Helle Søholm

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.

Tertiary centres have improved survival compared to other hospitals in the Copenhagen area after out-of-hospital cardiac arrest ☆

AIMS Out-of-hospital cardiac arrest (OHCA) has been reported to carry very varying morbidity and mortality. However, it remains unclear whether this is caused by intrinsic factors of the OHCA or due to the level of in-hospital care. The aim of this study is to compare 30-day and long-term mortality after OHCA at tertiary heart centres and non-tertiary university hospitals. METHODS AND RESULTS Data from the Copenhagen OHCA registry from June 2002 through December 2010 included a total of 1218 consecutive patients treated by the same mobile emergency care unit (MECU) with either return of spontaneous circulation (ROSC) or on-going resuscitation (n=53) at hospital arrival. The MECU transported patients to the nearest hospital unless an ECG on scene suggested ST-segment elevation myocardial infarction, in which case patients were transported to the nearest tertiary centre for acute coronary angiography. Therefore, patients with ST-elevation myocardial infarction (n=198) were excluded from the analysis. 30-day mortality was 56% vs. 76% and long term (up to 8years) mortality was 78% vs. 94% for tertiary and non-tertiary hospitals, respectively, both p<0.001. Multivariate analysis showed that admission to a non-tertiary hospital was independently associated with increased risk of death (HR=1.32, 95% CI: 1.09-1.59, p=0.004). Exclusion of patients with on-going resuscitation at admission resulted in HR=1.34 (1.11-1.62), p=0.003. A matched pair propensity score analysis of 255 patients confirmed the results of the proportional hazard analysis (HR=1.35, 95% CI: 1.11-1.65 p=0.003). CONCLUSION Admission to tertiary centres is associated with lower mortality rates after OHCA compared with non-tertiary hospitals.

Factors Associated With Successful Resuscitation After Out-of-Hospital Cardiac Arrest and Temporal Trends in Survival and Comorbidity.

STUDY OBJECTIVE Out-of-hospital cardiac arrest has an overall poor prognosis. We sought to identify what temporal trends and influencing factors existed for this condition in one region. METHODS We studied consecutive out-of-hospital cardiac arrest patients from 2007 to 2011 with attempted resuscitation in Copenhagen. From an Utstein database, we assessed survival to admission and comorbidity with the Charlson comorbidity index from the National Patient Registry and employment status from the Danish Rational Economic Agents Model database. We used logistic regression analyses to identify factors associated with outcome. RESULTS Of a total of 2,527 attempted resuscitations in out-of-hospital cardiac arrest patients, 40% (n=1,015) were successfully resuscitated and admitted to the hospital. The strongest independent factors associated with successful resuscitation were shockable primary rhythm (multivariate odds ratio [OR]=3.9; 95% confidence interval [CI] 3.1 to 5.0), witnessed arrest (multivariate OR=3.5; 95% CI 2.7 to 4.6), and out-of-hospital cardiac arrest in a public area (multivariate OR=2.1; 95% CI 1.6 to 2.8), whereas no comorbidity (multivariate OR=1.1; 95% CI 0.8 to 1.45), sex (multivariate OR=1.14; 95% CI 0.91 to 1.44), and employment status (multivariate OR=1.17; 95% CI 0.89 to 1.56) were not independently associated with outcome. The number of patients with a high comorbidity burden (Charlson comorbidity index ≥3) increased during the study period (P trend <.001), from 18% to 31% (P trend <.001), whereas the percentage of out-of-hospital cardiac arrest patients with successful resuscitation to hospital admission increased by 3% per year during the study period, from 37% in 2007 to 43% in 2011 (P trend <.001). CONCLUSION Our observations confirm the importance of key features that influence out-of-hospital cardiac arrest survival to hospital admission but are not highly influenced by public health actions. Despite increased illness burden, this short term outcome from cardiac arrest improved as care system efforts matured.

Sinus bradycardia during hypothermia in comatose survivors of out-of-hospital cardiac arrest – A new early marker of favorable outcome? ☆

BACKGROUND Bradycardia is a common finding in patients undergoing therapeutic hypothermia (TH) following out-of-hospital cardiac arrest (OHCA), presumably as a normal physiological response to low body temperature. We hypothesized that a normal physiological response with sinus bradycardia (SB) indicates less neurological damage and therefore would be associated with lower mortality. METHODS We studied 234 consecutive comatose survivors of OHCA with presumed cardiac etiology and shockable primary rhythm, who underwent a full 24-h TH-protocol (33°C) at a tertiary heart center (years: 2004-2010). Primary endpoint was 180-day mortality; secondary endpoint was favorable neurological outcome (180-day cerebral performance category: 1-2). RESULTS SB, defined as sinus rhythm <50 beats per minute during TH, was present in 115 (49%) patients. Baseline characteristics including sex, witnessed arrest, bystander cardiopulmonary resuscitation and time to return of spontaneous circulation were not different between SB- and no-SB patients. However, SB-patients were younger, 57±14 vs. 63±14 years, p<0.001 and less frequently had known heart failure (7% vs. 20%, p<0.01). Patients experiencing SB during the hypothermia phase of TH had a 17% 180-day mortality rate compared to 38% in no-SB patients (p<0.001), corresponding to a 180-day hazard ratio (HRadjusted=0.45 (0.23-0.88, p=0.02)) in the multivariable analysis. Similarly, SB during hypothermia was directly associated with lower odds of unfavorable neurological outcome (ORunadjusted=0.42 (0.23-0.75, p<0.01). CONCLUSION Sinus bradycardia during therapeutic hypothermia is independently associated with a lower 180-day mortality rate and may thus be a novel, early marker of favorable outcome in comatose survivors of OHCA.

Prognostic Implications of Level-of-Care at Tertiary Heart Centers Compared With Other Hospitals After Resuscitation From Out-of-Hospital Cardiac Arrest

Background—Studies have found higher survival rates after out-of-hospital cardiac arrest and admission to tertiary heart centers. The aim was to examine the level-of-care at tertiary centers compared with nontertiary hospitals and the association with outcome after out-of-hospital cardiac arrest. Methods and Results—Consecutive out-of-hospital cardiac arrest patients (n=1078) without ST-segment–elevation myocardial infarction admitted to tertiary centers (54%) and nontertiary hospitals (46%) were included (2002–2011). Patient charts were reviewed focusing on level-of-care and comorbidity. Survival to discharge differed significantly with 45% versus 24% of patients discharged alive (P<0.001), and after adjustment for prognostic factors admissions to tertiary centers were still associated with lower 30-day mortality (hazard ratio, 0.78 [0.64–0.96; P=0.02]), independent of comorbidity. The adjusted odds of predefined markers of level-of-care were higher in tertiary centers: admission to intensive care unit (odds ratio [OR], 1.8 [95% confidence interval, 1.2–2.5]), temporary pacemaker (OR, 6.4 [2.2–19]), vasoactive agents (OR, 1.5 [1.1–2.1]), acute (<24 hours) and late coronary angiography (OR, 10 [5.3–22] and 3.8 [2.5–5.7]), neurophysiological examination (OR, 1.8 [1.3–2.6]), and brain computed tomography (OR, 1.9 [1.4–2.6]), whereas no difference in therapeutic hypothermia was noted. Patients at tertiary centers were more often consulted by a cardiologist (OR, 8.6 [5.0–15]), had an echocardiography (OR, 2.8 [2.1–3.7]), and survivors more often had implantable cardioverter defibrillator’s implanted (OR, 2.1 [1.2–3.6]). Conclusions—Admissions to tertiary centers were associated with significantly higher survival after out-of-hospital cardiac arrest in patients without ST-segment–elevation myocardial infarction in the Copenhagen area even after adjustment for prognostic factors including comorbidity. Level-of-care seems higher in tertiary centers both in the early phase, during the intensive care unit admission, and in the workup before discharge. The varying level-of-care may contribute to the survival difference; however, differences in comorbidity do not seem to matter significantly.

Resuscitation of patients suffering from sudden cardiac arrests in nursing homes is not futile

BACKGROUND Survival after out-of-hospital cardiac arrest (OHCA) has increased in recent years, and new data are therefore needed to avoid unsubstantiated statements when debating futility of resuscitation attempts following OHCA in nursing home (NH)-residents. We aimed to investigate the outcome and prognosis after OHCA in NH. METHODS Consecutive Emergency Medical Service (EMS) attended OHCA-patients in Copenhagen during 2007-2011 were included. Utstein-criteria for pre-hospital data and review of individual patient charts for in-hospital post-resuscitation care were collected. RESULTS A total of 2541 consecutive OHCA-patients were recorded, 245 (10%) of who were current NH-residents. NH-patients were older, more frequently female, had more witnessed arrests, fewer shockable primary rhythm and assumed cardiac aetiology, but shorter time to the return of spontaneous circulation (ROSC) compared to OHCA in non-nursing homes (non-NH). Overall 30-day survival rate was 9% in NH and 18% in non-NH, p<0.001. Of the 245 NH-arrests 79 (32%) patients were admitted to hospital compared to 937 (41%) from non-NH (p<0.001). Thirty-day survival rate in patients admitted to hospital were 27% for NH- and 42% for non-NH-patients, p<0.001. OHCA in NH was, however, not associated with a significantly worse prognosis (HR=0.88 (0.64-1.21), p=0.4) after adjustment for known prognostic factors including co-morbidity. CONCLUSIONS Nursing home residents resuscitated from OHCA and admitted to hospital have similar survival rates as non-NH-patients when adjusting for known prognostic factors and pre-existing co-morbidity. A policy of not attempting resuscitation in nursing homes at all may therefore not be justified.

Hemodynamics and vasopressor support in therapeutic hypothermia after cardiac arrest: Prognostic implications ☆

AIM Inducing therapeutic hypothermia (TH) in Out-of-Hospital Cardiac Arrest (OHCA) can be challenging due to its impact on central hemodynamics and vasopressors are frequently used to maintain adequate organ perfusion. The aim of this study was to assess the association between level of vasopressor support and mortality. METHODS In a 6-year period, 310 comatose OHCA patients treated with TH were included. Temperature, hemodynamic parameters and level of vasopressors were registered from admission to 24h after rewarming. Level of vasopressor support was assessed by the cardiovascular sub-score of Sequential Organ Failure Assessment (SOFA). The population was stratified by use of dopamine as first line intervention (D-group) or use of dopamine+norepinephrine/epinephrine (DA-group). Primary endpoint was 30-day mortality and secondary endpoint was in-hospital cause of death. RESULTS Patients in the DA-group carried a 49% all-cause 30-day mortality rate compared to 23% in the D-group, plog-rank<0.0001, corresponding to an adjusted hazard ratio (HR) of 2.0 (95% CI: 1.3-3.0), p=0.001). The DA-group had an increased 30-day mortality due to neurological injury (HR=1.7 (95% CI: 1.1-2.7), p=0.02). Cause of death was anoxic brain injury in 78%, cardiovascular failure in 18% and multi-organ failure in 4%. The hemodynamic changes of TH reversed at normothermia, although the requirement for vasopressor support (cardiovascular SOFA≥3) persisted in 80% of patients. CONCLUSIONS In survivors after OHCA treated with TH the induced hemodynamic changes reversed after normothermia, while the need for vasopressor support persisted. Patients requiring addition of norepinephrine/epinephrine on top of dopamine had an increased 30-day all-cause mortality, as well as death from neurological injury.

Impact of time to return of spontaneous circulation on neuroprotective effect of targeted temperature management at 33 or 36 degrees in comatose survivors of out-of hospital cardiac arrest.

AIM Time to Return of Spontaneous Circulation (ROSC) has a plausible relation to severity of hypoxic injury before and during resuscitation in Out-of-Hospital Cardiac Arrest (OHCA), and has consistently been associated with adverse outcome. The effect of Targeted Temperature Management (TTM) may not be similar over the full spectrum of time to ROSC. This study investigated the possible beneficial effect of targeting 33°C over 36°C on the prognostic importance of time to ROSC. METHODS In predefined sub-study of the TTM-trial (NEJM 2013) we investigated the relationship between time to ROSC, level of TTM and mortality and neurological outcome as assessed by the Cerebral Performance Category (CPC) scale and modified Rankin Scale (mRS) after 180 days. RESULTS Prolonged time to ROSC was significantly associated with increased mortality with a hazard ratio (HR) of 1.02 per minute (95% CI 1.01-1.02). Level of TTM did not modify the association of time to ROSC and mortality, pinteraction=0.85. Prolonged time to ROSC was associated with reduced odds of surviving with a favorable neurological outcome for CPC (p=0.008 for CPC 1-2) and mRS (p=0.17, mRS 0-3) with no significant interaction with level of TTM. CONCLUSION Time to ROSC remains a significant prognostic factor in comatose OHCA patients with regards to risk of death and risk of adverse neurological outcome. For any time to ROSC, targeting 33°C in TTM was not associated with benefit with regards to reducing mortality or risk of adverse neurological outcome compared to targeting 36°C.

Resuscitation and post resuscitation care of the very old after out-of-hospital cardiac arrest is worthwhile

BACKGROUND Out-of-hospital cardiac arrest (OHCA) is associated with a poor prognosis. As comorbidity and frailty increase with age; ethical dilemmas may arise when OHCA occur in the very old. OBJECTIVES We aimed to investigate mortality, neurological outcome and post resuscitation care in octogenarians (≥80) to assess whether resuscitation and post resuscitation care should be avoided. METHODS During 2007-2011 consecutive OHCA-patients were attended by the physician-based Emergency Medical Services-system in Copenhagen. Pre-hospital data based on Utstein-criteria, and data on post resuscitation care were collected. Primary outcome was successful resuscitation; secondary endpoints were 30-day mortality and neurological outcome (Cerebral Performance Category (CPC)). RESULTS 2509 OHCA-patients with attempted resuscitation were recorded, 22% (n=558) were octogenarians/nonagenarians. 166 (30% of all octogenarians with resuscitation attempted) octogenarians were successfully resuscitated compared to 830 (43% with resuscitation attempted) patients <80 years. 30-day mortality in octogenarians was significantly higher after adjustment for prognostic factors (HR=1.61 CI: 1.22-2.13, p<0.001). Octogenarians received fewer coronary angiographies (CAG) (14 vs. 37%, p<0.001), and had lower odds of receiving CAG by multivariate logistic regression (OR: 0.19, CI: 0.08-0.44, p<0.001). A favorable neurological outcome (CPC 1/2) in survivors to discharge was found in 70% (n=26) of octogenarians compared to 86% (n=317, p=0.03) in the younger patients. CONCLUSION OHCA in octogenarians was associated with a significantly higher mortality rate after adjustment for prognostic factors. However, the majority of octogenarian survivors were discharged with a favorable neurological outcome. Withholding resuscitation and post resuscitation care in octogenarians does not seem justified.

Bradycardia During Targeted Temperature Management: An Early Marker of Lower Mortality and Favorable Neurologic Outcome in Comatose Out-of-Hospital Cardiac Arrest Patients.

Objectives:Bradycardia is common during targeted temperature management, likely being a physiologic response to lower body temperature, and has recently been associated with favorable outcome following out-of-hospital cardiac arrest in smaller observational studies. The present study sought to confirm this finding in a large multicenter cohort of patients treated with targeted temperature management at 33°C and explore the response to targeted temperature management targeting 36°C. Design:Post hoc analysis of a prospective randomized study. Setting:Thirty-six ICUs in 10 countries. Patients:We studied 447 (targeted temperature management = 33°C) and 430 (targeted temperature management = 36°C) comatose out-of-hospital cardiac arrest patients with available heart rate data, randomly assigned in the targeted temperature management trial from 2010 to 2013. Interventions:Targeted temperature management at 33°C and 36°C. Measurements and Main Results:Endpoints were 180-day mortality and unfavorable neurologic function (cerebral performance category 3–5). Patients were stratified by target temperature and minimum heart rate during targeted temperature management (< 50, 50–59, and ≥ 60 beats/min [reference]) at 12, 20, and 28 hours after randomization. Heart rates less than 50 beats/min and 50–59 beats/min were recorded in 132 (30%) and 131 (29%) of the 33°C group, respectively. Crude 180-day mortality increased with increasing minimum heart rate (< 50 beats/min = 32%, 50–59 beats/min = 43%, and ≥ 60 beats/min = 60%; plog-rank < 0.0001). Bradycardia less than 50 beats/min was independently associated with lower 180-day mortality (hazard ratioadjusted = 0.50 [0.34–0.74; p < 0.001]) and lower odds of unfavorable neurologic outcome (odds ratioadjusted = 0.38 [ 0.21–0.68; p < 0.01]) in models adjusting for potential confounders including age, initial rhythm, time to return of spontaneous circulation, and lactate at admission. Similar, albeit less strong, independent associations of lower heart rates and favorable outcome were found in patients treated with targeted temperature management at 36°C. Conclusions:This study confirms an independent association of bradycardia and lower mortality and favorable neurologic outcome in a large cohort of comatose out-of-hospital cardiac arrest patients treated by targeted temperature management at 33°C. Bradycardia during targeted temperature management at 33°C may thus be a novel, early marker of favorable outcome.