Acute Heart Attacks Disappearing Amongst COVID-19 Lockdown & Social Distancing - Is it for real?

4 MAR 2020

Worldwide, including within Australia, cardiologists have noticed an anecdotal slowdown of acute heart attacks through the emergency departments through to coronary care and intensive care. The New England Journal of Medicine has now published an article on the topic from Northern Italy(1), one of the regions hit the hardest by the outbreak of COVID-19.

The research(1) showed that – in the period of Feb 20 to March 31 this year, when compared to the same period last year – total incidence of acute heart attack rate is down by 30%, with major heart attacks (STEMI) down by 25% and the less major form (NSTEMI) down by 44%.

This Northern Italy findings throughout the lock-down and social distancing period(1) is replicated across the USA which showed a 38% drop(2), and in Spain who exhibited a 40% drop(3) in cases of major heart attacks (STEMI).

No one knows for sure the causal factors driving this observation. Speculation is thus abounds and these are just some of the plausible explanations:

1. Air and noise pollution in urban areas which have both been linked to higher incidence of heart attacks(4-9) have majorly decreased due to social isolation and the implementation of extensive lockdown rules(10).

2. People are eating out less. Home cooked meals are generally healthier than restaurant food and cooked with less fat and salt. High fat loading post meal is known to cause instability of cholesterol plaques increasing the risk of a heart attack(11), whilst transient rise in blood pressure following a high salt meal will do the same(12).

3. Patients with heart disease are more prone to severe COVID-19 infection requiring hospitalization and ICU and have much higher mortality c/t those without (read more here), thus at risk patients might eventually die as a result of COVID-19 infection or its complications (including heart attacks) without being added to the statistics encompassing daily incidence of heart attacks presenting to the emergency department.

4. Less stress from driving in traffic, long drives, fatigues from work, work pressures, feuds and angst from dealing with relatives, colleagues and bosses may outweigh the stress from lockdown and social distancing.

5. Social distancing and lockdown in addition to a potentially increased awareness of optimising immunity has resulted in less infection from bad bouts of colds, the flu and community-acquired pneumonia which and are known to raise the risk of acute heart attacks(13).

6. There is a possibility, though unlikely, a minority of patients suffered acute heart attacks at home and didn’t seek medical attention.

What might we learn from this potential silver lining of a pandemic lockdown?

1. Breathing cleaner air, less noise pollution reduce risk of acute cardiac events;

2. Simpler (less rich, less salty and fatty) home cooked meals appear to be more heart healthy than restaurant foods;

3. Less stress, more “self” time indeed can be good for heart health;

4. Awareness in keeping up good immunity (read more here) can pay dividends, especially as the southern hemisphere Winter approaches. So rug up, and keep warm.

References:

1. Reduced Rate of Hospital Admissions for ACS during Covid-19 Outbreak in Northern Italy. NEJM 2020. De Filippo O et al. DOI: 10.1056/NEJMc2009166

2. Reduction in ST-Segment Elevation Cardiac Catheterization Laboratory Activations in the United States during COVID-19 Pandemic. Garcia S et al. JACC 2020, doi.org/10.1016/j.jacc.2020.04.011

3. Impacto de la pandemia de COVID-19 sobre la actividad asistencial en cardiología ntervencionista en España. Rodríguez-Leor O, et al. REC Interv Cardiol. 2020. ttps://doi.org/10.24875/RECIC.M20000120

4. Increased Particulate Air Pollution and the Triggering of Myocardial Infarction. Peters A et al. Circulation 2001. doi.org/10.1161/01.CIR.103.23.2810

5. Loss of life expectancy from air pollution compared to other risk factors: a worldwide perspective. Lelieveld J et al. Cardiovasc Res 2020. doi.org/10.1093/cvr/cvaa0 25

6. Cardiovascular disease burden from ambient air pollution in Europe reassessed using novel hazard ratio functions. Lelieveld J et al. Eur Heart J 2019. doi.org/10.1093/eurheartj/ehz135

7. Environmental noise and the cardiovascular system. Munzel T et al. JACC 2018. doi: 10.1016/j.jacc.2017.12.015

8. Road Traffic Noise and Incident Myocardial Infarction: A Prospective Cohort Study. Sørensen M et al. PLoS One 2012. doi: 10.1371/journal.pone.0039283

9. Occupational Exposure to Noise and Mortality from Acute Myocardial Infarction. Davies H et al. Epidemiology 2005. DOI: 10.1097/01.ede.0000147121.13399.bf

10. https://www.nationalgeographic.com/science/2020/04/pollution-made-the-pandemic-worse-but-lockdowns-clean-the-sky/ (accessed 30-Aprial 2020).

11. Plaque Rupture After Short Periods of Fat Feeding in the Apolipoprotein E–Knockout Mouse. Johnson J. Circulation 2005. doi.org/10.1161/01.CIR.0000158435.98035.8D

12. The Effect of High Salt Intake on Endothelial Function: Reduced Vascular Nitric Oxide in the Absence of Hypertension. Boegehold MA. J Vasc Res 2013. doi.org/10.1159/000355270

13. Acute Myocardial Infarction After Laboratory-Confirmed Influenza Infection. Kwong JC et al. NEJM 2018. doi: 10.1056/NEJMc1805679.