Impact of the COVID-19 pandemic on the use of myocardial perfusion imaging for the assessment of coronary artery disease: a Brazilian experience

Abstract

The COVID-19 pandemic and the lockdown period caused deep effects on healthcare, including cardiac imaging, with a possible negative influence on the evaluation of coronary artery disease (CAD). This study aimed to evaluate the impact of the COVID-19 pandemic on myocardial perfusion imaging (MPI) performance and results in a Brazilian, Nuclear Cardiology laboratory. Patients with or without known CAD who underwent MPI in three 30-day periods (pre-pandemic [mid-February to mid-March 2020], lockdown [April-May 2020], and post-lockdown [August 2020]) were studied. MPI volumes dropped from 204 pre-lockdown to 43 during lockdown (78.9% reduction), rising to 248 after lockdown. The use of pharmacologic stress increased from 36.3% to 53.5% during lockdown. The frequency of abnormal MPI tests did not differ significantly among the time intervals, as well as the frequency of myocardial ischemia. Younger age, ≥1 cardiac risk factor, and known CAD were independent predictors of the performance of MPI during the lockdown period. In conclusion, a large reduction of MPI performance occurred during lockdown, when imaging was sought mainly by younger patients, with cardiac risk factors or known CAD. There was no significant difference in the frequency of abnormal MPI or of myocardial ischemia among the periods, which might indicate missed cases of CAD during lockdown; therefore, the consequences of cardiac testing reductions should be continuously assessed.