HDL cholesterol level predicts survival in men after coronary artery bypass graft surgery: 20-year experience from The Cleveland Clinic Foundation.

BACKGROUND: HDL cholesterol (HDL-C) is an important independent predictor of atherosclerosis, yet the role that HDL-C may play in the prediction of long-term survival after CABG remains unclear. The risk associated with a low HDL-C level in post-CABG men has not been delineated in relation to traditional surgical variables such as the use of arterial conduits, left ventricular function, and extent of disease. METHODS AND RESULTS: We performed a prospective, observational study of 432 men who underwent CABG between 1978 and 1979 in whom preoperative HDL-C values were available. Baseline lipid and lipoprotein values, history of diabetes mellitus and hypertension, left ventricular ejection fraction, extent of disease, and use of internal thoracic arteries were recorded. Hazard ratios (HRs) were determined in the patients with and without a low HDL-C level, which was defined as the lowest HDL-C quartile (HDL-C 35 mg/dL) were 50% more likely to survive at 15 years than were patients with low HDL-C level (35 mg/dL were 50% more likely to survive without a subsequent myocardial infarction or revascularization (HR 1.42, P:=0.02). CONCLUSIONS: HDL-C is an important predictor of survival in post-CABG patients. In this study of >8500 patient-years of follow-up, HDL-C was the most important metabolic predictor of post-CABG survival. One third fewer patients survive at 15 years if their HDL-C levels are

Sustained angina relief 5 years after transmyocardial laser revascularization with a CO(2) laser.

BACKGROUND: Although transmyocardial laser revascularization (TMR) has provided symptomatic relief of angina over the short term, the long-term efficacy of the procedure is unknown. Angina symptoms as assessed independently by angina class and the Seattle Angina Questionnaire (SAQ) were prospectively collected up to 7 years after TMR. METHODS: Seventy-eight patients with severe angina not amenable to conventional revascularization were treated with a CO(2) laser. Their mean age was 61+/-10 years at the time of treatment. Preoperatively, 66% had unstable angina, 73% had had >/=1 myocardial infarction, 93% had undergone >/=1 CABG, 42% had >/=1 PTCA, 76% were in angina class IV, and 24% were in angina class III. Their average pre-TMR angina class was 3.7+/-0.4. RESULTS: After an average of 5 years (and up to 7 years) of follow-up, the average angina class was significantly improved to 1.6+/-1 (P=0.0001). This was unchanged from the 1.5+/-1 average angina class at 1 year postoperatively (P=NS). There was a marked redistribution according to angina class, with 81% of the patients in class II or better, and 17% of the patients had no angina 5 years after TMR. A decrease of >/=2 angina classes was considered significant, and by this criterion, 68% of the patients had successful long-term angina relief. The angina class results were further confirmed with the SAQ; 5-year SAQ scores revealed an average improvement of 170% over the baseline results. CONCLUSIONS: The long-term efficacy of TMR persists for >/=5 years. TMR with CO(2) laser as sole therapy for severe disabling angina provides significant long-term angina relief.

Functional status and quality of life in patients with heart failure undergoing coronary bypass surgery after assessment of myocardial viability.

OBJECTIVES: The aim of this study was to evaluate whether preoperative clinical and test data could be used to predict the effects of myocardial revascularization on functional status and quality of life in patients with heart failure and ischemic LV dysfunction. BACKGROUND: Revascularization of viable myocardial segments has been shown to improve regional and global LV function. The effects of revascularization on exercise capacity and quality of life (QOL) are not well defined. METHODS: Sixty three patients (51 men, age 66+/-9 years) with moderate or worse LV dysfunction (LVEF 0.28+/-0.07) and symptomatic heart failure were studied before and after coronary artery bypass surgery. All patients underwent preoperative positron emission tomography (PET) using FDG and Rb-82 before and after dipyridamole stress; the extent of viable myocardium by PET was defined by the number of segments with metabolism-perfusion mismatch or ischemia. Dobutamine echocardiography (DbE) was performed in 47 patients; viability was defined by augmentation at low dose or the development of new or worsening wall motion abnormalities. Functional class, exercise testing and a QOL score (Nottingham Health Profile) were obtained at baseline and follow-up. RESULTS: Patients had wall motion abnormalities in 83+/-18% of LV segments. A mismatch pattern was identified in 12+/-15% of LV segments, and PET evidence of viability was detected in 30+/-21% of the LV. Viability was reported in 43+/-18% of the LV by DbE. The difference between pre- and postoperative exercise capacity ranged from a reduction of 2.8 to an augmentation of 5.2 METS. The degree of improvement of exercise capacity correlated with the extent of viability by PET (r = 0.54, p = 0.0001) but not the extent of viable myocardium by DbE (r = 0.02, p = 0.92). The area under the ROC curve for PET (0.76) exceeded that for DbE (0.66). In a multiple linear regression, the extent of viability by PET and nitrate use were the only independent predictors of improvement of exercise capacity (model r = 0.63, p = 0.0001). Change in Functional Class correlated weakly with the change in exercise capacity (r = 0.25), extent of viable myocardium by PET (r = 0.23) and extent of viability by DbE (r = 0.31). Four components of the quality of life score (energy, pain, emotion and mobility status) significantly improved over follow-up, but no correlations could be identified between quality of life scores and the results of preoperative testing or changes in exercise capacity. CONCLUSIONS: In patients with LV dysfunction, improvement of exercise capacity correlates with the extent of viable myocardium. Quality of life improves in most patients undergoing revascularization. However, its measurement by this index does not correlate with changes in other parameters nor is it readily predictable.

Mechanisms of hemolysis with mitral prosthetic regurgitation. Study using transesophageal echocardiography and fluid dynamic simulation.

OBJECTIVES: The aims of this study were to define the hydrodynamic mechanisms involved in the occurrence of hemolysis in prosthetic mitral valve regurgitation and to reproduce them in a numeric simulation model in order to estimate peak shear stress. BACKGROUND: Although in vitro studies have demonstrated that shear stresses > 3,000 dynes/cm2 are associated with significant erythrocyte destruction, it is not known whether these values can occur in vivo in conditions of abnormal prosthetic regurgitant flow. METHODS: We studied 27 patients undergoing reoperation for significant mitral prosthetic regurgitation, 16 with and 11 without hemolysis. We classified the origin and geometry of the regurgitant jets by using transesophageal echocardiography. By using the physical and morphologic characteristics defined, several hydrodynamic patterns were simulated numerically to determine shear rates. RESULTS: Eight (50%) of the 16 patients with hemolysis had paravalvular leaks and the other 8 had a jet with central origin, in contrast to 2 (18%) and 9 (82%), respectively, of the 11 patients without hemolysis (p = 0.12, power 0.38). Patients with hemolysis had patterns of flow fragmentation (n = 2), collision (n = 11) or rapid acceleration (n = 3), whereas those without hemolysis had either free jets (n = 7) or slow deceleration (n = 4) (p < 0.001, power 0.99). Numeric simulation demonstrated peak shear rates of 6,000, 4,500, 4,500, 925 and 950 dynes/cm2 in these five models, respectively. CONCLUSIONS: The distinct patterns of regurgitant flow seen in these patients with mitral prosthetic hemolysis were associated with rapid acceleration and deceleration or high peak shear rates, or both. The nature of the flow disturbance produced by the prosthetic regurgitant lesion and the resultant increase in shear stress are more important than the site of origin of the flow disturbance in producing clinical hemolysis.

Cystic medial necrosis of the aorta in patients without Marfan's syndrome: surgical outcome and long-term follow-up.

A retrospective analysis was performed to determine the surgical outcome and long-term follow-up of patients with documented cystic medial necrosis of the aorta. Ninety-three patients were diagnosed as having cystic medial necrosis at the Cleveland Clinic between July 1963 and December 1987 (72% men aged 26 to 77 years, mean 55). Patients who met the standard diagnostic criteria for Marfan's syndrome were deliberately excluded. Sixty-eight percent of the patients had a diastolic murmur and chest roentgenogram revealed a dilated aortic arch in 58% and cardiomegaly in 63%. Cardiac catheterization in 76 patients demonstrated aortic root dilation in 78%, aortic regurgitation in 72%, aortic dissection in 32% and coronary artery disease in 32%. Ninety patients underwent surgery including composite graft repair with reimplantation of the coronary arteries in 34%. Follow-up, obtained on 90 (97%) of the 93 patients, ranged in duration from 0 to 137 months (mean 29). Thirty-four of the 90 patients died (age range 30 to 75 years, mean 60). Ninety-four percent of the known causes of death were related to the cardiovascular system; 65% were the result of aortic dissection or rupture or sudden death. Ninety-six percent of survivors were in New York Heart Association functional class I or II. Overall estimated survival at 1, 3 and 5 years was 72.2%, 63.5% and 57.4%, respectively. Actuarial survival in patients who underwent composite graft reconstruction was 84% at 5 years. The presence of a diastolic murmur at initial presentation was associated with a poor prognosis (p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Benefits of intraoperative echocardiography in the surgical management of hypertrophic cardiomyopathy.

OBJECTIVES: The purpose of this study was to determine the role of intraoperative echocardiography in planning the site and extent of myectomy and in ensuring adequate control of the left ventricular outflow tract gradient. BACKGROUND: Although intraoperative echocardiography has been found to be beneficial in patients undergoing valve repair, its impact on surgical decisions in patients undergoing septal myectomy for hypertrophic cardiomyopathy has not been described. METHODS: In 50 patients undergoing septal myectomy over a 5-year period, epicardial echocardiography was performed before cardiopulmonary bypass to establish the extent of outflow tract obstruction, locate its site and plan the myectomy. In 30 patients, transesophageal echocardiography was also used to corroborate data on outflow tract anatomy and examine the mitral valve. RESULTS: In 40 patients (80%) the initial myectomy resulted in a reduction of the maximal outflow tract gradient from 88 +/- 45 to 24 +/- 11 mm Hg, measured by epicardial continuous wave Doppler echocardiography. Ten patients (20%) were shown by postbypass intraoperative echocardiography to have an unsatisfactory result, based on a persistent gradient > 50 mm Hg (n = 7) or persistent mitral regurgitation of greater than moderate severity (n = 3). The postbypass two-dimensional echocardiogram was then used to direct the surgeon toward the most likely site of continued obstruction, and cardiopulmonary bypass was reinstituted to permit further myectomy (n = 9) or mitral valve repair (n = 1). After the second or subsequent period of cardiopulmonary bypass, the outflow tract gradient (26 +/- 14 mm Hg) was substantially reduced and was not significantly different from the postbypass gradient (24 +/- 11 mm Hg) in the group with initial surgical success. At postoperative follow-up (20 +/- 37 weeks), the maximal measured outflow tract gradient (22 +/- 21 mm Hg) showed no difference between patients with immediate surgical success and those requiring a second period of cardiopulmonary bypass for further resection. CONCLUSIONS: Intraoperative echocardiography proved a useful tool to guide the site and extent of septal myectomy, leading to more adequate surgical resection and to persistence of satisfactory control of the outflow tract obstruction into the early follow-up period.

Coronary artery surgery in women compared with men: analyses of risks and long-term results.

A surgical experience with 2,445 consecutive women who underwent isolated bypass grafting was analyzed for comparison with 18,079 consecutive men. Severe or unstable angina occurred preoperatively in 60% of women and 45% of men (p less than 0.001). Despite less three vessel disease (44 versus 56%, p less than 0.001) and better left ventricular contraction (normal in 60% of women and 53% of men [p less than 0.001]), women had a higher operative mortality rate (2.9 versus 1.3%). When matched for age, severity of angina and extent of coronary atherosclerosis, women still had twice the operative mortality of men. In matched patients, body surface area was the strongest predictor of operative risk, even when the model was adjusted for gender. When the model was adjusted for body surface area, gender was not an important predictor of operative death. The smaller size of women, rather than their sex, appears to explain the difference in operative mortality. After a mean interval of 2 years, women had a lower overall graft patency rate (76.4%) than men (82.1%) (p less than 0.001). At 5 and 10 years postoperatively, a higher percent of men were angina-free. Yet, survival for women (90.6%) and for men (93.0%) at 5 years, and at 10 years (78.6 and 78.2%, respectively) was not dissimilar.

Marfan's syndrome: natural history and long-term follow-up of cardiovascular involvement.

A retrospective analysis was undertaken to define the natural history and long-term follow-up of a group of patients with Marfan's syndrome. Eighty-four patients were diagnosed between January 1959 and June 1987 as having Marfan's syndrome; 68% were male; their ages ranged from 2 to 67 years (mean 26.6). Sixteen patients constituted the early surgical group (those who underwent surgery before 1979; mean age 36.1 years). Nineteen patients constituted the late surgical group (surgery in 1979 or later; mean age 33.3 years). The nonsurgical group comprised 49 patients (mean age 19.3 years). Fifty-seven percent of the patients had a diastolic murmur and 38% had cardiomegaly at presentation. Fifty-seven percent underwent cardiac catheterization, which revealed aortic root dilation (85%), aortic regurgitation (73%), aortic dissection (33%) and mitral regurgitation (36%). Thirteen of the 19 patients in the late surgical group received a composite graft repair of the ascending aorta as compared with only 2 of the 16 in the early surgical group. Follow-up information was obtained on 81 (96%) of 84 patients; the follow-up time was 2 to 332 months (mean 99). Thirty-one of the 81 patients died at age 3 to 63 years (mean age 35 years); 87% of the known causes of death were related to the cardiovascular system. Sixty-one percent of deaths were the result of aortic dissection or rupture or sudden cardiac death. Of the 50 survivors, 98%, including all patients in the late surgical group, were in functional class I or II. Overall survival at 5, 10 and 15 years after operation was 78.4%, 57.1% and 49.5%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Young adults with coronary atherosclerosis: 10 year results of surgical myocardial revascularization.

This study reviews data on 107 patients, aged 35 years or younger, who underwent surgical coronary revascularization from 1971 to 1975. Early clinical events included one operative death and five nonfatal perioperative myocardial infarctions. Late follow-up (mean interval after operation 115 months) demonstrated actuarial survival rates of 94% at 5 years and 85% at 10 years. Fifteen late deaths, 23 nonfatal myocardial infarctions, 13 reoperations and return of severe angina in 10 patients were considered late clinical events. Actuarial survival free of early or late clinical events was 77% at 5 years and 53% at 10 postoperative years. Testing of clinical, angiographic and operative variables for influence on survival and event-free survival showed that survival was decreased by multivessel disease and impaired left ventricular function; event-free survival was decreased by a family history of coronary disease and cigarette smoking. Both survival and event-free survival were decreased by diabetes and elevated serum cholesterol. Postoperative cardiac catheterization (64 patients, mean postoperative interval 47 months) demonstrated that mammary artery graft patency (25 of 27, 93%) exceeded vein graft patency (49 of 88, 56%, p less than 0.01). The atherogenic diatheses of young adults may compromise the operative result, whereas use of internal mammary artery grafts may enhance the palliation of bypass surgery.

Fungal prosthetic valve endocarditis in 16 patients. An 11-year experience in a tertiary care hospital.

Fungal prosthetic valve endocarditis (PVE) is an infrequent but serious complication of valve replacement surgery. To examine its long-term outcome, we retrospectively studied 16 patients with 19 episodes of definite fungal PVE. The mean age was 51 years (range, 27-71 yr). Onset of fungal PVE ranged from 8 days to 3.4 years after valve replacement. Candida albicans was the most common (56%) pathogen isolated. A portal of entry was identified in only 25% of the patients; the presence of intravascular catheters (50%) and prior bacterial endocarditis (38%) were leading predisposing factors. Fever (83%) was the most consistent clinical finding. Potentially serious embolic events, particularly strokes (32%), were common at presentation. Transesophageal echocardiography (sensitivity = 100%) was more useful than transthoracic echocardiography (sensitivity = 60%) in detecting lesions due to fungal PVE. Combined valve replacement surgery and amphotericin B (mean total dose of 1.8 g) in 15 patients resulted in an 87% in-hospital survival and 67% overall survival with a mean follow-up of 4.5 years (range, 5 mo to 16 yr). Two patients had 3 late relapses of fungal PVE up to 9 years after the preceding episode. Each relapse was treated with repeat valve replacement and amphotericin B; in addition, oral azole was utilized for chronic suppression, although the efficacy of this strategy remains unproven. Because of the possibility of relapse, long-term follow-up is essential even after surgical and prolonged antifungal therapy.

Early and late results of coronary angioplasty and bypass in octogenarians.

Early and late results were evaluated for octogenarians undergoing first time revascularization with percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG). The study group consisted of 142 patients with CABG and 53 with PTCA. The groups with PTCA and CABG differed with respect to number of patients with angina class III to IV (92 and 67%, respectively; p less than 0.001), number with 3-vessel disease (34 and 77%, respectively; p less than 0.001), presence of left main trunk disease (2 and 24%, respectively; p less than 0.001) and number with normal or mildly impaired left ventricular function (82 and 65%, respectively; p less than 0.034). The groups with PTCA and CABG had similar procedural complications, including myocardial infarction (6 and 4%, respectively) and stroke (0 and 4%, respectively). Hospital mortality was low (6% with CABG and 2% with PTCA). Three year survival, excluding hospital mortality, was 87% in patients with CABG and 81% in those with PTCA (p = 0.493). Octogenarians underwent revascularization procedures with relatively low morbidity and mortality. In regard to the excellent long-term survival, "very" elderly patients with severe coronary artery disease should be considered for revascularization despite advanced age.

Correlation of preoperative myocardial function, perfusion, and metabolism with postoperative function at rest and stress after bypass surgery in severe left ventricular dysfunction.

Previous studies of dobutamine echocardiography (DE) and positron emission tomography (PET) showed similar accuracy for predicting improvement in resting wall motion after revascularization, although limited direct comparative data are available. We sought to compare the relative accuracy of detecting contractile reserve, ischemia, perfusion, and myocardial metabolism for predicting functional recovery after coronary bypass surgery in 94 consecutive patients (aged 63+/-11 years) with chronic coronary disease and depressed left ventricular function (ejection fraction 28+/-5%). PET imaging comprised rest and dipyridamole stress myocardial perfusion images, with fluorodeoxyglucose to define metabolism-perfusion mismatch. A standard dobutamine-atropine stress was used, with evaluation of low- and peak-dose echocardiographic responses. Regional function was assessed after 13+/-16 weeks at rest in 68 patients who underwent isolated coronary bypass operation without evidence of perioperative infarction, and at rest and stress in a subgroup of 29 patients. Concordance between methods for evaluating abnormal segments (ischemic, viable, and scar) and accuracy of both tests for predicting improvement in regional function were identified. Concordance between PET and DE for identifying viable or nonviable myocardium was 63% using a 16-segment model. For predicting improved resting function after surgery, the sensitivity of PET (84%) was superior to DE (69%, p<0.001), but DE was more specific (78% vs. 37%, p<0.0001) and more accurate (75% vs. 53%, p<0.001) in predicting recovery at rest. Analysis of postoperative recovery of segmental function during stress also showed the specificity of DE to exceed that of PET (89% vs. 32%, p<0.001). The accuracy of DE was enhanced by evaluation of function during stress (86%, p<0.001), but this was not altered with PET (52%, p = NS). Thus, PET is more sensitive than DE in predicting functional recovery, but DE is more specific than PET. Evaluation of left ventricular functional recovery during stress may be preferable to assessment at rest.

Frequency of acute myocardial infarction in valve repairs versus valve replacement for pure mitral regurgitation.

Three hundred thirty-five consecutive isolated mitral valve operations for mitral regurgitation in patients with no significant coronary artery disease were reviewed over a 26-month period for the presence of a perioperative acute myocardial infarction (AMI). Of 224 patients undergoing mitral valve repair 12 (5.4%) had electrocardiographic and cardiac enzyme evidence of perioperative AMI develop. Of 111 patients undergoing mitral valve replacement none had perioperative AMI develop as determined by electrocardiographic and enzyme criteria (p = 0.01). All 12 infarctions after valve repair involved the inferior wall by electrocardiographic or echocardiographic criteria. Although no patient had significant clinical difficulty in recovery, 7 of the 12 patients (58%) were left with Q waves upon hospital discharge. The etiology of the AMI is believed to be air emboli introduced at the time of testing valve competence during left ventricular insufflation under pressure. Changes in surgical technique may reduce or eliminate this complication.

Clinical markers, management, and long-term follow-up of early ischemia after coronary artery bypass grafting.

In summary, the occurrence of angina or myocardial infarction within 1 year after coronary bypass is associated with a high incidence of significant angiographic abnormalities. Early angiography is necessary to identify high-risk patients who could undergo revascularization. Patients with other markers of ischemia should have a noninvasive approach (stress imaging test) as initial evaluation, before coronary angiography is considered. When technically feasible, coronary angioplasty can be performed safely and with a high success rate. Repeat coronary bypass in this group of patients is associated with higher in-hospital complications. Patients with less compromised coronary anatomy can be treated medically with a good long-term outcome.

Atherosclerosis of the left main coronary artery: 5 years results of surgical treatment.

Three hundred consecutive patients received coronary arterial bypass grafts as treatment for stenosis of the left main coronary artery. Ostial stenosis was more prevalent among women (P less than 0.001). Operative (hospital) mortality was 4 percent (12 of 300). Among 148 survivors who underwent recatheterization after a mean interval of 16.5 months, the graft patency rate was 88 percent. After a minimal follow-up period of 49 months and a mean interval of 69 months, 75 percent of the survivors were asymptomatic and 94 percent were employed or fully active. The actuarial 5 year survival rate was 88.2 percent. The presence of right coronary artery disease, abnormal preoperative ventricular function and incomplete revascularization adversely affected survival, but the differences did not reach statistical significance. Comparison of this long-term follow-up study with controlled and noncontrolled studies of nonsurgical treatment of obstructions of the left main coronary artery indicates that myocardial revascularization alleviates cardiac symptoms and increases life expectancy in patients with severe atherosclerosis of this artery.

Applicability of mitral valvuloplasty techniques in a North American population.

Records of 520 patients who underwent mitral valve operations were reviewed to determine the pathophysiology, etiology, anatomy of the valve lesion and use of valvuloplasty techniques. Pure mitral regurgitation, present in 269 patients (52%), was the most common lesion while rheumatic valvulitis, seen in 286 patients (55%), was the most common etiology. Degenerative lesions were found in 168 patients, 33% of the total and 63% of the pure mitral regurgitation group. Two-hundred seventy patients (52%) were treated with valvuloplasty techniques. The incidence of reconstructive procedures was determined for each of the various patient subsets. Overall hospital mortality was 5.6% in the series: 8.4% for mitral replacement compared with 3% for mitral valvuloplasty (p = 0.007). Among patients undergoing primary isolated mitral procedures, hospital mortality for replacement was 7.5% compared with 1.4% for valvuloplasty (p = 0.018). Mitral valvuloplasty seems to provide a therapeutic alternative applicable to the spectrum of mitral valve pathology seen in a North American population.

Relation of serum triglyceride levels to survival after coronary artery bypass grafting.

We performed a prospective observational study on 6,602 subjects (94% for 5 years and 34% for 10 to 15 years) who underwent coronary artery bypass graft surgery (CABG) between 1982 and 1992. We examined whether triglyceride concentrations adjusted for other factors (total cholesterol, history of diabetes mellitus, systemic hypertension, left ventricular function, number of coronary arteries significantly narrowed, and use of the internal thoracic arteries) explained total and event-free survival. These analyses were duplicated within gender (1,354 women and 5,248 men). This approach allowed a determination of any gender-related disparities in lipid predictors. Triglycerides in the highest quartile were associated with an increased risk of mortality of 20% (confidence interval [CI] 1.0 to 1.4). Similar risk was seen for event-free survival. Although there was no evidence of gender differences in adjusted survival (p = 0.33), a gender by triglyceride interaction (p = 0.004) indicated that the response to high triglycerides as related to survival did differ by gender. Specifically, women had a dramatically higher risk (hazard ratio [HR] 1.5, CI 1.1 to 2.1) than men (HR 1.1, CI 0.9 to 1. 3). Both men and women did have triglyceride-associated risk with regard to event-free survival (HR in men 1.2, CI 1.1 to 1.4; HR in women 1.4, CI 1.1 to 1.8). Examination of high-density lipoprotein cholesterol in a subcohort did not eliminate the observed triglyceride effects. Thus, triglyceride baseline values are primary determinants (similar to baseline left ventricular function or extent of coronary disease) for long-term total and event-free mortality after CABG in women but not in men.

Competing risks after coronary bypass surgery: the influence of death on reintervention.

OBJECTIVE: For groups of patients at high risk of death, such as older patients, the actual probability of experiencing a nonfatal event, such as reintervention, must be far smaller than the potential probability were there no attrition by death. Competing risks analysis quantifies the difference. METHODS: Multivariable analyses were performed for the competing events death before reintervention, reoperation, and percutaneous transluminal coronary angioplasty in 2001 patients after bilateral internal thoracic artery grafting and in 8123 after single internal thoracic artery grafting. Follow-up was 9.7 +/- 3.0 years and 10.8 +/- 5.2 years in bilateral and single internal thoracic artery groups, respectively. RESULTS: Patients receiving single grafts experienced shorter survival and more reinterventions (P <.0001). However, other risk factors for death included old age (P <.0001), but risk factors for reintervention included young age (P <.0001). This difference confounds interpretation of event-free survival that is clarified by competing risks analysis. Death reduced the potential benefit of bilateral internal thoracic artery grafting on reintervention by angioplasty from a median of 8.5% to 5.5% at 12 years and by reoperation from 9.3% to 6.8%, with progressively greater erosion of benefit from attrition by death as age increased. Competing risks simulation confirmed that young age was a true risk factor for reintervention, excluding the explanation that it reflected simply passive attrition by death as patients age. CONCLUSIONS: Even after accounting for attrition by interim deaths, bilateral versus single internal thoracic artery grafting and older age are associated with fewer reinterventions. However, in high-risk patients, its benefit on freedom from reintervention is eroded considerably by death.

Aortic valve replacement: is valve size important?

OBJECTIVE: We sought to determine whether aortic prosthesis size adversely influences survival after aortic valve replacement. METHODS: A total of 892 adults receiving a mechanical (n = 346), pericardial (n = 463), or allograft (n = 83) valve for aortic stenosis were observed for up to 20 years (mean, 5.0 +/- 3.9 years) after primary isolated aortic valve replacement. We used multivariable propensity scores to adjust for valve selection factors, multivariable hazard function analyses to identify risk factors for all-cause mortality, and bootstrap resampling to quantify the reliability of the results. RESULTS: Twenty-five percent of patients had indexed internal orifice areas of less than 1.5 cm(2)/m(2) and more than 2 SDs (Z-value) below predicted normal aortic valve size. Mechanical valve orifices were smaller (1.3 +/- 0. 29 cm(2)/m(2), Z = -2.2 +/- 1.16) than pericardial (1.9 +/- 0.36 cm(2)/m(2), Z = -0.40 +/- 1.01) or allograft valves (2.1 +/- 0.50, Z = 0.24 +/- 1.17). The overall survival was 98%, 96%, 86%, 69%, and 49% at 30 days and 1, 5, 10, and 15 years postoperatively. Univariably, survival was weakly and inversely related to manufacturer valve size (P =.16) and internal orifice diameter (P =. 2) but completely unrelated to indexed valve area (P =.6) or Z-value (P =.8). These, and univariable differences among valve types (P =. 004), were accounted for by different prevalences in patient risk factors and not by valve size or type per se. Bootstrap resampling indicated that these findings had a less than 15% chance of being incorrect. CONCLUSIONS: Survival after aortic valve replacement is strongly related to patient risk factors but appears not to be adversely affected by moderate patient-prosthesis mismatch (down to about 4 SDs below normal). Aortic root enlargement to accommodate a large prosthesis may be required in few situations.

Axillary artery: an alternative site of arterial cannulation for patients with extensive aortic and peripheral vascular disease.

The increasing number of patients with extensive aortic and peripheral vascular atherosclerosis or aneurysms who are undergoing cardiac operations present difficult decisions as to the optimal site of arterial cannulation for cardiopulmonary bypass. Femoral artery cannulation is the most common alternative to ascending aortic cannulation, but severe iliofemoral disease or the danger of atheroemboli caused by retrograde perfusion through an atherosclerotic or aneurysmal descending aorta may make this approach impossible or undesirable. We have used axillary artery cannulation for cardiac operations in 35 patients for indications including severe aortic atherosclerosis (n = 16), extensive aortic aneurysms (n = 11), and aortic dissection (n = 8). The cardiac operations performed were coronary artery bypass grafting (n = 9) aortic valve replacement (n = 1), aortic valve replacement and coronary artery bypass grafting (n = 5), repair of mitral valve periprosthetic leak (n = 1), and resection of ascending and/or aortic arch (n = 19). Deep hypothermia with circulatory arrest was used in 26 patients and retrograde cerebral perfusion in 18. All patients awoke from the operation and no patient had a cerebrovascular accident. One patient required axillary artery thrombectomy and one patient had a mild ipsilateral brachial plexus paresis after the operation. Four patients died in the hospital. We conclude that axillary artery cannulation is a safe and effective means of providing antegrade arterial flow during cardiopulmonary bypass in patients with severe atherosclerotic or aneurysmal disease. This strategy may lower the prevalence of stroke associated with cardiopulmonary bypass in these patients.