Residual ischemia after angiographically successful left main (LM) bifurcation percutaneous coronary intervention (PCI) was identified in 13.2% of patients, and is associated with a higher risk of cardiovascular death at 3 years, a new study shows.
William Wijns, MD, PhD, of the National University of Ireland, Galway, presented these results during a late-breaking trial session Tuesday at EuroPCR 2023 in Paris. A manuscript reporting the results was simultaneously published online in the European Heart Journal.
Left main coronary artery disease (LMCAD) is typically managed with LM bifurcation PCI, which compared with isolated ostial or shaft lesions, involves more complex procedures and less-than-optimal outcomes.
The purpose of this study was to examine the prognostic implications of ischemia, according to artificial intelligence-powered Murray Bifurcation Fractal Law-based QFR (µQFR), after LM bifurcation PCI. This post hoc, blinded, in silico analysis was performed using a prospective cohort of patients with LMCAD from 2014-2016. The primary outcome was 3-year cardiovascular death.
Physiologically significant residual ischemia was defined as post-PCI µQFR values ≤0.80 left anterior descending (LAD) or left circumflex (LCX) coronary artery. Two assessments were performed in the main vessel (LM-LAD) and side branch (LCX) using the angiogram. Overall, 13.2% of patients had post-PCI residual ischemia after LM bifurcation PCI (residual ischemia group: n=155, 77.4% male, 26.5% had prior PCI; no residual ischemia group: n=1,015, 79.8% male, 23.9% had prior PCI).
Independent predictors of residual ischemia—such as multivessel disease, LM moderate-to-severe calcification and previous myocardial infarction—were predicted using two multivariable logistic models. The primary outcome occurred in 5.4% of patients with residual ischemia (hazard ratio [HR]=3.20, 95% confidence interval [CI]=1.16-8.80, p=0.001) and 1.3% of patients with no residual ischemia; patients with residual ischemia experienced higher rates of bifurcation-oriented composite endpoint (BOCE, defined as the composite of cardiovascular death, target bifurcation-related myocardial infarction or target bifurcation revascularization; 17.8%, HR=2.79, 95% CI=1.68-4.64, p<0.0001; no residual ischemia=5.8%).
The minimal µQFR value for patient-level post-PCI was defined as the lower µQFR value in the LAD and LCX. For every 0.1 decrease in µQFR value, the risk of BOCE increased 29% and the risk of 3-year cardiovascular death increased 27%, respectively. This indicates an inverse and continuous relationship.
In conclusion, it is clinically reasonable to perform a physiological assessment post-PCI due to the prognostic benefits, even when the PCI is otherwise successful, Wijns said.