Value of delayed-enhancement cardiovascular magnetic resonance imaging in predicting myocardial viability after surgical revascularization.
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BACKGROUND: Despite the accepted utility of delayed-enhancement MRI in identifying irreversible myocardial injury, no study has yet assessed its role as a viability tool exclusively in the setting of coronary artery bypass surgery (CABG), and no study has repeated delayed-enhancement MRI late after revascularization. In a clinical trial in which patients underwent CABG by either the off-pump or on-pump surgical technique, we hypothesized that (1) preoperative delayed-enhancement MRI would have high diagnostic accuracy in predicting viability and (2) the occurrence of perioperative myocardial necrosis would affect late regional wall motion recovery. METHODS AND RESULTS: Fifty-two patients undergoing multivessel CABG were studied by preoperative and early (day 6) and late (6 months) postoperative cine MRI for global and regional functional assessment and delayed-enhancement MRI for assessment of irreversible myocardial injury. Preoperatively, 611 segments (21%) had abnormal regional function, whereas 421 segments (14%) showed evidence of hyperenhancement. At 6 months after revascularization, 57% (343 of 611) of dysfunctional segments improved contraction by at least 1 grade. When all preoperative dysfunctional segments were analyzed, there was a strong correlation between the transmural extent of hyperenhancement and the recovery in regional function at 6 months (P<0.001). Of a total of 96 previously dysfunctional but nonenhancing or minimally hyperenhancing myocardial segments that did not improve regional function at 6 months, 35 (36%) demonstrated new perioperative hyperenhancement in the early postoperative MRI scan. CONCLUSIONS: Delayed-enhancement MRI is a powerful predictor of myocardial viability after surgery, suggesting an important role for this technique in clinical viability assessment. (+info)
On-pump versus off-pump coronary artery bypass surgery in a matched sample of women: a comparison of outcomes.
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BACKGROUND: Women have consistently higher mortality and morbidity than men after coronary artery bypass grafting (CABG). Whether elimination of cardiopulmonary bypass and performance of coronary artery bypass grafting off-pump (OPCAB) have a beneficial effect specifically in women has not been defined. METHODS AND RESULTS: From January 1998 through March 2002, 21 902 consecutive female patients at 82 hospitals underwent isolated CABG, as reported in an administrative database. Propensity score computer matching was performed based on 13 variables representing patient characteristics and preoperative risk factors to correct for and minimize selection bias. A total of 7376 (3688 pairs) women undergoing CABG surgery were able to be successfully matched. In a propensity score computer-matched cohort, multivariate logistic regression (odds ratio) revealed that women undergoing on-pump surgery had a 73.3% higher mortality (P=0.002) and a 47.2% higher risk of bleeding complications (P=0.019). CONCLUSIONS: In a retrospective analysis of women undergoing CABG, computer-matched to minimize selection bias, off-pump surgery led to decreased mortality and morbidity including bleeding complications. (+info)
Why is off-pump coronary surgery uncommon in Canada? Results of a population-based survey of Canadian heart surgeons.
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BACKGROUND: Off-pump coronary artery bypass (OPCAB) is proposed to improve clinical outcomes and decrease resource use. However, off-pump surgery is not widely used in Canada. The purpose of this study was to determine the current use of OPCAB in Canada and determine why surgeons have not adopted this technique. METHODS AND RESULTS: The study was a population-based survey of all adult Canadian cardiac surgeons in practice >1 year. Eligible division heads and surgeons were contacted by mail. Of 19 806 isolated coronary bypass surgeries performed by respondents in Canada last year, 3164 (16.0%) were performed off-pump. More than 50% of Canadian surgeons performed OPCAB in <5% of coronary cases, and only 17% of surgeons performed OPCAB in >25% of coronary cases. Only 4 responding centers performed OPCAB in >25% of cases. Respondents were divided into those who performed <5% of cases off-pump (nonadopters), 5% to 25% off-pump (intermediate users), or >25% off-pump (enthusiasts). Mean number of distal anastomoses in off-pump cases were 1.7+/-0.6, 1.6+/-0.6, and 3.3+/-0.5 for nonadopters, intermediate users, and enthusiasts, respectively (P=0.001). Eleven percent of nonadopters, 55% of intermediate users, and 81% of enthusiasts believed OPCAB improved clinical outcomes (P<0.0001). Only 23% of all respondents felt OPCAB use would increase in the next 5 years. CONCLUSIONS: Concerns regarding incomplete revascularization and lack of proven clinical benefit have limited OPCAB to being performed routinely by only a small number of surgeons in Canada. (+info)
Role of coronary collaterals in off-pump and on-pump coronary bypass surgery.
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BACKGROUND: Collaterals limit infarct size, preserve viability, and reduce mortality in patients with acute myocardial infarction. In patients with stable coronary disease, collaterals are associated with less angina and ischemia during angioplasty and fewer ischemic events during follow-up. The role of collaterals has not been studied in patients undergoing off-pump or on-pump bypass surgery. METHODS AND RESULTS: The population consisted of the 281 patients randomized to off-pump or on-pump CABG in the Octopus Study. Collaterals were defined on the baseline angiogram with the Rentrop score and were present in 49% and 51% of the patients in the off-pump and on-pump group, respectively. Perioperative myocardial infarction was defined by a creatine kinase-MB to CK ratio >10% and occurred in 18.2% in the off-pump group and 32.5% in the on-pump group. The unadjusted OR of perioperative myocardial infarction in the presence of collaterals was 0.31 (95% CI 0.17 to 0.84) in the off-pump group and 1.06 (95% CI 0.29 to 3.85) in the on-pump group After adjustment for age, gender, hypertension, hypercholesterolemia, diabetes, multivessel disease, ventricular dysfunction, incomplete revascularization, and ischemic time, the OR was 0.34 (95% CI 0.14 to 0.84) in the off-pump group and 1.28 (95% CI 0.30 to 5.40) in the on-pump group, respectively. Kaplan-Meier estimates of event-free survival at 1 year were 87% in patients with and 69% in those without collaterals after off-pump CABG. These estimates were 66% and 63%, respectively, after on-pump CABG. CONCLUSIONS: Collaterals protect against perioperative myocardial infarction during off-pump surgery but not during on-pump surgery and are associated with a better 1-year event-free survival. (+info)
Cardiomed coronary flow meter for prevention of early occlusion in aortocoronary bypass grafting.
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INTRODUCTION: The number of patients undergoing technically demanding off-pump myocardial revascularization is increasing, these days. Some researchers question the quality of the aortocoronary bypasses done on the beating heart and consequently their good patency. MATERIAL AND METHODS: 50 consecutive patients underwent off pump coronary surgery using sequential bypass technique, at our department. The quality of constructed grafts was evaluated using the CardioMed Trace System (CM4008, Medi-Stim As, Oslo, Norway) (TTFM). RESULTS: All sequential bypasses showed good per-operative quality with a mean fl ow of 69.4 ml/min. CONCLUSION: TTFM seems to be an effective tool for the per-operative aortocoronary bypass patency verification and should help to prevent early graft occlusion. ABBREVIATIONS: TTFM transit time flow meter. (+info)
One-year coronary bypass graft patency: a randomized comparison between off-pump and on-pump surgery angiographic results of the PRAGUE-4 trial.
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BACKGROUND: Off-pump coronary bypass surgery has become a widely used technique during recent years. However, limited data are available with regard to 1-year patency of bypass grafts implanted on the beating heart in unselected consecutive bypass surgery candidates. The aim of this study was to compare 1-year angiographic patency of bypass grafts done on the beating heart (off pump) with those done classically (on pump). METHODS AND RESULTS: The PRAGUE-4 trial randomized 400 consecutive nonselected cardiac surgery candidates into group A (on pump; n=192) and group B (off pump; n=208). One-year follow-up coronary angiography was done in 255 patients. The arterial graft patency after 1 year was 91% in both groups. Saphenous graft patency was 59% (on pump) versus 49% (off pump; P=NS). Saphenous graft patency per patient was lower in the off-pump group: 0.7 patent anastomosis per patient versus 1.1 patent anastomosis in the on-pump group (P<0.01). There were 46% on-pump patients with all grafts patent versus 52% off-pump patients (P=NS). Grafts anastomosed distally to collateralized chronic total occlusions of native coronary arteries remained patent in 100% on the left anterior descending artery compared with 23% on other arteries (P<0.0001). CONCLUSIONS: The patency of arterial coronary bypass grafts done on the beating heart is excellent and equal to grafts done on pump. The off-pump procedure in the unselected patient population results in fewer patent saphenous grafts per patient. (+info)
Off-pump coronary artery bypass grafting: single center experience with 1,000 consecutive patients.
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BACKGROUND: Advances in surgical techniques and retractor-stabilizer devices allowing access to all coronary segments have resulted in increased interest in off-pump coronary artery bypass. The residual motion in the anastomotic site and potential hemodynamic derangements, however, render this operation technically more demanding. OBJECTIVES: To evaluate the OPCAB experience in a single Israeli center. METHODS: Between 2000 and 2003 in our institution, 1,000 patients underwent off-pump operations. Patients were grouped by the type of procedure, i.e., minimally invasive direct coronary artery bypass or mid-sternotomy OPCAB. RESULTS: One hundred MIDCAB operations were performed. Of the 900 OPCAB, 767 patients received multiple grafts with an average of 2.6 +/- 0.6 grafts per patient (range 2-4) and the remaining patients underwent single grafting during hybrid or emergency procedures. In the multiple-graft OPCAB group, complete revascularization was achieved in 96%. Multiple arterial conduits were used in 76% of the patients, and total arterial revascularization without aortic manipulation, using T-graft (35%) or in situ configurations, was performed in 61%. The respective rates for early mortality, myocardial infarction and stroke in the MIDCAB were 1%, 0% and 2%, and 2%, 1.3% and 0.9% in the multiple-vessel OPCAB groups. Multivariate analysis identified renal dysfunction (odds ratio 11.5, confidence interval 3.02-43.8; P < 0.0001) and emergency operation (OR 8.74, CL 1.99-38.3; P = 0.004) as predictors of mortality. The proportion of off-pump procedures increased from 9% prior to the study period to 59%. CONCLUSIONS: The use of OPCAB does not compromise the ability to achieve complete myocardial revascularization. Our procedure of choice is OPCAB using arterial conduits, preferably the 'no-touch' aorta technique. (+info)
Off-pump bypass surgery: the early experience, 1969-1985.
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This is a review of 733 patients who underwent off-pump bypass surgery of the right coronary artery and left anterior descending coronary artery between 1969 and 1985. Two hundred sixty-four patients underwent single bypass of the left anterior descending coronary artery, and 79 patients underwent single bypass of the right coronary artery. Both the left anterior descending and right coronary arteries were bypassed in 390 patients. In contrast to the present-day use of mechanical devices to stabilize the target vessel, a 4-suture surgical technique was used for this purpose. This technique, which we illustrate, proved less cumbersome and made the graft anastomosis easy to perform. Our early experience (1969 through 1972) in operating on 199 patients resulted in an operative mortality rate of 4.5% (9/199). From 1973 through 1985, improved patient selection and use of the left internal thoracic artery as the conduit of choice for bypass of the left anterior descending coronary artery reduced the operative mortality rate for 534 patients to 1.3% (7/534). Routine postoperative angiograms were not performed; therefore, the graft patency rate is not available. However, an ongoing 34-year follow-up study of the 264 patients who underwent a single left anterior descending bypass showed the saphenous vein graft to be open in 64.3% (18/28) patients and the left internal thoracic graft in 92.2% (59/64) of patients studied. Seventy-four of the 264 patients in this study were still alive in 2003. (+info)