Association of medical therapies with survival according to SPECT MPI findings

Myocardial perfusion imaging (MPI) results in downstream changes to medication prescription. While the benefits of medical therapy for coronary artery disease(CAD) are established, how this varies with MPI findings is unknown. Our goal was to evaluate the association of medical therapy with survival among patients undergoing MPI, including differential associations as a function of imaging findings. Consecutive patients who underwent SPECT MPI for suspected CAD between January 2015 and December 2021 were identified. Multivariable Cox regression modeling was used to assess the associations between medical therapy and all-cause mortality. In total, 7,802 patients were included with mean age 66.1±12.0 and 3841(49.2%) male. Angiotensin converting enzyme inhibitors/angiotensin receptor blockers(ACE/ARBs) were associated with lower mortality (adjusted hazard ratio[HR] 0.79, 95% CI 0.69-0.89, p<0.001). Beta-blockers were not associated with mortality overall (adjusted HR 1.00, 95% CI 0.88-1.13, p=0.995), but were associated with lower mortality among patients with more ischemia (HR 0.94 per summed difference score point, 95% CI 0.90-0.97, p-value <0.001). Statins were associated with greater survival in patients with coronary calcium (adjusted HR 0.73, 95% CI 0.57 – 0.92, p=0.009), but not in patients without coronary calcium (adjusted HR 1.18, 95% CI 0.92 – 1.51 p=0.200). ACE/ARB prescription was significantly associated with improved survival. Beta-blocker prescription was associated with greater survival in patients with ischemia and statins were in patients with coronary calcification. Findings from MPI may identify patients more likely to benefit from specific therapies, suggesting a role for hybrid MPI in guiding medical therapy for CAD. Condensed Abstract:SPECT MPI is commonly used to evaluate suspected CAD and those results influence initiation of medical therapy. We evaluated the associations between medical therapy and all-cause mortality in patients without known CAD undergoing SPECT MPI, including possible effect modification by imaging findings. Patients who were prescribed ACE/ARB therapy experienced improved survival. Statin prescriptions were associated with improved survival in patients with coronary artery calcium and beta-blocker prescriptions were associated with improved survival in patients with ischemia. SPECT MPI not only provides diagnostic value but may also inform patient management to improve patient outcomes.