Impact of COVID-19 pandemic early response measures on myocardial infarctions and acute cardiac care in Singapore.

The COVID -19 pandemic impacted acute myocardial infarction (AMI) attendances, ST-elevation myocardial infarction (STEMI) treatments, and outcomes. We collated data from majority of primary percutaneous coronary intervention (PPCI)-capable public healthcare centres in Singapore to understand the initial impact COVID-19 had on essential time-critical emergency services. We present data comparisons from 'Before Disease Outbreak Response System Condition (DORSCON) Orange', 'DORSCON Orange to start of circuit breaker (CB)', and during the first month of 'CB'. We collected aggregate numbers of weekly elective PCI from four centres and AMI admissions, PPCI, and in-hospital mortality from five centres. Exact door-to-balloon (DTB) times were recorded for one centre; another two reported proportions of DTB times exceeding targets. Median weekly elective PCI cases significantly decreased from 'Before DORSCON Orange' to 'DORSCON Orange to start of CB' (34 vs 22.5, P = 0.013). Median weekly STEMI admissions and PPCI did not change significantly. In contrast, the median weekly non-STEMI (NSTEMI) admissions decreased significantly from 'Before DORSCON Orange' to 'DORSCON Orange to start of CB' (59 vs 48, P = 0.005) and were sustained during CB (39 cases). Exact DTB times reported by one centre showed no significant change in the median. Out of three centres, two reported significant increases in the proportion that exceeded DTB targets. In-hospital mortality rates remained static. In Singapore, STEMI and PPCI rates remained stable, while NSTEMI rates decreased during DORSCON Orange and CB. The severe acute respiratory syndrome (SARS) experience may have helped prepare us to maintain essential services such as PPCI during periods of acute healthcare resource strain. However, data must be monitored and increased pandemic preparedness measures must be explored to ensure that AMI care is not adversely affected by continued COVID fluctuations and future pandemics.

Containing the Spread of Coronavirus Disease 2019 (COVID-19): Meteorological Factors and Control Strategies (preprint)

The novel coronavirus disease 2019 (COVID-19) has spread globally and the meteorological factors vary greatly across the world. Understanding the effect of meteorological factors and control strategies on COVID-19 transmission is critical to contain the epidemic. Using individual-level data in mainland China, Hong Kong, and Singapore, and the number of confirmed cases in other regions, we explore the effect of temperature, relative humidity, and control measures on the spread of COVID-19. We found that high temperature mitigates the transmission of the disease. High relative humidity promotes COVID-19 transmission when temperature is low, but tends to reduce transmission when temperature is high. Implementing classical control measures can dramatically slow the spread of the disease. However, due to the occurrence of pre-symptomatic infections, the effect of the measures to shorten onset-to-isolation time is markedly reduced and the importance of contact tracing and quarantine and social distancing increases. The analytic results also highlight the importance of early intervention to contain the spread of COVID-19.