A registry analysis shows inferior results in the composite outcome of death, myocardial infarction or stroke for percutaneous coronary intervention (PCI) as compared to coronary artery bypass grafting (CABG) in patients with moderate or severe left ventricular (LV) dysfunction at baseline, but no difference between PCI and CABG in LMCA patients with mild LV dysfunction at baseline.
Sangwoo Park, MD, of Ulsan University Hospital, South Korea, and colleagues reported these findings in a manuscript published in the Sept. 22 issue of the Journal of the American College of Cardiology.
LMCA disease is associated with high mortality and morbidity caused by a large area of jeopardized myocardium. However, the optimal revascularization strategy for patients with LMCA disease and left ventricular dysfunction is still unclear. The authors examined long-term comparative outcomes after PCI or CABG in patients with LMCA disease according to the severity of left ventricular dysfunction.
The authors evaluated 3,488 patients with LMCA disease who underwent CABG (n=1,355) or PCI (n=2,133) from the IRIS-MAIN (Interventional Research Incorporation Society-Left MAIN Revascularization) registry.
LV function was categorized according to left ventricular ejection fraction (LVEF) as normal function (LVE F≥55%), mild dysfunction (LVEF ≥45% to <55%), moderate dysfunction (LVEF ≥35% to <45%), or severe dysfunction (LVEF <35%). The primary outcome was a composite of death, myocardial infarction or stroke.
Of the analyzed population, with a median follow-up of 3.8 years, 2,641 (75.7%) patients had normal LVEF, and 403 (11.6%) had mild LV dysfunction, 260 (7.5%) had moderate dysfunction, and 184 (5.3%) had severe dysfunction at baseline. Compared with CABG, PCI was associated with a higher adjusted risk of the primary outcome in patients with moderate (hazard ratio [HR], 2.23; 95% confidence interval [CI], 1.17-4.28) or severe (HR, 2.45; 95% CI, 1.27-4.73) dysfunction. However, PCI and CABG had similar risks of the primary outcome in patients with normal (HR, 0.80; 95% CI, 0.59 to 1.07) or mild (HR, 1.17; 95% CI, 0.63 to 2.17) dysfunction (p-interaction = 0.004).
“These findings imply that the severity of LV dysfunction should be essentially considered in the decision making related to the optimal revascularization strategy for LMCA disease; for patients with moderate or severe LV dysfunction, CABG should be considered as the first choice of revascularization strategy if the surgical risk is acceptable,” Park and colleagues write.
In an accompanying editorial, Gregg W. Stone, MD, of the Icahn School of Medicine at Mount Sinai and the Cardiovascular Research Foundation, New York, writes that long-term results show no difference in all-cause death, myocardial infarction and stroke for PCI vs. CABG in the long run, and increased risk of long-term revascularization for PCI. Even so, he adds, the two are not equal, with CABG patients showing more symptoms in the long run and that “repeat revascularization is arguably less important than other adverse events, such as atrial fibrillation, major bleeding, and acute renal insufficiency, that occur less frequently after PCI.”
Stone pointed out that the study by Park and colleagues, conducted at 50 Asian hospitals, differs from another registry analysis from New York state showing that, in patients with LVEF ≤35%, PCI showed a similar risk of death, a lower risk of stroke, and a higher risk of myocardial infarction in comparison with CABG.
“The totality of evidence suggests that PCI with contemporary (drug-eluting stents) and CABG results in similar long-term mortality in most patients with LMCAD,” he writes. “However, notwithstanding the New York state study, CABG may offer superior long-term outcomes for those with moderately or severely reduced LVEF, especially if complete revascularization cannot be achieved by PCI.”
Stone adds that mechanical circulatory support could help improve outcomes in patients with moderate to severe LV dysfunction.
In the end, however, he writes, “Conclusive guidance would thus require a definitive large-scale randomized trial of optimal PCI versus optimal CABG in patients with ischemic cardiomyopathy and (LMCA disease), a study that is not likely to be performed.”
Therefore, clinicians must factor in LV function when deciding on a treatment course, including whether to perform PCI or CABG, for high-risk patients with complex LMCA disease, Stone concludes.
Park S, Ahn J-M, Kim TO, et al. Revascularization in Patients With Left Main Coronary Artery Disease and Left Ventricular Dysfunction. J Am Coll Cardiol 2020;76:1395-406.
Stone GW. Revascularization Choices for Left Main Coronary Artery Disease: Does Left Ventricular Function Matter? J Am Coll Cardiol 2020;76:1407-9.
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