Outcome with invasive versus medical treatment of stable coronary artery disease: influence of perfusion defect size, ischaemia, and ejection fraction

Our aim was to address the combined influence of myocardial perfusion defects and left ventricular ejection fraction (LVEF) on outcome with coronary revascularisation in stable CAD patients.Of 527 patients with ischaemia by myocardial perfusion scintigraphy, 343 had medical therapy (Med) and 184 revascularisation (Revasc). During 5.3 years of follow-up, there was no intergroup difference in rates of death/myocardial infarction. Propensity score adjustment demonstrated a benefit of Revasc over Med with large defects (>14% of the myocardium), marked ischaemia (>10% of the myocardium), or LVEF <50%. However, defect size, ischaemia, and LVEF were correlated. In multivariate models, the Med versus Revasc hazard ratio (HR) was 4.06 times larger for LVEF <50% than for LVEF ≥50% (p=0.04) and 3.01 times larger for marked compared to mild/moderate ischaemia (p=0.11), whereas the effect of large compared to small/moderate defects vanished when adjusted for LVEF and ischaemia (HR=1.01, p=0.99). Considering the outcome difference as a function of both LVEF and ischaemia, we found no advantage or even a disadvantage of revascularisation in patients with mild/moderate ischaemia and preserved LVEF.A benefit of revascularisation was found only in case of marked ischaemia or LVEF <50%. For treatment triage, both perfusion parameters and LVEF should be considered.