Prognostic Value of Stress Myocardial Perfusion Imaging Across the Spectrum of Cardiovascular Risk

Vinh D Doan; Chengyi Zheng; James Onwuzurike; Aiyu Chen; Yi-Lin Wu; Ming-Sum Lee

doi:10.1016/j.cjca.2024.05.002

Prognostic Value of Stress Myocardial Perfusion Imaging Across the Spectrum of Cardiovascular Risk

Can J Cardiol. 2024 May 9:S0828-282X(24)00355-6. doi: 10.1016/j.cjca.2024.05.002. Online ahead of print.

Authors

Vinh D Doan¹, Chengyi Zheng², James Onwuzurike³, Aiyu Chen², Yi-Lin Wu², Ming-Sum Lee⁴

Affiliations

¹ Department of Internal Medicine, Kaiser Permanente Los Angeles Medical Center, Los Angeles, CA.
² Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena, CA.
³ Department of Cardiology, Kaiser Permanente Los Angeles Medical Center, Los Angeles, CA.
⁴ Department of Cardiology, Kaiser Permanente Los Angeles Medical Center, Los Angeles, CA. Electronic address: mingsum@gmail.com.

PMID: 38734205
DOI: 10.1016/j.cjca.2024.05.002

Abstract

Background: Single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is widely used to identify ischemia. There is limited research to evaluate if there is a risk threshold below which SPECT-MPI may not add significant prognostic value.

Methods: Between January 1, 2012, and December 31, 2018, individuals who underwent SPECT-MPI were stratified into four risk groups. The primary outcome was acute myocardial infarction (MI) or death. Multivariable Cox proportional hazards regression analysis was used to calculated HRs with 95% CIs.

Results: Among 48,845 patients (52.3% male, median age 67 years), 8.5% were low risk, 4.8% borderline risk, 18.1% intermediate risk, and 68.6% high risk based on the American College of Cardiology pooled cohort equation. Ischemia was more commonly detected in the high-risk cohort (19.4% in high-risk vs. 6.5% in low-risk). SPECT-MPI testing was associated with a significantly increased use of preventive medications such as statin therapy, regardless of stress test results. At a median follow-up of 4.2 years, there was no significant association between ischemia and death or MI in the low-risk cohort (adjusted HR 1.91, 95% CI 0.94-3.92) or the borderline-risk cohort (adjusted HR 1.58, 95% CI 0.79-3.15). Ischemia was associated with a higher risk of death or MI in the intermediate-risk (adjusted HR 1.57, 95% CI 1.24-1.99) and high-risk groups (adjusted HR 1.54, 95% CI 1.44-1.64).

Conclusion: SPECT-MPI was less useful for risk stratification among low-risk patients due to their low event rates regardless of test result.

Keywords: Stress testing; coronary artery disease; low-value care; risk stratification.