Patients with non-ST-elevation acute coronary syndromes undergoing coronary artery bypass grafting in the modern era of antithrombotic therapy

Percutaneous Coronary Intervention vs Coronary Artery Bypass Graft Surgery for Left Main Disease in Patients With and Without Acute Coronary Syndromes: A Pooled Analysis of 4 Randomized Clinical Trials

Importance

Patients with left main coronary artery disease presenting with an acute coronary syndrome (ACS) represent a high-risk and understudied subgroup of patients with atherosclerosis.

Objective

To assess clinical outcomes after PCI vs CABG in patients with left main disease with vs without ACS.

Design, Setting, and Participants

Data were pooled from 4 trials comparing PCI with drug-eluting stents vs CABG in patients with left main disease who were considered equally suitable candidates for either strategy (SYNTAX, PRECOMBAT, NOBLE, and EXCEL). Patients were categorized as presenting with or without ACS. Kaplan-Meier event rates through 5 years and Cox model hazard ratios were generated, and interactions were tested. Patients were enrolled in the individual trials from 2004 through 2015. Individual patient data from the trials were pooled and reconciled from 2020 to 2021, and the analyses pertaining to the ACS subgroup were performed from March 2022 through February 2023.

Main Outcomes and Measures

The primary outcome was death through 5 years. Secondary outcomes included cardiovascular death, spontaneous myocardial infarction (MI), procedural MI, stroke, and repeat revascularization.

Results

Among 4394 patients (median [IQR] age, 66 [59-73] years; 3371 [76.7%] male and 1022 [23.3%] female) randomized to receive PCI or CABG, 1466 (33%) had ACS. Patients with ACS were more likely to have diabetes, prior MI, left ventricular ejection fraction less than 50%, and higher SYNTAX scores. At 30 days, patients with ACS had higher all-cause death (hazard ratio [HR], 3.40; 95% CI, 1.81-6.37; P < .001) and cardiovascular death (HR, 3.21; 95% CI, 1.69-6.08; P < .001) compared with those without ACS. Patients with ACS also had higher rates of spontaneous MI (HR, 1.70; 95% CI, 1.25-2.31; P < .001) through 5 years. The rates of all-cause mortality through 5 years with PCI vs CABG were 10.9% vs 11.5% (HR, 0.93; 95% CI, 0.68-1.27) in patients with ACS and 11.3% vs 9.6% (HR, 1.19; 95% CI, 0.95-1.50) in patients without ACS (P = .22 for interaction). The risk of early stroke was lower with PCI vs CABG (ACS: HR, 0.39; 95% CI, 0.12-1.25; no ACS: HR, 0.35; 95% CI, 0.16-0.75), whereas the 5-year risks of spontaneous MI and repeat revascularization were higher with PCI vs CABG (spontaneous MI: ACS: HR, 1.74; 95% CI, 1.09-2.77; no ACS: HR, 3.03; 95% CI, 1.94-4.72; repeat revascularization: ACS: HR, 1.57; 95% CI, 1.19-2.09; no ACS: HR, 1.90; 95% CI, 1.54-2.33), regardless of ACS status.

Conclusion and Relevance

Among largely stable patients undergoing left main revascularization and with predominantly low to intermediate coronary anatomical complexity, those with ACS had higher rates of early death. Nonetheless, rates of all-cause mortality through 5 years were similar with PCI vs CABG in this high-risk subgroup. The relative advantages and disadvantages of PCI vs CABG in terms of early stroke and long-term spontaneous MI and repeat revascularization were consistent regardless of ACS status.

Trial Registration

ClinicalTrials.gov Identifiers: NCT00114972, NCT00422968, NCT01496651, NCT01205776.

A systematic review and meta-analysis of percutaneous coronary intervention compared to coronary artery bypass grafting in non-ST-elevation acute coronary syndrome

Non-ST-elevation acute coronary syndrome (NSTE-ACS) affects millions of patients. Although an invasive strategy can improve survival, the optimal treatment [i.e., percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG)] is not clear. We performed a meta-analysis of studies reporting outcomes between PCI and CABG in patients with NSTE-ACS. MEDLINE, EMBASE and Cochrane Library were assessed. The primary outcome was long-term mortality. Inverse variance method and random model were performed. We identified 13 observational studies (48,891 patients). No significant difference was found in the primary endpoint [CABG vs. PCI, incidence rate ratio (IRR) 0.93, 95% confidence interval (CI) 0.70; 1.23]. CABG was associated with lower long-term major adverse cardiovascular events (MACE) (IRR 0.64, 95% CI 0.54; 0.76) and lower long-term re-revascularization (IRR 0.37, 95% CI 0.30; 0.47). There was no significant difference in long-term myocardial infarction (CABG vs. PCI, IRR 0.96, 95% CI 0.50; 1.84) and peri-operative mortality (CABG vs. PCI, odds ratio 1.36, 95% CI 0.94; 1.95). For the treatment of NSTE-ACS, CABG and PCI are associated with similar rates of long-term mortality and myocardial infarction. CABG is associated with lower rates of long-term MACE and re-revascularization. Randomized comparisons in this setting are necessary.

The potential role of anticoagulant therapy for the secondary prevention of ischemic events post-acute coronary syndrome

Abstract The use of dual antiplatelet therapy has led to a substantial reduction in ischemic events post-acute coronary syndrome (ACS). Despite this, recurrent event rates remain high. Recent research has combined antiplatelet with anticoagulant therapy to reduce recurrent event rates further. Compared with standard medical therapy, rivaroxaban demonstrated improved efficacy outcomes and significantly reduced mortality after an ACS. Although clear benefits of novel oral anticoagulants post-ACS have been proven, concerns regarding bleeding are still a barrier to widespread use. This review explores key trials of dual antiplatelet therapy and examines the latest research in anticoagulation aiming to optimize clinical outcomes post-ACS.

Current antithrombotic agents for acute coronary syndromes: focus on bleeding risk

The formation of an intravascular thrombus underlies the clinical symptoms associated with acute coronary syndromes (ACS). Plaque rupture signals the recruitment and activation of platelets, initiation of the coagulation cascade, and generation of thrombin, resulting in the formation of a platelet-rich thrombus. Use of antithrombotic therapy, including antiplatelet and anticoagulant agents, is a crucial element in reducing the overall morbidity and mortality in patients with ACS. Current antiplatelet and anticoagulant therapies act on distinct sites in platelet activation pathways and the coagulation cascade, but because these agents target pathways necessary for protective hemostasis, their use increases the risk for bleeding complications. Previously, bleeding was considered an unavoidable side effect of ACS management with few clinical implications; however, bleeding has since been shown to be an independent predictor of short- and long-term mortality in patients with ACS. Therefore, the prevention of bleeding has become equally as important as the prevention of further ischemic events. Strategies to limit bleeding include bleeding risk stratification, appropriate dosing of antithrombotic drugs, use of the lowest dose of aspirin with proven efficacy, avoidance of combinations of antithrombotic agents unless for a proven indication, use of drugs proven to reduce the risk of bleeding, and choice of radial access over femoral access in case of invasive strategy. In this context, several novel therapeutic approaches are currently under clinical evaluation, including new antiplatelet agents, such as protease-activated receptor 1 antagonists, and new anticoagulants, such as direct-acting antagonists of factor Xa and factor IIa (thrombin). This review discusses antiplatelet and anticoagulant treatment strategies for the management of ACS, with a particular focus on their associated bleeding risks.

Prevalence, predictors, and impact of conservative medical management for patients with non-ST-segment elevation acute coronary syndromes who have angiographically documented significant coronary disease

OBJECTIVES

We sought to characterize the utilization and impact of a conservative medical management strategy for patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS) and significant coronary artery disease on early angiography.

BACKGROUND

Practice guidelines recommend an early invasive management strategy for NSTE ACS, but revascularization procedures may not always be performed after early angiography, even when significant coronary artery disease is present.

METHODS

We evaluated 8,225 intermediate- to high-risk NSTE ACS patients with at least 1 coronary lesion >50% stenosis on early angiography from the SYNERGY (Superior Yield of the New Strategy of Enoxaparin, Revascularization, and Glycoprotein IIb/IIIa Inhibitors) trial (2001 to 2003), comparing patients treated with conservative medical management with those who underwent in-hospital percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) within 7 days of randomization.

RESULTS

A total of 2,633 patients (32%) were medically managed, 4,294 (52%) underwent PCI, and 1,298 (16%) underwent CABG. The strongest independent predictors of conservative medical management versus any intervention were prior CABG, lower body weight, lack of a reinfarction between randomization and catheterization, and 3-vessel disease. With conservative medical management, the cumulative risk of 1-year mortality after discharge increased rapidly during the first 90 days and thereafter remained higher at 7.7% compared with that seen in patients treated with PCI (3.6%) or CABG (6.2%).

CONCLUSIONS

One-third of patients with NSTE ACS and significant coronary disease on early angiography were managed without in-hospital revascularization in the SYNERGY trial, and these patients had an increased risk of late mortality. These findings highlight the need for novel treatment approaches for NSTE ACS patients who are not candidates for revascularization. (SYNERGY trial; NCT00043784).