Current trends in bilateral internal thoracic artery use for coronary revascularization: Extending benefit to high-risk patients.

BACKGROUND: We sought to identify the trends in bilateral internal thoracic artery use and determine the degree to which the survival advantage of bilateral internal thoracic artery revascularization persists among perceived "high-risk" patients, compared with the use of left internal thoracic artery alone. METHODS: A retrospective review was conducted of patients who underwent isolated coronary artery bypass grafting for multivessel coronary artery disease at the Mayo Clinic between January 2000 and December 2015. Propensity score matching was performed between patients with bilateral internal thoracic artery and left internal thoracic artery alone grafts (1011 matched pairs). Effect of bilateral internal thoracic artery use on survival in "high-risk" patients (ejection fraction <40%, body mass index ≥30, age ≥70 years, diabetes, chronic lung disease, cerebrovascular accident) was evaluated. RESULTS: A total of 6468 isolated coronary artery bypass grafts were performed (5431 using left internal thoracic artery alone, 1037 using bilateral internal thoracic artery). There was an increasing trend in bilateral internal thoracic artery use (P value for linear trend = .005), with the percentage of coronary artery bypass grafting cases with bilateral internal thoracic artery doubling over the last 4 years (13% in 2012 to 27% in 2015). Propensity-matched comparisons showed a survival advantage for bilateral internal thoracic artery (hazard ratio, 0.81; 95% confidence interval, 0.66-0.99; P = .043). Risk of deep sternal wound infection, although higher in the bilateral internal thoracic artery group, was not significant (1.2% vs 0.5%; P = .088). None of the "high-risk" subsets of patients showed an adverse effect of bilateral internal thoracic artery on survival. CONCLUSIONS: Bilateral internal thoracic artery use in coronary artery bypass grafting is increasing over time. There is a consistent survival benefit with bilateral internal thoracic artery use, extending to patients with higher-risk comorbidities, suggesting the need for further expansion in use of this technique.

Incidence and clinical implications of intraoperative bilateral internal thoracic artery graft conversion: Insights from the Arterial Revascularization Trial.

BACKGROUND: The Arterial Revascularization Trial has been designed to answer the question whether the use of bilateral internal thoracic arteries can improve 10-year outcomes when compared with single internal thoracic arteries. In the Arterial Revascularization Trial, a significant proportion of patients initially allocated to bilateral internal thoracic arteries received other conduit strategies. We sought to investigate the incidence and clinical implication of bilateral internal thoracic artery graft conversion in the Arterial Revascularization Trial. METHODS: Among patients enrolled in the Arterial Revascularization Trial (n = 3102), we excluded those allocated to single internal thoracic arteries (n = 1554), those who did not undergo surgery (n = 16), and those who underwent operation but withdrew after randomization (n = 7). Propensity score matching was used to compare converted versus nonconverted bilateral internal thoracic artery groups. RESULTS: A total of 1525 patients were operated with the intention to receive bilateral internal thoracic artery grafting. Of those, 233 (15.3%) were converted to other conduit selection strategies. Incidence of conversion largely varied across 131 participating surgeons (from 0% to 100%). The most common reason for bilateral internal thoracic artery graft conversion was the evidence of at least 1 internal thoracic artery that was not suitable, which was reported in 77 cases. Patients with intraoperative bilateral internal thoracic artery graft conversion received a lower number of grafts (2.95 ± 0.84 vs 3.21 ± 0.74; P < .001). However, the hospital mortality rate was comparable to that of those who did not require bilateral internal thoracic artery graft conversion (0% vs 1.6%; P = .1), as well as the incidence of major complications. At 5 years, we found a nonsignificant excess of deaths (11.9% vs 8.4%; P = .1) and major adverse events (17.1% 13.2%; P = .1) mainly driven by an excess of revascularization in patients requiring conversion. CONCLUSIONS: The incidence of intraoperative bilateral internal thoracic artery graft conversion is not infrequent. Bilateral internal thoracic artery graft conversion is not associated with increased operative morbidity, but its effect on late outcomes remains uncertain.

National Trends and Geographic Variation in Bilateral Internal Mammary Artery Use in the United States.

BACKGROUND: The goal of this study was to characterize the adoption rate and regional variation in bilateral internal mammary artery (BIMA) use during coronary artery bypass grafting (CABG) in the United States. METHODS: Observational study of 100% sample of fee-for-service Medicare beneficiaries aged 65 years or older, continuously enrolled in Parts A and B from 2009 to 2014 (n = 162,860,439). Rates of beneficiaries receiving a BIMA versus single internal mammary artery (SIMA) during CABG are expressed per 1,000 beneficiaries and aggregated by Hospital Referral Region (HRR). An HRR is a validated unit for quantifying regional variation in health care. RESULTS: The absolute national rate of BIMA use declined during the study period from 0.21 claims per 1,000 beneficiaries in 2009 to 0.13 in 2014 (p < 0.001). When indexed to overall CABG volume, no change was seen in the frequency of BIMA use over time (p = 0.883). SIMA use ranged from 1.3 to 8.5 claims per 1,000 Medicare beneficiaries, whereas BIMA use ranged from 0 to 1.5 (p < 0.001). A significant correlation was found between regional volume of SIMA use and likelihood of BIMA use (correlation coefficient 0.673, p < 0.001). Although both SIMA and BIMA use correlated with regional volume of diagnostic cardiac catheterization, the correlation was stronger for SIMA use (correlation coefficient 0.962 versus 0.682, p < 0.001). CONCLUSIONS: Over the past 5 years, no growth was seen in BIMA use among Medicare beneficiaries, and the frequency of BIMA use during CABG remained low. There was significant regional variation in BIMA use, however, which demonstrates opportunity for continued growth of BIMA grafting.

Frequency and Predictors of Internal Mammary Artery Graft Failure and Subsequent Clinical Outcomes: Insights From the Project of Ex-vivo Vein Graft Engineering via Transfection (PREVENT) IV Trial.

BACKGROUND: The internal mammary artery (IMA) is the preferred conduit for bypassing the left anterior descending (LAD) artery in patients undergoing coronary artery bypass grafting. Systematic evaluation of the frequency and predictors of IMA failure and long-term outcomes is lacking. METHODS AND RESULTS: The Project of Ex-vivo Vein Graft Engineering via Transfection (PREVENT) IV trial participants who underwent IMA-LAD revascularization and had 12- to 18-month angiographic follow-up (n=1539) were included. Logistic regression with fast false selection rate methods was used to identify characteristics associated with IMA failure (≥75% stenosis). The relationship between IMA failure and long-term outcomes, including death, myocardial infarction, and repeat revascularization, was assessed with Cox regression. IMA failure occurred in 132 participants (8.6%). Predictors of IMA graft failure were LAD stenosis <75% (odds ratio, 1.76; 95% confidence interval, 1.19-2.59), additional bypass graft to diagonal branch (odds ratio, 1.92; 95% confidence interval, 1.33-2.76), and not having diabetes mellitus (odds ratio, 1.82; 95% confidence interval, 1.20-2.78). LAD stenosis and additional diagonal graft remained predictive of IMA failure in an alternative model that included angiographic failure or death before angiography as the outcome. IMA failure was associated with a significantly higher incidence of subsequent acute (<14 days of angiography) clinical events, mostly as a result of a higher rate of repeat revascularization. CONCLUSIONS: IMA failure was common and associated with higher rates of repeat revascularization, and patients with intermediate LAD stenosis or with an additional bypass graft to the diagonal branch had increased risk for IMA failure. These findings raise concerns about competitive flow and the benefit of coronary artery bypass grafting in intermediate LAD stenosis without functional evidence of ischemia. CLINICAL TRIAL REGISTRATION: URL: http:/www.clinicaltrials.gov. Unique identifier: NCT00042081.

Cardiac surgical procedures for the coronary sequelae of Kawasaki disease.

OBJECTIVES: The aim of this article is to make an evaluation on the clinical features of patients with Kawasaki disease who require a cardiac surgical procedure including coronary artery bypass grafting, coronary arterial aneurysmorrhaphy or heart transplantation. METHODS: English literature of Kawasaki disease for cardiac surgery (1990-2011) was retrieved in the Pubmed database. The clinical features of the patient setting from the representative articles were collected and analyzed. RESULTS: Patients with Kawasaki disease were very young, with some requiring a cardiac surgical procedure at a very early age. The interval between the onset and the surgical operation was 9.5±9.4 years. The prevalence of myocardial infarction and re-infarction was high. Giant aneurysm, critical stenosis with calcification and thrombus formation of the coronary arteries often warrant coronary artery bypass, heart transplantation or coronary arterial aneurysm plication. The left internal mammary artery to the left anterior descending coronary artery was the most commonly used graft in coronary artery bypass. Graft patency rate was 82.4% at 21.4±32.3 (range 0.1-252) month follow-up. The early and late mortalities of this patient setting were 0.6 and 3.0%, respectively. CONCLUSIONS: Patients with Kawasaki disease may develop coronary artery lesions prone to aneurysmal formation with calcification and thrombus and may require coronary artery bypass at a very early age. With the left internal mammary artery as the first choice of bypass graft, the long-term patency and patient survival was satisfactory.

Multiple arterial grafts improve late survival of patients undergoing coronary artery bypass graft surgery: analysis of 8622 patients with multivessel disease.

BACKGROUND: Use of the left internal mammary artery (LIMA) in multivessel coronary artery disease improves survival after coronary artery bypass graft surgery; however, the survival benefit of multiple arterial (MultArt) grafts is debated. METHODS AND RESULTS: We reviewed 8622 Mayo Clinic patients who had isolated primary coronary artery bypass graft surgery for multivessel coronary artery disease from 1993 to 2009. Patients were stratified by number of arterial grafts into the LIMA plus saphenous veins (LIMA/SV) group (n=7435) or the MultArt group (n=1187). Propensity score analysis matched 1153 patients. Operative mortality was 0.8% (n=10) in the MultArt and 2.1% (n=154) in the LIMA/SV (P=0.005) group, which was not statistically different (P=0.996) in multivariate analysis or the propensity-matched analysis (P=0.818). Late survival was greater for MultArt versus LIMA/SV (10- and 15-year survival rates were 84% and 71% versus 61% and 36%, respectively [P<0.001], in unmatched groups and 83% and 70% versus 80% and 60%, respectively [P=0.0025], in matched groups). MultArt subgroups with bilateral internal mammary artery/SV (n=589) and bilateral internal mammary artery only (n=271) had improved 15-year survival (86% and 76%; 82% and 75% at 10 and 15 years [P<0.001]), and patients with bilateral internal mammary artery/radial artery (n=147) and LIMA/radial artery (n=169) had greater 10-year survival (84% and 78%; P<0.001) versus LIMA/SV. In multivariate analysis, MultArt grafts remained a strong independent predictor of survival (hazard ratio, 0.79; 95% confidence interval, 0.66-0.94; P=0.007). CONCLUSIONS: In patients undergoing isolated coronary artery bypass graft surgery with LIMA to left anterior descending artery, arterial grafting of the non-left anterior descending vessels conferred a survival advantage at 15 years compared with SV grafting. It is still unproven whether these results apply to higher-risk subgroups of patients.

Use of bilateral internal thoracic artery during coronary artery bypass graft surgery in Canada: The bilateral internal thoracic artery survey.

OBJECTIVE: The internal thoracic artery is the gold standard conduit in coronary artery bypass grafting. Although the right and left internal thoracic arteries are excellent conduits, the use of the bilateral internal thoracic artery is not widespread. A recent report of the Society of Thoracic Surgery revealed that only a small percentage of patients receive a bilateral internal thoracic artery in North America. The aim of this study was to determine the current use of the bilateral internal thoracic artery during coronary artery bypass grafting among cardiac surgeons in Canada and identify the main concerns that limit the use of these conduits. METHODS: We developed an online survey with 17 questions about the use of the bilateral internal thoracic artery in different clinical scenarios. An invitation to participate was sent to all the adult cardiac surgeons currently in practice in Canada. RESULTS: A total of 101 surgeons (69%) of 147 currently in practice across 27 different hospitals completed the survey. Forty percent of surgeons use the bilateral internal thoracic artery only sometimes (6%-25% of cases), 37% of surgeons use the bilateral internal thoracic artery very infrequently (<5% cases), 16% of surgeons use the bilateral internal thoracic artery often (26%-50%), and only 7% of surgeons use the bilateral internal thoracic artery very often (>50%). The most common concerns in the use of the bilateral internal thoracic artery are the risk of sternal wound infection and the unknown superiority of the right internal thoracic artery over other conduits. CONCLUSIONS: The majority of Canadian cardiac surgeons consider few clinical features, such as insulin-dependent diabetes mellitus or morbid obesity, as contraindications to the use of bilateral internal thoracic artery. However, the reported use of the bilateral internal thoracic artery is low. A wider diffusion of this technique is warranted to improve the results of coronary surgery.

Autologous microsurgical breast reconstruction and coronary artery bypass grafting: an anatomical study and clinical implications.

OBJECTIVE: To identify possible avenues of sparing the internal mammary artery (IMA) for coronary artery bypass grafting (CABG) in women undergoing autologous breast reconstruction with deep inferior epigastric artery perforator (DIEP) flaps. BACKGROUND: Optimal autologous reconstruction of the breast and coronary artery bypass grafting (CABG) are often mutually exclusive as they both require utilisation of the IMA as the preferred arterial conduit. Given the prevalence of both breast cancer and coronary artery disease, this is an important issue for women's health as women with DIEP flap reconstructions and women at increased risk of developing coronary artery disease are potentially restricted from receiving this reconstructive option should the other condition arise. METHODS: The largest clinical and cadaveric anatomical study (n=315) to date was performed, investigating four solutions to this predicament by correlating the precise requirements of breast reconstruction and CABG against the anatomical features of the in situ IMAs. This information was supplemented by a thorough literature review. RESULTS: Minimum lengths of the left and right IMA needed for grafting to the left-anterior descending artery are 160.08 and 177.80 mm, respectively. Based on anatomical findings, the suitable options for anastomosis to each intercostals space are offered. In addition, 87-91% of patients have IMA perforator vessels to which DIEP flaps can be anastomosed in the first- and second-intercostal spaces. CONCLUSION: We outline five methods of preserving the IMA for future CABG: (1) lowering the level of DIEP flaps to the fourth- and fifth-intercostals spaces, (2) using the DIEP pedicle as an intermediary for CABG, (3) using IMA perforators to spare the IMA proper, (4) using and end-to-side anastomosis between the DIEP pedicle and IMA and (5) anastomosis of DIEP flaps using retrograde flow from the distal IMA. With careful patient selection, we hypothesize using the IMA for autologous breast reconstruction need not be an absolute contraindication for future CABG.

A statewide quality collaborative for process improvement: internal mammary artery utilization.

BACKGROUND: The Michigan Society of Thoracic and Cardiovascular Surgeons (MSTCVS) Quality Collaborative is a voluntary, surgeon-directed quality initiative involving all cardiac surgery programs in Michigan. Understanding that internal mammary artery (IMA) use during coronary artery bypass grafting is an important process measure associated with improved outcomes, this analysis reviews our methodology to understand IMA use and increase appropriate IMA use statewide. METHODS: Adult cardiac Society of Thoracic Surgeons data were collected at each Michigan site and submitted quarterly to the Duke Clinical Research Institute and the MSTCVS. Seven cardiac surgery programs with IMA use less than 90% in isolated coronary artery bypass grafting were identified as low IMA users. An improvement plan was adopted at the state level and included quarterly monitoring of IMA use, documenting the rationale for IMA exclusion, evidence-based lectures, feedback letters to sites, and physician-led site visits if no improvement was noted. RESULTS: From 2005 through 2008, 29,114 patients underwent coronary artery bypass grafting in Michigan. Internal mammary artery utilization varied widely at the beginning of this investigation, ranging from 66.2% to 98.4%. Seven Michigan programs were identified as low IMA users. Using the MSTCVS Quality Collaborative's process-improvement plan, collectively the seven low IMA users increased IMA grafting from 82.0% to 92.7% (p < 0.0001). Michigan IMA use increased from 91.9% to 95.8% (p < 0.0001) and is now higher than The Society of Thoracic Surgeons' average. CONCLUSIONS: The MSTCVS Quality Collaborative identified programs with low IMA use and created an environment to enhance IMA utilization during coronary artery bypass grafting, a significant operative process. These findings illustrate the value of a statewide surgeon-directed quality initiative in improving processes and outcomes for patients.

Prevalence and variability of internal mammary artery graft use in contemporary multivessel coronary artery bypass graft surgery: analysis of the Society of Thoracic Surgeons National Cardiac Database.

BACKGROUND: Use of an internal mammary artery (IMA) is a well-recognized, nationally endorsed quality indicator for evaluating the process of operative care for coronary artery bypass graft surgery. An objective assessment of the current status of IMA use has not been systematically performed. METHODS AND RESULTS: This cross-sectional observational study analyzed data on 541 368 coronary artery bypass graft surgery procedures reported by 745 hospitals in the Society of Thoracic Surgeons National Cardiac Database from 2002 through 2005. We assessed the current status of IMA use, the association of hospital volume and IMA use, and disparities in IMA use by patient gender and race and by region of hospital location. Rates of using at least 1 IMA and bilateral IMA were 92.4% and 4.0%, with increasing trends over the years. Hospital volume was not significantly associated with IMA use. IMAs were used less frequently in women than men (for at least 1 IMA: odds ratio, 0.62; 95% confidence interval, 0.61 to 0.63; for bilateral IMA: odds ratio, 0.65; 95% confidence interval, 0.63 to 0.68) and less frequently in nonwhite patients than white patients (for at least 1 IMA: odds ratio, 0.84; 95% confidence interval, 0.81 to 0.87; for bilateral IMA: odds ratio, 0.79; 95% confidence interval, 0.75 to 0.83). There were significant differences in frequency of IMA use by hospital region. CONCLUSIONS: Frequency of IMA use in coronary artery bypass graft surgery is increasing; however, many patients still do not receive the benefits of IMA grafts, and some hospitals have a very low IMA use rate. Hospital volume is not associated with IMA use in coronary artery bypass graft surgery. Analysis of this critical performance measure reveals significant gender and race disparities.

Does bilateral pedicle internal thoracic artery harvest increase the risk of mediastinitis?

PURPOSE: Bilateral in situ internal thoracic artery (ITA) bypassing may result in excellent myocardial revascularization without increasing the risk of deep sternal wound infection. Although there have been concerns with the use of pedicled bilateral ITA, the risk of infection may not be greater than the use of skeletonized ITA. MATERIALS AND METHODS: The present study was retrospectively undertaken to determine if pedicled BITA grafts are associated with a higher risk of sternal wound complications. A total of 207 patients who underwent bilateral ITA bypasses with or without existing diabetes mellitus, and 162 patients of those received bilateral pedicled ITA and 98 patients received unilateral ITA bypass grafts. RESULTS: No sternal wound complications were noted in either the bilateral ITA or unilateral left ITA groups. CONCLUSION: Bilateral pedicled ITA harvesting was not associated with a greater incidence of infectious sternal complications compared to patients receiving unilateral ITA bypass grafts.

Does Bilateral Pedicle Internal Thoracic Artery Harvest Increase the Risk of Mediastinitis?

PURPOSE: Bilateral in situ internal thoracic artery (ITA) bypassing may result in excellent myocardial revascularization without increasing the risk of deep sternal wound infection. Although there have been concerns with the use of pedicled bilateral ITA, the risk of infection may not be greater than the use of skeletonized ITA. MATERIALS AND METHODS: The present study was retrospectively undertaken to determine if pedicled BITA grafts are associated with a higher risk of sternal wound complications. A total of 207 patients who underwent bilateral ITA bypasses with or without existing diabetes mellitus, and 162 patients of those received bilateral pedicled ITA and 98 patients received unilateral ITA bypass grafts. RESULTS: No sternal wound complications were noted in either the bilateral ITA or unilateral left ITA groups. CONCLUSION: Bilateral pedicled ITA harvesting was not associated with a greater incidence of infectious sternal complications compared to patients receiving unilateral ITA bypass grafts.

Patency of internal thoracic artery compared to vein grafts - postoperative angiographic findings in 1189 symptomatic patients in 12 years.

BACKGROUND: The evidence respecting the superior patency of ITA-grafts compared to SVG is conclusive. This study evaluates the angiographic findings in 1,189 symptomatic patients who received either one or both ITA-grafts with or without additional SVG. METHODS: 1,189 patients (975 males, aged 62.4 +/- 9.1 years), operated between 2/93 and 7/05, underwent angiography due to reappearance of angina. Data were compared for patency of single ITA (n = 618), bilateral ITA (n = 416) or SVG (n = 2,218). Re-catherization was performed after 3.8 +/- 2.7 years. Severe bypass stenosis or graft occlusion was related to the target vessels. RESULTS: 3,668 bypasses were performed in 1189 patients. The occlusion rate was 16.5 % for SVG and 7.0 % for all ITAs ( P < 0.001). Severe stenosis was detected in 4.8 % of SVG and in 3.7 % of ITAs ( P < 0.05). Patency was 89.6 % for LITA, 88.7 % for RITA, and 78.7 % for SVG. The occlusion rate for LITA was: to LAD 6.6 %, DIA 8.5 %, obtuse marginal branch/CX 11.5 %. The occlusion rate for RITA was: to LAD 4.6 %, RCA 9.1 %., diag. branch 7.1 %. The occlusion rate for vein grafts was: to LAD 17.3 %, DIA 14.4 %, obtuse marginal branch/CX 15.9 %, to RCA 17.0 %. Patency for all ITAs was 89.3 % vs.78.7 % for all SVG ( P < 0.05). Despite symptoms, bypass patency was found in 711 patients (59.8 %). CONCLUSION: The superior patency of ITA-grafts could be documented angiographically in a negatively selected, symptomatic population. Graft occlusion was at least twofold higher for SVG.

Implementation of a continuous quality improvement program for percutaneous coronary intervention and cardiac surgery at a large community hospital.

BACKGROUND: Continuous quality improvement (CQI) is widely used in other industries and has been promoted as a method for quality control in medicine. The national databases developed by the American College of Cardiology and the Society of Thoracic Surgeons have greatly facilitated data collection for CQI. Hospitals can encounter barriers to CQI, however, which include creating the proper organizational infrastructure and engaging physicians and hospital administrators in the process. These barriers are particularly evident in large community hospitals. METHODS: We describe the organizational infrastructure for CQI, including committee structure, methods of repeated data collection and feedback, and maintenance of data integrity and confidentiality. We report demographic data and clinical outcomes for patients undergoing percutaneous coronary intervention and coronary artery bypass surgery before and after implementation of our CQI program. RESULTS: Since 1995, we have maintained a CQI process driven by repeated collection of valid, confidential, operator-specific data. We have observed sustained physician and administration participation and buy-in. During the follow-up period, patient complexity increased and observed outcomes improved, although the improvement was clearly multifactorial. CONCLUSIONS: We describe the organization of a CQI program at a large complex community hospital. Our CQI program was successfully implemented, has been sustained, and is associated in observed improvement in patient outcomes. The program described here may be a useful model for other similar hospitals that are attempting to create a program to address quality improvement.

Patients with in-stent restenosis have an increased risk of mid-term venous graft failure.

BACKGROUND: This study was designed to evaluate if patients in whom in-stent restenosis developed had an higher risk of early venous graft failure compared with normal patients. METHODS: The study cohort comprised 120 patients (60 with previous in-stent restenosis and 60 controls) who received a total of 165 complementary venous grafts on the circumflex or right coronary artery system (84 in the restenosis group and 81 in the control group). All patients were prospectively followed-up and underwent reangiography at 5-years follow-up. RESULTS: In the restenosis group, 28 venous grafts (33.%) were perfectly patent, 10 showed major irregularities, and 46 were occluded. In the control patients, 50 grafts (61.7%) were perfectly patent (p < 0.001 compared with the restenosis series), 12 showed major irregularities (p = .74), and 19 were occluded (p < 0.0001). In contrast, the 5-year outcome of internal thoracic artery grafts was not affected by history of in-stent restenosis. CONCLUSIONS: Patients who developed in-stent restenosis have an higher risk of early venous graft failure compared with the control patients. Arterial grafts should probably be preferred in these patients.

Impact of internal mammary artery conduit on long-term outcomes after percutaneous intervention of saphenous vein graft.

BACKGROUND: The influence of an internal mammary artery (IMA) graft on long-term outcomes after percutaneous saphenous vein graft (SVG) intervention is currently unknown. METHODS AND RESULTS: To examine the impact of IMA on outcomes in patients undergoing SVG interventions, we analyzed 2119 patients from the Duke Cardiovascular Disease Database (1986-2003) with prior coronary artery bypass surgery undergoing cardiac catheterization who had at least 1 SVG graft. Patients were categorized into 4 groups: group I, SVG intervention and patent IMA; group II, no SVG intervention and patent IMA; group III, SVG intervention without patent IMA; and group IV, no SVG intervention without patent IMA. At a median follow-up of 4.8 years (interquartile range, 2.1 to 8.8 years), adjusted survival rates in groups I, II, III, and IV were 72.8%, 72.3%, 64.5%, and 58.9%, respectively. Multivariate Cox proportional hazards modeling showed similar survival for groups I and II (P=0.63) and for groups III and IV (P=0.33). The presence of IMA graft was related to lower long-term mortality (adjusted hazard ratio [HR], 0.69; 95% CI, 0.58 to 0.82), whereas SVG intervention was not associated with long-term mortality (adjusted HR, 0.94; 95% CI, 0.81 to 1.10). In contrast, the adjusted event-free rates for nonfatal myocardial infarction were lower in the SVG intervention groups (groups I and III) than in the non-SVG intervention groups (groups II and IV) (HR for SVG intervention versus no SVG intervention, 3.19; 95% CI, 2.18 to 4.66), with the presence of patent IMA conferring no significant benefit on this outcome (HR, 1.37; 95% CI, 0.91 to 2.08). CONCLUSIONS: In patients undergoing SVG interventions, survival, but not nonfatal myocardial infarction, is favorably influenced by the presence of patent IMA. In contrast, SVG intervention had no measurable survival benefit but was associated with an increased risk of nonfatal myocardial infarction.

Occurrence and risk factors for reintervention after coronary artery bypass grafting.

BACKGROUND: Reintervention after coronary artery bypass grafting (CABG) is common. We sought to determine its occurrence and identify patient characteristics and operative techniques that influence the need or bias for reintervention. METHODS AND RESULTS: From 1971 to 1998, 48,758 patients underwent primary isolated CABG, and 1000 patients per year were actively followed-up every 5 years (n =26,927). A multivariable time-related analysis was performed to model freedom from first coronary reintervention (either reoperation or percutaneous coronary intervention) and identify patient and operative characteristics associated with first reintervention. A total of 3997 patients underwent coronary reintervention, percutaneous in 1638 and reoperation in 2359. Freedom from reintervention was 99%, 96%, 88%, 73%, 60%, and 46% at 1, 5, 10, 15, 20, and 25 years, respectively. Risk of reintervention (hazard function) demonstrated a short, rapidly declining early phase followed by a longer, slow-rising late phase. Patient variables increasing the likelihood of coronary reintervention included younger age (P<0.0001), higher triglycerides (P=0.002), lower high-density lipoprotein (P=0.006), diabetes mellitus (P<0.0001), and more extensive coronary artery disease (P=0.0005). Increasing extent of arterial grafting performed at primary operation decreased the likelihood of coronary reintervention (P<0.0001). CONCLUSIONS: Reintervention after primary CABG is common. Risk factors for arteriosclerosis and type of bypass conduit influence the need or bias for repeat coronary therapy. Aggressive post-CABG risk factor reduction and extensive arterial grafting at primary operation should decrease coronary reinterventions.