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

Aims: 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. Methods and results: 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. Conclusions: 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.