PHWR Public Health Weekly Report

Sudden cardiac arrest (SCA) refers to the abrupt decrease or cessation of cardiac activity, leading to the failure of the heart to pump blood effectively. Without immediate intervention, oxygen deprivation causes irreversible brain damage and systemic organ failure, eventually leading to death. However, prompt action by witnesses, including activating emergency medical services (EMS) by calling 119, performing cardiopulmonary resuscitation (CPR), and providing immediate advanced care by healthcare professionals, can significantly improve survival rates and mitigate complications.

Numerous countries, including the United States, Japan, and Northern Europe, have established a cardiac arrest database that continuously generates data to improve survival strategies for patients who experienced cardiac arrest. The Republic of Korea (ROK) initiated a national survey on cardiac arrest in 2008 using retrospective data from 2006. As a result, a monitoring system was established to monitor the incidence and outcomes of cardiac arrest, and the survey, approved in 2011 (approval number: 117088), was officially designated as national statistics. The survey and participant extraction process are currently conducted semi-annually, during the first half of the year and the second half of each year. The survey results are published from once a year to twice a year, beginning with the 2022 incidence statistics, to provide timely data. The number of patients with SCA in ROK has been steadily increasing, reaching approximately 30,000 cases annually. SCA more commonly occurs in males and older adults. Three out of four cases experience SCA caused by a disease, with cardiogenic conditions (characterized by intrinsic heart dysfunction without other apparent causes or classification under a specific disease category) accounting for approximately 70% of cases. Furthermore, the majority of SCA events occur at home and are most commonly witnessed by family members [1].

This article presents the key findings of the recently released “2023 Republic of Korea Sudden Cardiac Arrest Survey” along with the analysis of the country’s trends in the last 5 years (2018–2023) through a time-series comparison.

1. Survey Participants

The survey included all patients who experienced SCA and were transported to medical institutions by 119 EMS teams between January and December 2023. In collaboration with the National Fire Agency, semi-annual activity reports from the 119 EMS teams and detailed treatment records of patients who received CPR were analyzed to identify eligible participants. Patients whose primary symptom was recorded as “cardiac arrest” or “respiratory arrest,” who received “CPR” as part of the treatment, or for whom a “CPR patient emergency treatment table” was created were included in the study. Patients who experienced out-of-hospital SCA were excluded during the review of medical records at the medical institutions to which the patients were transferred.

Cooperation with relevant medical institutions is required for conducting the survey. In 2023, 434 out of 447 relevant medical institutions participated, achieving a completion rate of 97.1%. Additionally, 33,402 out of 33,586 cases were included in the survey, resulting in a completion rate of 99.5%.

2. Survey Content and Methods

Following the selection of eligible participants, the medical institutions to which they were transferred were visited. Data were collected from the medical records using a survey consisting of 47 questions across 6 domains. Patient characteristics (sex, age, place of residence, etc.), circumstances at the time of SCA (whether the arrest was witnessed, whether bystander CPR was performed, location, and activities at the time of arrest), and hospital treatment details (emergency room [ER] discharge, hospitalization outcomes, mortality, neurological status, type and time of treatment, etc.) were collected [2].

The survey was conducted by personnel from the Korea Disease Control and Prevention Agency’s (KDCA) Regional Centers for Disease Control and Prevention in the Capital, Chungcheong, Gyeongbuk, and Gyeongnam, as well as professional investigators from the “Establishment of an Emergency-based Sudden Cardiac Arrest Survey Database,” a private-sector subsidized project. The investigators underwent training on survey protocols and clinical management of SCA during the first three weeks and participated in monthly quality control meetings and clinical training. Quality control of the collected data was conducted in accordance with established protocols. Identified errors were subsequently corrected and supplemented.

3. Calculation Criteria

The number of incidents was determined based on the 33,586 cases transferred via 119 EMS teams. The number of cases requiring confirmation of post-rescue outcomes, such as whether CPR was performed, survival status, and recovery of brain function, was calculated based on the data of 33,402 cases who completed the medical record survey. Survival was defined as cases where the ER or post-hospitalization treatment outcome was discharge, voluntary discharge, or transfer. Brain function recovery was assessed by determining the patient’s ability to perform daily tasks independently and was indicated by a Cerebral Performance Category score of 1 or 2. Patients who were transferred from the ER to another medical center were surveyed at the receiving facility and included in both the survival and recovery analyses.

In 2023, 33,586 cases who experienced SCA were transferred to medical institutions by 119 EMS teams, with an incidence rate of 65.7 per 100,000 population. In terms of sex, the incidence rates were 85.1 males and 46.4 females per 100,000 population. In terms of age, the incidence rate was 466.7 individuals aged ≥80 years, which was notably higher compared with the 8.6 per 100,000 population in those aged 0–9 years. Patients aged ≥70 years accounted for 17,954 cases, representing 53.5% of the total. By province, Gyeonggi reported the highest number of SCA cases (7,944), while Jeju had the highest incidence rate per 100,000 population (95.1), followed by Gangwon (94.4) and Chungbuk (91.4). Sejong had the lowest incidence rate (41.1), followed by Seoul (48.3) and Gwangju (50.5) (Table 1).

Table 1 The occurrence of sudden cardiac arrest by sex, age, city and province in 2023

Category	Occurrence (cases)a)	Proportion (%)	Incidence rate (cases per 100,000 population)b)
Total	33,586	100.0	65.7
Sex
Male	21,674	64.5	85.1
Female	11,905	35.4	46.4
Unknown	-c)	-	-
Age (yr)
0–9	296	0.9	8.6
10–19	394	1.2	8.4
20–29	867	2.6	13.8
30–39	1,159	3.5	17.6
40–49	2,375	7.1	29.9
50–59	4,272	12.7	49.7
60–69	6,259	18.6	83.8
70–79	7,232	21.5	186.3
80 and over	10,722	31.9	466.7
Unknown	10	0.0	-
City and provinced)
Seoul	4,505	13.4	48.3
Busan	2,361	7.0	71.7
Daegu	1,278	3.8	53.9
Incheon	1,816	5.4	61.2
Gwangju	717	2.1	50.5
Daejeon	793	2.4	55.1
Ulsan	714	2.1	64.7
Sejong	158	0.5	41.1
Gyeonggi	7,944	23.7	58.6
Gangwon	1,441	4.3	94.4
Chungbuk	1,453	4.3	91.4
Chungnam	1,864	5.5	87.9
Jeonbuk	1,589	4.7	90.4
Jeonnam	1,641	4.9	90.8
Gyeongbuk	2,170	6.5	84.8
Gyeongnam	2,502	7.4	76.9
Jeju	640	1.9	95.1

^a)The number of sudden cardiac arrest patients transported to hospitals by the 119 emergency medical services. Calculated based on emergency activity reports. ^b)Based on the resident registration population in 2023, Statistics Korea. ^c)Data is not presented when the number of cases is fewer than 10. ^d)Based on the patient’s location at the time of occurrence..

The rate of bystander-performed CPR has steadily increased each year, reaching 31.3% in 2023, exceeding 30% for the first time since the start of the survey. In terms of city and province, the gap between the highest and lowest CPR rates was 36.1%p, with Daegu having the highest rate at 50.9%, followed by Seoul and Incheon. Meanwhile, Jeonnam had the lowest rate at 14.8%. Although the rate of bystander-performed CPR increased in most cities and provinces compared with the previous year (2022), it decreased in Busan, Sejong, and Gyeongnam (Table 2).

Table 2 The rate of bystander^a) cardiopulmonary resuscitation^b), by city and province in 2018–2023

Category	2018	2019	2020	2021	2022	2023
Total	23.5	24.7	26.4	28.8	29.3	31.3
Gap (maximum–minimum)	24.4	26.2	27.9	33.6	32.5	36.1
Seoulc)	37.0	38.4	40.7	44.0	44.9	47.8
Busan	17.1	18.7	19.7	20.8	20.0	16.4
Daegu	34.3	35.0	35.1	35.6	45.6	50.9
Incheon	17.8	23.2	27.2	31.2	29.8	43.9
Gwangju	14.6	12.2	12.8	17.2	16.4	20.3
Daejeon	26.8	32.7	28.9	31.2	32.0	33.9
Ulsan	15.0	14.8	16.8	20.0	16.0	20.1
Sejong	22.8	25.8	17.8	40.9	39.7	39.1
Gyeonggi	28.9	29.9	31.8	36.0	37.2	37.4
Gangwon	18.3	22.4	25.5	24.2	28.0	28.7
Chungbuk	20.2	22.4	22.3	32.1	29.1	33.8
Chungnam	17.6	17.6	15.7	20.1	15.0	18.1
Jeonbuk	18.4	18.8	17.8	23.8	24.1	25.1
Jeonnam	12.6	12.5	20.5	10.4	13.1	14.8
Gyeongbuk	13.6	16.8	15.5	20.7	21.5	21.9
Gyeongnam	18.1	15.9	23.7	21.1	21.3	18.4
Jeju	19.6	19.1	20.9	17.7	26.8	27.4

Values are presented as percentage. ^a)Cardiopulmonary resuscitation performed by a bystander, excluding on-duty paramedics and medical professionals. ^b)Based on sudden cardiac arrest patients transported to hospitals by the 119 emergency medical services for whom medical record survey have been completed. ^c)Based on the location of the occurrence..

Among the 33,402 cases with completed medical record reviews out of all SCA patients, 2,881 survived, resulting in a survival rate of 8.6%. This represents a return to the rate observed in 2019, prior to the coronavirus disease 2019 (COVID-19) pandemic, and an increase of 0.8%p from the previous year. A total of 1,863 cases demonstrated brain function recovery, resulting in a recovery rate of 5.6%, which represents a 0.5%p increase from the previous year. Similar to the survival rate, the brain function recovery rate has also returned to pre-COVID-19 levels (Figure 1). The survival rate was highest in Sejong (14.6%), followed by Seoul (12.4%) and Gwangju (11.0%). Meanwhile, Gyeongbuk reported the lowest survival rate (6.1%). The brain function recovery rate was also highest in Sejong (13.3%), followed by Seoul (8.1%) and Jeju (7.0%). Gyeongbuk had the lowest recovery rate (3.8%) (Figure 2).

Figure 1. Changes in survival rate and brain function recovery rate of sudden cardiac arrest patients, 2018–2023

Figure 2. Survival rate and brain function recovery rate of sudden cardiac arrest patients by city and province in 2023

Both survival and brain function recovery rates were higher when CPR was performed by bystanders, excluding on-duty paramedics and medical professionals, compared with the non-performance of CPR. Based on 2023 results, survival rates were 13.2% for those who received CPR and 7.8% for those who did not, showing a 1.7-fold difference. Additionally, the brain function recovery rates were 9.8% for those who received CPR and 4.2% for those who did not, showing a 2.3-fold difference (Figure 3).

Figure 3. Survival rate and brain function recovery rate of sudden cardiac arrest patients according to bystander cardiopulmonary resuscitation in 2023
CPR=cardiopulmonary resuscitation.

SCA occurs when the heart suddenly stops beating, and the longer it remains in that state, the lower the chances of survival and recovery. Thus, immediate response is critical. According to the “2024 National Fire Agency Statistical Yearbook”, 119 EMS teams transported a total of approximately 2 million patients in 2023 [3], with around 30,000 of these patients being transported due to SCA. More than half of the patients with SCA are aged ≥70 years, and this number is expected to increase in the future due to the country’s aging population.

The rate of bystander-performed CPR has steadily increased every year, reaching 31.3% in 2023. The “5th National Health Plan” has set a target rate of 37.0% for bystander-performed CPR by 2030 [4], which can be achieved if the average annual increase of 1.6%p over the past 5 years is maintained. However, significant disparities exist between cities and provinces. Hence, measures should be taken to mitigate these disparities, such as revising the CPR training programs to better accommodate the specific characteristics and needs of each local government.

Out-of-hospital cases of SCA most commonly occur at home (47.0%) during the performance of daily activities (30.6%) and are often witnessed by family members (35.8%). Given the critical role of witnesses in improving survival outcomes, individuals who are not healthcare providers should learn how to perform CPR and use an automated external defibrillator (AED), and be able to execute these skills in real-life situations.

To increase the survival rate of patients who experienced SCA and raise awareness of the importance of CPR, the KDCA has developed and distributed age-specific educational materials. These resources ensure that not only adults but also infants, children, and adolescents can perform CPR if they encounter someone experiencing cardiac arrest. Furthermore, multi-faceted efforts are being made to increase the CPR implementation rate, including holding events where individuals share testimonials of performing CPR and using an AED in actual cardiac arrest situations. Participants can also submit educational videos to promote CPR, with the winning entries being publicly showcased. Moreover, to ensure that the Korean guidelines for CPR reflect the latest scientific evidence, the KDCA is collaborating with experts in related fields to review the evidence and revise the guidelines every 5 years, with plans for a final announcement in December 2025.

Ethics Statement: Not applicable.

Funding Source: None.

Acknowledgments: None.

Conflict of Interest: The authors have no conflicts of interest to declare.

Author Contributions: Conceptualization: JSK. Data curation: JSK. Formal analysis: JSK. Supervision: JEL, EHJ. Writing – original draft: JSK. Writing – review & editing: JSK, JEL, EHJ.