The Clinical Importance of Risk Factor Modification: Looking at Both Myocardial Viability (MV) and Myocardial...

Area of Science:

• Cardiology
• Nuclear Medicine
• Medical Imaging

Background:

• Coronary artery disease (CAD) management often involves risk factor modification (RFM), including lipid lowering and stress reduction.
• Previous studies on RFM's impact on CAD primarily assessed changes in myocardial blood flow (Q) via myocardial perfusion imaging (MPI), neglecting myocardial viability (MV).

Purpose of the Study:

• To evaluate the distinct and combined outcomes of MPI and MV following RFM in patients with CAD.
• To compare the effectiveness of RFM on myocardial blood flow versus myocardial viability.

Main Methods:

• A longitudinal study involving 31 patients with CAD, assessed over 1 year using Positron Emission Tomography (PET).
• Comparison of baseline and 1-year PET results for 224 myocardial segments, evaluating both MPI and MV.
• One patient had an additional 2-year follow-up, contributing to 32 total comparisons.

Main Results:

• Improvement in MPI was observed in 25.9% of segments, with 49.6% stabilizing and 24.6% progressing.
• Myocardial viability (MV) improved in 36.6% of segments, stabilized in 37.0%, and worsened in 26.3%.
• Combined MPI and MV showed improvement in 50.9% and stabilization in 30.4% of segments. Notably, 15% of segments showed progression of CAD and loss of MV despite RFM.

Conclusions:

• Risk factor modification (lipid lowering and stress reduction) alone is insufficient to guarantee stabilization or regression of atherosclerosis in all patients.
• A significant percentage of myocardial segments demonstrated disease progression or loss of viability, highlighting the need to investigate additional factors for effective CAD reversal.
• Future research should explore other contributing factors beyond lipid levels and stress for comprehensive CAD management and potential reversal.