Impact of ischaemia and scar on the therapeutic benefit derived from myocardial revascularization vs. medical therapy...

Area of Science:

• Cardiology
• Nuclear Cardiology
• Cardiovascular Imaging

Background:

• Pre-revascularization ischemia testing is recommended for patients with coronary artery disease (CAD).
• The interplay between ischemia extent, myocardial scar, and revascularization outcomes on patient survival remains unclear.

Purpose of the Study:

• To investigate the relationship between the extent of myocardial ischemia, myocardial scar burden, and the survival benefit of early revascularization in patients with known CAD.
• To determine if prior myocardial infarction (MI) influences the survival benefit of revascularization.

Main Methods:

• A large observational study included 13,555 patients who underwent stress myocardial perfusion scintigraphy (MPS).
• Ischemia (%I) and scar (%F) were quantified using SPECT MPS.
• Cox proportional hazards modeling, adjusted for propensity scores and baseline characteristics, was used to assess all-cause death (ACD).

Main Results:

• A significant three-way interaction was found between %I, early revascularization, and history of CAD (HxCAD).
• %I identified a survival benefit with early revascularization in patients without prior MI, but not in those with prior MI.
• Excluding patients with >10% scar, %I identified a survival benefit in all patients, suggesting scar burden modifies the benefit of revascularization.

Conclusions:

• Patients with significant ischemia and limited myocardial scar benefit from early revascularization.
• Medical therapy without early revascularization may be superior for patients with minimal ischemia or extensive scar.