The impact of COVID-19 pandemic on AMI and Stroke mortality in Lombardy: Evidence from the epicenter of the pandemic

Rossi, C.; Berta, P.; Curello, S.; Lovaglio, P. G.; Magoni, M.; Metra, M.; Roccaro, A. M.; Verzillo, S.; Vittadini, G.

Background: The Covid-19 pandemic has enormously impacted the delivery of clinical healthcare and hospital management practices in most of the hospitals around the world for both Covid and no-Covid patients. In this context, it is extremely important to assess whether the clinical management of no-Covid cases has not seriously been compromised during the first epidemic outbreak. Among no-Covid cases, patients with acute myocardial infarction (AMI) and stroke need non-deferrable emergency care and are the natural candidates as no-Covid patients to be studied. Preliminary evidence suggests that i) the time from onset of symptoms to emergency department (ED) presentation has increased in Covid-19 times as well 30-day mortality during the pandemic has been higher. We aimed to complement this evidence assessing if the additional stress due to the high inflow of Covid-19 patients at hospital level has modified AMI and Stroke admission criteria and related mortality rates in a causal inference framework. Methods: To study the impact of Covid pandemic on mortality rates for AMI and Stroke we adopt two quasi-experimental approaches, regression-discontinuity design (RDD) and difference-in-regression-discontinuity (DRD) designs by which we identify the plausible causal effect on mortality of the Covid-19-related hospital stress due to the introduction of State of Emergency restrictions. Findings: We check the causal effect of the Covid-19 pandemic on mortality rates of AMI and stroke over several time-windows of 15-days around the implementation date of the State of Emergency restrictions for COVID-19 (March, 9th). Despite the potential adverse effect on expected mortality due to a longer time to hospitalization, the AMI and Stroke mortality rates are overall not statistically different from the one observed in the control group. The obtained results provided by RDD and DRD models are robust also when we account for seasonality and unobserved factors. Interpretation: In a quasi-experimental setting we assessed the causal impact of the hospital and staff extra-burden generated by the first wave of Covid-19 patients on mortality rates of no-Covid non-deferrable urgent cases (AMI and Stroke) hospitalized at Spedali Civili of Brescia, one of the most hit provinces in Italy by Covid-19 during March and May 2020. We find a non-statistically significant impact on mortality rates for AMI and Stroke patients providing evidence of the hospital ability to manage -with the implementation of a double track organization- the simultaneously delivery of high quality cares to both Covid and no-Covid patients. Availability of similar data for the regional context as a whole is needed to further substantiate the findings and explore existing differences in efficacy of different managerial settings implemented in Lombardy hospitals.