Duration of Device-Based Fever Prevention after Cardiac Arrest.

BACKGROUND: Guidelines recommend active fever prevention for 72 hours after cardiac arrest. Data from randomized clinical trials of this intervention have been lacking. METHODS: We randomly assigned comatose patients who had been resuscitated after an out-of-hospital cardiac arrest of presumed cardiac cause to device-based temperature control targeting 36°C for 24 hours followed by targeting of 37°C for either 12 or 48 hours (for total intervention times of 36 and 72 hours, respectively) or until the patient regained consciousness. The primary outcome was a composite of death from any cause or hospital discharge with a Cerebral Performance Category of 3 or 4 (range, 1 to 5, with higher scores indicating more severe disability; a category of 3 or 4 indicates severe cerebral disability or coma) within 90 days after randomization. Secondary outcomes included death from any cause and the Montreal Cognitive Assessment score (range, 0 to 30, with higher scores indicating better cognitive ability) at 3 months. RESULTS: A total of 393 patients were randomly assigned to temperature control for 36 hours, and 396 patients were assigned to temperature control for 72 hours. At 90 days after randomization, a primary end-point event had occurred in 127 of 393 patients (32.3%) in the 36-hour group and in 133 of 396 patients (33.6%) in the 72-hour group (hazard ratio, 0.99; 95% confidence interval, 0.77 to 1.26; P = 0.70) and mortality was 29.5% in the 36-hour group and 30.3% in the 72-hour group. At 3 months, the median Montreal Cognitive Assessment score was 26 (interquartile range, 24 to 29) and 27 (interquartile range, 24 to 28), respectively. There was no significant between-group difference in the incidence of adverse events. CONCLUSIONS: Active device-based fever prevention for 36 or 72 hours after cardiac arrest did not result in significantly different percentages of patients dying or having severe disability or coma. (Funded by the Novo Nordisk Foundation; BOX ClinicalTrials.gov number, NCT03141099.).

Blood-Pressure Targets in Comatose Survivors of Cardiac Arrest.

BACKGROUND: Evidence to support the choice of blood-pressure targets for the treatment of comatose survivors of out-of-hospital cardiac arrest who are receiving intensive care is limited. METHODS: In a double-blind, randomized trial with a 2-by-2 factorial design, we evaluated a mean arterial blood-pressure target of 63 mm Hg as compared with 77 mm Hg in comatose adults who had been resuscitated after an out-of-hospital cardiac arrest of presumed cardiac cause; patients were also assigned to one of two oxygen targets (reported separately). The primary outcome was a composite of death from any cause or hospital discharge with a Cerebral Performance Category (CPC) of 3 or 4 within 90 days (range, 0 to 5, with higher categories indicating more severe disability; a category of 3 or 4 indicates severe disability or coma). Secondary outcomes included neuron-specific enolase levels at 48 hours, death from any cause, scores on the Montreal Cognitive Assessment (range, 0 to 30, with higher scores indicating better cognitive ability) and the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability) at 3 months, and the CPC at 3 months. RESULTS: A total of 789 patients were included in the analysis (393 in the high-target group and 396 in the low-target group). A primary-outcome event occurred in 133 patients (34%) in the high-target group and in 127 patients (32%) in the low-target group (hazard ratio, 1.08; 95% confidence interval [CI], 0.84 to 1.37; P = 0.56). At 90 days, 122 patients (31%) in the high-target group and 114 patients (29%) in the low-target group had died (hazard ratio, 1.13; 95% CI, 0.88 to 1.46). The median CPC was 1 (interquartile range, 1 to 5) in both the high-target group and the low-target group; the corresponding median modified Rankin scale scores were 1 (interquartile range, 0 to 6) and 1 (interquartile range, 0 to 6), and the corresponding median Montreal Cognitive Assessment scores were 27 (interquartile range, 24 to 29) and 26 (interquartile range, 24 to 29). The median neuron-specific enolase level at 48 hours was also similar in the two groups. The percentages of patients with adverse events did not differ significantly between the groups. CONCLUSIONS: Targeting a mean arterial blood pressure of 77 mm Hg or 63 mm Hg in patients who had been resuscitated from cardiac arrest did not result in significantly different percentages of patients dying or having severe disability or coma. (Funded by the Novo Nordisk Foundation; BOX ClinicalTrials.gov number, NCT03141099.).

Oxygen Targets in Comatose Survivors of Cardiac Arrest.

BACKGROUND: The appropriate oxygenation target for mechanical ventilation in comatose survivors of out-of-hospital cardiac arrest is unknown. METHODS: In this randomized trial with a 2-by-2 factorial design, we randomly assigned comatose adults with out-of-hospital cardiac arrest in a 1:1 ratio to either a restrictive oxygen target of a partial pressure of arterial oxygen (Pao2) of 9 to 10 kPa (68 to 75 mm Hg) or a liberal oxygen target of a Pao2 of 13 to 14 kPa (98 to 105 mm Hg); patients were also assigned to one of two blood-pressure targets (reported separately). The primary outcome was a composite of death from any cause or hospital discharge with severe disability or coma (Cerebral Performance Category [CPC] of 3 or 4; categories range from 1 to 5, with higher values indicating more severe disability), whichever occurred first within 90 days after randomization. Secondary outcomes were neuron-specific enolase levels at 48 hours, death from any cause, the score on the Montreal Cognitive Assessment (ranging from 0 to 30, with higher scores indicating better cognitive ability), the score on the modified Rankin scale (ranging from 0 to 6, with higher scores indicating greater disability), and the CPC at 90 days. RESULTS: A total of 789 patients underwent randomization. A primary-outcome event occurred in 126 of 394 patients (32.0%) in the restrictive-target group and in 134 of 395 patients (33.9%) in the liberal-target group (hazard ratio, 0.95; 95% confidence interval, 0.75 to 1.21; P = 0.69). At 90 days, death had occurred in 113 patients (28.7%) in the restrictive-target group and in 123 (31.1%) in the liberal-target group. On the CPC, the median category was 1 in the two groups; on the modified Rankin scale, the median score was 2 in the restrictive-target group and 1 in the liberal-target group; and on the Montreal Cognitive Assessment, the median score was 27 in the two groups. At 48 hours, the median neuron-specific enolase level was 17 µg per liter in the restrictive-target group and 18 µg per liter in the liberal-target group. The incidence of adverse events was similar in the two groups. CONCLUSIONS: Targeting of a restrictive or liberal oxygenation strategy in comatose patients after resuscitation for cardiac arrest resulted in a similar incidence of death or severe disability or coma. (Funded by the Novo Nordisk Foundation; BOX ClinicalTrials.gov number, NCT03141099.).

A randomised double-blind pilot trial comparing a mean arterial pressure target of 65 mm Hg versus 72 mm Hg after out-of-hospital cardiac arrest.

BACKGROUND: After resuscitation from out-of-hospital cardiac arrest, mean arterial pressure below 65 mm Hg is avoided with vasopressors. A higher blood-pressure target could potentially improve outcome. The aim of this pilot trial was to investigate the effect of a higher mean arterial pressure target on biomarkers of organ injury. METHODS: This was a single-centre, double-blind trial of 50 consecutive, comatose out-of-hospital cardiac arrest patients randomly assigned in a 1:1 ratio to a mean arterial pressure target of 65 mm Hg (MAP65) or 72 mm Hg (MAP72). Modified blood pressure modules with a -10% offset were used, enabling a double-blind study design. End-points were biomarkers of organ injury including markers of endothelial integrity (soluble trombomodulin) brain damage (neuron-specific enolase) and renal function (estimated glomerular filtration rate). RESULTS: Mean arterial pressure was significantly higher in MAP72 with a mean difference of 5 mm Hg (pgroup=0.03). After 48 h, soluble trombomodulin (median (interquartile range)) was 8.2 (6.7-12.9) ng/ml and 8.3 (6.0-10.8) ng/ml (p=0.29), neuron-specific enolase was 20 (13-31 µg/l) and 18 (13-44 µg/l) p=0.79) and estimated glomerular filtration rate (mean (±standard deviation)) was 61±19 ml/min/1.73m2 and 48±22 ml/min/1.73 m2 (p=0.08) for the MAP72 and MAP65 groups, respectively. Renal replacement therapy was needed in eight patients (31%) in MAP65 and three patients (13%) in MAP72 (p=0.14). CONCLUSIONS: Double-blind allocation to different mean arterial pressure targets is feasible in comatose out-of-hospital cardiac arrest patients. A mean arterial pressure target of 72 mm Hg compared to 65 mm Hg did not result in improved biomarkers of organ injury. We observed a trend towards preserved renal function in the MAP72 group.

Biomarkers predictive of late cardiogenic shock development in patients with suspected ST-elevation myocardial infarction.

BACKGROUND: Cardiogenic shock complicating ST-elevation myocardial infarction is characterised by progressive left ventricular dysfunction causing inflammation and neurohormonal activation. Often, cardiogenic shock develops after hospital admission. Whether inflammation and a neurohormonal activation precede development of clinical cardiogenic shock is unknown. METHODS AND RESULTS: In 93% of 2247 consecutive patients with suspected ST-elevation myocardial infarction admitted at two tertiary heart centres, admission plasma levels of pro-atrial natriuretic peptide, copeptin, mid-regional pro-adrenomedullin and stimulation-2 were measured on hospital admission. Patients were stratified according to no cardiogenic shock development and cardiogenic shock developed before (early cardiogenic shock) or after (late cardiogenic shock) leaving the catheterization laboratory. In total, 225 (10%) patients developed cardiogenic shock, amongst these patients late cardiogenic shock occurred in 64 (2.9%). All four biomarkers were independently associated with the development of late cardiogenic shock (odds ratio per two-fold increase in risk: 1.19-3.13) even when adjusted for the recently developed Observatoire Régional Breton sur l'Infarctus risk score for prediction of late cardiogenic shock development. Furthermore, pro-atrial natriuretic peptide, copeptin and mid-regional pro-adrenomedullin, but not stimulation-2, added significant predictive information, when added to the Observatoire Régional Breton sur l'Infarctus risk score (area under the receiver-operating characteristic curve, pro-atrial natriuretic peptide: 0.87, p=0.0008; copeptin: 0.86, p<0.05; mid-regional pro-adrenomedullin: 0.88, p=0.006). CONCLUSIONS: Pro-atrial natriuretic peptide, copeptin, mid-regional pro-adrenomedullin and stimulation-2 admission plasma concentration were associated with late cardiogenic shock development in patients admitted with suspected ST-elevation myocardial infarction. Pro-atrial natriuretic peptide, mid-regional pro-adrenomedullin and copeptin had independent predictive value for late cardiogenic shock development.

"Endothelial Dysfunction in Resuscitated Cardiac Arrest (ENDO-RCA): Safety and efficacy of low-dose Iloprost, a prostacyclin analogue, in addition to standard therapy, as compared to standard therapy alone, in post-cardiac-arrest-syndrome patients."

OBJECTIVE: An increasingly recognized prognostic factor for out-of-hospital-cardiac-arrest (OHCA) patients is the ischemia-reperfusion injury after restored blood circulation. Endothelial injury is common in patients resuscitated from cardiac arrest and is associated with poor outcome. This study was designed to investigate if iloprost infusion, a prostacyclin analogue, reduces endothelial damage in OHCA patients. METHODS: 50 patients were randomized in a placebo controlled double-blinded trial and allocated 1:2 to 48-hours iloprost infusion, (1 ng/kg/min) or placebo (saline infusion). Endothelial biomarkers (soluble thrombomodulin (sTM), sE-selectin, syndecan-1, soluble vascular endothelial growth factor (sVEGF), vascular endothelial cadherine (VEcad), nucleosomes) and sympathoadrenal activation (epinephrine/norepinephrine) from baseline to 48 and 96-hours were evaluated. RESULTS: Iloprost infusion did not influence endothelial biomarkers by the 48-hour endpoint. A rebound effect was observed with higher biomarker plasma values in the iloprost group (sTM p=0.02; Syndecan p=0.004; nucleosomes p<0.001; VEcad p<0.03) after 96-hours. There was a significant difference in 180-day mortality in favor of placebo. There was no difference regarding total adverse events between groups (p=0.73). Two patients were withdrawn in the iloprost group due to hypotension. CONCLUSIONS: The administration of low-dose iloprost (1ng/kg/min) to OHCA patients did not significantly influence endothelial biomarkers as measured by the 48- hour endpoint. A rebound effect was however observed in the 96-hour statistical model, with increasing endothelial biomarker levels after cessation of the iloprost-infusion.

Right Ventricular and Pulmonary Vascular Function are Influenced by Age and Volume Expansion in Healthy Humans.

BACKGROUND: Patients with heart failure (HF) often show signs of right ventricular (RV) dysfunction. The RV function of coupled with the pulmonary circulation (tricuspid annular plane systolic excursion [TAPSE]/pulmonary arterial systolic pressure [PASP]) has been shown to divide HF patients into distinct prognostic strata, but less is known about which factors influence this prognostic marker, and whether those factors can be modified. We sought to obtain normative values and discern the individual effects of age, sex, and fluid overload on RV function. METHODS AND RESULTS: Sixty healthy subjects aged 20-80 years were enrolled in this prospective study. Right heart catheterization with hemodynamic measurements were performed at rest after a rapid saline solution infusion (10 mL/kg, 150 mL/min). Linear regression and Spearman correlation models were used to estimate associations between TAPSE/PASP and relevant variables. In healthy persons of all ages, the median (5th-95th percentiles) normative TASPE-PASP ratio was 1.25 (0.81-1.78) mm/mm Hg. The correlation between progressive age and declining TAPSE/PASP was significant (r = -0.35; P = .006). Sex did not influence TAPSE/PASP (P = .30). Rapid fluid expansion increased central venous pressure from 5 ± 2 mm Hg to 11 ± 4 mm Hg after fluid infusion (P < .0001). This resulted in a 32% decrease in the TAPSE-PASP ratio after fluid infusion, compared to baseline (P < .0001). CONCLUSIONS: The TAPSE-PASP ratio was affected by age, but not sex. TAPSE/PASP is not only a reflection of intrinsic RV function and pulmonary vascular coupling, but fluid status also dynamically affects this index of RV function. Normative values with invasive measurements were obtained for future assessment of HF patients.

Refractory out-of-hospital cardiac arrest with ongoing cardiopulmonary resuscitation at hospital arrival - survival and neurological outcome without extracorporeal cardiopulmonary resuscitation.

BACKGROUND: The prognosis in refractory out-of-hospital cardiac arrest (OHCA) with ongoing cardiopulmonary resuscitation (CPR) at hospital arrival is often considered dismal. The use of extracorporeal cardiopulmonary resuscitation (eCPR) for perfusion enhancement during resuscitation has shown variable results. We aimed to investigate outcome in refractory OHCA patients managed conservatively without use of eCPR. METHODS: We included consecutive OHCA patients with refractory arrest or prehospital return of spontaneous circulation (ROSC) in the Copenhagen area in 2002-2011. RESULTS: A total of 3992 OHCA patients with resuscitation attempts were included; in 2599, treatment was terminated prehospital, and 1393 (35%) were brought to the hospital either with ROSC (n = 1285, 92%) or with refractory OHCA (n = 108, 8%). Of patients brought in with refractory OHCA, 56 (52%) achieved ROSC in the emergency department. There were no differences between patients with refractory OHCA or prehospital ROSC with regard to age, sex, comorbidities, or etiology of OHCA. Time to emergency medical services (EMS) arrival was similar, whereas time to ROSC (when ROSC was achieved) was longer in refractory OHCA patients (EMS, 6 (5-9] vs. 7 [5-10] min, p = 0.8; ROSC, 15 [9-22] vs. 27 [20-41] min, p < 0.001). Independent factors associated with transport with refractory OHCA instead of prehospital termination of therapy were OHCA in public (OR, 3.6 [95% CI, 2.2-5.8]; p < 0.001), witnessed OHCA (OR, 3.7 [2.0-7.1]; p < 0.001), shockable rhythm (OR, 3.0 [1.9-4.7]; p < 0.001), younger age (OR, 1.2 [1.1-1.2]; p < 0.001), and later calendar year (OR, 1.4 [1.2-1.6]; p < 0.001). Thirty-day survival was 20% in patients with refractory OHCA compared with 42% in patients with prehospital ROSC (p < 0.001). Four of 28 refractory OHCA patients with duration of resuscitation > 60 min achieved ROSC. No difference in favorable neurological outcome in patients surviving to discharge was found (prehospital ROSC 84% vs. refractory OHCA 86%; p = 0.7). CONCLUSIONS: Survival after refractory OHCA with ongoing CPR at hospital arrival was significantly lower than among patients with prehospital ROSC. Despite a lower survival, the majority of survivors with both refractory OHCA and prehospital ROSC were discharged with a similar degree of favorable neurological outcome, indicating that continued efforts in spite of refractory OHCA are not in vain and may still lead to favorable outcome even without eCPR.

Women have a worse prognosis and undergo fewer coronary angiographies after out-of-hospital cardiac arrest than men.

BACKGROUND: Out-of-hospital cardiac arrest is more often reported in men than in women. OBJECTIVES: We aimed to assess sex-related differences in post-resuscitation care; especially with regards to coronary angiography, percutaneous coronary intervention, mortality and functional status after out-of-hospital cardiac arrest. METHODS: We included 704 consecutive adult out-of-hospital cardiac arrest-patients with cardiac aetiology in the Copenhagen area from 2007-2011. Utstein guidelines were used for the pre-hospital data. Vital status and pre-arrest comorbidities were acquired from Danish registries and review of patient charts. Logistic regression was used to assess differences in functional status and use of post-resuscitation care. Cox regression was used to assess differences in 30-day mortality. We used 'smcfcs' and 'mice' imputation to handle missing data. RESULTS: Female sex was associated with higher 30-day mortality after adjusting for age and comorbidity (hazard ratio (HR): 1.42, confidence interval (CI): 1.13-1.79, p<0.01), this was not significant when adjusting for primary rhythm (HR: 1.12, CI: 0.88-1.42, p=0.37). Women less frequently received coronary angiography <24 h in multiple regression after out-of-hospital cardiac arrest (odds ratio (OR)CAG=0.55, CI: 0.31-0.97, p=0.041), however no difference in percutaneous coronary intervention was found (ORPCI=0.55, CI: 0.23-1.36, p=0.19). Coronary artery bypass grafting was less often performed in women (ORCABG: 0.10, CI: 0.01-0.78, p=0.03). There was no difference in functional status at discharge between men and women ( p=1). CONCLUSION: Female sex was not significantly associated with higher mortality when adjusting for confounders. Women less often underwent coronary angiography and coronary artery bypass grafting, but it is not clear whether this difference can be explained by other factors, or an actual under-treatment in women.

Usefulness of Serum B-Type Natriuretic Peptide Levels in Comatose Patients Resuscitated from Out-of-Hospital Cardiac Arrest to Predict Outcome.

N-terminal pro-B-type natriuretic (NT-proBNP) is expressed in the heart and brain, and serum levels are elevated in acute heart and brain diseases. We aimed to assess the possible association between serum levels and neurological outcome and death in comatose patients resuscitated from out-of-hospital cardiac arrest (OHCA). Of the 939 comatose OHCA patients enrolled and randomized in the Targeted Temperature Management (TTM) trial to TTM at 33°C or 36°C for 24 hours, 700 were included in the biomarker substudy. Of these, 647 (92%) had serum levels of NT-proBNP measured 24, 48, and 72 hours after return of spontaneous circulation (ROSC). Neurological outcome was evaluated by the Cerebral Performance Category (CPC) score and modified Rankin Scale (mRS) at 6 months. Six hundred thirty-eight patients (99%) had serum NT-proBNP levels ≥125 pg/ml. Patients with TTM at 33°C had significantly lower NT-proBNP serum levels (median 1,472 pg/ml) than those in the 36°C group (1,914 pg/ml) at 24 hours after ROSC, p <0.01 but not at 48 and 72 hours. At 24 hours, an increase in NT-proBNP quartile was associated with death (Plogrank <0.0001). In addition, NT-proBNP serum levels > median were independently associated with poor neurological outcome (odds ratio, ORCPC 2.02, CI 1.34 to 3.05, p <0.001; ORmRS 2.28, CI 1.50 to 3.46, p <0.001) adjusted for potential confounders. The association was diminished at 48 and 72 hours after ROSC. In conclusion, NT-proBNP serum levels are increased in comatose OHCA patients. Furthermore, serum NT-proBNP levels are affected by level of TTM and are associated with death and poor neurological outcome.

Post-hypothermia fever is associated with increased mortality after out-of-hospital cardiac arrest.

OBJECTIVE: Post-cardiac arrest fever has been associated with adverse outcome before implementation of therapeutic hypothermia (TH), however the prognostic implications of post-hypothermia fever (PHF) in the era of modern post-resuscitation care including TH has not been thoroughly investigated. The aim of the study was to assess the prognostic implication of PHF in a large consecutive cohort of comatose survivors after out-of-hospital cardiac arrest (OHCA) treated with TH. METHODS: In the period 2004-2010, a total of 270 patients resuscitated after OHCA and surviving a 24-h protocol of TH with a target temperature of 32-34°C were included. The population was stratified in two groups by median peak temperature (≥38.5°C) within 36h after rewarming: PHF and no-PHF. Primary endpoint was 30-days mortality and secondary endpoint was neurological outcome assessed by Cerebral Performance Category (CPC) at hospital discharge. RESULTS: PHF (≥38.5°C) was associated with a 36% 30-days mortality rate compared to 22% in patients without PHF, plog-rank=0.02, corresponding to an adjusted hazard rate (HR) of 1.8 (95% CI: 1.1-2.7), p=0.02). The maximum temperature (HR=2.0 per °C above 36.5°C (95% CI: 1.4-3.0), p=0.0005) and the duration of PHF (HR=1.6 per 8h (95% CI: 1.3-2.0), p<0.0001) were also independent predictors of 30-days mortality in multivariable models. Good neurological outcome (CPC1-2) versus unfavourable outcome (CPC3-5) at hospital discharge was found in 61% vs. 39% in the PHF group compared to 75% vs. 25% in the No PHF group, p=0.02. CONCLUSIONS: Post-hypothermia fever ≥38.5°C is associated with increased 30-days mortality, even after controlling for potential confounding factors. Avoidance of PHF as a therapeutic target should be evaluated in prospective randomized trials.