Introduction
The recent COVID-19 emergency affected worldwide healthcare systems causing a rapid redefinition of the daily medical practice organization at every level [1–3]. To contain the spread of COVID-19 and to optimize hospital resources, all non-urgent diagnostic imaging studies, including nuclear cardiology procedures, have been postponed limiting the use of all available elective diagnostic imaging tools [4]. Suddenly, all the gained knowledge regarding the prognostic power of early diagnosis in all medicine fields have given the way to emergency measures with great concern about the clinical implications of primary prevention tool stoppage [5]. The reduction of timely diagnosis may have substantial consequences on diseases with high mortality rate, such as coronary artery disease (CAD) [6]. However, the real effect of this abrupt interruption has not yet been quantified.
Italy was among the first countries dramatically stricken by COVID-19 outbreak [7]. Therefore, the evaluation of the impact of containment measures against COVID-19 spread on the non-COVID-19 diseases in Italy may measure the magnitude of the effect on larger scale. Piccolo et al. [8] recently investigated the association between the outbreak of COVID-19 and percutaneous coronary intervention (PCI) rates for acute coronary syndrome (ACS) in the Campania region, accounting for about 10% of the entire Italian population. They found evidence that the outbreak of COVID-19 was associated with a decline by 32% in the number of PCI for ACS suggesting two potential explanations. If on one hand chest pain, which is the most frightening sign who lead patients to emergency room, might be underestimated due to the COVID-19 fear, on the other, physical activity that might trigger an ACS has significantly decreased during lockdown. The aim of this study was to assess the impact of the COVID-19 pandemic on stress single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) work-up for ischemic heart disease during the lockdown imposed by the Italian Government [7]. For this purpose, we reviewed the data of stress SPECT-MPI performed between February and May 2020, in comparison with the corresponding months of the years 2017, 2018, and 2019.