Remote Ischemic Conditioning to Enhance Resuscitation (RICE) Pilot

Attrition assessed as the proportion of randomized subjects who do not remain on allocated therapy for the intended study duration among subjects randomly allocated. On therapy for the intended study duration consists of completing three cycles of inflation-deflation.

Time frame: Completion of their allocated study intervention, an average of 30 minutes from enrollment

Accrual is the proportion of eligible subjects who have the study device applied

Time frame: Before leaving the emergency department

Cardiac Function assessed as left ventricular ejection fraction (LVEF) using echocardiograms ordered for clinical indications.

Time frame: Within 48 hours of index arrest

Population: This analysis is based on the number of participants with an LVEF recorded.

Clinical Instability at Discharge assessed using the Kosecoff Index measured at discharge based on the presence of nine symptoms and signs associated with increased risk of rehospitalization. Instability will be the presence of any of these. Clinical instability at discharge was defined by the Kosecoff Index. https://pubmed.ncbi.nlm.nih.gov/2214063/ This was scored as 1 point for the presence and 0 for the absence of each of the following during the 24 h prior to discharge: Fever, temperature \>38.3°C Urinary incontinence Chest pain Shortness of breath Confusion Heart rate \>=130 beats/min Respiratory rate \>=30/min Diastolic blood pressure \>= 105 mmHg Systolic blood pressure \< 90 mmHg Heart rate \< 50 bpm Premature ventricular contractions on telemetry

Time frame: Discharge or 30 days after index arrest

Population: Participants were included in this analysis if they survived to discharge. Three participants (all from the control group) were missing data on this metric and were also excluded from the analysis.

Favourable Neurologic Status at Discharge assessed using modified Rankin Score (MRS) \< 3 at hospital discharge or 30 days after index arrest. Modified Rankin Scale is scored from zero to six. Higher values represent a worse outcome. Favorable neurologic status is defined as a modified Rankin score 0, 1 or 2.

Time frame: Discharge or 30 days after index arrest

Hospital Free Survival (HFS) assessed as number of days alive and permanently out of hospital up to 30 days post arrest

Time frame: Within 30 days of index arrest

Myocardial Injury assessed as peak serum troponin in ng/mL at any time point within 24 h of index arrest.

Time frame: Within 24 hours of index arrest

Population: Participants with an elevated serum troponin (\>0.03) were included in the analysis.

Cardiogenic Shock assessed as systolic BP \< 80 mmHg during any 6 h period within 48 h of the index arrest not due to a correctable cause, and treated with pressors or inotropes or placement of a mechanical cardiac assist device (e.g. intra-aortic balloon pump). Cardiogenic shock correlates with survival after resuscitation from cardiac arrest.

Time frame: Within 48 hours of index arrest

Renal Dysfunction assessed using Risk, Injury, Failure, Loss, End Stage criteria.

Time frame: Within 24 hours of index arrest

Population: In order to calculate the RIFLE score, both a baseline creatinine level (prior to the index cardiac arrest) and a first recorded creatinine level (after the index cardiac arrest) were required. Only those participants with both creatinine values were included in the analysis. For this analysis, participants with a creatinine level which was 1.5 times above baseline or more were counted as positive for AKI.

STEMI assessed as the presence of electrocardiographic (ECG) and biomarker criteria for acute myocardial infarction within 48 h of the index arrest. Note that ST-elevation on the first 12-lead ECG after resuscitation is a poor predictor of acute infarction in this population. These patients often develop infarctions during the subsequent 48 h.

Time frame: Within 48 hours of index arrest

Population: One participant in the control group did not have data recorded for this metric (unknown) and was not included in the analysis.

Survival to 30 Days After Cardiac Arrest assessed as alive 30 days after the index cardiac arrest as confirmed by a brief telephone interview.

Time frame: 30 days after index arrest

Survival to Discharge assessed as alive when discharged from hospital to home, nursing facility or rehabilitation. Patients transferred to another acute care facility (e.g. to undergo implantable defibrillator placement) will be considered still hospitalized.

Time frame: Discharge or 30 days after index arrest

Treatment Success assessed as the proportion of intervention group patients who remain alive and on their allocated therapy for the intended study duration.

Time frame: 30 minutes from initiation of study intervention

assessed as the reduction of support (i.e. reducing pressors, lab draws or medications) or withdrawal of support (i.e. extubation, stopping drips/meds, changing to comfort care only) during hospitalization.

Time frame: Discharge or 30 days after index arrest

Population: There was missing data on the participants not included in this analysis.

device failure will be defined as discontinuation of use of the device prior to the end of allocated treatment interval because of mechanical failure as opposed to provider preference.

Time frame: 30 minutes from initiation of study intervention

Related to Cardiac Arrest The following are commonly observed in patients who experience cardiac arrest, and may or may not be attributable to specific resuscitation therapies. These will be monitored and reported but not classified as serious adverse events. Clinical diagnoses of pneumonia, cerebral bleeding, stroke, seizures, bleeding requiring transfusion or surgical intervention, rearrest, pulmonary edema, serious rib fractures, sternal fractures, internal thoracic or abdominal injuries as noted in the hospital discharge summary.

Time frame: Discharge or 30 days after index arrest

Population: Participants were included in this analysis if they survived to discharge. Also excluded were 3 participant (all from the control group) with missing data.

Pain assessed using the Richmond Agitation-Sedation Scale at 30 and 60 minutes after randomization in control and intervention group patients. No gold standard exists for pain assessment in sedated and ventilated patients.

Time frame: Within 24 hours of Enrollment

Sepsis assessed within one week of index arrest as either i) the presence of microbiologically proven, clinically proven, or suspected infection; or ii) presence of Systemic Inflammatory Response Syndrome (SIRS); and iii) development of at least one organ dysfunction within the preceding 24 hours.

Time frame: Within 1 week of Enrollment

Thrombophlebitis assessed as symptomatic non central nervous system venous or arterial thrombus documented radiographically or ultrasonographically in the upper extremity to which the study intervention was applied.

Time frame: Within 1 week of Enrollment

These will be defined as any serious unexpected adverse effect on health or safety or any unexpected life-threatening problem caused by, or associated with, a device, if that effect or problem was not previously identified in nature, severity, or degree of incidence in the investigation plan or application, or any other unexpected serious problem associated with a device that relates to the rights, safety or welfare of subjects. Death or neurological impairment will not be considered an adverse event in this study, as it is an expected part of the natural history of the illness for a large proportion of the population.

Time frame: Discharge or 30 days after index arrest