Less Myocardial Infarction and Stroke Hospitalizations During Middle East Respiratory Syndrome Coronavirus Epidemic in Korea.

Viral infections are known to impact coronary disease, and acute myocardial infarction (AMI) may be triggered by the inflammatory cytokine response to infection. , Cytokines promote local inflammation in atherosclerotic plaques within the coronary artery, which can lead to plaque destabilization, rupture, and eventually AMI development. Psychological adversity, depression, stress at home or work, social isolation, and loneliness are also known factors contributing to acute vascular event. Recent outbreaks of coronavirus (CoV), including severe acute respiratory syndrome, and Middle East respiratory syndrome (MERS) have been associated with a increase in patients presenting with cardiovascular complications in several countries. Here, we explored the prevalence of AMI-, and acute stroke hospitalization during 2015 MERS-CoV epidemic in Korea.

This retrospective observational study analyzed data from the Korean general patient population from 1 January 2014 to 31 December 2016. Each case of AMI and stroke was validated using codes I210 to I219 and I60 to I64 in accordance with the Korean Standard Classification of Diseases. AMI and stroke-related hospitalization cases were identified in the National Emergency Department Information System (NEDIS) database. In total, 185 reports of patients infected with the MERS-CoV were recorded between 20 May and 4 July 2015 (over 46-day period) in Korea. These data are publicly available and maintained by the Korea Centers for Disease Control and Prevention.

Of 185 confirmed cases of MERS-CoV, the male-female ratio was approximately 3:2 (59.5% male and 40.5% female). The highest prevalence of MERS-CoV infection was reported in the 50 to 59 year age group, and the majority of cases were reported during the 1st and 2nd week of June 2015. Thirty-eight deaths were recorded as being caused by MERS-CoV (case-fatality rate 20.5%).

Analysis of the distribution of monthly AMI cases shows that the minimum was recorded in June 2015 at the rate of 0.42% per 100,000 patients (Figure 1 ), which was lower than the same month in other years (0.45% in 2014 [relative risk reduction, RRR: 7.2%], and 0.50% in 2016 [RRR: 16.6%], as well as an average of 0.47% for 2014 and 2016 [RRR: 12.1%]). The distribution of monthly stroke cases exhibited a very similar trend as with AMI, with the minimum recorded in June 2015 at 1.32% per 100,000 patients, which was similarly lower than the same month in the other years (1.47% in 2014 [RRR: 10.2%], and 1.60% in 2016 [RRR: 18.2%], with an average of 1.53% for 2014 and 2016 [RRR: 14.4%]).

Figure 1

Distribution of monthly cases of hospitalizations, caused by (A) AMI; (B) and stroke in 2014, 2015, and 2016. The peak of the Korean MERS-CoV epidemic outbreak occurred between the 4th week of May and the 1st week of July in 2015. AMI = acute myocardial infarction; MERS-CoV = Middle East respiratory syndrome coronavirus; RRR = relative risk reduction.

We identified significant reduction of 12.1% for AMI-, and 14.4% for stroke hospitalization during the 2015 MERS-CoV epidemic in Korea. At that time, a significant proportion of Koreans were observing social distancing guidelines, resulting in lower levels of social interaction and physical activity. This may have reduced overall levels of physical exertion within the population, and a subsequent reduction in acute cardiovascular events such as AMI during the 2015 MERS-CoV epidemic. Another possible factor is that patients in households practicing social distancing may have been less able to be admitted to emergency departments, instead leading to a increase in out-of-hospital cardiac arrests. Data to support this possibility has not been recorded in the NEDIS database. Importantly, similar decline of hospitalizations for acute coronary emergencies has been spotted in US over COVID-19 pandemic, which may represent a universal mechanism for any current coronavirus infections in general, and MERS-CoV in particular five years ago.

Author Contributions

Moo Hyun Kim has full access to all study data and takes responsibility for the integrity of the data and the accuracy of the data analysis. Concept and design: Moo Hyun Kim. Acquisition, analysis, or interpretation of data: All authors. Drafting of the manuscript: Cai De Jin. Critical revision for important intellectual content: Victor Serebruany. Statistical analysis: Kwang Min Lee. Obtained funding: Moo Hyun Kim. Supervision: Moo Hyun Kim, Sung-Cheol Yun.

Role of the Funder/Sponsor

The funder was involved in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication by way of individuals employed by the funding institution who are included as authors or in the acknowledgments.