Long-Term Outcomes of Coronary Artery Bypass Grafting Using an Internal Thoracic Artery versus a Radial Artery as a Second Arterial Graft.

PURPOSE: To compare the outcomes of left circumflex artery (LCx) revascularization using an internal thoracic artery (ITA) or radial artery (RA) as the second arterial graft. METHODS: Patients who underwent primary isolated coronary artery bypass grafting with left anterior descending artery revascularization using an ITA and LCx revascularization using another bilateral ITA (BITA group) or an RA (ITA-RA group) were included. All-cause mortality (primary endpoint), cardiac death, major adverse cardiac events, in-hospital death, and deep sternal wound infection (secondary endpoints) were evaluated. RESULTS: Among 790 patients (BITA, n = 548 (69%); ITA-RA, n = 242 (31%)), no significant difference in all-cause mortality between the groups was observed (hazard ratio (HR): 0.87; 95% confidence interval (CI): 0.67-1.12; p = 0.27) during follow-up (mean, 10 years). Multivariate analysis revealed that the BITA group exhibited significantly lower rates of long-term all-cause mortality (HR: 0.63; 95% CI: 0.48-0.84; p = 0.01). In the propensity-matched cohort (n = 480, 240 pairs), significantly fewer all-cause deaths occurred in the BITA group (HR: 0.66; 95% CI 0.47-0.93; p = 0.02). There were no significant differences in secondary outcomes. CONCLUSIONS: When used as second grafts for LCx revascularization, ITA grafts may surpass RA grafts in reducing all-cause mortality 10 years postoperatively.

Bilateral vs Single Internal Mammary Artery Grafts for Coronary Artery Bypass in the United States.

BACKGROUND: The use of the bilateral internal mammary artery (BIMA) in coronary artery bypass grafting remains controversial. The objective of this study was to investigate the long-term outcomes using the BIMA vs the single internal mammary artery (SIMA) in the United States. METHODS: Medicare beneficiaries who underwent primary isolated coronary artery bypass surgery using the SIMA or BIMA from 1999 to 2010 were included in this retrospective study, with follow-up through 2014. Greedy matching algorithms were used for 1:4 matching on propensity score based on age, gender, year of surgery, and comorbidities. Kaplan-Meier survival analyses were performed. The primary outcome was death from any cause. RESULTS: A total of 1,156,339 and 25,005 patients who were 72 ± 7.6 years of age and 70.3 ± 7.9 years of age underwent primary isolated coronary artery bypass surgery using SIMA and BIMA, respectively. Matching created comparable groups with 95,780 SIMA and 24,160 BIMA patients. Matched median survival using SIMA vs BIMA was 11.8 vs 12.4 years (P < .001) and 9.6 vs 10 years in diabetic patients (P = .006), respectively. At 10 years of follow-up, the respective survival rates of using SIMA vs BIMA were 58.3% vs 61.1%, respectively. The stratified matched median survival using SIMA vs BIMA with 1, 2, 3, and 4 or more aortocoronary bypasses were 11.8 vs 12.3 years (P = .005), 11.7 vs 12.5 years (P < .001), 11.9 vs 12.3 years (P = .01), and 11.4 vs 12 years (P = .02), respectively. CONCLUSIONS: Primary isolated coronary artery bypass surgery using the BIMA rather than the SIMA was associated with improved long-term survival. This survival advantage was independent of aortocoronary bypass grafts or patient diabetes status.

Does Bilateral Internal Mammary Artery Grafting Better Suit Patients With Diabetes?　- Two Different Ways to Explore Outcomes.

BACKGROUND: This analysis compared short-term mortality, sternal wound infection (SWI), and long-term survival outcomes in diabetic patients who underwent coronary artery bypass grafting (CABG) with bilateral (BIMA) vs. single (SIMA) internal mammary artery, as well as in diabetic vs. non-diabetic patients undergoing BIMA grafting.Methods and Results:Nineteen studies were included in the study, covering 21,143 different patients. Of these patients, 6,464 underwent CABG with BIMA, 10,264 underwent CAGB with SIMA, 11,584 had diabetes, and 6,717 did not. Compared with SIMA, BIMA had a significantly lower risk of in-hospital mortality (odds ratio [OR] 0.73, P=0.02), but a significantly higher risk of SWI (OR 1.30, P=0.04). However, compared with non-diabetic patients who underwent CABG with BIMA, diabetic patients with BIMA grafting did not have significantly higher risks of either mortality (OR 1.22, P=0.53) or SWI (OR 1.10, P=0.72). No significant differences were detected with different harvesting techniques. Longer term, BIMA was associated with a significantly higher rate of survival than SIMA (hazard ratio [HR] 0.76, P<0.001). CONCLUSIONS: Results from the 2 types of comparisons indicate that BIMA is a preferable option for diabetic patients, even though it has a higher risk of infection. CABG with BIMA is also associated with a long-term survival benefit.

Off-pump Revascularization with Bilateral versus Single Mammary Arteries-A Propensity Score-Matched Analysis.

BACKGROUND: Coronary artery bypass grafting is the first-line therapy for severe multivessel coronary artery disease. We aimed to investigate the clinical outcome in patients undergoing isolated off-pump surgery with the single or bilateral internal mammary artery (SIMA or BIMA) approach. METHODS: We performed a propensity score-matched analysis in 1,852 consecutive patients, aged 50 to 70 years, who underwent myocardial revascularization at our institution between July 2009 and August 2016. Primary end point was the probability of survival. RESULTS: Mean follow-up was 36.3 (range: 0.1-89.6) months. The probability of survival in the SIMA and BIMA groups was 98.6 and 99.0% at year 1, 92.0 and 92.5% at year 5, and 85.6 and 81.6% at year 7, respectively, with a hazard ratio (HR) of mortality for the BIMA group versus the SIMA group of 0.98 (95% confidence interval[CI]: 0.64-1.52; p = 0.94). There was evidence for interaction between diabetes and study group on mortality risk (HR = 2.59, 95% CI: 1.07-6.23; p = 0.034). Freedom from mediastinitis/wound infection was higher in the SIMA group than in the BIMA group (99.5 and 96.9%, respectively; HR of an event = 6.39, 95% CI: 2.88-14.18; p < 0.001). The corresponding values in the subgroups of diabetic patients were 98.6 and 90.9%, respectively (HR = 6.45, 95% CI: 2.24-18.58; p = 0.001). Mediastinitis/wound infection was associated with increased mortality risk (HR = 2.96, 95% CI: 1.29-6.78; p = 0.010). CONCLUSION: Overall, our data indicate similar probability of survival up to a maximum follow-up of 7 years by off-pump surgery with the SIMA or BIMA approach. However, in diabetic patients, the clinical outcome indicates caution regarding the use of the BIMA approach.

Long-Term Outcome of Total Arterial Myocardial Revascularization Versus Conventional Coronary Artery Bypass in Diabetic and Non-Diabetic Patients: A Propensity-Match Analysis.

OBJECTIVE: Despite the improved survival in patients with multi-vessel coronary disease compared to conventional myocardial revascularization associated with the use of multiple arterial grafting for myocardial revascularization, it has been adopted in the minority of centers. We sought to evaluate the long-term outcome of patients with and without diabetes undergoing total arterial versus conventional myocardial revascularization. METHODS: Among 1000 consecutive patients undergoing CABG, we performed a propensity-match analysis to compare patients with multi-vessel disease receiving total arterial (G1 = 618 pts) versus conventional myocardial revascularization (LIMA-LAD plus vein grafts, G2 = 382 pts). The primary end-point was survival free from all-cause and cardiac-related mortality, while the secondary end-point was the occurrence of major cardiac and cerebrovascular accidents. RESULTS: Hospital mortality was similar (G1: 0 pts. vs G2: 1 pts., 0.3%, p = .91). At a median follow-up of 101 months (range 11-185 months), total arterial grafting was associated with significantly improved survival free from overall (G1 = 76.5 ±â€¯3.0% vs G2 = 66.0 ±â€¯3.1%; p < .001) and cardiac mortality (general population: G1 = 90.8 ±â€¯2.1% vs G2 = 84.2 ±â€¯1.9%, p = .043; diabetics:G1 = 84.7 ±â€¯2.1 vs G2: 79.3 ±â€¯3.4; p = .035) as well as occurrence of MACCEs (general population:G1 = 80.1 ±â€¯3.2% vs G2 = 70.8 ±â€¯2.9%; p > .001; diabetics:G1 = 77 ±â€¯6 vs G2 = 53 ±â€¯5.8; p < .001). Cox regression analysis identified diabetes (HR = 1.94, CI 95% = 1.12-2.93; p < .001) and the use of veins (HR = 1.81, CI 95% = 1.32-2.65; p < .001) as independent predictors for all-cause mortality; among diabetics, vein grafts was the strongest predictor of MACCEs (HR = 2.41, CI 95% = 1.27-4.59; p = .007) and cardiac mortality (HR = 3.24, CI 95% = 1.69-6.23; p < .001). CONCLUSIONS: Long-term survival following total arterial CABG is remarkably improved compared to conventional grafting with vein grafts especially in diabetic patients.

[Exclusive coronary revascularization with both mammary arteries. Analysis of 73 patients]. / Resultados a 5 años de la revascularización exclusiva con dos arterias mamarias en pacientes con enfermedad coronaria multivaso.

BACKGROUND: Exclusive coronary revascularization with both mammary arteries could result in lower rates of adverse events in the long term. AIM: To describe the five-year evolution of a cohort of patients operated on with this technique. MATERIAL AND METHODS: Follow up analyzing survival of 73 patients aged 59 ± 9 years (82% men) who underwent exclusive coronary surgery with two mammary arteries between December 1,2010 and April 12,2017. We studied their clinical characteristics, surgical results, operative morbidity and mortality and adverse events up to June 30, 2018. RESULTS: Six patients had two-vessel lesions and 67 three-vessel lesions. The operative risk calculated by additive and logistic EuroSCORE was 2.5 and 2.3%, respectively. A mean of 3.75 anastomoses /patient were performed, 116 with left mammary artery (73 to the anterior descending artery, 38 to a diagonal artery and 5 for other objectives) and 158 with right mammary artery (69 to a first marginal artery, 23 to a second marginal artery and 64 to posterior descending artery). There was one case of mediastinitis and one (1.5%) patient died. The mean follow-up was 64.6 ± 23.7 months. The 5-year survival was 90.4%. CONCLUSIONS: Coronary revascularization with two exclusive mammary arteries allowed a complete revascularization of the heart with a low rate of complications and adverse effects at five years.

Bilateral Internal Thoracic Artery Grafting Concomitant With Other Cardiac Operations　- Insights From a European Multicenter Retrospective Study on 1,123 Consecutive Patients.

BACKGROUND: The use of bilateral internal thoracic artery (BITA) grafting concomitant with other cardiac operations is regarded as a risky strategy and the long-term advantages of BITA use remain unproven.Methods and Results:Pooled results from 3 series of patients (totaling 1,123 patients; mean age, 71.3 years; mean EuroSCORE II, 7.4%) undergoing combined coronary surgery using BITA were reviewed. Predictors of immediate and long-term adverse outcomes were identified by multivariable analyses. In-hospital and 30-day mortality was 7.9% and 6.3%, respectively. Diabetes on insulin (P=0.045), severe renal impairment (P<0.0001), extracardiac arteriopathy (P=0.0058), New York Heart Association class III-IV (P=0.017), recent myocardial infarction (P=0.0009), left ventricular dysfunction (P=0.0054), pulmonary hypertension (P=0.0016), active infective endocarditis (P=0.0011), and prolonged cross-clamp time (P=0.04) were predictors of in-hospital death. Multiple transfusions (27.3%), prolonged mechanical ventilation or reintubation (16.7%), acute kidney injury (11.5%), and sternal wound infections (10.4%) were relevant postoperative complications. Any neurological dysfunction occurred in 5.4% of cases. Median follow-up was 4.2 years. Female sex, chronic dialysis, extracardiac arteriopathy, and left ventricular dysfunction were predictors of both cardiac/cerebrovascular death and major adverse cardiac/cerebrovascular events (MACCE). The 10-year adjusted survival free of cardiac/cerebrovascular death, cerebrovascular accident after discharge, and MACCE was 84.2%, 94.8% and 54.6%, respectively. CONCLUSIONS: BITA grafting concomitant with other cardiac operations may be performed with satisfactory results. Long-term outcomes mostly depend on sex, preoperative comorbidities, and baseline cardiac function.

Resultados a 5 años de la revascularización exclusiva con dos arterias mamarias en pacientes con enfermedad coronaria multivaso / Exclusive coronary revascularization with both mammary arteries: analysis of 73 patients

Background: Exclusive coronary revascularization with both mammary arteries could result in lower rates of adverse events in the long term. Aim: To describe the five-year evolution of a cohort of patients operated on with this technique. Material and Methods: Follow up analyzing survival of 73 patients aged 59 ± 9 years (82% men) who underwent exclusive coronary surgery with two mammary arteries between December 1,2010 and April 12,2017. We studied their clinical characteristics, surgical results, operative morbidity and mortality and adverse events up to June 30, 2018. Results: Six patients had two-vessel lesions and 67 three-vessel lesions. The operative risk calculated by additive and logistic EuroSCORE was 2.5 and 2.3%, respectively. A mean of 3.75 anastomoses /patient were performed, 116 with left mammary artery (73 to the anterior descending artery, 38 to a diagonal artery and 5 for other objectives) and 158 with right mammary artery (69 to a first marginal artery, 23 to a second marginal artery and 64 to posterior descending artery). There was one case of mediastinitis and one (1.5%) patient died. The mean follow-up was 64.6 ± 23.7 months. The 5-year survival was 90.4%. Conclusions: Coronary revascularization with two exclusive mammary arteries allowed a complete revascularization of the heart with a low rate of complications and adverse effects at five years.

Are two internal thoracic grafts better than one? An analysis of 5301 cases.

OBJECTIVES: Although bilateral internal thoracic artery (BITA) grafting is associated with improved survival, many surgeons are reluctant to use this technique due to its greater complexity and the potentially increased risk of sternal infection. This observational study examined if BITA grafting provides improved outcomes compared with single internal thoracic artery (SITA) grafting in patients with multivessel coronary disease. METHODS: Patients in our institution who underwent BITA grafting during 1996-2011 were compared to those who underwent SITA grafting during the same period. To adjust for differences in demographic and clinical characteristics, patients were matched by propensity score. The Cox model was used to identify predictors of decreased survival and the Kaplan-Meier analysis was performed, both for the entire cohort and for the matched cohort. RESULTS: SITA patients were older than BITA patients, included more females, and were more likely to have chronic obstructive lung disease, an ejection fraction <30%, diabetes, renal insufficiency, peripheral vascular disease and emergency and repeat operations. Three-vessel and left main diseases were more common among BITA patients, and operative mortality was reduced (2.1% vs 3.6% for SITA, P = 0.002). Sternal infection and stroke rates were similar for the groups. Ten-year Kaplan-Meier survival of BITA patients was better (71.2% vs 56.8%, respectively, P < 0.001). BITA grafting was found to be a predictor of better survival in the analysis of the matched cohort (P < 0.001). CONCLUSIONS: Our results support the routine use of BITA grafting in patients who undergo myocardial revascularization.

Is the era of bilateral internal thoracic artery grafting coming for diabetic patients? An updated meta-analysis.

OBJECTIVE: Because of an increased risk of sternal wound complications, the use of bilateral internal thoracic artery grafting in diabetic patients remains controversial. The objective of the present meta-analysis is to compare the safety and efficacy of single internal thoracic artery and bilateral internal thoracic artery grafting in the diabetic population. METHODS: Four electronic databases, including PubMed, the Cochrane Library, Embase, and ISI Web of Knowledge, were comprehensively searched. Prospective randomized trials or observational studies comparing single internal thoracic artery and bilateral internal thoracic artery were considered eligible for the current study. RESULTS: A literature search yielded 1 randomized controlled trial and 17 observational studies (129,871 diabetic patients: 124,233 single internal thoracic arteries and 5638 bilateral internal thoracic arteries). Pooled analysis demonstrated overall incidence of deep sternal wound infection in the bilateral internal thoracic artery grafting group was significantly higher than in the single internal thoracic artery grafting group (3.26% for bilateral internal thoracic artery vs 1.70% for single internal thoracic artery). No significant difference was found between both groups in terms of risk of deep sternal wound infection when the skeletonized harvesting technique was adopted. Furthermore, in-hospital mortality was comparable between both groups (2.80% for bilateral internal thoracic artery vs 2.36% for single internal thoracic artery). However, compared with single internal thoracic artery grafting, bilateral internal thoracic artery grafting could confer a lower risk for long-term overall mortality (hazard ratio, 1.41; 95% confidence interval, 1.18-1.67; P < .001; I2 = 63%) and cardiac mortality (hazard ratio, 3.15; 95% confidence interval, 2.23-4.46; P < .001; I2 = 0%). CONCLUSIONS: Compared with single internal thoracic artery grafting, bilateral internal thoracic artery grafting is associated with enhanced long-term survival among diabetic patients. Skeletonization of bilateral internal thoracic artery is not associated with an increased risk of deep sternal wound infection. Therefore, surgeons should be encouraged to adopt bilateral internal thoracic artery grafting in a skeletonized manner more routinely in diabetic patients.

Long-segment patchplasty of diffuse left anterior descending artery disease on the beating heart.

OBJECTIVE: The rate of patients with diffuse left anterior descending artery (LAD) disease being referred for surgery has increased as a result of advances in endovascular techniques. In surgery of diffuse or multisegment LAD disease, surgical procedures with or without endarterectomy can be performed. In this article, we report our results of longsegment onlay patchplasty of the LAD with a left internal thoracic artery (LITA) graft without endarterectomy, on the beating heart, in patients with multisegment LAD disease. METHODS: We retrospectively analysed patients who underwent coronary artery bypass grafting surgery in our hospital between 1 January 2015 and 31 July 2017. We included LITA onlay patchplasty patients with multisegment LAD disease who had been operated on the beating heart. We excluded patients who underwent coronary endarterectomy and were operated on under cardiopulmonary bypass. RESULTS: In this period, 54 patients with multisegment LAD disease were treated with LITA patchplasty on the beating heart. The mean length of the arteriotomy was 42.8 ± 13.3 mm (25-75 mm). There were two postoperative myocardial infarctions (3.7%) and three deaths (5.5%). In the remaining patients, there was no haemodynamic instability that needed long-term (> 24 hour) inotropic support. Patients were discharged from hospital on postoperative 9.3 ± 7.1 days with dual antiplatalet therapy. CONCLUSIONS: Bypass grafting of the LAD with long-segment LITA onlay patchplasty can safely be performed in patients with multisegment LAD disease, with acceptable early-term results. In this procedure, proximal and distal segments of the diseased LAD are revascularised with LITA grafts, which may improve long-term survival and quality of life.

Off-pump onlay-patch grafting using the left internal mammary artery for a diffusely diseased left anterior descending artery: in-hospital and mid-term outcomes.

BACKGROUND: The aims of this study were to evaluate the in-hospital and mid-term outcomes of the off-pump onlay-patch grafting procedure using the left internal mammary artery (LIMA) for a diffusely diseased left anterior descending artery (LAD) and to identify the risk factors for postoperative LIMA graft failure in a single-center retrospective study. PATIENTS AND METHODS: A total of 63 patients (52 males, 65.7±9.0 years) undergoing LAD arteriotomy with or without concomitant endarterectomy, followed by reconstruction using LIMA onlay-patch at the time of off-pump coronary artery bypass grafting at our institute from January 2014 to December 2016 were reviewed. The operative mortality, major postoperative morbidity, follow-up all-cause mortality, major adverse cardiac events at follow-up, and postoperative LIMA graft patency were analyzed. The risk factors for postoperative LIMA graft failure on the basis of baseline and surgical characteristics were identified by multivariable logistic regression analysis. RESULTS: Eighteen (28.6%) patients underwent concomitant open LAD endarterectomy. The operative mortality rate was 1.6%. Major postoperative morbidity included perioperative myocardial infarction (3.2%), low cardiac output (1.6%), and reoperation for bleeding (1.6%). During the follow-up period of 24.2±9.5 months, all-cause mortality was 1.7% and the incidence of major adverse cardiac events was 6.8%. No repeat revascularization was recorded. In total, 88.1% of LIMA grafts showed FitzGibbon grade A patency determined by noninvasive coronary computed tomography angiography during follow-up. In addition, concomitant LAD endarterectomy and intraoperative LIMA graft flow were found to be independent risk factors for mid-term LIMA graft failure by multivariable logistic regression analysis (odds ratio=2.681, 95% confidence interval: 1.314-9.856, P=0.007 and odds ratio=0.932, 95% confidence interval: 0.791-0.976, P=0.021, respectively). CONCLUSION: Revascularization of a diffusely diseased LAD using the off-pump LIMA onlay-patch technique results in encouraging clinical outcomes with favorable angiographic results. Concomitant LAD endarterectomy and intraoperative LIMA graft flow are associated with the risk of postoperative LIMA graft failure.

Current Readings: Single vs Bilateral Internal Mammary Artery in Coronary Artery Bypass Grafting.

There is strong retrospective data demonstrating that bilateral internal mammary artery (BIMA) grafting leads to better long-term survival as compared to left internal mammary artery grafting. However, this survival advantage was not corroborated by the interim results of the Arterial Revascularization Trial. Today, there are barriers to widespread adoption of BIMA grafting. One of the main disadvantages of the use of BIMA grafts is the higher risk of deep sternal wound infection. Deep sternal wound infections can be minimized by skeletonized harvesting of the internal mammary artery grafts, which preserve blood flow to the sternum. Also, utilizing the BIMA graft as a "Y" graft may lead to more complete revascularization compared to its in situ use. BIMA grafting on average takes 25 minutes longer operating time with a higher in-hospital costs. We eagerly await the 10-year results of the Arterial Revascularization Trial to determine the truly unbiased randomized long-term effectiveness of BIMA grafting.

Graft failure and recurrence of symptoms after coronary artery bypass grafting.

OBJECTIVES: Saphenous vein grafts (SVGs) most often used in coronary artery bypass grafting (CABG) are subject to graft disease and have poor long-term patency, however the clinical implication of this is not completely known. We aim to assess the influence of graft failure on the postoperative recurrence of coronary artery disease (CAD) symptoms in relation to the contribution from progression of atherosclerosis in the native coronary vessels. DESIGN: Within the SWEDEHEART registry we identified 46,663 CABG cases between 2001 and 2015 with patient age 40-80 years where single internal mammary artery (IMA) anastomosis (IMA), single IMA with one (1SVG) or multiple SVG anastomoses (2+ SVG) had been performed. Clinical characteristics as well as mortality and postoperative incidence of coronary angiography were recorded and multivariable adjusted hazard ratios were calculated. Indications for the angiographies and occurrence of graft failure were also registered. RESULTS: The adjusted hazard ratio for death was similar for the three groups. The adjusted hazard ratio for being submitted to angiography as compared to 2+ SVG was (95% CI) 1.24 (1.06-1.46) for IMA and 1.21 (1.15-1.28) for 1SVG. Failed grafts were found at the first postoperative angiography with preceding CAD symptoms in 21.4% of patients in the IMA group, 41.6% in the 1SVG group and 61.1% in the 2+ SVG group. CONCLUSIONS: A substantial amount of angiographies occur in patients without any graft failure and a large part of postoperative recurrence of CAD symptoms and are likely attributed to IMA failure or progression of atherosclerosis in the native coronary arteries.

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.

Coronary Revascularization With Single Versus Bilateral Mammary Arteries: Is It Time to Change?

BACKGROUND: Arterial conduits are preferred to venous conduits for coronary artery bypass grafting because of longer patency. A single internal mammary artery (SIMA) is used routinely. Bilateral internal mammary arteries (BIMA) are used less frequently. We sought to determine whether BIMA were superior to SIMA. METHODS: From our regional registry of consecutive open heart operations, we identified 47,984 patients who underwent isolated coronary artery bypass grafting from 1992 to 2014. Of the 1,482 BIMA patients, 1,297 were propensity matched to a cohort of SIMA patients. Short-term outcomes were compared using standard statistical techniques. Long-term survival was compared using Kaplan-Meier estimators and compared using a log-rank test. RESULTS: BIMA patients were younger and had fewer comorbid conditions than SIMA patients. After propensity weighting, BIMA and SIMA patients were well matched. There was no difference in in-hospital outcomes for BIMA versus SIMA patients for mortality (1.2% [n = 15] vs 0.8% [n = 10], p = 0.315), stroke (0.7% [n = 9] vs 0.7% [n = 9), p = 1.000), bleeding (2.2% [n = 28] vs 2.8% [n = 36], p = 0.311), or mediastinitis (0.8% [n = 10] vs 0.9% [n = 12], p = 0.667). The median follow-up was 12 years. Survival was better for BIMA than SIMA (adjusted hazard ratio, 0.79; 95% confidence interval, 0.69 to 0.91; p < 0.001). Survival curves began to separate after 5 years. At 15 years, the absolute difference in survival was 8.4%. CONCLUSIONS: In a large regional experience, BIMA is associated with no upfront risk of adverse events and improved long-term survival compared with SIMA. Our results indicate that BIMA conduits should be considered more frequently during coronary artery bypass grafting due to their demonstrated survival advantage.

Favourable long-term outcome after coronary artery bypass grafting in a nationwide cohort.

OBJECTIVES: In a nationwide cohort, we analyzed long-term outcome following coronary artery bypass grafting, using the combined strategy of left internal mammary artery to the left anterior descending artery and saphenous vein as secondary graft to other coronary targets. METHODS: 1,507 consecutive patients that underwent myocardial revascularization during 2001-2012 in Iceland. Mean follow-up was 6.8 years. Major adverse cardiac and cerebrovascular events were depicted using the Kaplan-Meier method. Cox-regression was used to define risk factors. Relative survival was estimated by comparing overall survival to the survival of Icelanders of the same age and gender. RESULTS: Mean age was 66 years, 83% were males, mean EuroSCOREst was 4.5, and 23% of the procedures were performed off-pump. At 5 years, 19.7% had suffered a major adverse cardiac or cerebrovascular event, 4.5% a stroke, 2.2% myocardial infarction, and 6.2% needed repeat revascularization. Overall 5-year survival was 89.9%, with a relative survival of 0.990. Independent predictors of major adverse cardiac and cerebrovascular events were left ventricular ejection fraction ≤30%, a previous history of percutaneous coronary intervention, chronic obstructive lung disease, chronic kidney disease, diabetes, and old age. The same variables and an earlier year of operation were predictors of long-term mortality. CONCLUSIONS: The long-term outcome following myocardial revascularization, using the left internal mammary artery and the great saphenous vein as conduits, is favourable and improving. This is reflected by the 5-year survival of 89.9%, deviating minimally from the survival rate of the general Icelandic population, together with a freedom from major adverse cardiac and cerebrovascular events of 80.3%.

Should Bilateral Internal Thoracic Artery Grafting Be Used in Patients After Recent Myocardial Infarction?

BACKGROUND: Bilateral internal thoracic artery grafting (BITA) is associated with improved survival. However, surgeons do not commonly use BITA in patients after myocardial infarction (MI) because survival is good with single internal thoracic artery grafting (SITA). We aimed to compare the outcomes of BITA with those of SITA and other approaches in patients with multivessel disease after recent MI. METHODS AND RESULTS: In total, 938 patients with recent MI (<3 months) who underwent BITA between 1996 and 2011 were compared with 682 who underwent SITA. SITA patients were older and more likely to have comorbidities (diabetes mellitus, chronic obstructive pulmonary disease, chronic renal failure, peripheral vascular disease), to be female, and to have had a previous MI. Acute MI and 3-vessel disease were more prevalent in the BITA group. Operative mortality of BITA patients was lower (3.0% versus 5.8%, P=0.01), and sternal infections and strokes were similar. Median follow-up was 15.21 years (range: 0-21.25 years). Survival of BITA patients was better (70.3% versus 52.5%, P<0.001). Propensity score matching was used to account for differences in preoperative characteristics between groups. Overall, 551 matched pairs had similar preoperative characteristics. BITA was a predictor of better survival in the matched groups (hazard ratio: 0.679; P=0.002; Cox model). Adjusted survival of emergency BITA and SITA patients was similar (hazard ratio: 0.883; P=0.447); however, in the nonemergency group, BITA was a predictor of better survival (hazard ratio: 0.790; P=0.009; Cox model). CONCLUSIONS: This study suggests that survival is better with BITA compared with SITA in nonemergency cases after recent MI, with proper patient selection.

Ultrastructural and histomorphologic properties of the internal thoracic artery: implications for coronary revascularization.

Coronary artery disease represents a major health problem worldwide for which coronary artery bypass surgery remains a standard of care. Among the several grafts that are available, the internal thoracic artery (ITA) has long been considered the best as several advantages have been described compared with other vessels (e.g. saphenous vein or radial artery), namely, an absent to minor atherosclerotic development. In fact, several studies showed the presence of preatherosclerotic lesions, such as intimal and/or medial thickening, medial fibrosis, among others, in the presence of certain cardiovascular risk factors as well as established atherosclerotic lesions (i.e. type II or more lesions). This paper primarily aimed at reviewing the current knowledge on the histomorphological characteristics of ITA as well as the comparative histomorphology of ITA with other vessel grafts currently in use in coronary surgery. As some of the evidence is not clear or consensual, this paper also aimed at reviewing the main histopathological, histomorphometrical, and ultrastructural findings in ITAs from patients with known cardiovascular risk factors (e.g. aging, obesity, hypertension, diabetes, smoking, and others). As the presence of preatherosclerotic and/or atherosclerotic lesions may compromise the success of the myocardial revascularization and lead to graft failure, contributing toward the associated morbidity and/or mortality, it is essential to improve the scientific knowledge on the structural characterization of ITAs and its correlation with the cardiovascular risk profile.