2025 Volume 7 Issue 1 Pages 17-26
BACKGROUND
The current report shows a comparison of changes in pre- and in-hospital procedures, treatments and outcomes of patients with out-of-hospital cardiac arrest (OHCA) during the SOS-KANTO study periods.
METHOD
This study included patients aged ≥18 years who experienced bystander-witnessed OHCA of cardiac etiology, which was confirmed by emergency medical service (EMS) providers at the scene, received cardiopulmonary resuscitation (CPR) from EMS providers, and were subsequently transported to the participating institutions.
The primary outcome measure was patient survival with favorable neurological outcomes at 1 month from cardiac arrest. The secondary outcomes were the proportions of bystander CPR cases, advanced CPR procedures performed by EMS providers, pre-hospital return of spontaneous circulation (ROSC) rates, and post-resuscitation treatment administration.
RESULTS
Data of 1,515 patients from the SOS-KANTO 2017 study and 2,189 patients from the 2012 study were analyzed. Bystander CPR and advanced CPR procedures were performed more frequently and reliably by EMS providers in the 2017 than in the 2012 study. The rate of pre-hospital ROSC to total ROSC was higher in the 2017 study (35.7% vs 29.0%), and in-hospital treatments and post-resuscitation care was provided more frequently in the 2017 study. However, the 2017 study showed no significant difference in the survival rate with favorable neurological outcomes at 1 month, compared with the 2012 study. (9.0% vs 8.5%).
CONCLUSION
High quality of prior to ROSC and post-resuscitation care following ROSC was maintained in the 2017 study. However, the 2017 study showed no significant difference in the survival rate with favorable neurological outcomes at 1 month, compared with the 2012 study.
In 2000, no out-of-hospital cardiac arrest (OHCA) registry integrated both pre- and in-hospital information. Consequently, most data regarding OHCA were derived exclusively from either pre- or in-hospital registries. Without an integrated registry, it was challenging to comprehensively assess resuscitation strategies including those at the scene and in hospital. Therefore, in 2002, the Japanese Association for Acute Medicine of KANTO (JAAM-KANTO) conducted a survey of survivors after OHCA in the Kanto region (SOS-KANTO study), which was the first expansive and a multi-center collaborative registry in Japan containing detailed information spanning both pre- and in-hospital stages to understand and contribute to establishing an emergency medical care system for patients with OHCA1). In 2012, a similar registry, the SOS-KANTO 2012 study, was conducted at 67 centers in the same region2). These data were registered after the implementation of two major revisions of the resuscitation guidelines (the 2000 version was revised in 2005 and the 2005 version in 2010)3–5). These guidelines recommended that post-resuscitation care is a critical component of the chain of survival and demands a comprehensive, structured, multidisciplinary system that requires consistent implementation for optimal patient outcomes. In 2004 in Japan, automated external defibrillators, which could not previously be used by people who were not medically trained, were made available to them, and the medical procedures and administration of medication by emergency medical personnel were expanded. As a result, favorable neurological outcomes at 1 month increased significantly, compared with those in 2002. The results of the 2012 study clearly revealed the effect of the changes in these guidelines and in pre- and in-hospital emergency medical systems for OHCA over 10 years2). A new registry was planned in 2017 as the SOS-KANTO 2017 study to investigate the quality of the treatment and outcomes of OHCA and to challenge unknown areas in cardiopulmonary resuscitation (CPR). The American Heart Association guidelines for CPR were updated in 20156), and the importance of high-quality chest compressions were reemphasized. However, the crucial links in the adult chain of survival for OHCA were unchanged from 20105). Even after that, these guidelines have been updated from time to time. The 2019 update summarizes the most recent published evidence for and recommendations on the use of dispatcher-assisted CPR, advanced airways, vasopressors, and extracorporeal CPR during cardiac arrest7,8). Therefore, the key objective of the current study was to compare changes in pre- and in-hospital procedures and treatments, with those in the 2012 study, in addition to related outcomes, to verify whether CPR quality has been maintained and whether the outcome has been improved, considering impact of these guidelines. However, the SOS-KANTO 2017 investigators faced challenges due to the coronavirus disease 2019 (COVID-19) pandemic during patient enrollment.
The SOS-KANTO 2017 study was a multicenter prospective cohort study planned by the JAAM-KANTO. Each hospital voluntarily participated in this study. Announcements were made broadly to the emergency hospitals involved in the JAAM-KANTO. For the 2012 study, we determined the enrollment items from the submitted research questions and allowed all facilities that applied to participate in the analysis. The study included 67 emergency hospitals, and data were collected between January 2012 and March 2013. All patients with OHCA transported by the emergency medical service (EMS) providers to the participating facilities were registered through a paper-based information system. Regarding the 2017 study, we rigorously examined the submitted research questions and built a database of registries based on the adopted research questions, and 42 facilities participated. In this study, case accumulation was scheduled for September 2019 to August 2020. Compared with the 16,452 patients in the SOS-KANTO 2012 study, the targeted number of patients in the SOS-KANTO 2017 study was approximately 10,000, and the survey period was extended depending on the number of registered cases. As a result, the study period was extended to March 2021, as less than 10,000 registered cases were accumulated during the planned registration period. All patients with OHCA transported by the EMS providers to the participating facilities were registered in a website.
This study was conducted in adherence to the principles of the Declaration of Helsinki and was approved by the relevant institutional review boards of all 42 institutions. Our analysis did not include any personal identifying information; therefore, the requirement for informed consent was waived (Ethical Review Board of Kimitsu Chuo Hospital, Approval Number 440).
DEFINITIONS AND DATA COLLECTIONCardiac arrest was defined as the absence of mechanical cardiac activity, determined by absence of pulse and normal breathing9). All patients with cardiac arrest who were transported to the participating hospitals by EMS providers were included in both SOS-KANTO studies (2012 and 2017). Pre- and in-hospital treatments were generally provided to patients by EMS personnel, physicians, and other healthcare providers in line with the national guidelines of the Japan Resuscitation Council, which were based on the international guidelines in place at the relevant times (i.e., 2010 guidelines for the SOS-KANTO 2012 and 2015 guidelines update for the SOS-KANTO 2017)5,6–8). The EMS providers collected prehospital information in the standardized Utstein style9): sex and age of the patient, initial cardiac rhythm, and the time course of resuscitation. Additional information included pre-hospital treatment. The EMS providers obtained additional information from the bystanders who performed CPR regarding whether they were trained in CPR or received dispatcher-assisted CPR instruction. “Dispatcher-assisted CPR” is defined as CPR performed by laypersons at the incident scene during OHCA under the instructions of individuals at emergency telephone call centers, who are charged with answering emergency calls.
Causes of cardiac arrest were determined by the attending physicians. Patients were diagnosed with cardiac arrest from (presumed) cardiac etiology unless an obvious non-cardiac etiology was observed. The institutional researchers collected in-hospital information: medications and interventions, return of spontaneous circulation (ROSC) after arrival at the hospital, hospital admission, laboratory data, duration of hospital stay, and neurological outcome following initial cardiac arrest. Post-resuscitation care was defined as the provision of targeted temperature management and/or percutaneous coronary angiogram/intervention. In the 2012 study, the cerebral performance category (CPC) scale was used to evaluate prearrest status, and responses were scored as follows: category 1, good cerebral performance; category 2, moderate cerebral disability; category 3, severe cerebral disability; and category 4, coma/vegetative state9). However, in the 2017 study, the clinical frailty scale (CFS) was used and scored as follows: level 1, very fit; level 2, well; level 3, managing well; level 4, vulnerable; level 5, mildly frail; level 6, moderately frail; level 7, severely frail; level 8, very severely frail; level 9, terminally ill10). The difference between CPC2 and CPC3, and CFS4 and CFS5 is based on whether a person depends on others for daily support. Therefore, CFS5 or more was used as an exclusion criterion in the 2017 study. Neurological outcomes were evaluated and reported using the CPC scale11).
PARTICIPANTSThe study included patients aged ≥18 years who experienced bystander-witnessed OHCA of cardiac etiology, which was confirmed by EMS providers at the scene; who CPR from EMS providers; and who were subsequently transported to the participating institutions; and who were diagnosed with cardiac arrest from (presumed) cardiac etiology by the attending physicians.
Exclusion criteria were as follows: (i) patients with missing data regarding inclusion criteria or main outcomes (i.e., one-month neurological outcome, whether bystander CPR was carried out or ROSC was achieved); (ii) bystander CPR performed by health care providers or EMS personnel on the job and/or off the job; (iii) onset of cardiac arrest subsequent to the arrival of paramedics or at the hospital; (iv) patients classified as having CFS level 5 or higher prior to cardiac arrest; (v) only respiratory arrest at the time of EMS provider arrival; or (vi) no treatment carried out at the participating hospital without the achievement of ROSC.
OUTCOME MEASURESThe primary outcome measure was patient survival with favorable neurological outcomes 1 month after cardiac arrest, which was defined as CPC 1 or 2. The secondary outcomes were the proportions of bystander CPR cases, ROSC achieved, and pre- and post-resuscitation treatments.
STATISTICAL ANALYSESDescriptive statistics were utilized to compare patient characteristics between the 2017 and 2012 studies. Univariate comparisons for categorical data were analyzed as risk difference (RD) with 95% confidence interval (CI). All analyses were carried out using Stata/IC 16.0 (StataCorp, College Station, TX, USA)
The study period was extended to March 2021, as less than 10,000 registered cases were accumulated during the planned registration period. After reaching the target of nearly 10,000 (9,909) cases for the SOS-KANTO 2017 study, 1,515 cases were included, along with 2,189 from the SOS-KANTO 2012 study, totaling 3,704 cases (Fig. 1).
CA, cardiac arrest; RA, respiratory arrest; CPC, Cerebral Performance Category; CPR, cardiopulmonary resuscitation; EMS, emergency medical service
Table 1 shows the baseline patient characteristics for the SOS-KANTO 2012 and 2017 studies. There was no difference in the average age between the 2012 and 2017 studies (69.5 years vs 70.2 years). In each study, male patients accounted for the majority of the populations: 71.1% in 2012 and 69.8% in 2017. Patients with OHCA in the Tokyo Metropolitan area accounted for 48.5% (2012) and 47.9% (2017) of the OHCA populations. The population of OHCA occurring at home did not change (65.1%). Bystander CPR increased by more than 6.6% from 2012 to 2017 (38.9% vs 45.5%). The proportions of dispatcher-assisted CPR cases were 46.1% and 49.1% in the 2012 and 2017 studies, respectively. Approximately 5% of all cases involved public-access defibrillation use in each study period. The incidence of initial shockable rhythms documented by EMS providers was 25.2% in each study period. However, the populations of pulseless electrical activity increased from 2012 to 2017 (26.1% vs 31.3%).
| Variables | 2012 study n = 2189 |
2017 study n = 1515 |
||
|---|---|---|---|---|
| Age, mean (SD), years | 69.5 | (14.6) | 70.2 | (15.0) |
| Male patients (%) | 1557 | (71.1) | 1058 | (69.8) |
| Tokyo Metropolitan area (%) | 1062 | (48.5) | 726 | (47.9) |
| Daytime (%) | 1312 | (59.9) | 932 | (61.5) |
| Location (%) | ||||
| Home | 1426 | (65.1) | 932 | (61.5) |
| Public space | 371 | (16.9) | 506 | (33.4) |
| Others or unknown | 392 | (17.9) | 77 | (5.1) |
| Bystander CPR performed (%) | 852 | (38.9) | 690 | (45.5) |
| Bystander after training course | 219 | (5.7) | 89 | (12.9) |
| Dispatcher-assisted bystander CPR | 393 | (46.1) | 339 | (49.1) |
| Bystander CPR without assistance | 89 | (10.4) | 38 | (5.5) |
| unknown or data missing | 151 | (17.7) | 224 | (32.5) |
| Public-access defibrillation (layperson) (%) | 118 | (5.4) | 79 | (5.2) |
| Initial rhythm documented by EMS (%) | ||||
| VF | 552 | (25.2) | 382 | (25.2) |
| Pulseless electrical activity | 571 | (26.1) | 474 | (31.3) |
| Asystole | 949 | (43.4) | 565 | (37.3) |
| Others or unknown | 117 | (5.3) | 51 | (3.4) |
SD, standard deviation; CPR, cardiopulmonary resuscitation
EMS, emergency medical service; VF, ventricular fibrillation
As shown in Table 2, on-scene EMS response times shortened from 2012 to 2017 (9 min vs 7 min). However, scene-to-hospital arrival times in 2017 was longer than that in 2012 (27 min vs 25 min).
| Variables | 2012 study n = 2189 |
2017 study n = 1515 |
RD (95% CI) | ||
|---|---|---|---|---|---|
| Call-to-EMS at the scene, median (IQR), min | 9 | (4) | 7 | (3) | |
| Scene-to-hospital arrival, median (IQR), min | 25 | (12) | 27 | (12) | |
| Use of doctor car (%) | 33 | (1.5) | 13 | (0.9) | 7.0 (5.6 to 8.6) |
| Airway management by EMS (%) | |||||
| Bag valve mask | 985 | (45.0) | 530 | (35.0) | −10.0 (−13.2 to −6.8) |
| Advanced airway management | 1089 | (49.7) | 895 | (59.1) | 9.3 (6.1 to 12.6) |
| Others or unknown | 115 | (5.3) | 90 | (5.9) | 7.0 (−0.8 to 2.2) |
| Prehospital defibrillation (layperson and EMS) (%) | 812 | (37.1) | 514 | (33.9) | −3.1 (−6.3 to −0.0) |
| Intravenous lines inserted by EMS (%) | 733 | (33.5) | 650 | (42.9) | 9.4 (6.2 to 12.6) |
| Adrenalin administration by EMS (%) | 607 | (27.7) | 555 | (36.6) | 8.9 (5.8 to 2.0) |
| Defibrillation performed at ER (%) | 504 | (23.0) | 303 | (20.0) | −3.0 (−5.7 to 0.3) |
| Adrenalin administration at ER (%) | 1732 | (79.1) | 1115 | (73.6) | −5.5 (−8.3 to −2.7) |
| Vasopressin administration at ER (%) | 14 | (0.6) | 2 | (0.1) | −0.5 (−0.9 to −0.1) |
| Atropine administration at ER (%) | 121 | (5.5) | 12 | (0.8) | −4.7 (−5.8 to −3.7) |
| Amiodarone administration at ER (%) | 276 | (12.6) | 212 | (14.0) | 1.4 (−0.8 to 3.6) |
| Nifekalant administration at ER (%) | 46 | (2.1) | 15 | (1.0) | −1.1 (−1.9 to −0.3) |
| Lidocaine administration at ER (%) | 101 | (4.6) | 17 | (1.1) | −3.5 (−4.5 to −2.5) |
| Use of extracorporeal membrane oxygenation (%) | 177 | (8.1) | 148 | (9.8) | 1.7 (−0.2 to 3.6) |
IQR, interquartile range; EMS, emergency medical service; ER, emergency room; RD, risk difference; CI, confidence interval
Regarding airway management by EMS providers, the rate of advanced airway management in 2017 was higher than that in 2012 (59.1% vs 49.7%, RD, 9.3; 95% CI 6.1 to 12.6).
The use of intravenous lines to provide fluid (42.9% vs 33.5%, RD 9.4; 95% CI 6.2 to 12.6) and administer adrenalin (36.6% vs 27.7%, RD 8.9; 95% CI 5.8 to 12.0) was successfully carried out by EMS providers more frequently in 2017 than in 2012.
In the hospital emergency department, less adrenalin was administered in the 2017 study relative to the 2012 study (73.6% vs 79.1%, RD −5.5; 95% CI −8.3 to 2.7), and atropine, vasopressin, lidocaine, and nifekalant were almost no longer administered in the 2017 study. However, amiodarone was administered in the two study periods (14.0% vs 12.6%, RD 1.4; 95% CI −0.8 to 3.6).
There was no difference between the two study periods regarding the use of extracorporeal membrane oxygenation (9.8% vs 8.1%, RD 1.7; 95% CI −0.2 to 3.6).
POST-RESUSCITATION CARE FOLLOWING ROSCAs shown in Table 3, post-resuscitation care, targeted temperature management, or coronary angiography/intervention was provided in approximately 50% of patients with sustained ROSC in the 2017 study. This occurred more frequently than in the 2012 study. Post-resuscitation care was provided in 27.8% in 2017 and 25.2% in 2012 (RD 4.8; 95% CI 1.2 to 8.3). However, as there was a considerable amount of data missing in 2012, the difference in the incidence of post-resuscitation care in the 2017 study was unclear.
| Characteristic | 2012 study n = 940 |
2017 study n = 607 |
RD (95% CI) | ||
|---|---|---|---|---|---|
| Post-resuscitation care administered (%) | |||||
| None | 242 | (25.7) | 299 | (49.3) | 23.5 (18.7 to 28.4) |
| Coronary angiography/intervention only | 104 | (11.1) | 96 | (15.8) | 4.8 (1.2 to 8.3) |
| Therapeutic hypothermia only | 71 | (7.6) | 32 | (5.3) | −2.3 (4.7 to 0.2) |
| Both | 237 | (25.2) | 169 | (27.8) | 2.6 (1.2 to 8.3) |
| Unknown | 286 | (30.4) | 11 | (1.8) | 1.8 (30.4 to19.2) |
RD, risk difference; CI, confidence interval
As shown in Table 4, the rate of total ROSC was 42.9% in 2012 and 40.1% in 2017 (RD −2.9; 95% CI −6.1 to 0.3). The rate of prehospital ROSC was higher in 2017 than in 2012 (35.7% vs 29.0% RD 6.7; 95% CI 1.9 to 11.5). Regarding the primary outcome, the 2017 study showed no significant difference in the survival rate with favorable neurological outcomes (CPC1 & CPC2) at 1 month, compared with the 2012 study. (9.0% vs 8.5%, RD −0.4; 95% CI −2.3 to 1.4).
| Variables | 2012 study n = 2189 |
2017 study n = 1515 |
RD (95% CI) | ||
|---|---|---|---|---|---|
| Total ROSC (%) | 940 | (42.9) | 607 | (40.1) | −2.9 (−6.1 to 0.3) |
| Pre−hospital ROSC | 273 | (29.0) | 217 | (35.7) | 6.7 (1.9 to 11.5) |
| CPC 1 & 2 (favorable neurological outcomes) | 196 | (9.0) | 129 | (8.5) | −0.4 (−2.3 to 1.4) |
| CPC 1 | 164 | (7.5) | 95 | (6.3) | −1.2 (−2.9 to 0.4) |
| CPC 2 | 32 | (1.5) | 34 | (2.2) | 0.8 (−0.1 to 1.7) |
| CPC 3 | 37 | (1.7) | 19 | (1.3) | −0.4 (−1.2 to 0.3) |
| CPC 4 | 44 | (2.0) | 31 | (2.0) | 0.0 (−0.9 to 1.0) |
| CPC 5 | 1912 | (87.3) | 1336 | (88.2) | 0.8 (−1.3 to 3.0) |
ROSC, return of spontaneous circulation; CPC, cerebral performance category; RD, risk difference; CI, confidence interval
The objective of the current report was to compare these pre- and in-hospital procedures and treatments and resulting outcome changes between the SOS-KANTO 2012 and 2017 studies. The American Heart Association guidelines for CPR have been updated from time to time between these studies. However, the SOS-KANTO 2017 investigators faced challenges due to the coronavirus disease 2019 (COVID-19) pandemic during patient enrollment. As a result, regarding the primary outcome, the 2017 study showed no significant difference in the survival rate with favorable neurological outcomes (CPC1 & CPC2) at 1 month, compared with the 2012 study. Considering impact of these guidelines, changes in pre- and in-hospital procedures and treatments and the impact of the COVID-19 pandemic during the study period will be discussed.
PATIENT DEMOGRAPHICS AND EVENT CHARACTERISTICSThe results indicate that more laypeople performed bystander CPR in 2017 than in 2012. Among them, the numbers of people who performed dispatcher-assisted CPR and those who completed a training course increased between the two study periods. In the updated 2015 guidelines, there is increased emphasis on the rapid identification of potential cardiac arrest by dispatchers, with immediate provision of CPR instructions to the caller. This increase may be the result of widespread public awareness by the guidelines. There was no change in the incidence of cardiac arrest at home and in public places in 2012 vs 2017, and no difference in the incidence of initial rhythm was found between the study periods. This is probably because the participants were bystander-witnessed patients with OHCA of cardiac etiology in both studies, and cardiovascular disease has been associated with the incidence of initial shockable rhythm in patients with OHCA. From the patient demographics and event characteristics, no factors were found to lower the quality of resuscitation in OHCA.
PRE- AND IN-HOSPITAL CARES PRIOR TO ROSCThe median call-to-EMS time at the scene decreased by approximately 2 minutes, while the scene-to-hospital arrival time increased by 2 minutes. Total pre-hospital time was unchanged. Advanced CPR procedures were performed more frequently and reliably by EMS providers in 2017 compared with 2012.
Previously, many drugs were listed for use during CPR, but each time the guidelines were revised, these drugs were reorganized. Atropine is not recommended for routine use in the management of pulseless electrical activity or asystole and was removed from the cardiac arrest algorithm in the 2010 guidelines. Vasopressin, previously recommended as a vasopressor, has no benefit as an alternative to epinephrine in cardiac arrests and was removed from the adult cardiac arrest algorithm in the 2015 guidelines. Lidocaine, which was removed from the cardiac arrest algorithm in the 2010 guidelines, was rerecommended as an alternative to amiodarone in the 2015 guidelines. However, its use did not increase. Therefore, it was largely in disuse, leaving only adrenaline and amiodarone as emergency drugs during CPR.
The use of extracorporeal membrane oxygenation (ECMO) slightly increased in 2017 compared with 2012. As there was insufficient evidence to recommend the routine use of ECMO for patients with cardiac arrest, it was considered for limited settings in the 2015 guidelines. Regarding pre- and in-hospital treatments prior to ROSC, the quality of resuscitation in OHCA in 2017 was not inferior, but rather higher than that in 2012.
POST-RESUSCITATION CARE FOLLOWING ROSCTargeted temperature management is an intervention used with the aim of minimizing post-anoxic injury and improving neurological outcome after cardiac arrest12). Coronary angiography/intervention is recommended to be performed emergently for OHCA patients with suspected cardiac arrest13). Therefore, in both studies, these two interventions were selected for post-resuscitation care. In the 2017 study, post-resuscitation care was provided in approximately 50% of patients with sustained ROSC, and more than half received targeted temperature management and coronary angiography/intervention. However, as there was a considerable amount of data missing in 2012, the difference in the incidence of post-resuscitation care provided in the 2017 study was unclear.
RETURN OF SPONTANEOUS CIRCULATION AND NEUROLOGICAL OUTCOMESCompared with the 2012 study, pre-hospital ROSC increased but favorable neurological outcomes slightly decreased in the 2017 study. Despite the higher quality of pre- and in-hospital treatments prior to ROSC and post-resuscitation care following ROSC, no improvement in primary outcome was observed in the 2017 study compared with the 2012 study. Tanaka, et al. analyzed the same registry data used in our study, which was divided into pre- and post- pandemic periods14). The study showed that pre-hospital ROSC and favorable neurological outcomes of the patients declined. However, similar to our results, most prehospital and in-hospital treatments did not change between the pre- and post-COVID-19 pandemic periods.
IMPACT OF THE COVID-19 PANDEMICIn Western countries, comparisons of outcomes (e.g., ROSC, ROSC sustained to hospitalization, survival to hospital discharge) before and during the early stages of the pandemic varied by region, and the outcomes declined in many regions15–17). One of the factors that affected this was the incidence COVID-19. In the early pandemic stage, the incidence of COVID-19 increased to 3,336 cases per million person-years in the United Kingdom, 3,270 cases in Italy, and 4,479 cases in the United States18), and the outcomes of patients with OHCA in these countries declined. Increase in the incidence of COVID-19 caused reductions in the rate of bystander CPR, delays in EMS response and transport times, and increase in incidence of non-shockable rhythms. Thus, the worsening outcomes recorded may be related to a combination of these factors. In addition, the recommendation to find a balance between the need for urgent care for patients with COVID-19 and protection of healthcare providers from infections may have influenced these results19). The incidence in Japan during the study period was low at 670 per million18), and few participating facilities in the SOS-KANTO 2017 study made practice changes that lowered resuscitation quality in OHCA. No modifications or changes were observed in the management of OHCA by the EMS providers, especially with 75% not making changes in their airway management protocols20). However, Tanaka et al. reported results similar to those in the U.S. and Europe during the pandemic in the latter half of our study period14). Given that the cumulative incidence of COVID-19 reached 3,555 per million at the end of this study in Japan, COVID-19 may have had some effect on the prognosis of patients with OHCA at the end of the study14,18). The key objective of the current report was to verify whether the quality of CPR has been maintained and whether the outcome has been improved during the SOS-KANTO study periods. However, no improvement in primary outcome was observed.
LIMITATIONSThis study had several limitations. First, although announcements were made broadly to all the emergency hospitals involved in the JAAM-KANTO, the number of participating facilities decreased. This reason is that in many facilities in the Kanto Region, clinicians and administrators spend considerable time and effort to gather clinical data, a burden which may detract from their engagement in clinical research and contributions to registries21). Of the 67 facilities that participated in the 2012 study, only 30 facilities participated in the 2017 study and twelve new facilities joined the study. Therefore, it is undeniable that the results were affected by differences between facilities. And approximately half of the patients were registered from the Tokyo Metropolitan area, and the results might have been influenced by the area. This might have caused a sampling bias, and our study patients might not reflect the overall population of the nation. However, a substantial proportion of cases were registered from the Tokyo Metropolitan area in the 2012 study. This trend was the same as that in the 2017 study, and the participating facilities were widely distributed within the regions. Therefore, comparing changes in pre- and in-hospital procedures and treatments, as well as related outcomes in the same area, might be useful. Second, there was a considerable amount of data missing, which may have influenced the results of the analysis. Third, this study may not be comparable to those conducted in Western countries because the patients included in this study had witnessed cardiogenic OHCA. Fourth, this study had been somewhat affected by the COVID-19 pandemic. Finally, we only presented epidemiological data; consequently, we could not report on factors that may have contributed to the outcomes. We could not clarify whether these changes are atrue clinical improvements or the impact of the COVID-19 pandemic. However, the aim of the 2017 study was to verify that the quality of pre- and in-hospital CPR was preserved, and considering the outcomes compared with those of the 2012 study, the goal of this study was achieved.
The 2017 study showed no significant difference in the survival rate with favorable neurological outcomes (CPC1 & CPC2) at 1 month, compared with the 2012 study. However, high quality of pre- and in-hospital treatments prior to ROSC and post-resuscitation care following ROSC was maintained in the 2017 study.
All members that participated in the current study are the member of Japanese Association for Acute Medicine of Kanto. We declare that we have no financial conflict of interest.
Not applicable
Tokyo Women’s Medical University (Munekazu Takeda), Kimitsu Chuo Hospital (Nobuya Kitamura), Chiba University Hospital (Taka-aki Nakada), The University of Tokyo (Hideo Yasunaga, Shotaro Aso), Nippon Medical School Musashikosugi Hospital (Takashi Tagami), Chiba Kaihin Municipal Hospital (Yosuke Homma, Yoshihisa Tateishi), Nippon Medical School Hospital (Tomoko Ogasawara), Keio University Hospital (Kei Hayashida), Tokyo Bay Urayasu/Ichikawa Medical Center (Hiraku Funakoshi), Juntendo University Nerima Hospital (Tomohisa Nomura), Tokyo Dental College Ichikawa General Hospital (Masaru Suzuki), Tokyo Metropolitan Bokutoh Hospital (Kazuhiro Sugiyama), Nihon University Hospital (Atsushi Sakurai)
Tokai University School of Medicine (Yoshihide Nakagawa); St.Marianna University School of Medicine, Yokohama Seibu Hospital (Minoru Yoshida); Saitama Medical Center Department of Emergency Medicine(ER) (Masaki Hisamura); Kawasaki Municipal Hospital Emergency and Critical Care Center (Kunio Kanao); Japanese Red Cross Maebashi Hospital (Jun Maruyama); Juntendo University Urayasu Hospital (Tadashi Ishihara); Tokyo Women’s Medical University Hospital (Munekazu Takeda); Kimitsu Chuo Hospital (Nobuya Kitamura); Chiba University Graduate School of Medicine (Taku Oshima); Dokkyo Medical University Saitama Medical Center (Daisuke Sugimoto); National Defense Medical College (Mayuko Kaneko); Nihon University Hospital (Atsushi Sakurai); Nippon Medical School Tamanagayama Hospital (Chie Tanaka); Tokyo Women’s Medical University Yachiyo Medical Center (Tomohito Sadahiro); Japanese Red Cross Medical Center (Yuta Moroe); National Hospital Organization Mito Medical Center (Yusuke Tsutsumi); Tokyo Metropolitan Tama Medical Center (Tomohide Koyama); Gunma University Graduate School of Medicine (Kazunori Fukushima MD); Saitama Red Cross Hospital (Kazuya Kiyota); Tokyo Metropolitan Bokutoh Hospital (Kazuhiro Sugiyama); Keio University Hospital (Ryo Yamamoto); Teikyo University School of Medicine (Ryuichi Nishi); National Center for Global Health and Medicine Hospital (Makiko Yamamoto); Medical Hospital of Tokyo Medical and Dental University (Naoshi Urushibata); Juntendo University Nerima Hospital (Hiroki Takami); Nihon University Itabashi Hospital (Nami Sawada); National Center for Child Health and Development (Shima Ohnishi); Chiba Aoba Municipal Hospital (Shunsuke Otani); Matsudo City Hospital (Masayuki Yagi); Japanese Red Cross Narita Hospital (Yoshihisa Tateishi); Tokyo Bay Urayasu/Ichikawa Medical Center (Yosuke Honma); OTA Memorial Hospital (Kazuki Akieda); Tokyo Dental College Ichikawa General Hospital (Masaru Suzuki) ; Tokyo The Jikei University Kashiwa Hospital (Izumu Hasegawa); Jichi Medical University Saitama Medical Center (Masahiro Kashiura MD); IUHW Narita Hospital (Ryuhei Igeta); University of Tsukuba Hospital (Yasuaki Koyama MD); Seirei Hamamatsu General Hospital (Takahiro Atsumi); Seirei Mikatagahra General Hospital (Go Makishi); Eastern Chiba Medical Center (Tomoaki Hashida); Nagoya University Hospital (Yuma Yasuda); Saiseikai Utsunomiya Hospital (Koichi Fujii)
(http://www.jaam- kanto.jp/sos_kanto/sos_kanto2017_contributors.html
