Incidence and clinical implications of intraoperative BITA grafts conversion. Insights from the Arterial Revascularization Trial

Background: The arterial revascularization trial (ART) has been designed to answer the question whether the use of bilateral internal thoracic arteries (BITA) can improve 10-year outcomes when compared to single internal thoracic artery (SITA). In the ART, a significant proportion of patients initially allocated to BITA received other conduit strategies. We sought to investigate the incidence and clinical implication of BITA grafts conversion in the ART. Methods: Among patients enrolled in the ART (n=3102), we excluded those allocated to SITA (n=1554), those who did not undergo surgery (n=16) and those operated on but withdrew after randomization (n=7). Propensity score matching was used to compare converted vs non-converted BITA groups. Results: A total of 1525 patients were operated with intention to receive BITA grafting. Of those, 233 (15.3%) were converted to other conduit selection strategies. Incidence of conversion largely varied across 28 centres involved (from 0% to 42.9%). The most common reason for BITA grafts conversion was the evidence of at least one internal thoracic artery not suitable which was reported in 77 cases. Patients with intraoperative BITA graft conversion received a lower number of grafts (2.95±0.84 vs 3.21±0.74; P<0.001). However, hospital mortality rate was comparable to those who did not require BITA graft conversion (0 vs 1.6%; P=0.1) as well as the incidence of major complications. At 5 years we found a non-significant excess of deaths (11.9% vs 8.4%; P=0.1) and major adverse events (17.1% 13.2%; P=0.1) mainly driven by an excess of revascularization in patients requiring conversion. Conclusions: The incidence of intraoperative BITA graft conversion is not irrelevant . BITA graft conversion is not associated with increased operative morbidity but its effect on late outcomes remain uncertain

Impact of dual antiplatelet therapy after coronary artery bypass surgery on 1-year outcomes in the Arterial Revascularization Trial

OBJECTIVES: There is still little evidence to boldport routine dual antiplatelet therapy (DAPT) with P2Y12 antagonists following coronary artery bypass grafting (CABG). The Arterial Revascularization Trial (ART) was designed to compare 10-year survival after bilateral versus single internal thoracic artery grafting. We aimed to get insights into the effect of DAPT (with clopidogrel) following CABG on 1-year outcomes by performing a post hoc ART analysis. METHODS: Among patients enrolled in the ART (n  = 3102), 609 (21%) and 2308 (79%) were discharged on DAPT or aspirin alone, respectively. The primary end-point was the incidence of major adverse cerebrovascular and cardiac events (MACCE) at 1 year including cardiac death, myocardial infarction, cerebrovascular accident and reintervention; safety end-point was bleeding requiring hospitalization. Propensity score (PS) matching was used to create comparable groups. RESULTS: Among 609 PS-matched pairs, MACCE occurred in 34 (5.6%) and 34 (5.6%) in the DAPT and aspirin alone groups, respectively, with no significant difference between the 2 groups [hazard ratio (HR) 0.97, 95% confidence interval (CI) 0.59-1.59; P  = 0.90]. Only 188 (31%) subjects completed 1 year of DAPT, and in this subgroup, MACCE rate was 5.8% (HR 1.11, 95% CI 0.53-2.30; P  = 0.78). In the overall sample, bleeding rate was higher in DAPT group (2.3% vs 1.1%; P  = 0.02), although this difference was no longer significant after matching (2.3% vs 1.8%; P  = 0.54). CONCLUSIONS: Based on these findings, when compared with aspirin alone, DAPT with clopidogrel prescribed at discharge was not associated with a significant reduction of adverse cardiac and cerebrovascular events at 1 year following CABG

Assessment of data quality in an international multi-centre randomised trial of coronary artery surgery

ART is a multi-centre randomised trial of cardiac surgery which provided a unique opportunity to evaluate the data from a large number of centres from a variety of countries. We attempted to assess data quality, including recruitment rates, timeliness and completeness of the data obtained from the centres in different socio-economic strata

Post-operative atrial fibrillation and long-term risk of stroke after isolated coronary artery bypass graft surgery

Background: Post-operative atrial fibrillation (pAF) following coronary artery bypass graft-ing (CABG) is a common complication. Whether pAF is associated with an increased risk of cerebrovascular accident (CVA) remains uncertain. We investigated the association between pAF and long-term risk of CVA by performing a post-hoc analysis of 10-year outcomes of the Arterial Revascularization Trial (ART). Methods: For the present analysis, among patients enrolled in the ART (n=3102), we ex-cluded those who did not undergo surgery (n=25), had a prior history of atrial fibrillation (n=45), or had no information regarding the incidence of pAF (n=9). The final population consisted of 3023 patients of whom 734 (24.3%) developed pAF with the remaining 2289 maintaining sinus rhythm (SR). Competing risk and Cox regression analysis were used to investigate the association between pAF and the risk of CVA. Results: At 10 years, the cumulative incidence of CVA was 6.3% (4.6-8.1) vs 3.7% (2.9-4.5) in patients with pAF and SR respectively. pAF was an independent predictor of CVA at 10 years (HR 1.53; 95%CI 1.06-2.23; P-value=0.025) even when CVAs that occurred during the index admission were excluded from the analysis (HR 1.47; 95% 1.02-2.11; P=0.04). Conclusions: Patients with pAF after CABG are at higher risk of CVA. These findings chal-lenge the notion that pAF is a benign complication.</p

Five-year costs from a randomised comparison of bilateral and single internal thoracic artery grafts

Background: The use of bilateral internal thoracic arteries (BITA) for coronary artery bypass grafting (CABG) may improve survival compared with CABG using single internal thoracic arteries (SITA). We assessed the long-term costs of BITA compared with SITA. Methods: Between June 2004 and December 2007, 3102 patients from 28 hospitals in seven countries were randomised to CABG surgery using BITA (n=1548) or SITA (n=1554). Detailed resource use data were collected from the initial hospital episode and annually up to 5 years. The associated costs of this resource use were assessed from a UK perspective with 5 year totals calculated for each trial arm and pre-selected patient subgroups. Results: Total costs increased by approximately £1000 annually in each arm, with no significant annual difference between trial arms. Cumulative costs per patient at 5-year follow-up remained significantly higher in the BITA group (£18 629) compared with the SITA group (£17 480; mean cost difference £1149, 95% CI £330 to £1968, p=0.006) due to the higher costs of the initial procedure. There were no significant differences between the trial arms in the cost associated with healthcare contacts, medication use or serious adverse events. Conclusions: Higher index costs for BITA were still present at 5-year follow-up mainly driven by the higher initial cost with no subsequent difference emerging between 1 year and 5 years of follow-up. The overall cost-effectiveness of the two procedures, to be assessed at the primary endpoint of the 10-year follow-up, will depend on composite differences in costs and quality-adjusted survival

Safety of Perioperative Aprotinin Administration During Isolated Coronary Artery Bypass Graft Surgery: Insights From the ART (Arterial Revascularization Trial)

Background There is still uncertainty about the safety of aprotinin for coronary artery bypass graft surgery. The ART (Arterial Revascularization Trial) was designed to compare survival after bilateral versus single internal thoracic artery grafting. Many of the ART patients (≈30%) received perioperative aprotinin. We investigated the association between perioperative aprotinin administration and short‐term (in‐hospital) and long‐term outcomes by performing a post hoc analysis of the ART. Methods and Results Among patients enrolled in the ART (n=3102) from 2004 to 2007, we excluded those who did not undergo surgery (n=18) and those with no information about use of perioperative aprotinin (n=9). Finally, 836 of 3076 patients (27%) received aprotinin. Propensity matching was used to select 536 pairs for final comparison. Aprotinin was also associated with an increased risk of hospital mortality (9 [1.7%] versus 1 [0.2%]; odds ratio, 9.12; 95% confidence interval [CI], 1.15–72.2; P=0.03), intra‐aortic balloon pump insertion (37 [6.9%] versus 17 [3.2%]; odds ratio, 2.26; 95% CI, 1.26–4.07; P=0.006), and acute kidney injury (102 [19.0%] versus 76 [14.2%]; odds ratio, 1.42; 95% CI, 1.03–1.97; P=0.03). Aprotinin was not associated with a lower incidence of transfusion (37 [6.9%] versus 28 [5.2%]; odds ratio, 1.34; 95% CI, 0.81–2.23; P=0.25) and reexploration (26 [4.9%] versus 19 [3.5%]; hazard ratio, 1.39; 95% CI, 0.76–2.53; P=0.28). At 5 years, all‐cause mortality was significantly increased in the aprotinin group (56 [10.6%] versus 38 [7.3%]; hazard ratio, 1.51; 95% CI, 1.0–2.28; P=0.045). Conclusions In the present post hoc ART analysis, aprotinin was associated with a significantly increased risk of early and late mortality

Associations between adding a radial artery graft to single and bilateral internal thoracic artery grafts and outcomes. Insights from the Arterial Revascularization Trial

Background—Whether the use of the radial artery (RA) can improve clinical outcomes in coronary artery bypass graft (CABG) surgery remains unclear. The Arterial Revascularization Trial (ART) was designed to compare survival after bilateral internal thoracic artery (BITA) over single left internal thoracic artery (SITA). In the ART, a large proportion of patients (~20%) also received a RA graft instead of a saphenous vein graft (SVG). We aimed to investigate the associations between using the RA instead of SVG to supplement SITA or BITA grafts and outcomes by performing a post-hoc analysis of the ART.  Methods—Patients enrolled in the ART (n=3102) were classified based on conduits actually received (as treated). The analysis included 2737 patients who received a RA graft (RA group, n=632) or SVG only (SVG group, n=2105) in addition to SITA or BITA grafts. The primary endpoint was the composite of myocardial infarction, cardiovascular death and repeat revascularization at 5 years. Propensity score matching and stratified Cox regression were used to compare the two strategies.  Results—MI, cardiovascular death and repeat revascularization cumulative incidence was 2.3% (95%CI 1.1-3.4), 3.5% (95%CI 2.1-5.0) and 4.4% (95%CI 2.8-6.0) in the RA group and 3.4% (95%CI 2.0-4.8), 4.0% (95%CI 2.5-5.6) and 7.6% (95%CI 5.5- 9.7) in the SVG group respectively. The composite endpoint was significantly lower in the RA group (8.8%; 95%CI 6.5-11.0) when compared with the SVG group (13.6%; 95%CI 10.8-16.3) (P=0.005). This association was present when a RA graft was used to supplement both SITA and BITA grafts (interaction P=0.62).  Conclusions—This post-hoc ART analysis showed that an additional RA was associated with lower risk for mid-term major adverse cardiac events when used to supplement SITA or BITA grafts

Off-pump versus on-pump coronary artery bypass grafting: Insights from the Arterial Revascularization Trial

Background: The long-term effects of off-pump coronary artery bypass continue to be controversial because some studies have reported increased adverse event rates with off-pump coronary artery bypass when compared with on-pump coronary artery bypass. The Arterial Revascularization Trial compared survival after bilateral versus single internal thoracic artery grafting. The choice of off-pump coronary artery bypass versus on-pump coronary artery bypass was based on the surgeon's discretion. We performed a post hoc analysis of the Arterial Revascularization Trial to compare 5-year outcomes with 2 strategies. Methods: Among 3102 patients enrolled in the Arterial Revascularization Trial, we selected 1260 patients who underwent off-pump coronary artery bypass versus 1700 patients who underwent on-pump coronary artery bypass with cardioplegic arrest for the present comparison. Primary outcomes were 5-year mortality and incidence of major cardiac and cerebrovascular events, including cardiovascular death, myocardial infarction, cerebrovascular accident, and revascularization after index procedure. Propensity score matching selected 1260 pairs for final comparison. Stratified Cox models were used for treatment effect estimate. Results: Hospital mortality was comparable between off-pump coronary artery bypass and on-pump coronary artery bypass groups (12 [1.0%] vs 15 [1.2%]; P = .7). Conversion rate to on-pump during off-pump coronary artery bypass was 29 of 1260 (2.3%). When compared with off-pump coronary artery bypass not converted, off-pump coronary artery bypass converted to on-pump presented a remarkably higher hospital mortality (10.3% vs 0.7%; P < .001). At 5 years, the mortality rate was 110 (8.9%) versus 102 (8.3%) in the off-pump coronary artery bypass and on-pump coronary artery bypass groups, respectively, with no significant difference (hazard ratio, 1.14; 95% confidence interval, 0.86-1.52; P = .35). Incidence of major cardiac and cerebrovascular events was 175 (14.3) versus 169 (13.8) in the off-pump coronary artery bypass and on-pump coronary artery bypass groups, respectively, with no significant difference (hazard ratio, 1.05; 95% confidence interval, 0.84-1.31; P = .65). Conclusions: The present post hoc Arterial Revascularization Trial analysis supports the hypothesis that both off-pump coronary artery bypass and on-pump coronary artery bypass are equally effective and safe

Randomized trial of bilateral versus single internal-thoracic-artery grafts

Background: The use of bilateral internal thoracic (mammary) arteries for coronary-artery bypass grafting (CABG) may improve long-term outcomes as compared with the use of a single internal-thoracic-artery plus vein grafts. Methods: We randomly assigned patients scheduled for CABG to undergo single or bilateral internal-thoracic-artery grafting in 28 cardiac surgical centers in seven countries. The primary outcome was death from any cause at 10 years. The composite of death from any cause, myocardial infarction, or stroke was a secondary outcome. Interim analyses were prespecified at 5 years of follow-up. Results: A total of 3102 patients were enrolled; 1554 were randomly assigned to undergo single internal-thoracic-artery grafting (the single-graft group) and 1548 to undergo bilateral internal-thoracic-artery grafting (the bilateral-graft group). At 5 years of follow-up, the rate of death was 8.7% in the bilateral-graft group and 8.4% in the single-graft group (hazard ratio, 1.04; 95% confidence interval [CI], 0.81 to 1.32; P=0.77), and the rate of the composite of death from any cause, myocardial infarction, or stroke was 12.2% and 12.7%, respectively (hazard ratio, 0.96; 95% CI, 0.79 to 1.17; P=0.69). The rate of sternal wound complication was 3.5% in the bilateral-graft group versus 1.9% in the single-graft group (P=0.005), and the rate of sternal reconstruction was 1.9% versus 0.6% (P=0.002). Conclusions: Among patients undergoing CABG, there was no significant difference between those receiving single internal-thoracic-artery grafts and those receiving bilateral internal-thoracic-artery grafts with regard to mortality or the rates of cardiovascular events at 5 years of follow-up. There were more sternal wound complications with bilateral internal-thoracic-artery grafting than with single internal-thoracic-artery grafting. Ten-year follow-up is ongoing. (Funded by the British Heart Foundation and others; ART Current Controlled Trials number, ISRCTN46552265.