Incidence and outcome of myocardial infarction treated with percutaneous coronary intervention during COVID-19 pandemic

Figure 1. Incidence rate of myocardial infarction (MI) interventions and COVID-19 in Sweden as well as its capital city Stockholm. (A) Visualises the incidence rate of MI for each 7-day period during COVID-19 pandemic (1 March–May 2020) and the reference period (1 March 1–7 May, the years 2015–2019) together with the incidence of COVID-19 in Sweden. The incidence of MI is presented as daily incidence (absolute numbers) and the incidence rate per 100 000 inhabitants per year in brackets. (B) Visualised the same information but for Stockholm county. A clear decline in MI incidence can be observed since the beginning of the pandemic both nationwide and isolated to Stockholm. On 12 April, a national campaign was launched throughout major newspapers, television channels, on the web and social media, aimed to inform and encourage patients with symptoms suggestive of MI to seek medical care. The inflow of patients with MI returned to typical levels both nationally as well as in Stockholm by 7 May 2020 reflecting how adequate countermeasures can reverse the indirect effects of COVID-19 pandemic on healthcare-seeking behaviour.

Figure 2. Results of primary, secondary and subgroup analyses. Forest plot showing the incidence rate ratios (IRRs) of myocardial infarction (MI) during COVID-19 pandemic in Sweden compared with the reference period together with absolute number during the given time period (COVID-19 pandemic vs reference period). The daily incidence rate in absolute numbers can be calculated by dividing events by days at risk (COVID-19 pandemic=68; reference period=340). A conversion formula and calculation example to convert daily incidence rates to incidence rate per 100 000 inhabitants can be found in the online supplemental material. AMI, acute myocardial infarction; NSTEMI, non-ST-elevation myocardial infarction; STEMI, ST-elevation myocardial infarction.

Figure 3. 1-survival graph showing case fatality within 7 days during the pandemic compared with the reference period. (A) shows the failure estimates for the entire population stratified by pandemic and reference period together with results from Cox proportional regression models. No difference in case fatality can be observed. (B) shows the failure estimates for Stockholm county stratified by pandemic and reference period together with results from Cox proportional regression models. The adjusted models were adjusted for baseline differences found in table 1 except for time from symptom onset and first ECG to percutaneous coronaryintervention.