Efficacy of lipid lowering therapy in inducing arrest or reversal of coronary disease: Serial assessment of perfusion with PET predicts clinical outcome

Abstract

Background: PET myocardial perfusion imaging (PET MPI) identifies coronary disease (CAD) progression and reversal in response to lipid lowering therapy (LLT), however, the optimal lipid values necessary to reverse CAD are unknown. In practice, NCEP ATP III guidelines (NCEP) are used as clinical targets. The purpose of this study was to evaluate the efficacy of aggressive LLT, beyond NCEP guidelines, to induce arrest or reversal of CAD as assessed with PET MPI. Methods: 147 patients with iv dipyridamole stress induced myocardial perfusion defects at baseline, treated for 1.5 years to beyond NCEP guidelines, underwent follow-up PET MPI and outcome assessment for MI, coronary death, CABG, CVA, and PTCI. Paired stress PET MPI studies were analyzed with automated software to determine the average uptake of 82-Rb in the anterior, septal, inferior, lateral and apical segments, normalized to peak myocardial activity. Baseline and follow-up MPI studies were then compared with the paired t-test, to identify significant improvement, worsening, or stabilization in segmental perfusion in each patient. Results: With LLT: 24 patients demonstrated improvement in myocardial perfusion, 96 patients no change, and 27 progression of CAD despite LLT. At mean follow-up of 15 months after the second PET study, coronary events occurred in 4.2%, 4.2%, and 22.2% respectively. Conclusions: PET MPI identifies 18% of patients with progressive CAD despite successful LLT which exceeds NCEP guidelines. These patients with progressive CAD identified by PET, have a significant (five fold ) increased risk of subsequent hard coronary events, compared with those patients demonstrating CAD arrest or reversal. Baseline Follow Up % Change p-value Total Cholesterol 169 +/− 38 152 +/− 30 −10.1 0.0001 LDL 96 +/− 35 84 +/− 23 −12.5 0.001 HDL 45 +/− 13 49 +/− 14 8.9 0.01 Triglyceride 136 +/− 73 106 +/− 60 −22.1 0.0001