Single Internal Thoracic Artery Group Research Articles

Bilateral Internal Thoracic Artery Grafting: Is It Reasonable in Octogenarians?

The feasibility of using bilateral internal thoracic artery (BITA) grafts for coronary artery bypass grafting (CABG) in octogenarians is not clear. This study aimed to compare outcomes between use of BITA and single internal thoracic artery (SITA) grafts in octogenarians undergoing isolated CABG. Isolated CABG was performed in 1,566 patients at the Sakakibara Heart Institute between September 2004 and December 2012. Of these, 125 consecutive octogenarians were included and divided into two groups, according to the use of BITA grafts (101 subjects) or SITA grafts (24 subjects). Early and late outcomes were compared between groups. The preoperative patient characteristics were similar between the two groups. Early outcomes were similar, including hospital death or deep sternal infection. The estimated 5-year survival rate was similar in the BITA and SITA groups (78% vs 62%, p = 0.269). Freedom from major adverse cardiac or cerebrovascular events was significantly higher in the BITA group than in the SITA group after 5 years (90% vs 75%, p = 0.032). Our results suggest that use of BITA grafts for CABG is feasible and beneficial in octogenarians, resulting in improved late outcomes without increased operative risk.

Abstract 40: Should Bilateral Internal Thoracic Artery Grafting Be Used in Emergency Patients?

HYPOTHESIS: Bilateral Internal Thoracic Artery (BITA) grafting is not often used in emergency coronary artery bypass grafting (CABG) due to questionable survival benefit ,relative complexity and increased risk of sternal infection compared to operations incorporating Single Internal Thoracic Artery (SITA). The purpose of this study is to compare early and long term outcome of emergent patients undergoing BITA grafting, to that of emergent patients undergoing CABG with SITA METHODS: Four hundred thirty eight emergency patients underwent BITA grafting between 1996 and 2008. They were compared with 339 emergency patients who underwent CABG with SITA RESULTS: Occurrence of female gender (18.5% vs. 29.5%, P< 0.001, in the BITA and SITA groups, respectively), diabetes (25.3% vs. 38.6%, P< 0.001), age 70+ (61.0% vs.39.7%, P< 0.001), chronic obstructive pulmonary disease (5.7% vs.13.9%, P< 0.001) EF <30% (12.1% vs. 17.1%, P< 0.001), and chronic renal failure (7.1% vs. 17.1%, p< 0.001) was lower in the BITA group. On the other hand critical preoperative state (35.4% vs. 26.0%, P= 0.003), and recent myocardial infarction (39.5% vs. 32.7%, P= 0.031) were more prevalent among BITA patients. Euro score I of SITA patients was significantly higher (10.58 ± 4.1 vs.8.65 ± 3.5, P= 0.016). Operative mortality (5.3% vs 7.4%, BITA vs. SITA), and sternal wound infections (2.7% vs. 2.1%) were not significantly different between groups. Mean follow-up was 8.75 ± 4.75 years. Ten year survival (Kaplan-Meier) of SITA patients with euro score 11+ was similar to that of BITA patients with euro score 11+. (34% vs. 37%, log rank test) .However, Kaplan-Meier 10 year survival of BITA patients with euro score I of 10 or lower was significantly better(80% vs. 68%, , BITA and SITA groups, respectively , P= 0.012 ).Assignment to the BITA group in the subset with lower euro score was also associated with better propensity adjusted survival ( HR 4.8 p < 0.001, compared to the SITA group, COX model) CONCLUSIONS: This large cohort study shows that,BITA grafting may be used in emergency patients., In medium and low risk emergency patients long term outcome is better than that of patients treated with SITA

Guidance for the use of bilateral internal thoracic arteries according to survival benefit across age groups

Increasing evidence from observational cohort studies supports a survival advantage from bilateral internal thoracic artery (BITA) relative to single internal thoracic artery (SITA) grafts in patients undergoing coronary artery bypass grafting. Whether the survival benefit from BITA is related to patient age and any potential age cutoff for the loss of survival benefit from BITA remain to be determined. Flexible parametric spline survival model was used to investigate the survival benefit from BITA across patient age groups. The study population consisted of 4190 patients undergoing coronary artery bypass grafting with SITA (n = 3442; 81%) or BITA (n = 748; 19%). A total of 376 deaths (BITA, n = 29; SITA, n = 347) were recorded after a mean follow-up of 4.9 ± 3.2 years (maximum, 12.2 years). Nonparametric survival probabilities at 1-, 5-, and 10-year follow-ups were 94.9% ± 0.3% versus 98.0% ± 0.5%, 90.7% ± 0.5% versus 95.5% ± 0.9%, and 84.2% ± 1.0% versus 93.7% ± 1.4% in the SITA and BITA groups, respectively. Interaction between age and BITA (age*BITA) was found to affect survival significantly (coefficient, 0.056; SE, 0.02; P = .015). BITA was associated with reduced risk of mortality in patients aged 69 years and younger (fully adjusted hazard ratio, 0.49; 95% confidence interval, 0.24-0.98; P = .04). On the other hand, for patients aged older than 69 years, BITA did not add any significant survival advantage (adjusted hazard ratio, 1.27; 95% confidence interval, 0.75-2.14; P = .37). This study provides robust scientific evidence for the loss of survival benefit from BITA for patients older than 69 years.

Bilateral internal thoracic artery grafting increases long-term survival in elderly patients.

Bilateral internal thoracic artery (BITA) grafting is extensively underused in coronary artery bypass graft surgery and it is mostly preserved for patients under the age of 70. The purpose of the present study was to compare outcomes in propensity score-matched patients aged 70 years or greater using a BITA, with patients using a single internal thoracic artery (SITA) graft. Among 18 761 patients operated on in our unit until December 2006, we selected 3496 patients aged 70 years or greater; of these, 1328 received a BITA (BITA group) and 2168 received a SITA (SITA group). Propensity score matching was used to reduce the preoperative patient variability. The 3-month and 10-year survival, stroke, myocardial infarction and sternal wound complication rate (defined as sternal instability or need for refixation) were compared between the two groups. After the correction, 892 patients per group were selected. Survival at 3 months was 90.6% in the SITA group and 91.6% in the BITA group (P = 0.34) and at 10 years was 38.9 and 57.5% (P = 0.02), respectively. The rates of stroke (1.01 vs 1.12%, P = 1), myocardial infarction (1.91 vs 2.13%, P = 0.86) and sternal wound complications (3.30 vs 5.42%, P = 0.17) were all similar between the SITA and BITA groups, respectively. The use of BITA grafting in elderly patients improves the 10-year survival rate, with similar postoperative morbidity. Thus, using adequate selection criteria, this technique should be routinely extended also to patients older than 70 years.

Sequential Internal Thoracic Artery Bypass Is Safe but Does Not Improve Survival

The benefit of adding an internal thoracic artery (ITA) sequential bypass to single or bilateral ITA graft to improve arterial revascularization is not established. The goal of this study is to evaluate the safety and the potential benefit of ITA sequential bypass in coronary artery surgery. We retrospectively reviewed a cohort of 1,400 consecutive, prospectively followed patients who underwent off-pump coronary artery bypass surgery for multivessel disease between September 1996 and November 2007 at the Montreal Heart Institute. Among them, 1,315 (93.9%) patients had 2- or 3-vessel disease and received at least 1 ITA graft. The following 4 groups were investigated: group 1, single ITA grafting alone (n=758); group 2, single ITA+sequential grafting (n=151); group 3, bilateral ITA grafting alone (n=308); and group 4, bilateral ITA+sequential grafting (n=98). Mean follow-up was 63±33 months and completed in 97% of the cohort. Single ITA patients were older, had more diabetes, chronic obstructive pulmonary disease, peripheral vascular disease, emergency surgery, and heart failure. The rates of complete revascularization, conversion to cardiopulmonary bypass, perioperative mortality, and myocardial infarction were similar in all groups. After correcting for risk factors, better overall, cardiac, and major adverse cardiac event (MACE)-free survival were observed in the bilateral ITA groups compared with the single ITA groups. Adding sequential ITA bypass grafting did not significantly impact survival or MACE-free survival. In our series, bilateral ITA grafting improved overall and MACE-free survival. Adding a sequential ITA bypass grafting was safe but did not add significant benefit in off-pump coronary artery bypass surgery.

Bilateral internal thoracic artery use in patients with low ejection fraction: is there any additional long-term benefit?

The use of bilateral internal thoracic arteries (BITA) has been associated with improved long-term outcomes following coronary artery bypass graft (CABG) surgery. The objective of this study was to evaluate the impact of BITA use on long-term survival among patients with low ejection fraction (EF) undergoing CABG. Between April 1991 and October 2011, 2035 consecutive patients underwent primary BITA grafting. Among them, there were 129 patients with left ventricular EF ≤40%. During the same time period, 1666 primary CABGs were performed using a single internal thoracic artery (SITA) in patients with EF ≤40%. A propensity score optimal matching algorithm was used to create the matched SITA and BITA groups (n = 111 in each group). Also, Cox regression multivariable analyses were performed to determine the independent risk factors for long-term mortality. The date of death was obtained from provincial vital statistics. There was no difference in operative mortality between matched BITA and SITA (n = 2, 1.8% vs n = 1, 0.9%, respectively, P = 0.6) groups. The mean follow-up was 8.6 ± 5.1 and 7.7 ± 5.5 years for BITA and SITA groups, respectively (P = 0.2). Five-, 10- and 15-year survival rates were 93.7, 77.5 and 59.0% in the matched BITA patients vs 82.8, 68.1 and 65.2% in the matched SITA patients (P = 0.3). In multivariate analysis, the independent risk factors for late mortality among hospital survivors were: insulin-dependent diabetes [adjusted hazard ratio (HR): 3.4, 95% confidence interval (CI): 1.4-8.4, P = 0.008], perioperative intra-aortic balloon pump insertion (HR: 3.2, 95% CI: 1.5-6.9, P = 0.004), postoperative deep sternal wound infection (HR: 7.4, 95% CI: 2.2-24.1, P = 0.001) and neurological complications (HR: 3.5, 95% CI: 1.4-8.4, P = 0.006). Choice of BITA versus SITA was not an independent predictor of long-term mortality (P = 0.3). The use of a second internal thoracic artery (ITA) does not prolong late survival in patients with low EF undergoing CABG compared with a propensity-matched group of SITA graft patients.

Bilateral internal thoracic artery grafting for peripheral arterial disease patients

Peripheral arterial disease (PAD) is known to have a poor prognosis. Some reports have also described poor late results after coronary artery bypass grafting (CABG). However, there have been few reports about whether bilateral internal thoracic artery grafting improves the long-term survival of PAD patients after CABG. We performed this study to clarify whether or not this is the case. One hundred and thirty-six PAD patients who underwent elective CABG with two or more grafts were enrolled in this study. Patients were divided into two groups, 71 patients in the bilateral internal thoracic artery (BITA) group and 65 patients in the single internal thoracic artery (SITA) group. The maximum follow-up period was 19 years, with a mean of 5.7 ± 4.4 years. We investigated the long-term results based on three factors; survival, freedom from cardiac death, and freedom from cardiac events. The 3-, 5- and 10-year survival rates in the BITA group were 83.0, 74.2, and 43.1%, respectively. And those in the SITA group were 79.4, 67.7, and 32.3%, respectively. There were no significant differences between the two groups (p = 0.5843). There were also no statistically significant differences between the two groups in terms of the freedom from cardiac death (p = 0.8589) or in the freedom from cardiac events (p = 0.9445). No long-term advantage was observed for CABG with BITA in comparison to SITA alone in patients with PAD.

Is Bilateral Internal Thoracic Artery Use Safe in the Elderly?

The strategy of bilateral mammary artery grafting is often not considered for elderly patients due to perceived concerns of increased morbidity and mortality. The objective of this study is to explore the safety of bilateral mammary in elderly patients. Out of 7746 patients who underwent coronary artery bypass grafting using at least one internal thoracic artery (ITA), there were 3940 patients aged 65 years or greater, and of those, 3581 patients had a single ITA (SITA) and 359 patients had bilateral ITAs (BITAs). The primary outcome was the incidence of major adverse cardiac or cerebrovascular events (MACCEs). Secondary outcomes included re-exploration for bleeding, blood transfusions, sternal wound infections, and intensive care unit and hospital length of stay. The incidence of mortality and MACCE were similar in both groups (mortality BITA 2.6%, SITA 3.6%, p = 0.25, MACCE BITA 8.5%, SITA 6.1%, p = 0.13). Superficial and deep sternal site infections were significantly more prevalent in the BITA group than the SITA group [superficial OR 0.42, 95% CI [0.23-0.75] (p = 0.003) and deep OR 0.29, 95% CI [0.14-0.58 (p = 0.0005)]. Use of BITA is safe in the elderly with respect to mortality and early cardiovascular outcome. BITA use in the elderly is associated with an increased risk of sternal wound infection. Our experience in this situation suggests that there is a maximum age (approximately 74 years) beyond which the combined risk of MACCE and wound complications supersedes the benefits in terms of sternal infections.

Does Off-Pump Bilateral Internal Thoracic Artery Grafting Increase Operative Risk in Dialysis Patients?

We compared short-term outcomes of patients with chronic dialysis receiving bilateral internal thoracic artery (BITA) grafting with single internal thoracic artery (SITA) grafting using propensity score analysis. Between 2002 and 2008, 656 consecutive patients underwent isolated coronary artery bypass grafting (99.1% off-pump). Of these, 56 patients with chronic dialysis and multivessel disease were retrospectively compared according to surgical technique, BITA (n = 32) or SITA (n = 23) grafting. In an attempt to minimize the selection bias, propensity scores were created based on 13 preoperative factors (C statistics, 0.914). There was no significant difference in age, left ventricular ejection fraction, prevalence of diabetes mellitus, and logistic euroSCORE between the 2 groups. All patients underwent revascularization using the off-pump technique without conversion to cardiopulmonary bypass. All arterial conduits were harvested using skeletonization technique. Except for 1 patient, all ITAs were used as in situ graft. Complete revascularization was achieved in all patients. There was no significant difference in occurrence of mediastinitis, impaired wound healing, and stroke between the 2 groups. The 30-day mortality was 6.3% in the BITA group and 13.0% in the SITA group (P = .64). After adjusting for propensity score, BITA grafting was not associated with impaired wound healing (odds ratio, 0.63; 95% confidence interval, 0.04 to 8.79; P = .73) and 30-day mortality (odds ratio, 0.60; 95% confidence interval, 0.05 to 6.82; P = .68). In situ skeletonized BITA grafting is safe and feasible in dialysis patients with multivessel disease.

Efficacy of Bilateral Internal Thoracic Artery Grafting in Patients With Chronic Kidney Disease

This study compared short-term and long-term outcomes in propensity score-matched patients with chronic kidney disease receiving bilateral internal thoracic artery (ITA) or single ITA grafting and assessed any benefit of bilateral ITA grafting for survival. Among 656 consecutive patients undergoing isolated coronary artery bypass grafting (99.1% by off-pump technique) between 2002 and 2008, 361 had chronic kidney disease with no history of dialysis. After excluding 10 patients who would not be potential candidates for bilateral ITA grafting because they were aged older than 85 years and 15 who had only one target vessel at the left coronary area, we identified 157 propensity score-matched pairs. Propensity scores were created based on 13 preoperative factors (C statistics, 0.787). During a mean observation of 2.9 years, the rates of overall death and cardiac death (myocardial infarction, heart failure, and sudden death) in the bilateral ITA group were significantly lower than those in the single ITA group (5.1% vs 15.9%, p=0.01; 1.3% vs 8.3%, p=0.01). In multivariate Cox models including bilateral ITA grafting and all other potential predictors, bilateral ITA grafting was significantly associated with a lower risk for overall death (hazard ratio, 0.29; 95% confidence interval, 0.10 to 0.89; p=0.03) and cardiac death (hazard ratio, 0.14; 95% confidence interval, 0.03 to 0.63; p=0.02). Among patients with chronic kidney disease, bilateral ITA grafting provides better long-term survival than single ITA grafting.

Long-Term Results of Bilateral Internal Thoracic Artery Grafting in Dialysis Patients

We evaluated the perioperative and long-term results of bilateral internal thoracic artery grafting in dialysis patients. One hundred one consecutive patients on chronic dialysis who underwent isolated coronary artery bypass grafting were retrospectively compared according to the surgical technique, bilateral internal thoracic artery (BITA) grafting (n = 76) or single internal thoracic artery (SITA) grafting (n = 25). Hospital mortality was 5.3% in the BITA group and 8.0% in the SITA group (p = not significant). The incidence of mediastinitis was not different (7.9% in the BITA group and 8.0% in the SITA group). The median duration of follow-up was 3.1 years (range, 0.1 to 10.9). Survival and freedom from cardiac mortality were not different between the two groups, but the BITA group had a trend toward better results. Freedom from cardiac events (including cardiac-related death, myocardial infarction, percutaneous coronary intervention, redo coronary artery bypass grafting, and congestive heart failure) was superior in the BITA group (p = 0.03). Calcification of the ascending aorta, peripheral vascular disease, insulin-dependent diabetes mellitis, and age were the independent risk factors of late death. Perioperative results of BITA grafting in dialysis patients were not different from the results of SITA grafting. However, the long-term results of BITA grafting in dialysis patients were better than the results of SITA grafting. Overall, our results support the continued use of BITA grafting in dialysis patients.

Does bilateral ITA grafting increase perioperative complications?☆Outcome of 4462 patients with bilateral versus 4204 patients with single ITA bypass

Superior patency of internal thoracic artery (ITA) grafting to saphenous veins is conclusive. The aim of the present study was to compare the early outcome of patients receiving either bilateral ITA (BITA) or single ITA (SITA) grafts and to identify risk factors for perioperative complications, such as obesity, diabetes mellitus, or advanced age. All 8666 patients with isolated coronary artery bypass grafting (CABG, including emergent cases or redos) operated between January 1994 and June 2004 receiving either BITA (n=4462) or SITA (n=4204) grafting were analyzed retrospectively. Demographic data were comparable for both groups concerning mean age (65.3+/-9.4 years vs 64.9+/-9.3 years), range (35-89 years (p=0.05)), diabetes incidence (29.3% vs 2.6% (p=0.08)), dialysis-dependent renal failure (0.7% vs 0.6% (p=0.4)), preoperative ejection fraction (EF) mean (61.8% vs 61.2% (p=0.07)) but not for gender (80.4% vs 76.7% males (p=0.00)), body mass index (BMI) mean (27.2+/-3.6 vs 26.9+/-3.5 (p=0.00)), COPD (7.0% vs 8.5% (p=0.00)), and hyperlipidemia (78.3% vs 74.3% (p=0.00)). In the BITA group, right ITA (RITA) was directed preferentially to the left anterior descending artery (LAD), left ITA (LITA) to the lateral wall. In the SITA group, the LAD was revascularized with the left ITA. Additional bypasses were performed with saphenous vein grafts (SVG). The number of anastomoses was higher in the BITA group (3.8+/-0.9 vs 3.1+/-0.9 (p=0.00)); therefore, duration of surgery (mean: 189+/-46.3 min vs 164+/-46.2 min) and cross-clamp time (62.0+/-17.9 min vs 51.0+/-18.0 min) significantly prolonged (p=0.00). Incidence of rethoracotomy due to bleeding (2.9% vs 0.6%; p=0.00) or sternal refixation with (0.7% vs 0.2%; p=0.00) or without infection (1.4% vs 0.6%; p=0.00) was higher in the BITA group, strongly associated with diabetes mellitus and duration of surgery but not with BMI>27. Thirty-day mortality revealed 2.6% versus 3.2% (p=0.1) but was significantly lower for diabetic patients in the BITA group (3.1% vs 4.7%; p=0.00). CABG using both ITAs can be performed routinely with good clinical results and low mortality. Compared with single ITA grafting, sternal and bleeding complications were slightly increased. Diabetes mellitus, BITA grafting, duration of surgery but not obesity or COPD could be identified as independent risk factors for sternal complications. Dialysis-dependent renal failure, EF<30%, emergent cases, and the absence of BITA grafting were predictors for increased perioperative mortality.

Does Bilateral Internal Thoracic Artery Grafting Increase Long-Term Survival of Diabetic Patients?

The purpose of the present study was to determine whether long-term survival in diabetic patients increased after bilateral internal thoracic artery (BITA) coronary bypass compared with matched patients with single internal thoracic artery (SITA) coronary bypass. The propensity for BITA was determined using logistic regression analysis and each BITA patient was matched with one SITA patient. Between January 1992 and March 2002, 980 matched diabetic patients (490 BITA versus 490 SITA) underwent coronary artery bypass surgery. Long-term survival data were obtained from the National Death Index (mean follow-up, 4.7 +/- 3.0 years). Groups were compared by Cox proportional hazard models and Kaplan-Meier survival plots. Multivariate Cox regression analysis determined that BITA grafting had no significant effect on long-term survival (hazard ratio 0.89, 95% confidence interval: 0.69 to 1.14, p = 0.343). There were no differences in 30-day mortality (3.9% for BITA versus 3.7%, p = 0.999) and major postoperative complications except for length of stay (11.4 days for BITA versus 12.7 days, p < 0.001). Five-year survival rate was 79.9% in the BITA group and 75.7% in the SITA group (p = 0.252). There was no difference in 5-year survival rate between matched patients younger than 60 or from 70 to 79 years old. However, BITA patients aged 60 to 69 years had better 5-year survival rates (84.1% versus 71.0%, p = 0.0196), whereas the opposite was observed in patients aged more than 79 years (5-year survival for BITA 43.1% versus 70.0%, p = 0.016). Bilateral internal thoracic artery grafting had no significant effect on long-term survival for diabetic patients, but it may increase long-term survival in patients aged 60 to 69 years, whereas SITA grafting may be beneficial for patients more than 79 years old.

The Effect of Bilateral Internal Thoracic Artery Grafting on Survival During 20 Postoperative Years

To compare survival of patients receiving bilateral internal thoracic artery grafts and single internal thoracic artery grafts more than 20 postoperative years, assess magnitude of benefit, and identify predictors of benefit. From cohorts of 8123 patients receiving single internal thoracic artery grafts and 2001 receiving bilateral internal thoracic artery grafts during primary isolated bypass operations for multivessel coronary disease between 1971 and 1989, we identified 1152 propensity-matched pairs. Mean follow-up of survivors was 16.5 years, with 51 patients followed for 20 years or more. Hazard function methodology was used to identify risk factors for mortality, compare survival, and assess magnitude of benefit. Comparison of the matched pairs showed survival of the bilateral internal thoracic artery and single internal thoracic artery groups at 7, 10, 15, and 20 years was 89% versus 87%, 81% versus 78%, 67% versus 58%, and 50% versus 37%, respectively (p < 0.0001). Divergence of bilateral internal thoracic artery and single internal thoracic artery hazard function curves continued to widen through 20 postoperative years. At 20 years, bilateral internal thoracic artery grafting was predicted to produce worse survival in 2.8% of patients, a survival advantage of less than 5% in 12.9%, greater than 10% in 52%, and greater than 15% in 7.6%. Combinations of cardiac and noncardiac descriptors were used to define higher and lower risk patient subsets. Advanced age, abnormal left ventricular function and noncardiac risk factors decreased overall survival but the incremental benefit of bilateral internal thoracic artery grafting persisted. Bilateral internal thoracic artery grafting produces improved survival compared with single internal thoracic artery grafting during the second postoperative decade, and the magnitude of that benefit increases through 20 postoperative years.

Early mortality and morbidity of bilateral versus single internal thoracic artery revascularization: propensity and risk modeling

OBJECTIVESWe examined whether bilateral internal thoracic artery (BITA) revascularization is associated with any increased in-hospital mortality and complications compared with single internal thoracic artery (SITA) revascularization.BACKGROUNDDespite proven long-term benefits, BITA revascularization has been slow to be adopted because of fear of increased early morbidity.METHODSWe evaluated 1,697 consecutive patients undergoing BITA (n = 867) or SITA (n = 830) revascularization. We used propensity score analyses and adjusted risk models to address differences between arms.RESULTSThere were 20 (2.3%) deaths in the BITA group versus 26 (3.1%) in the SITA group (odds ratio 0.73, p = 0.30). Propensity analysis identified several parameters that affected the decision to use BITA. Adjusting for propensity score and all potential risk factors, the odds ratio for death with BITA versus SITA was practically 1. Bilateral internal thoracic artery revascularization did not increase the number of in-hospital complications with the possible exception of deep sternal wound infections (11 [1.3%] vs. 3 [0.4%], p = 0.057). In multivariate modeling BITA increased the risk of deep sternal wound infections only in emergent cases and in older patients; the excess risk was negligible among 1,206 patients (71.1% of total) who did not have emergent revascularization and were ≤70 years old (risk difference 0.3%, p = 0.74). There was no difference in length of stay after adjustment for propensity factors (mean 11.3 vs. 11.7 days, p = 0.66).CONCLUSIONSBilateral internal thoracic artery revascularization grafting confers no increased risk for early death and does not prolong hospital stay. The small increase in the risk of deep sternal wound infections does not affect the majority of patients.

Competing risks after coronary bypass surgeryThe influence of death on reintervention

Objective: For groups of patients at high risk of death, such as older patients, the actual probability of experiencing a nonfatal event, such as reintervention, must be far smaller than the potential probability were there no attrition by death. Competing risks analysis quantifies the difference. Methods: Multivariable analyses were performed for the competing events death before reintervention, reoperation, and percutaneous transluminal coronary angioplasty in 2001 patients after bilateral internal thoracic artery grafting and in 8123 after single internal thoracic artery grafting. Follow-up was 9.7 ± 3.0 years and 10.8 ± 5.2 years in bilateral and single internal thoracic artery groups, respectively. Results: Patients receiving single grafts experienced shorter survival and more reinterventions ( P < .0001). However, other risk factors for death included old age ( P < .0001), but risk factors for reintervention included young age ( P < .0001). This difference confounds interpretation of event-free survival that is clarified by competing risks analysis. Death reduced the potential benefit of bilateral internal thoracic artery grafting on reintervention by angioplasty from a median of 8.5% to 5.5% at 12 years and by reoperation from 9.3% to 6.8%, with progressively greater erosion of benefit from attrition by death as age increased. Competing risks simulation confirmed that young age was a true risk factor for reintervention, excluding the explanation that it reflected simply passive attrition by death as patients age. Conclusions: Even after accounting for attrition by interim deaths, bilateral versus single internal thoracic artery grafting and older age are associated with fewer reinterventions. However, in high-risk patients, its benefit on freedom from reintervention is eroded considerably by death. (J Thorac Cardiovasc Surg 2000;119:1221-32)

Two internal thoracic artery grafts are better than one

Objective: Does the use of bilateral internal thoracic artery (ITA) grafts provide incremental benefit relative to the use of a single ITA graft? Methods: We conducted a retrospective, nonrandomized, long-term (mean follow-up interval of 10 postoperative years) study of patients undergoing elective primary isolated coronary bypass surgery who received either single (8123 patients) or bilateral ITA grafts (2001 patients), with or without additional vein grafts. Multiple statistical methods including propensity score matching, and multivariable parsimonious and nonparsimonious risk factor analyses were used to address the issues of patient selection and heterogeneity. Results: In-hospital mortality was 0.7% for both the bilateral and single ITA groups. Survival for the bilateral ITA group was 94%, 84%, and 67%, and for the single ITA group 92%, 79%, and 64% at 5, 10, and 15 postoperative years, respectively ( P < .001). Death, reoperation, and percutaneous transluminal coronary angioplasty were more frequent for patients undergoing single rather than bilateral ITA grafting, and this observation remained true despite multiple adjustments for patient selection, sampling, and length of follow-up. The differences between the bilateral and single ITA groups were greatest in regard to reoperation. The extent of benefit of bilateral ITA grafting varied according to patient-related variables, but no patient subsets were identified for whom single ITA grafting could be predicted to provide an advantage. Conclusions: Patients who received 2 ITA grafts had decreased risks of death, reoperation, and angioplasty. (J Thorac Cardiovasc Surg 1999;117:855-72)