Do particulate emboli from the ascending aorta in coronary bypass grafting correlate with aortic wall thickness?

This study investigated the previously uncertain relationship of embolic load captured during coronary artery bypass grafting and the extent of ascending aortic atherosclerosis as measured by wall thickness. Patients (n=113) underwent isolated arrested heart coronary artery bypass grafting. Ascending aortic wall thickness measures were obtained by epiaortic ultrasound. Aortic segmental values (distal, mid, proximal) were determined by the summation of measures (anterior lateral, posterior, medial) at each segment. An intraaortic filter (EMBOL-X) System, Edwards Lifesciences, Irvine, CA) was placed into the arterial cannula, distal to the aortic measurements, just before releasing the aortic cross-clamp. Particulate debris was found in 96% (109/113) of filters. Mean number of particles was 6.8+/-4.8 (range 0-23) and mean particle surface area was 5.5+/-7.0 mm(2) (range 0-51 mm(2)). Total aortic wall thickness, distal third, mid third, and proximal third thicknesses were 27.4+/-4.4 mm, 9.5+/-2.0 mm, 9.0+/-1.9 mm, and 8.8+/-1.4 mm, respectively. There was no significant correlation between the number of particles or surface area and any of the aortic wall thickness measures. These results suggest that during on-pump, arrested heart coronary artery bypass grafting, embolic load from the ascending aorta is independent of the extent of ascending aortic atherosclerosis in patients with low or moderate risk aortic pathology.

The influence of ascending aortic atherosclerosis on the long-term survival after CABG.

OBJECTIVE: Ascending aortic atherosclerosis is a risk factor for perioperative morbidity and mortality in coronary surgery. It was the aim of our study to determine the role of atherosclerosis of the ascending aorta and other factors for the survival rate during long-term follow-up after CABG. METHODS: From 500 out of 580 CABG patients (aged 67 (33-85) years, 77% male), who underwent intraoperative epiaortic ultrasound for assessment of ascending aortic wall thickness, a complete follow up regarding long-term survival was achieved. The median follow-up time was 55 (1-78) months. RESULTS: 53/500 (11%) patients died within the follow-up period, and the cumulative survival rate was 95, 90, and 84% after 1, 3, and 5 years, respectively (including hospital deaths). A significantly lower long-term survival was present in patients with: an age of 70 years or more (P<0.001), COPD (P=0.005), preoperative elevated serum creatinine of >1.2mg/dl (P=0.007), preoperative LVEF <40% (P=0.033), ascending aortic wall thickness of 4mm or more (P=0.001), carotid artery disease (P<0.001), peripheral vascular disease (P<0.001), and acute operation (P=0.009). Multivariate analysis revealed carotid artery disease, LVEF <40%, peripheral vascular disease, and advanced age to be independent risk factors. CONCLUSION: Patients with ascending aortic atherosclerosis are at risk for a decreased long-term survival after CABG. Besides, preoperative elevated serum creatinine, COPD, carotid artery disease, LVEF <40%, peripheral vascular disease, and advanced age are risk factors for a decreased long-term survival after CABG.

Risk factors for late stroke after coronary artery bypass grafting.

BACKGROUND: Postoperative stroke is a severe complication immediately after coronary artery bypass grafting, and it significantly deteriorates the postoperative quality of life if it occurs in the long term. It was the aim of our study to determine factors associated with the occurrence of new strokes during long-term follow-up after coronary artery bypass grafting. METHODS: From 387 of 500 patients undergoing coronary artery bypass grafting (age, 67 years [33-84 years]; 76% male) who had intraoperative epiaortic ultrasonography for assessment of ascending aortic wall thickness, a complete follow-up regarding postoperative stroke was achieved. The median follow-up time was 52 months (9-74 months). RESULTS: A stroke occurred in 26 (7%) of 387 patients, and the cumulative freedom from stroke was 99%, 95%, and 89% after 1, 3, and 5 years, respectively. A significantly lower freedom from stroke was present in patients with an age of 70 years or more (P = .007), preoperative unstable angina (P = .031), chronic obstructive pulmonary disease (P = .009), carotid artery disease (P < .001), preoperative history of neurologic events (P < .001), and a maximum ascending aortic wall thickness of 4 mm or more (P = .010). Multivariate analysis revealed preoperative history of neurologic events (P = .021) to be an independent risk factor. CONCLUSION: Patients with ascending aortic atherosclerosis, older age (> or =70 years), preoperative unstable angina, chronic obstructive pulmonary disease, and carotid artery disease are at risk for late postoperative stroke after coronary artery bypass grafting. A history of neurologic events is of special predictive importance.

Factors associated with presence of ascending aortic atherosclerosis in CABG patients.

BACKGROUND: The indication for epiaortic scanning during coronary artery operation is still a matter of debate. Whether this test should be carried out selectively or on a routine basis is unclear. The aim of this study was to determine factors that predict the presence of atherosclerotic ascending aortic wall thickening in patients undergoing coronary artery bypass grafting (CABG). METHODS: A total of 500 CABG patients underwent epiaortic scanning using a high-frequency linear ultrasonic probe. Maximum ascending aortic wall thickness was measured and correlated with patient-related variables. RESULTS: Maximum ascending aortic wall thickness significantly correlated with age (p < 0.001), preoperative creatinine level (p = 0.004), European system for cardiac operative risk evaluation (EuroSCORE, p < 0.001), and maximum descending aortic wall thickness (p < 0.001). Body mass index and left ventricular ejection fraction showed no correlation with maximum ascending aortic wall thickness. Of the categorical variables, hypertension (p = 0.02), unstable angina (p = 0.04), chronic obstructive pulmonary disease (p = 0.02), cerebrovascular disease (p < 0.001), and peripheral vascular disease (p < 0.001) were associated with increased ascending aortic wall thickness whereas sex, diabetes, acute cases, and previous cardiac operation were not. Multivariate analysis revealed maximum descending aortic wall thickness (p < 0.001), cerebrovascular disease (p = 0.03), and peripheral vascular disease (p = 0.04) as independent variables significantly associated with maximum ascending aortic wall thickness. CONCLUSIONS: If epiaortic scanning is not carried out routinely for detection of ascending aortic arteriosclerosis it should at least be performed in patients with old age, hypertension, unstable angina, chronic obstructive pulmonary disease, cerebrovascular disease, peripheral vascular disease, elevated creatinine levels, higher EuroSCOREs, and increased wall thickness of the descending aorta.

Modification of surgical technique for ascending aortic atherosclerosis: impact on stroke reduction in coronary artery bypass grafting.

OBJECTIVE: Use of epiaortic scanning in coronary surgery is still a matter of debate. It is unclear whether the findings obtained by epiaortic scanning lead to effective changes in surgical technique that may reduce stroke rates. METHODS: Epiaortic scanning was performed in 352 patients undergoing primary coronary artery bypass grafting before opening the pericardium using a 7.5-MHz ultrasonic probe. In the presence of moderate atherosclerosis (maximum aortic wall thickness of 3 to 5 mm), primarily single aortic crossclamping was carried out. In cases of severe sclerosis (maximum aortic wall thickness > 5 mm), aortic no-touch techniques on the beating heart were used. RESULTS: The degree of ascending aortic atherosclerosis was normal or mild in 151 patients (42.9%), moderate in 167 patients (47.5%), and severe in 34 patients (9.6%). The operative technique was modified in 31.1% of patients with moderate aortic sclerosis and in 91.2% of patients with severe aortic sclerosis. Perioperative mortality was 0.0% for mild disease, 3.0% for moderate disease, and 8.8% for severe disease (P =.005). Corresponding stroke rates reached 2.0%, 2.4%, and 2.9% (P =.935). Logistic regression adjusting for EuroSCORE showed that ascending aortic atherosclerosis was an independent predictor of perioperative mortality (P =.013, odds ratio 1.67, confidence interval 1.11-2.50). The influence of aortic disease on the stroke prevalence was probably due to chance (P =.935), demonstrating a potentially positive effect of operative modifications concerning stroke caused by aortic manipulation. CONCLUSIONS: We conclude that intraoperative screening of coronary artery bypass grafting patients by epiaortic scanning can reveal useful information about the operative risk and with an aortic no-touch concept, perioperative stroke rates in high-risk patients may be lower than predicted.