Abstract
Determination of changes in coronary artery disease (CAD) following risk factor modification
(lipid lowering and stress reduction) have focused only on changes in myocardial blood
flow (Q)/myocardial perfusion imaging (MPI) and not myocardial viability (MV). To
determine the outcome of each and to determine if there are differences in myocardial
viability versus coronary blood flow, 31 people were studied for 1 year with comparison
of baseline and 1-year PET results. One subject underwent an additional 2-year follow-up
study, providing a total of 32 comparisons. A total of 224 myocardial segments were
compared with improvement in MPI seen in 58 of 224 segments (25.9%), stabilization
in 111 of 224 (49.6%) segments, and progression of disease in 55 of 224 (24.6%) segments.
MV improved in 82 of 224 segments (36.6%), showed stabilization in 83 of 224 (37.0%)
of the segments, and worsening in 59 (26.3%) of 224 segments. When improvement in
either MPI or MV were added together, improvement was seen in 50.9% (p≤0.001) of the
segments and stabilization was seen in 30.4% (p≤0.001). Despite RFM as defined above,
progression of CAD and loss of myocardial viability was noted in 15% of the myocardial
segments studied. This study demonstrated that regardless of whether one looks at
MPI alone or a combination of MPI and MV, reduction of serum lipids and stress reduction
alone cannot guarantee stabilization or regression of atherosclerosis. Clearly there
are additional factors involved which play an important role in reveral of CAD which
must be addressed in future studies.
