Strategy for post coronary artery bypass grafting in patients with bypass graft stenosis: comparison of percutaneous transluminal coronary angioplasty for the native coronary artery, internal mammary artery and saphenous vein graft]

OBJECTIVES: The strategy for post coronary artery bypass grafting (CABG) was investigated in patients with graft stenosis. METHODS: The study included 123 post-CABG patients with graft stenosis. The patients were divided into three groups according to target vessels; saphenous vein graft (SVG; n = 72), internal mammary artery (IMA; n = 21) and native coronary artery (n = 30). Furthermore, SVG lesions were divided into proximal anastomosis (n = 23), body (n = 40) and distal anastomosis (n = 9). The procedural success rate and late patency rate were compared between the three groups. Furthermore, the relationships between pre percutaneous transluminal coronary angioplasty (PTCA) percentage diameter stenosis, procedural success rate and late patency rate were evaluated. RESULTS: Procedural success rate was similar in the three groups, but late patency rate was higher in the IMA group. Procedural success rate and late patency rate were significantly lower in proximal anastomoses compared to other sites of SVG stenoses, IMA group and native coronary artery group (p < 0.05). Totally occluded native coronary artery lesions had a high procedural success rate compared with occluded IMA and SVG lesions, but the late patency rate was not higher. Procedural success rate showed no significant difference for 75-99% stenotic lesions, but the late patency rate was significantly higher in the IMA group (p < 0.05). Patients in the stenting group had a greater late patency rate compared with the balloon angioplasty group. There was no significant difference in late patency rate between the IMA group and SVG group. CONCLUSIONS: Late patency rate of the IMA is higher than that of the native coronary artery. SVG with proximal anastomosis and severe stenosis shows a significantly lower late patency rate than the native coronary artery. Therefore, PTCA should be considered for the native coronary artery in the absence of chronic total occlusion.     

Long-term patency of saphenous vein and left internal mammary artery grafts after coronary artery bypass surgery: results from a Department of Veterans Affairs Cooperative Study

OBJECTIVES: This study defined long-term patency of saphenous vein grafts (SVG) and internal mammary artery (IMA) grafts. BACKGROUND: This VA Cooperative Studies Trial defined 10-year SVG patency in 1,074 patients and left IMA patency in 457 patients undergoing coronary artery bypass grafting (CABG). METHODS: Patients underwent cardiac catheterizations at 1 week and 1, 3, 6, and 10 years after CABG. RESULTS: Patency at 10 years was 61% for SVGs compared with 85% for IMA grafts (p < 0.001). If a SVG or IMA graft was patent at 1 week, that graft had a 68% and 88% chance, respectively, of being patent at 10 years. The SVG patency to the left anterior descending artery (LAD) (69%) was better (p < 0.001) than to the right coronary artery (56%), or circumflex (58%). Recipient vessel size was a significant predictor of graft patency, in vessels >2.0 mm in diameter SVG patency was 88% versus 55% in vessels 2.0 mm in diameter.     

Noninvasive quantitative evaluation of the patency of internal mammary artery grafts to the left anterior descending coronary artery by transthoracic Doppler echocardiography

OBJECTIVES: Evaluation of left anterior descending coronary artery (LAD) flow by transthoracic Doppler echocardiography (TTDE) may allow assessment of anastomosis of the internal mammary artery (IMA) grafted to the LAD. This study tested the feasibility of TTDE to evaluate anastomotic stenosis of the IMA grafted to the LAD. METHODS: TTDE was performed in 66 patients (48 men and 18 women, mean age 67 +/- 10 years) with left or right IMA grafts to the LAD. The distal IMA flow at the anastomosis was visualized and the percentage stenosis was evaluated by the continuity equation using the anastomotic and pre-anastomotic flow velocity measured by TTDE as well as by angiography. If the anastomotic flow was not visualized by TTDE, the absence of augmented diastolic flow of the proximal IMA, by using the supraclavicular approach, with diastolic to systolic mean velocity ratio < 0.25 was considered as anastomotic occlusion. RESULTS: Anastomotic flow was visualized and the percentage stenosis was obtained by the continuity equation in 50 patients. In 4 of the remaining 16 patients, the proximal IMA flow by TTDE showed the occlusion pattern. In these 54 (82%) patients, the percentage stenosis by TTDE showed a significant correlation with that by angiography (r2 = 0.86, p < 0.0001). In all the remaining 12 patients with the patent proximal IMA pattern but without visualized anastomotic flow, the patency was confirmed by angiography. CONCLUSIONS: TTDE enables direct visualization and quantitative evaluation of the anastomotic patency in patients with IMA graft to the LAD.     

Coronary artery bypass grafting by utilizing the internal mammary artery graft in 100 Japanese patients

The internal mammary artery (IMA) grafting for myocardial revascularization was performed in 100 Japanese patients during a three-year period. There were 86 males and 14 females with the mean age of 58 +/- 9 (37 approximately 75 year-old). Unilateral IMA was used in 88 patients and bilateral IMA was used in 12 patients. Sequential IMA grafting was performed in 5 patients. The sites of IMA grafting were 91 left anterior descending arteries (LAD), 16 diagonal branches, 8 circumflex arteries and 2 right coronary arteries. Saphenous vein or gastroepiploic artery was concomitantly used to bypass the other coronary arteries in 90 patients. The number of distal anastomosis ranged from 1 to 6 and the mean was 2.8 per patient. Two patients died within 30 days and one patient died at 3 months after surgery. Perioperative myocardial infarction was noted in 3 patients. Symptomatic relief was obtained in 94 (97%) of 97 survivors. The patency of the IMA graft at mean 2.2 postoperative months was 97% (58/60) in LAD, 100% (14/14) in the diagonal branch, 100% (5/5) in the circumflex artery, 100% (1/1) in the right coronary artery, and 98% (78/80) in over-all grafted coronary arteries. Pre- and postoperative exercise thallium scintigraphy in 13 patients, who received the IMA graft to severely stenosed LAD, showed significant improvement of the washout ratio (from 33.1 +/- 16.9% to 47.4 +/- 14.8%) which was nearly equivalent to that of the saphenous vein graft to LAD (from 24.8 +/- 6.2% to 48.1 +/- 6.6%, n = 7).(ABSTRACT TRUNCATED AT 250 WORDS)     

Follow-up angiography of 100 revascularizations of the anterior interventricular artery by the left internal mammary artery

One hundred and fifty patients who underwent revascularisation of the left anterior descending artery (LAD) by the left internal mammary artery (LIMA) between 1981 and 1983 were recalled for control coronary angiography one year after surgery. One hundred patients gave consent. The patency rate in these 100 patients was 90 per cent. The presumed causes of the 10 thromboses observed were: for LAD (5 cases), technical problems (3 cases), competitive flow (2 cases). Ten per cent of the patent LIMA grafts were abnormal: moderate stenosis of the anastomosis (5 cases), small LIMA (3 cases), stenosis of the middle segment of the LIMA (1 case). In addition, we observed 7 cases of competitive flows: 3 cases with a LAD which was not sufficiently stenotic, 4 cases with a large saphenous diagonal bypass graft. If a diagonal artery bypass is necessary, it is better to revascularize by either a latero-lateral anastomosis with the LIMA or by using the right IMA. Ninety per cent of the patent grafts were quite satisfactory ar 1 year: regular, supple, and perfectly congruent with the bypassed artery which was injected massively. As a number of North American teams have shown, this good patency rate seems to be maintained at long term, which is not the case with saphenous vein bypass grafts.     

Left internal mammary artery grafting to left anterior descending coronary artery by minimally invasive direct coronary artery bypass approach

New surgical techniques for the treatment of the isolated lesion of the left anterior descending coronary artery (LAD) include off-pump surgery, minimal access to the heart, and endoscopic or computer enhanced coronary artery bypass surgery. The term minimally invasive direct coronary artery bypass surgery (MIDCAB) is related to a leftside minithoracotomy, the harvest of the left internal mammary artery (IMA) under direct vision, and an anastomosis performed between IMA and LAD under direct vision, using the technique of mechanical local immobilization by a special device. Alternative techniques include endoscopic harvesting of the IMA, or as a new and still experimental approach, the closed-chest total endoscopic coronary artery bypass grafting (TECAB) with the use of a high tech telemanipulator system. The currently reported results demonstrate the safety of MIDCAB surgery (30-day mortality < 0.5%, perioperative myocardial infarction < 2%, early patency rate between 95% and 98%). Mid-term results after 6 months have shown a patency rate between 94% and 97%, and more than 90% of the patients are without any angina symptoms. Due to this promising results MIDCAB is an alternative treatment for high-grade LAD lesions.     

Usefulness of flow reserve in the left internal mammary artery to determine graft patency to the left anterior descending coronary artery

Two-dimensional Doppler echocardiography (DE) and intravascular Doppler-tipped guidewire (flowire) have been used to measure flow in aortocoronary conduits at rest and during hyperemia, but they have not been compared. We investigated which flow velocity parameters obtained with these 2 different techniques can predict left internal mammary artery (LIMA) graft patency. Twenty-nine patients with previous coronary artery bypass grafting referred for evaluation of symptoms of coronary artery disease were studied after cardiac catheterization using the flowire and DE. Proximal LIMA graft flow velocity was measured at rest and during hyperemia produced by 140 microg/kg/min of intravenous adenosine infusion over 6 minutes with both methods. Normal LIMA grafts and left anterior descending artery (LAD) distal to the anastomosis were present in 16 patients, whereas 13 had >70% graft or native vessel stenosis. The coronary flow velocity reserve (r = 0.79) and the diastolic-to-systolic velocity ratio during hyperemia (r = 0.73) correlated very well between the 2 techniques. Among the variables obtained with the 2 techniques, the intragraft coronary flow velocity reserve measured by both methods was the only independent predictor of graft/recipient LAD patency. This variable had a sensitivity and specificity of 86% at a cutoff point of 2.07 with the flowire method and 83% at a cutoff point of 1.54 with DE. The areas below the receiver-operating characteristic curves were 0.91 and 0.93, respectively. Coronary flow velocity reserve measurements obtained with DE appears a reliable noninvasive method for assessing LIMA graft and/or LAD distal to the anastomosis patency in patients after bypass surgery and correlate very well with those directly obtained by intravascular Doppler.     

Results of internal mammary artery-coronary artery bypass surgery and the characteristics of internal mammary artery grafts

Coronary artery bypass grafting utilizing the internal mammary artery (IMA) was performed in 108 patients with an operative mortality (less than 1 month) of 0% and a hospital mortality of 1.9%. The IMA was used most often in the left anterior descending artery system in combination with saphenous vein grafts (SVG) to the right and left circumflex artery systems. Although the IMA flow was smaller than the SVG flow when measured intraoperatively by an electromagnetic flow meter, postoperative clinical, electrocardiographic, isotopic, angiographic and coronary sinus flow-metric studies all demonstrated that the IMA can respond well to myocardial blood flow demand both at rest and during exercise, resulting in excellent clinical improvements with no detectable signs of flow deficiency. In addition, no signs of ischemia were detected in any of the 15 patients with stenosis in the left main trunk treated with an IMA graft. The IMA graft appears to have a great adaptive capacity to meet increased myocardial demand. Postoperative angiography performed at an average of 3 months after surgery in 60 unselected patients demonstrated an IMA patency rate of 98% in comparison with 88% patency in SVGs to the left anterior descending artery (p less than 0.05). Not only the patency rate, but also the graft wall characteristics were much better in IMA grafts than in SVGs. Some SVGs showed marked wall irregularity as early as 3 months after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)     

MSCT冠状动脉成像在冠状动脉旁路移植术后的应用

目的探讨64排MSCT冠状动脉成像在冠状动脉旁路移植术后的应用价值。方法分析行冠状动脉旁路移植术后于我院2012年3月至2014年2月期间行64层螺旋CT冠状动脉成像的患者35例。用评分的方法来客观评估冠状动脉桥血管吻合口及桥血管本身管腔狭窄的情况。对于中、重度狭窄的患者进一步行DSA检查,并与MSCT评估结果进行比较。结果35例患者共移植87支桥血管,其中评为2分的桥血管55支、评为1分的桥血管21支、评为0分的桥血管11支,桥血管通畅率为63．2％。评为1分的21支桥血管,经DSA检查18支桥血管评为1分、3支桥血管评为2分,正确率为85．7％;11支评为0分的桥血管经DSA检查均评为0分,正确率为100％。结论MSCT能够很好地显示冠状动脉旁路移植术后桥血管及其吻合口的狭窄及其程度,具有重要的实用价值。     

Significance of digital subtraction angiography for estimation of early results of myocardial revascularization after internal mammary artery grafting

Between 1st January and 31st December 1987 126 consecutive patients underwent full myocardial revascularization using at least one internal mammary artery bypass grafting in Department of Cardiovascular Surgery of University of Freiburg. In 78 patients (75 males, 3 females) DSA was performed within 8 days after surgery to evaluate dynamics of IMA-graft. The age ranged from 38 to 67 years (mean 53.4 years). DSA study was performed through the brachial artery, contrast medium was injected with flow of 10 ml/sec. in counter current. It was only one series of angiograms necessary to visualise flow from subclavian artery, through IMA to coronary artery. Among 78 investigated patients in 61 (78%) the distal anastomosis appeared to be widely patent and flow through the IMA and anastomosed coronary artery was sufficient. Patency of one of the branches of IMA or stenosis of IMA graft contributed to inadequate flow in 12 patients (15.6%). In 5 (6.4%) operated patients the IMA graft was not patent. Counter current intraarterial DSA requires much smaller amount of contrast medium than classical angiography, moreover avoiding of aortic catheterization with all risks involved. The counter current intraatrial DSA is an excellent technics of estimation of the flow to grafted coronary arteries. The method is easy to perform, repetitive and carry very small risk for the patient. Early postoperative evaluation of IMA-graft patency is essential for estimation of effectiveness of myocardial revascularisation and prognosis for the patient.     

Multislice computed tomography accurately detects stenosis in coronary artery bypass conduits

The aim of this study was to evaluate the accuracy of multislice computed tomography in detecting graft stenosis or occlusion after coronary artery bypass grafting, using coronary angiography as the standard. From January 2005 through May 2006, 25 patients (19 men and 6 women; mean age, 54 +/- 11.3 years) underwent diagnostic investigation of their bypass grafts by multislice computed tomography within 1 month of coronary angiography. The mean time elapsed after coronary artery bypass grafting was 6.2 years. In these 25 patients, we examined 65 bypass conduits (24 arterial and 41 venous) and 171 graft segments (the shaft, proximal anastomosis, and distal anastomosis). Compared with coronary angiography, the segment-based sensitivity, specificity, and positive and negative predictive values of multislice computed tomography in the evaluation of stenosis were 89%, 100%, 100%, and 99%, respectively. The patency rate for multislice computed tomography was 85% (55/65: 3 arterial and 7 venous grafts were occluded), with 100% sensitivity and specificity. From these data, we conclude that multislice computed tomography can accurately evaluate the patency and stenosis of bypass grafts during outpatient follow-up.     

Coronary artery size as a predictor of Y-graft patency following coronary artery bypass surgery

This study aims to evaluate the association between target vessel size and graft patency in the right IMA–right coronary territory anastomosis.A total of 402 patients who underwent CABG between 2005 and 2016 using the right IMA Y-graft to the posterolateral branch or posterior descending artery were enrolled. Preoperative coronary angiography was utilized to measure the size of the target coronary arteries in the right territory. Follow-up angiography and computed tomography at 6 to 12 months were used to determine graft patency.Thirty patients (7.5%) were found to have occluded graft. Larger target vessel size was associated with lower risk of graft occlusion (OR: 0.18, 95% CI:0.05–0.62, P = .007). The receiver operating characteristic (ROC) curve showed that the cutoff-value of 1.93 mm was found to have the maximum sum of sensitivity and specificity for graft patency (Area under the curve (AUC): 0.65, P = .01). Excluding patients with right coronary artery total occlusion, the discriminative performance of target vessel size became more prominent (AUC: 0.76, P < .01), with same cutoff value.In the setting of bilateral IMA composite grafting, the patency of right IMA to right coronary territory was influenced by the size of the target coronary artery. The influence of target coronary artery size was prominent in non-total occlusion patients. Careful selection of a target anastomosis site is recommended.     

Recruitable patency of the internal mammary artery graft.

A 46-year-old man underwent two coronary bypass operations and three percutaneous interventions over a period of 18 years. A non-functioning internal mammary artery (IMA) graft, was observed shortly after the second surgery. This graft was anastomosed to the left anterior descending (LAD) that had adequate flow from an older vein graft placed during the first surgery. Over the ensuing 8 years, the IMA graft regained patency after progressive occlusive disease in the competing vein graft.     

Hemodynamics and coronary blood flow during exercise after coronary artery bypass grafting with internal mammary arteries in children with Kawasaki disease

BACKGROUND. Saphenous vein grafts (SVG) and internal mammary artery (IMA) grafts have been used for coronary artery bypass grafting. In adult patients with bypass grafting for atherosclerotic coronary artery disease, IMA grafts have been reported to have long-term patency; however, results are conflicting on whether the graft is sufficient to meet increased myocardial oxygen demand during exercise. There have been no studies on hemodynamics and blood flow during exercise after bypass grafting with IMA in pediatric patients with Kawasaki disease. METHODS AND RESULTS. We studied 17 pediatric patients with Kawasaki disease (average age, 7.5 +/- 3.1 years), who underwent coronary artery bypass grafting with the IMA. The average number of coronary artery bypass grafts was 2.1 +/- 0.7/patient. For all patients, the left IMA was anastomosed to the left anterior descending coronary artery; for eight patients, the right IMA was also anastomosed to the right coronary artery. In addition, 11 SVGs were used. The postoperative patency rates after 1 month were 100% with the IMA graft and 91% with SVG. One year after the operation, the patency rates were 100% with IMA and 50% with SVG. Hemodynamics during exercise were measured with a bicycle ergometer, and coronary sinus blood flow was measured by the continuous thermodilution method in six patients. The relation between delta LVEDP (the difference between left ventricular end-diastolic pressure at rest and during exercise) and delta SVI (the difference between the stroke volume index at rest and during exercise) was analyzed. Four of six patients had reduced cardiac function before operation (delta LVEDP, positive; delta SVI, negative). However, after the operation, all patients demonstrated improvements in cardiac function during exercise (delta LVEDP, positive; delta SVI, positive). Coronary sinus flow per left ventricular mass increased after operation from 70 +/- 46 to 87 +/- 56 ml/min at rest (p less than 0.05) and from 139 +/- 118 to 183 +/- 150 ml/min during exercise (p less than 0.05). CONCLUSIONS. In conclusion, this study reveals improvements in both hemodynamics and coronary blood flow during exercise after coronary artery bypass grafting with IMA grafts in pediatric patients with Kawasaki disease.     

Atresia of the left internal mammary artery graft following percutaneous intervention of the left main

Because of its durability and patency, the left internal mammary artery (LIMA) is preferentially used to bypass obstructive lesions in the left main coronary artery (LMCA) and/or the left anterior descending coronary artery (LAD). The long-term patency of the LIMA graft is determined by several factors, principal among them being the dynamic competition between flow through the internal mammary artery graft and the LAD. We report a patient with LMCA stenosis and a well-functioning and mature LIMA graft, who after percutaneous intervention of the LMCA and normalized antegrade flow in the LAD, developed atresia of a large caliber LIMA graft.     

Coronary subclavian steal syndrome after internal mammary artery bypass grafting. A cause of severe postoperative recurrent myocardial ischemia

A 65-year-old underwent a triple bypass: internal artery mammary-descending coronary artery, aorta diagonal-lateral coronary (sequential). Three weeks later he started to have severe angina pectoris with ST depression in anterior EKG leads. A left transradial coronary angiography was performed. The examination showed a total occlusion of the left subclavian artery 2 cm after the aortic arch and a retrograde flow in the internal mammary artery (IMA). Via transfemoral approach, angiography showed the patency of the aorto-veinous sequential graft and a retrograde flow through anastomosis in the left mammary artery. The patient underwent a reimplantation of the IMA on the brachiocephalic artery. One month later the patient is doing well without chest pain. A coronary subclavian steal syndrome should be suspected in case of recurrent ischaemia after IMA bypass, particularly if there is more than 20 mmHg systolic pressure differential between the arms. Left transradial approach achieved diagnostic in case of total left subclavian artery occlusion.     

Subclavian coronary steal syndrome: an obligatory common fate between subclavian artery,internal mammary graft and coronary circulation

The long-term patency of the left internal mammary artery (IMA) has made it the preferred conduit for myocardial revascularization. The proximal segment of the subclavian artery becomes functionally connected to the coronary circulation as a result of IMA implantation during coronary artery bypass surgery. The subclavian coronary steal syndrome results from stenosis in the left subclavian artery proximal to the IMA, compromising blood flow to the myocardium. We describe 7 patients, aged 55-75 years, 1.7-10.5 years after coronary bypass who presented with recurrent angina due to subclavian artery stenosis. The IMA graft was found open in each patient. A true steal mechanism was not demonstrated, casting doubt on the syndrome's traditional name. Angioplasty and stenting of the subclavian artery resulted in the immediate disappearance of angina and continuous benefit at a follow-up of 3-32 months. The subclavian coronary steal syndrome, although rare, is a severe condition readily treated by angioplasty and stenting.     

Frequency of early occlusion and stenosis in a left internal mammary artery to left anterior descending artery bypass graft after surgery through a median sternotomy on conventional bypass: benchmark for minimally invasive direct coronary artery bypass

BACKGROUND: Uncertainty exists regarding the frequency of early occlusion when the left internal mammary artery (LIMA) is anastomosed to the left anterior descending artery (LAD) through a sternotomy with conventional coronary artery bypass grafting (CABG). The issue has gained importance for comparison with less invasive surgical approaches in which operative exposure may be limited and graft anastomosis more difficult. METHODS AND RESULTS: Data were analyzed from the International Multicenter Aprotinin Graft Patency Experience (IMAGE) trial in which 617 patients underwent conventional CABG of the LAD with a LIMA between April 1993 and May 1995. Coronary angiography was performed a mean of 10.8 days postoperatively. Patients were randomized to receive intraoperative aprotinin, an inhibitor of several serine proteinases, or placebo. Because no differences existed in patency rates of LIMA grafts between patients who received aprotinin and placebo, both groups were analyzed collectively. On coronary angiography, the LIMA was widely patent (<50% stenosis) in 561 patients (91%), had > or = 50% and <99% stenosis in 48 patients (7.8%), and was occluded in 8 patients (1.3%). Therefore, the LIMA was patent in 609 patients (98.7%). Conclusions-In the IMAGE trial, the largest and most contemporary early angiographic analysis of CABG available, early patency of the LIMA was >98% when anastomosed to the LAD. These data provide an important benchmark for less invasive surgical approaches in which the LIMA is anastomosed to the LAD.     

Coronary computed tomographic angiography for prediction of procedural and intermediate outcome of bypass grafting to left anterior descending artery occlusion with failed visualization on conventional angiography

Conventional coronary angiography (CCA) has considerable limitations regarding visualization of distal vessel segments in chronic total occlusion. We assessed the ability of coronary computed tomographic angiography (CCTA) to predict the success of coronary artery bypass grafting (CABG) to the chronically occluded left anterior descending coronary artery (LAD) incompletely visualized on CCA. Thirty symptomatic patients rejected for CABG on the basis of the CCA findings underwent preoperative CCTA before intended transmyocardial laser revascularization. The LAD was explored operatively in all patients, and CABG to the LAD was attempted if the distal vessel was suitable for anastomosis. The procedural outcome of CABG and the 6-month patency of the left internal mammary artery graft at follow-up CCTA were defined as the primary and secondary end point, respectively. The primary and secondary end points were achieved in 80% and 77% of patients, respectively. We found a significant correlation between the intraoperative and computed tomographic measurement of distal LAD diameter (R = 0.428, p = 0.037). On multivariate analysis, the maximum diameter of the distal LAD by CCTA (odds ratio 8.16, p = 0.043) was the only independent correlate of procedural success of CABG. A cutoff value of 1.5 mm for the mean distal LAD diameter predicted left internal mammary artery graft patency with 100% specificity and 83% sensitivity. Successful CABG resulted in significant improvements in angina class and left ventricular function in LAD segments at 6 months of follow-up. In conclusion, CCTA predicted both the procedural and the intermediate outcome of CABG to chronic LAD occlusion with failed visualization on CCA.     

Long-term patency of the right internal mammary artery used as a coronary bypass conduit and the effect of the recipient vessel

This study reviewed our experience with the long-term patency of the right internal mammary coronary artery (RIMA) bypass graft in 58 patients over 1 year. Thirty-one percent (n = 18) of patients had obstructive lesions in the RIMA. In vessels with any lesion, the percent stenosis was 85.5% (range 30% to 100%). Eleven of 38 patients (28%) with right-sided recipient vessels had significant stenosis, whereas 21% of left-sided recipient vessels had significant stenosis of the RIMA. When compared with left internal mammary artery grafting, the long-term patency of the RIMA was lower than expected and warrants larger prospective studies.