blood flow autoregulation may be impaired by microembolization known to occur during cardiopulmonary bypass, increasing the dependence of cerebral blood flow on mean arterial pressure.

Cox-Maze procedure for atrial fibrillation: Mayo Clinic experience.

The Cox-Maze procedure corrects atrial fibrillation in 90% of patients, and successful operation restores sinus rhythm, thereby reducing risks of thromboembolism and anticoagulant-associated hemorrhage. Symptoms such as palpitation and fatigability also improve with restoration of atrioventricular synchrony. At the Mayo Clinic, 221 Cox-Maze procedures were performed from March 1993 through March 1999. Over 75% of patients had associated cardiac disease and concomitant operations. Overall, early mortality was 1.4%, and the incidence of postoperative pacemaker implantation was 3.2%. Limiting incisions to the right atrium simplifies the operation for patients who primarily have tricuspid valve disease, and in early follow-up, outcome appeared to be as good as that achieved with biatrial incisions. The Cox-Maze procedure has proved particularly useful for patients with preoperative atrial fibrillation who require valvuloplasty for acquired mitral valve regurgitation; 87 patients have had this combined procedure, and there have been no early deaths. Further, our experience indicates that ventricular dysfunction is not a contraindication for operation and that restoration of sinus rhythm after the Cox-Maze procedure improves left ventricular ejection fraction in most patients.