Outcomes of radionuclide myocardial perfusion imaging and cardiac catheterization for coronary artery disease in Taiwan

Objectives This study sought to assess the rate of acute myocardial infarction (AMI) event after the stress myocardial perfusion imaging (MPI) as compared with the cardiac catheterization (CC).

Methods The Taiwanese National Health Insurance (NHI) program is a compulsory health insurance program in Taiwan. The program was established in 1995 and provides comprehensive medical care coverage for 99% of the residents of Taiwan. The study used the longitudinal health insurance database with 1000000 people randomly selected from the national health insurance research database. We identified patients with suspected CAD between 2000 and 2011 and divided them into two cohorts: the MPI cohort and the CC cohort. A Cox proportional hazards model was applied to estimate the risk of AMI in terms of hazard ratios (HRs) and 95% confidence intervals (CIs).

Results The CC and MPI cohorts both comprised 5940 people. The median follow-up periods was 5.37 years for the MPI cohort and 5.27 years for the CC cohort. The rate of AMI event didn’t increase in the MPI cohort than in the CC cohort (6.89 vs 6.27 per 1000 person-y, crude HR = 1.10, 95% CI = 0.91-1.34), with an adjusted HR of 1.11 (95% CI = 0.91-1.34). A subgroup analysis was perform for the MPI cohort. Among the 5940 patients in the MPI cohort, 1506 patients (25.3%) underwent at least one cardiac catheterization. The incidence of AMI event didn't decrease in MPI patients receiving subsequent cardiac catheterization as compared with MPI only (adjusted HR = 1.23; 95% CI = 0.93-1.62).

Conclusions In patients with suspected CAD, a strategy of initial stress MPI, as compared with CC didn’t increase the risk of further AMI event over a median follow-up of 5 years.