Impact of Prior Cerebrovascular Events on Patients with Unprotected Left Main Coronary Artery Disease Treated with Coronary Artery Bypass Grafting or Percutaneous Coronary Intervention
The treatment of unprotected left main coronary artery (ULMCA) disease has evolved significantly over the past decades, with coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) emerging as the primary revascularization strategies. However, the optimal approach for patients with prior cerebrovascular events (CVEs) remains a subject of debate. This study aims to evaluate the impact of prior CVEs on outcomes in patients with ULMCA disease treated with either CABG or PCI, providing insights into the optimal revascularization strategy for this high-risk population.
Background and Rationale
Atherosclerosis is a systemic disease that often affects multiple vascular beds, including the coronary and cerebral arteries. Consequently, patients with coronary artery disease (CAD) frequently have a history of CVEs, such as stroke, transient ischemic attack (TIA), or carotid artery disease. Approximately one in eight patients with CAD has a prior CVE, and these patients are at a higher risk of adverse outcomes following revascularization compared to those without CVEs. Despite this, patients with prior CVEs are often excluded from clinical trials comparing CABG and PCI, leaving a gap in the evidence base for guiding treatment decisions in this population.
CABG has traditionally been considered the standard of care for patients with complex coronary lesions, while PCI with drug-eluting stents (DES) is an acceptable option for those with less complicated disease. However, CABG is associated with a higher risk of perioperative stroke compared to PCI, which complicates the decision-making process for patients with prior CVEs. This study seeks to address this gap by comparing the outcomes of CABG and PCI in real-world patients with ULMCA disease and prior CVEs.
Study Design and Methods
This retrospective, single-center study included consecutive patients aged over 18 years who were diagnosed with ULMCA disease (defined as left main artery stenosis ≥50%) and underwent either CABG or PCI between January 2005 and March 2010 at Beijing Anzhen Hospital. The choice of revascularization modality (DES placement or CABG) was made at the discretion of the treating cardiologist and the patient. CABG was performed using standard bypass techniques, with the internal thoracic artery preferentially used for revascularization of the left anterior descending artery. Follow-up was conducted via telephone or outpatient visits.
The primary endpoint of the study was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, myocardial infarction (MI), stroke, and target vessel revascularization (TVR). TVR was defined as any surgical or interventional revascularization performed on previously treated vessels. Prior CVEs were defined as a history of stroke, TIA, or carotid artery disease.
Baseline Characteristics
Of the 2043 patients with ULMCA disease included in the study, 274 (13.4%) had a history of prior CVEs. Patients with prior CVEs were older and had a higher prevalence of comorbidities, including hyperlipidemia, hypertension, and peripheral vascular disease, compared to those without CVEs. Additionally, patients with prior CVEs were more likely to have chronic total occlusion (CTO) and were less likely to achieve complete revascularization. There were no significant differences in sex, smoking history, previous revascularization, left ventricular ejection fraction, creatinine levels, family history of CAD, or multivessel disease (MVD) between the two groups.
Among the 274 patients with prior CVEs, 130 underwent PCI and 144 underwent CABG. Among the 1769 patients without prior CVEs, 918 underwent PCI and 851 underwent CABG.
Outcomes
The median follow-up period was 21.53 months. Patients with prior CVEs experienced significantly higher rates of MACCE compared to those without CVEs (32.3% vs. 23.6%; hazard ratio [HR]: 1.96; 95% confidence interval [CI]: 1.37–2.81; P < 0.0001). This increase was driven by higher rates of MI (8.4% vs. 7.3%; HR: 3.02; 95% CI: 1.51–6.04; P < 0.0001). Although the incidence of stroke was higher in patients with prior CVEs (3.7% vs. 3.0%), the difference was not statistically significant (HR: 2.15; 95% CI: 0.78–5.94; P = 0.0550). There were no significant differences in all-cause death or TVR between the two groups.
After adjusting for age, hyperlipidemia, hypertension, peripheral vascular disease, and other relevant factors, Cox regression analysis confirmed a higher incidence of MACCE (adjusted HR: 2.11; 95% CI: 1.54–2.89; P < 0.0001), MI (adjusted HR: 2.24; 95% CI: 1.28–3.91; P = 0.0050), and stroke (adjusted HR: 3.64; 95% CI: 1.24–10.74; P = 0.0190) in patients with prior CVEs compared to those without. There were still no significant differences in all-cause death or TVR.
Comparison of PCI and CABG in Patients with Prior CVEs
Among patients with prior CVEs, there were no significant differences in baseline characteristics between those who underwent PCI and those who underwent CABG. However, the outcomes varied by revascularization modality. In patients with prior CVEs, the incidence of MI was higher after PCI than after CABG (12.7% vs. 4.4%; HR: 3.03; 95% CI: 1.19–7.75). In contrast, in patients without prior CVEs, the incidence of MI was 13.7% after PCI and 2.4% after CABG (HR: 1.62; 95% CI: 0.90–2.90).
The rate of stroke was lower after PCI compared to CABG in both patients with and without prior CVEs (Pinteraction: 0.0200). However, the rate of TVR was higher after PCI compared to CABG in both groups (Pinteraction: <0.0001). Consequently, the composite rate of death, MI, stroke, and TVR favored CABG in both patients with and without prior CVEs (Pinteraction: 0.5400).
Discussion
This study highlights several important findings regarding the impact of prior CVEs on outcomes in patients with ULMCA disease treated with CABG or PCI. First, patients with prior CVEs are more likely to have comorbidities, including hyperlipidemia, hypertension, and peripheral vascular disease, which are linked to similar predisposing risk factors and genetic predisposition. This underscores the systemic nature of atherosclerosis, which affects multiple vascular beds.
Second, the rate of MACCE was significantly higher in patients with prior CVEs compared to those without, driven primarily by increased rates of MI. This suggests that prior CVEs are a marker of more advanced and diffuse atherosclerotic disease, which may contribute to worse outcomes following revascularization.
Third, the study found that the rates of all-cause death, MI, and TVR favored CABG, while the rate of stroke favored PCI in both patients with and without prior CVEs. This is consistent with prior studies showing that CABG is associated with a higher risk of perioperative stroke, which remains a significant concern despite improvements in surgical techniques. However, the higher rate of MI after PCI in patients with prior CVEs suggests that PCI may not be the optimal strategy for this population.
Finally, the composite rate of death, MI, stroke, and TVR favored CABG in both patients with and without prior CVEs. This finding supports the view that prior CVEs should not be the sole reason to favor PCI over CABG. Instead, the decision should be made on a case-by-case basis, taking into account all relevant factors, including the patient’s overall health, coronary anatomy, and the presence of comorbidities.
Limitations
This study has several limitations. First, its retrospective design and non-randomized nature introduce the potential for selection bias and ascertainment bias. Second, the study was conducted at a single center, and the number of patients with prior CVEs was relatively small (n=274), which may limit the generalizability of the findings. Third, the study did not capture data on the SYNTAX score, which is an important factor in determining the complexity of coronary lesions and may influence outcomes. Larger, multicenter studies are needed to confirm these findings and provide more robust evidence for guiding treatment decisions in this population.
Conclusion
In conclusion, this study provides valuable insights into the impact of prior CVEs on outcomes in patients with ULMCA disease treated with CABG or PCI. Patients with prior CVEs are at higher risk of adverse outcomes, particularly MI, following revascularization. While CABG is associated with a higher risk of stroke, it appears to be the preferred strategy for reducing the overall risk of MACCE in this population. The decision to proceed with CABG or PCI should be made on an individual basis, taking into account the patient’s overall health, coronary anatomy, and the presence of comorbidities.
doi.org/10.1097/CM9.0000000000001645
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