Study setting {9}
Multicenter study carried out at the following sites:
- The Cardiac ICU at the Department of Cardiology, The Heart Centre, Copenhagen University Hospital - Rigshospitalet, Copenhagen
- The ICU, Copenhagen University Hospital - Gentofte Hospital, Copenhagen
- The Emergency Medical Services of the Capital Region of Denmark - Copenhagen
Eligibility criteria {10}
All resuscitated OHCA patients in the Capital Region of Denmark are screened for eligibility. The screening is performed by the on-duty physician manning the mobile critical care unit (CCU). The Danish Cardiac Arrest Registry will be used as a screening log during the trial. Following successful screening, the patient will be included, and study drug will be given. Inclusion in the STEROHCA trial does not prohibit participation in other trials.
Inclusion Criteria
- Age ≥18 years
- OHCA of presumed cardiac cause
- Unconsciousness (GCS ≤8) upon pre-hospital randomization
- Sustained ROSC for at least five minutes
- Randomization within 30 minutes of sustained ROSC
Exclusion Criteria
- Termination of resuscitation (TOR) exclusion criteria28,29
- Asystole as primary electrocardiogram (ECG) rhythm
- Female of childbearing potential (female aged 15-40, decided by the treating physician)
- Known therapy limitation (known decision made of no resuscitation or intensive therapy)
- Known allergy to glucocorticoid
- Known disease making 180-day survival unlikely
- Known pre-arrest modified Rankin Scale (mRS) score of 4-5
- Temperature upon admission <30° C
- >30 minutes to sustained ROSC
Who will take informed consent? {26a}
The trial will be conducted in accordance with the Declaration of Helsinki and follow European and national legislation on medical research in emergency situations with subjects temporarily incapacitated. Since subjects are incapacitated, they will not be able to provide informed consent prior to enrollment. According to Danish legislation, a proxy consent from a legal surrogate (trial guardian) is required on behalf of the patient prior to inclusion. The trial guardian providing informed consent will be a medical doctor with no involvement in the patient treatment in this trial. The consent will be filled out through the encrypted database program REDCap. Further, informed consent from the next of kin will be obtained at the earliest time possible. The latter consent will be obtained by the physician on call or a dedicated team of research personnel; all medical doctors. A consent from a secondary trial guardian will be obtained following admission of the patient in REDCap. Approvals from the relevant authorities can be seen in section {24}.
Additional consent provisions for collection and use of participant data and biological specimens {26b}
Approval from the local ethical committee will be needed for ancillary studies of patient data or biological specimens unless this is waived based on prior approvals or the design of the studies.
Interventions {11}
Explanation for the choice of comparators {6b}
We have chosen a single bolus infusion of 250 mg methylprednisolone (Solumedrol) for attenuation of the inflammatory response seen following OHCA. Pulse doses of methylprednisolone (≥250 mg) are widely used in the treatment of conditions such as prevention of organ rejection after transplantation, rheumatic diseases with acute deterioration, multiple sclerosis and acute injury of the bone marrow.30 At methylprednisolone doses above 250 mg, infusion time should be above 30 minutes, whereas doses below 250 mg can be completed within 5 minutes, according to the danish summary of product characteristics.
Intervention description {11a}
Patients allocated to methylprednisolone will receive a bolus infusion of 250 mg over five minutes. The study drug is prepared by a simple shaking-mechanism where 2 x 125 mg/2 mL of methylprednisolone powder is mixed preservative-free to a total volume of 4 mL. Patients allocated to placebo will receive a 4 mL infusion of isotonic saline. Infusion of study drug or placebo will be made as soon as possible following 5 minutes of stable ROSC in the prehospital setting.
Criteria for discontinuing or modifying allocated interventions {11b}
If the next of kin or the trial guardian of a patient refuses or withdraws consent to participate in the study, the patient will be withdrawn from the trial without prejudice to future medical care. Further, if the patient refuses or withdraws consent, when able to, no study observations will be made from the date of request and the patient will be removed from the study.
A patient can be withdrawn from the study by the sponsor-investigator if any of the following occurs: (1) significant intercurrent illness, (2) patient refusal to continue observations, (3) investigator decides that termination is in the best medical interest of the patient.
If withdrawal of consent occurs, observations will be completed to the date of withdrawal and a final evaluation of the patient’s withdrawal will be made at this point with an explanation for the withdrawal. If withdrawal is due to an adverse event, the patient will be followed until the adverse event is stabilized or resolved.
Strategies to improve adherence to interventions {11c}
All trial guardians and physicians including patients have relevant knowledge of the cardiological specialty and knowledge of the study from an obligatory instruction video and the handing out of the study protocol, protocol summaries and pocket cards. None of these physicians are involved with the primary care of the patient following admission. The study medicine is a single bolus infusion administered over 5 minutes and there is a low risk of missing or delaying the intervention following screening of the patient.
In-hospital personnel involved in the primary care of the patient, i.e. doctors and nurses, have relevant knowledge of the study through the instruction video and written instructions and have been trained in data collection study specific procedures.
Relevant concomitant care permitted or prohibited during the trial {11d}
According to temporary guidelines, all patients included in the study will be treated with standard therapies for OHCA, including targeted temperature management at 36 degrees, vasopressors and/or inotropes if needed and prophylactic antibiotics. Necessary cardiac interventions will not be delayed by the trial intervention. The specific care of all patients is left to the discretion of the treating physician.
Provisions for post-trial care {30}
Included patients will be insured by the Patient Compensation Association (the health system responsible for the trial sites, “Rigshospitalet” and “Gentofte Hospital”).
Outcomes {12}
Primary outcome:
Repeated daily measurements of IL-6 and NSE at admission and the following 24, 48 and 72 hours after admission.
Secondary outcomes:
Markers of inflammation: hsCRP, leucocyte- and differential count, plasma cytokine levels (IL-1b, IL-2, IL-4, IL-5, IL-7, IL-8, IL-10, IL-12, IL-13, IL-17A, GM-CSF, G-CSF, MCP-1, MIP-1beta, IFN-g and TNF-α) and procalcitonin measured daily the first three days from admission.
Markers of kidney and hepatic injury: Daily creatinine levels the first three days from admission. Daily measurements of ALAT, ASAT, ALP, bilirubin and INR the first three days from admission.
Markers of the coagulation system (only at the site “Rigshospitalet”): Plasma fibrinogen the first three days from admission, and thromboelastography (TEG) at admission and at 48 hours.
Protein and enzymatic protection: Daily proteomics and metabolomics samples the first three days from admission.
Hemodynamics: Daily evaluation by Swan-Ganz catheter (only at “Rigshospitalet”), bihourly analyses of arterial blood gases the first 36 hours and transthoracic echocardiogram (TTE) measured at time of admission and before hospital discharge.
Neuroprotection: Daily measurements of Tau and NfL levels the first three days from admission.
Cardiac protection: Daily measurements of TnT (at “Rigshospitalet”), TnI (at “Gentofte Hospital”) and CKMB levels the first three days from admission.
Clinical endpoints: Daily Sequential Organ Failure Assessment (SOFA) scores the first three days from admission. Survival and neurological outcome, decided by CPC and mRS score after five days, at discharge from the intensive ward and the hospital and following a minimum of 180 days from discharge through telephone interview.
Follow-up at 90 days following discharge in an ambulatory setting: MoCA-score for assessment of cognitive function and patients will be screened for quality of life, anxiety, depression and the return to daily living with their nearest relatives.
Safety: Cumulated daily incidence of any adverse event (AE) the first seven days, including “severe adverse event” (SAE) and “adverse event with believed relation to the study medicine” (SUSAR).
Participant timeline {13}
Besides the section presenting outcomes above ({12}) a time schedule for the study is presented as a schematic diagram in table 1.
Sample size {14}
The trial is powered at the co-primary endpoint. We chose a priori to power the trial at the ‘weakest’ of the two endpoints, ensuring that we would have sufficient power for both endpoints. As we were not able to find data regarding the effect of methylprednisolone on IL-6- or NSE levels from admission, we chose to power the trial towards a single measurement drawn 48 hours after admission. With the assumption that methylprednisolone would reduce IL-6 levels by 20%, the trial would achieve a power of 0.90 at an alpha-level of 0.025 if 112 patients were included. With the assumption that methylprednisolone would reduce NSE levels by 20%, the trial would achieve a power of 0.90 at an alpha-level of 0.025 if 114 patients were included.
Based on the above, inclusion of 120 patients would be sufficient to adjust for missingness due to withdrawn consent. Though, we estimated from previous studies that approximately 20% of resuscitated OHCA patients would die within 72 hours, i.e. before complete assessment of the co-primary endpoint. Further, due to the acute nature of the trial, we expect 10% of post-randomization exclusions and/or patients where consent is not obtained. To achieve a complete set of blood samples from 120 patients we, therefore, plan to include 1,30x120=156 patients. We will however stop the trial before if our target at 120 patients is reached.
Recruitment {15}
The study includes an enrolment period of up to 18 months, followed by a follow-up period of 6 months and analyses of paraclinical results another 12 months. The expected study period is based on previous clinical studies in OHCA patients at our department, where approximately 150 patients are included each year (including OHCA patients admitted from outside the Capital Region of Denmark).
Methods: Assignment of interventions
Allocation {16}
Sequence generation {16a}
The pharmacy of the Capital of Region of Denmark will prepare, box and label the study medicine and the placebo ampoules. The pharmacy is approved by the Danish Health authorities. Randomization will be generated by using the website randomization.com (http://www.randomization.com) with allocation in a 1:1 fashion with active study medicine and placebo randomized in permuted blocks of four. The pharmacy will be responsible for generation of the allocation sequence. Study medicine and placebo are placed in identical opaque boxes and will be numbered randomly according to allocation. Once prepared the pharmacy will ship twenty boxes to the five “physician staffed CCU” stations covering the Capital Region of Denmark. The CCUs are manned 24 hours 7 days a week with a physician (henceforth referred to as “CCU physician”) and an experienced paramedic. The responsible project physician will ensure that any CCU station always has boxes in storage and ready for use and when box storage is used the pharmacy will provide new boxes. Before each shift, the on-duty physician and paramedic will make sure that a minimum of two boxes are stored in their unit. When a patient is successfully screened the including physician will open one of these boxes and use the content (study medicine or placebo). The box number will be registered by the including physician and for safety reasons a photo of the box number will be taken to the prehospital journal and the empty box will be delivered to the department at hospital admission. All treating in-hospital personnel and study coordinators will remain blinded throughout the study. Still, in case of need for emergency unblinding, this can be done by the principal investigator at each site.
Concealment mechanism {16b}
Treatment allocation is managed as described above. The opaque boxes containing study medicine or placebo are identical besides the assigned unique allocation ID written on the box. Treatment assignment during the trial is only available for the including CCU physician and the accompanying medical assistant manning the CCU following screening of the patient and contact with the trial guardian for informed consent. Once informed consent is obtained, the including physician opens a random opaque box and infuse the content, i.e. study medicine or placebo. The box allocation number will be available at all time through information filled out in the prehospital journal, consent by the including physician and/or the delivery of the used box at the department of admission.
Implementation {16c}
Allocation of study medicine and placebo will be done by the pharmacy as described in {16a}. After inclusion and completion of study drug infusion, the including CCU physician will complete an electronic consent through REDCap with allocation number and confirm that inclusion is made following contact and consent from the trial guardian. No in-hospital personnel will have knowledge of allocation at any time and the including physician will not take further part in treatment of the patient. At trial completion the investigators will be informed of allocation.
Blinding {17}
Who will be blinded {17a}
All in-hospital personnel, research personnel and patients will be blinded to intervention allocation throughout the trial. The including prehospital CCU physician and the medical assistant will be blinded during screening, inclusion and randomization of the patient, but unblinded upon breaking concealment of the randomized box. Infusion is completed before arrival at the hospital and no information other than allocation number will be given at hospital admission. When follow-up is completed, and data collected the database will be locked and treatment allocation will be unblinded.
Procedure for unblinding {17b}
Information on treatment allocation is kept in concealed envelopes in a safe available to authorized personnel at each site. Unblinding will only occur if the knowledge is necessary for treatment of the patient or in case of safety reporting for the involved authorities. In any case of unblinding the PI will be contacted beforehand. The unblinding will be documented in the trial master file and the patient’s electronic case report fil (eCRF), and the sponsor-investigator will be informed within one day.
Methods: Data collection, management and analysis
Data collection
Assessment of outcomes {18a}
Patient data will be handled as ordinary chart records. All data will be kept according to national legislation, i.e. the General Data Protection Regulation (GDPR) and the Data Protection Act. Accept of the data handling and management will be applied for at these institutions before initiation of the study. All handling of personal data in the study is the responsibility of the principal investigator. The study database will be constructed in accordance with national legislation and local practice. Data is entered by study personnel and the database will be maintained for 15 years and anonymized if requested by relevant authorities. Data will be monitored by the Good Clinical Practice (GCP) unit, including review of consent forms and eligibility for the trial. The frequency of onsite monitoring will depend on compliance with the protocol, number of enrolled patients, and the quality of data handling. The principal investigator will be responsible for all data in the eCRF. At completion of the study, biomarkers will be analyzed, and data will be stored in an encrypted server with a backup function.
Participant retention and follow-up plan {18b}
Patients included are expected to remain in the ICU’s the first three days of admission until the primary endpoints are collected. If a patient awakes and is transferred to the ward, blood sampling will be done here, including samples for the research biobank to analyze the primary endpoints. If a patient is transferred to a local hospital within three days of admission, samples for the biobank are not taken but standard biochemistry will be taken routinely and will be collected. At both sites dedicated staff will be responsible for follow-up in the ambulatory setting at approximately 90 days following OHCA. The patient will be offered a visit at home if an ambulatory visit is not possible or not wanted by the patient. Patients who discontinue the study during follow-up will remain in the study database if an informed consent is obtained. After 180 days patients will be evaluated through a telephone interview.
Data management {19}
The database system REDCap® is used for data storage. REDCap is hosted and maintained by the Regional IT department and data quality will be monitored as described in “Assessment of outcomes {18a}”.
Confidentiality {27}
Patient confidentiality will be ensured throughout the trial according to national and international legislation (GDPR and the Data Protection Act). Data entered in REDCap are encrypted and will only be assessed by dedicated personnel. After trial completion, the biobank material analyses will be stored in a secured server and the results from the trial will only be available upon request if approval is provided by relevant authorities.
Plans for collection, laboratory evaluation and storage of biological specimens for genetic or molecular analysis in this trial/future use {33}
A research biobank is established from trial initiation and biological material is stored according to legislation and approvals. The material will be analyzed at an advanced laboratory following inclusion of the last participant. Currently, no genetic studies are planned, and future studies including the material are only possible with approval from relevant authorities.
Statistical methods
Statistical methods for primary and secondary outcomes {20a}
Analyses of primary and secondary outcomes will be conducted on the intention-to-treat population. Categorical variables will be presented as numbers and continuous variables will be presented as mean (±SD) or median (25th percentile-75th percentile), according to distribution. The primary analyses of the co-primary endpoint will include the modified intention-to-treat population.
Further, we will conduct sensitivity analyses of the co-primary endpoint including all randomized patients. In this analysis, values missing because a patient died prior to blood sampling will be replaced with the median value of the given biomarker in patients dying after blood sampling, but before 30 days.
Continuous endpoints, including the co-primary endpoint, will be assessed at multiple time points and analyzed by application of linear mixed models of covariance. For approximation of normal distribution, logarithmic transformation will be done, as appropriate. The application of linear mixed models will ensure that a higher power is achieved compared to the sample size calculation, which is based on a single measurement (see “Sample size {14}”). For analyses of categorical secondary outcomes, Chi-Squared or Fisher’s exact test will be applied.
Cox proportional hazard models will be applied and sequentially adjusted for the interaction between treatment arm and relevant variables (sex, age, primary ECG rhythm, time to ROSC, pPCI performed, NSE- and IL-6 levels). Differences in mortality between treatment arms will be depicted in Kaplan-Meier estimate plots and compared with the log-rank test.
R Studio, version 1.2.5001, will be used for all analyses (RStudio Team [2020]. RStudio: Integrated Development for R. RStudio, PBC, Boston, MA; URL: http://www.rstudio.com/).
Interim analyses {21b}
For monitoring of general safety, interim analyses of mortality and hospital length of stay will be performed after 60 participants have been included in the trial.
Methods for additional analyses (e.g. subgroup analyses) {20b}
Additional subgroup analyses will be performed on patients with ST-elevation myocardial infarction (primarily suspected in the ECG followed by pPCI) to decide whether active study drug, methylprednisolone, can mitigate the cardiac injury.
Another subgroup will be patients not intubated at admission since a part of included patients will wake up sufficiently, so intubation is not needed and therefore not go to the ICU. Primarily, the changes in markers of inflammation will be compared according to allocation to study drug or placebo and secondarily awake patients will be compared with comatose patients.
Methods in analysis to handle protocol non-adherence and any statistical methods to handle missing data {20c}
All analyses will be made on the modified intention-to-treat population. For missingness greater than 10% for the co-primary endpoint, multiple imputations by chained equations will be applied as sensitivity analysis with generation of 10 individual data sets.
Plans to give access to the full protocol, participant level-data and statistical code {31c}
Both protocol and data will be available upon reasonable request and approval from relevant authorities after the trial has been completed.
Monitoring
The coordinating center and trial steering committee {5d}
The trial is anchored at Rigshospitalet as the coordinating center. The trial steering committee (SC) will consist of LO, CH, JK and FF and will represent both participating centers (Rigshospitalet and Gentofte Hospital). Composition of the data monitoring committee (DMC) is described in {21a}. The local GCP-unit will monitor the trial according to national and international guidelines.
The data monitoring committee {21a}
The DMC will consist of Professor Lars Køber, Department of Cardiology, Rigshospitalet and Professor Anders Perner, Department of Anesthesiology, Rigshospitalet. Interim analyses and monitoring of overall conduct of the trial will be performed by the DMC and decisions are reported to the sponsor. The DMC is independent of the sponsor and has no competing interests that could impact the trial.
Harms: adverse events {22}
AEs will be recorded daily for the first seven days and further entered in a pre-specified form in the eCRF. AEs occurring after day seven will be evaluated at 30- and 180- days follow-up. For each AE, relationship to trial intervention will be rated as “probable”, “possible”, “unlikely” or “unknown”. Trial investigators will record and evaluate SAEs and SUSARs throughout the trial. If a life-threatening or fatal SUSAR occurs, the Danish Medicine Agency (DMA) will be notified by the sponsor within seven days. Further, the sponsor will inform the DMA on all follow-up action to these SUSARs no more than eight days after the reporting. Any other SUSARs will be reported to the DMA no later than 15 days from when the sponsor is informed. For assessment of potential causality between the trial intervention, i.e. whether the adverse event is suspected, the summary of product characteristics for Solumedrol will be used. All SAEs occurring at both trial centers will be submitted once a year by the sponsor and a safety report of all trial patients will be submitted to the DMA.
Auditing {23}
The DMC will perform interim analyses after 60 patients have participated in the trial and advice the sponsor and the SC thereafter. The DMC will have unlimited access to data upon request. The GCP monitoring will be externally done by the Copenhagen GCP unit and both on- and off-site monitoring will be performed throughout the trial. Monitoring frequency is decided by the GCP unit according to compliance with the trial protocol. The principal investigators will be responsible for all data entered in the eCRF.
Plans for protocol amendments (e.g. trial participants, ethical committees) {25}
Relevant protocol revisions and amendments have been communicated and authorized by all relevant authorities. No changes in the current protocol will be done and updates to the clinical trial registry have been done accordingly (https://clinicaltrials.gov/ct2/show/NCT04624776). The trial status will be updated as appropriate.
Dissemination plans {31a}
All trial analyses will be done by the SC, and the trial will be unblinded upon acceptance from the committee. Authorship will be granted according to ICMJE guidelines. The main results of the trial will be published in a peer-reviewed international journal regardless of the results and further presented at international congresses. Trial results will be communicated to participating patients and relevant patient relatives if this was requested in the informed consent form.