Out-of-hospital cardiac arrest during the COVID-19 pandemic

COVID-19 may be responsible also for undirect death. Lockdown, movement restrictions, and fear of contamination in hospitals could have led to a reluctance to call EMS or present to EDs and may have detrimental effects on population health.
Resuscitation of patients in out-of-hospital cardiac arrest (OHCA) may be adversely affected by COVID-19 concerns, for example by fear of contracting the infection through the delivery of CPR, and by an overwhelmed health system.

Mechanisms by which COVID-19 might cause cardiac arrest include

  • vascular inflammation
  • myocarditis
  • cardiac arrhythmias
  • thromboembolism
  • indirect effects
    • fear and anxiety
    • reduced or delayed presentation for non-COVID-19 related conditions (e.g. acute coronary syndromes)
    • self-harm and substance use precipitating in cardiac arrest due to worsened mental health during social isolation

1) Lombardy, Italy (Baldi et al. NEJM 2020)

  • Authors compared OHCA that occurred in 4 provinces of Lombardy region (Lodi, Cremona, Pavia, Mantua) during the first 40 days of the COVID-19 outbreak (February 21 through March 31, 2020) with those that occurred during the same period in 2019 (February 21 through April 1)
  • 58% increase in OHCA incidence during this period (362 vs. 229)
  • cumulative incidence of OHCA in 2020 was strongly associated with the cumulative incidence of COVID-19 (Spearman rank correlation coefficient, 0.87; 95% confidence interval, 0.83 to 0.91; P<0.001)
    • the increase in the number of cases of OHCA over the number in 2019 (133 additional cases) followed the time course of the COVID-19 outbreak
    • 103 patients who had OHCA were suspected to have or had received a diagnosis of COVID-19
    • 77.4% of the increase in OHCA cases were directly attributable to COVID-19
  • Similar patient characteristics (sex and age)
  • Differences in event characteristics during COVID-19 pandemic:
    • The medical cause of OHCA was 6.5% higher (346 [95.6%] vs 204 [89.1%])
    • OHCA at home was 7.3% higher (333 [92%] vs 194 [84.7%])
    • unwitnessed OHCA was 11.3% higher (199 [55%] vs 100 [43.7%])
    • median EMS arrival time was 3 minutes longer (15 min [12-20] vs 12 min [9-15])
    • bystander-CPR rate was 15.6% lower (59 [31.4%] vs 63 [47%])
  • 14.9% higher mortality in the field among patients with attempted resuscitation (189 [82.2%] vs 107 [67.3%])

2) Paris, France (Marijon et al. Lancet Public Health 2020)

  • Authors used the Paris-Sudden Death Expertise Center registry to compare OHCA incidence and patient characteristics from a 6-week period during the COVID-19 pandemic in Paris and its suburbs (6·8 million inhabitants, March 16 to April 26, 2020) with corresponding periods over the preceding 8 years
  • Two-times increase in OHCA incidence from a baseline of 13.42 (95% CI 12.77–14.07) to 26·64 (25.72–27.53) per million inhabitants
  • The incidence of OHCA rose in parallel with the incidence of COVID-19 hospital admissions
  • OHCA incidence decreased towards baseline near the end of the 6-week period in line with a decrease in COVID-19 incidence
  • Similar patient characteristics
  • Differences in event characteristics during COVID-19 pandemic:
    • around 13% (460 [90.2%] vs 2336 [76.8%]) more cases occurred inside the home
    • fewer patients presented with shockable rhythm (46 [9.2%] vs 472 [19.1%])
    • fewer patients received bystander-CPR (239 [47.8%] vs 1165 [63.9%])
    • fewer patients received public access defibrillation (2 [0.4%] vs 33 [3.0%])
    • ambulance response times were longer
    • the proportion of OHCAs where the ambulance crew started/continued resuscitation was lower (53.1% vs 66.2%)
      • irreversible death? DNR? fear of infection? overwhelmed health system?
  • Poorer survival during COVID-19 pandemic
    • fewer patients survived to hospital admission (67 [12.9%] of 521 vs 695 [22.8%] of 3052)
    • fewer survived to hospital discharge (16 [3.1%] of 517 vs 164 [5.4%] of 3052)
  • < 10% of all patients who had an OHCA had known or suspected COVID-19
  • 33% of the increase in OHCA cases were directly attributable to COVID-19

3) Greater Paris, France (Lapostolle et al, Resuscitation 2020)

The authors compared the management of OHCA during the COVID-period (February 24th, 2020, March 24th, 2020) and the reference period (2019).

During the COVID-19 period, compared to the reference 2019 period, they found:

  • similar age (69 years (52-82) vs 66 years (55-85), p=0.6)
  • more male (84% vs 60%, p = 0.02)
  • similar bystander-CPR rates (53% vs. 49%, p = 0.6) and AED use (7% vs 3%)
  • similar time between OHCA and mobile intensive care unit (MICU) departure (13 minutes [9-17] vs 15 minutes [7-30], p=0.7)
  • similar duration of no-flow (7 minutes [2-11] vs 9 [2-15], p = 0.8) and low-flow (35 minutes [20-48] vs 29 minutes [15-45], p = 0.8)
  • similar ROSC (18% vs 21%)
  • same mortality on day 1 (7% vs 7%)

4) California, USA (Wong et al. NEJM Catalyst 2020)

  • 45% more OHCA incidence on March 2020 than February 2020
  • all of these EMS heart patients tested negative for Covid-19
  • most of these patients declared dead at scene

5) Seattle and King County, WA (Sayre et al. Circulation 2020)

  • cohort investigation of OHCA attended by emergency medical services (EMS) in Seattle and King County, WA from January 1 to April 15, 2020
  • Included patients treated by EMS already dead on EMS arrival
  • The authors investigated the prevalence of COVID-19 in out-of-hospital cardiac arrests
  • hierarchical COVID-19 classification strategy that prioritized polymerase chain reaction (PCR) testing obtained pre or post mortem and clinical classification of a COVID-like illness if PCR testing was not performed
  • For EMS OHCA patients without PCR results, two authors classified COVID-like illness status using EMS records (febrile or respiratory illness or COVID-19 exposure) (kappa agreement 0.81)
  • During the active period of COVID-19 (February 26-April 15), EMS responded to 537 (50.3%) OHCAs of which 230 (48.1%) were EMS treated
    • COVID-19 was diagnosed by PCR or COVID-like illness in less than 10% of OHCA
      • 3.7% of dead on EMS arrival
      • 6.5% of EMS treated cases
    • 5% of OHCAs in homes and 11% of OHCAs in nursing homes involved COVID-19 patients, compared to none in public places
    • Bystander CPR was provided in 57%
  • The incidence of OHCA in 2020 was compared to prior years
    • The count of total cases year to date was similar for 2020 compared to 2019 and 2018 (incidence rate ratio 0.997 [95% CI 0.989-1.016, p=.72])
    • bystander CPR by location before and after the first COVID-19 death on February 26 were unchanged (p=0.46, Fisher’s Exact test).


  1. Baldi E, Sechi GM, Mare C, Canevari F, Brancaglione A, Primi R, et al. Out-of-Hospital Cardiac Arrest during the Covid-19 Outbreak in Italy. N Engl J Med 2020:NEJMc2010418.
  2. Marijon E, Karam N, Jost D, Perrot D, Frattini B, Derkenne C, et al. Out-of-hospital cardiac arrest during the COVID-19 pandemic in Paris, France: a population-based, observational study. The Lancet Public Health 2020:S2468266720301171.
  3. Lapostolle F, Agostinucci JM, Alhéritière A, Petrovic T, Adnet F. Collateral consequences of COVID-19 epidemic in Greater Paris. Resuscitation 2020;151:6–7.
  4. Wong LE, Hawkins JE, Langness S, et al. Where are all the patients? Addressing Covid-19 fear to encourage sick patients to seek emergency care. NEJM Catalyst Innovations in Care Delivery 2020; 1: 3.
  5. Sayre MR, Barnard LM, Counts CR, et al. Prevalence of COVID-19 in Out-of-Hospital Cardiac Arrest: Implications for Bystander CPR [published online ahead of print, 2020 Jun 4]. Circulation. 2020;10.1161/CIRCULATIONAHA.120.048951.
Tommaso Scquizzato
Tommaso Scquizzato

Tommaso Scquizzato is a researcher in the fields of cardiac arrest and resuscitation science at the Center for Intensive Care and Anesthesiology of San Raffaele Hospital in Milan, Italy. He is the Social Media Editor of Resuscitation, member of the Social Media Working Group of ILCOR, and member of the ERC BLS Science and Education Committee.

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