A practical risk score for early prediction of neurological outcome after out-of-hospital cardiac arrest: MIRACLE2.

AIMS: The purpose of this study was to develop a practical risk score to predict poor neurological outcome after out-of-hospital cardiac arrest (OOHCA) for use on arrival to a Heart Attack Centre. METHODS AND RESULTS: From May 2012 to December 2017, 1055 patients had OOHCA in our region, of whom 373 patients were included in the King's Out of Hospital Cardiac Arrest Registry (KOCAR). We performed prediction modelling with multivariable logistic regression to identify predictors of the primary outcome to derive a risk score. This was externally validated in two independent cohorts comprising 473 patients. The primary endpoint was poor neurological outcome at 6-month follow-up (Cerebral Performance Category 3-5). Seven independent predictors of outcome were identified: missed (unwitnessed) arrest, initial non-shockable rhythm, non-reactivity of pupils, age (60-80 years-1 point; >80 years-3 points), changing intra-arrest rhythms, low pH <7.20, and epinephrine administration (2 points). The MIRACLE2 score had an area under the curve (AUC) of 0.90 in the development and 0.84/0.91 in the validation cohorts. Three risk groups were defined-low risk (MIRACLE2 ≤2-5.6% risk of poor outcome); intermediate risk (MIRACLE2 of 3-4-55.4% of poor outcome); and high risk (MIRACLE2 ≥5-92.3% risk of poor outcome). The MIRACLE2 score had superior discrimination than the OHCA [median AUC 0.83 (0.818-0.840); P < 0.001] and Cardiac Arrest Hospital Prognosis models [median AUC 0.87 (0.860-0.870; P = 0.001] and equivalent performance with the Target Temperature Management score [median AUC 0.88 (0.876-0.887); P = 0.092]. CONCLUSIONS: The MIRACLE2 is a practical risk score for early accurate prediction of poor neurological outcome after OOHCA, which has been developed for simplicity of use on admission.

Outcome of conscious survivors of out-of-hospital cardiac arrest.

AIM: Only up to 20% of patients with out-of-hospital cardiac arrest (OHCA) receive immediate and optimal initial cardiac resuscitation and consequently regain consciousness soon after return of spontaneous circulation (ROSC). In the present study, we compared the outcome of conscious survivors of OHCA presenting with ST-elevation myocardial infarction (STEMI) in post-resuscitation electrocardiogram undergoing immediate invasive coronary strategy with randomly selected STEMI patients without preceding OHCA undergoing primary PCI. METHODS: We conducted a single-centre registry-based analysis of all conscious OHCA survivors with STEMI over the last 10 year period. We gathered clinical and angiographic data and compared them with a randomly selected cohort of non-OHCA patients with STEMI within the same period. Patients were matched by sex, age and STEMI location. RESULTS: 86 conscious survivors of OHCA were admitted between 2006 and 2016. OHCA was witnessed in all patients (85% EMS witnessed), and all patients presented with initial shockable rhythm. Clinical and angiographic features were well matched with randomly selected STEMI patients without OHCA presenting to our department within the same study period. Delay from symptoms to EMS arrival but not delay from EMS to PCI was significantly shorter in conscious OHCA survivors (1.2 ± 1.3 h vs 3.1 ± 3.8 h, p < 0.001), yielding decreased total myocardial ischemic time (2.6 ± 1.3 h vs 4.6 ± 4.0 h, p < 0.001). Hospital and 1-year survival with normal neurological condition in conscious survivors of OHCA (cerebral performance category 1) was excellent and numerically even better than survival of STEMI patients without OHCA. CONCLUSION: Conscious survivors of OHCA with STEMI have excellent survival if they undergo immediate invasive coronary strategy. Since there is no obvious post-resuscitation brain injury in this subgroup of OHCA patients, it is probably shorter duration of myocardial ischemia driven by shorter delay from symptoms to EMS arrival that contributes to the good outcome, which is at least similar to STEMI patients without OHCA.

Acute ST-elevation myocardial infarction after successful cardiopulmonary resuscitation.

After successful cardiopulmonary resuscitation, acute ST-elevation myocardial infarction (STEMI) may be documented. We investigated the incidence and prognosis of patients admitted to our department between 1 January 2000 and 31 December 2004. Among 2393 consecutive patients with STEMI, 135 (5.7%) presented after a return of spontaneous circulation (ROSC). Forty-nine patients (36%) regained consciousness and 86 patients (64%) remained unconscious during initial evaluation. The delay from collapse to advanced cardiac life support (ACLS) was longer in comatose patients (5.8 min versus 0.5 min; p<0.01) in those with a lower proportion of shockable rhythm (76% versus 96%; p<0.01) and in those with a less favourable course of ACLS were also documented. Primary percutaneous coronary intervention (PCI) was performed in all but one conscious patient with success rate (96% versus 94%; p=0.63) and hospital survival without neurological deficit (100% versus 94.8%; p=0.20) comparable to patients without cardiac arrest. In comatose patients, primary PCI was performed in 79% with a somewhat lower success rate (82%, p=0.21). Mechanical ventilation, haemodynamic support, haemodialysis and antimicrobial agents were used more frequently in comatose patients. Hospital survival among comatose patients was 51% and hospital survival with cerebral performance category (CPC) 1 or 2 was 29%. Accordingly, outcome of patients with STEMI who regain consciousness after ROSC and undergo primary PCI is comparable to patients without cardiac arrest. This is in contrast with comatose survivors who, despite aggressive reperfusion treatment, had a significantly worse outcome.

Impact of intensified postresuscitation treatment on outcome of comatose survivors of out-of-hospital cardiac arrest according to initial rhythm.

AIM: We investigated the impact of intensified postresuscitation treatment in comatose survivors of out-of-hospital cardiac arrest (OHCA) of presumed cardiac etiology according to the initial rhythm at the emergency medical team arrival. METHODS: Interventions and survival with Cerebral Performance Category (CPC) 1-2 within each group were retrospectively compared between the periods of conservative (1995-2003) and intensified (2004-2012) postresuscitation treatment. RESULTS: In shockable group, therapeutic hypothermia (TH) increased from 1 to 93%, immediate invasive coronary strategy from 28 to 78%, intraaortic balloon pump from 4 to 21%, vasopressors/inotropes from 47 to 81% and antimicrobial agents from 65 to 86% during the intensified period as compared to conservative period (p<0.001). This was associated with increased survival with CPC 1-2 from 27 to 47% (p<0.001). After adjusting for age, sex and prehospital confounders, TH (OR=2.12, 95% CI 1.25-3.61), percutaneous coronary intervention (OR 1.77, 95% CI 1.15-2.73) and antimicrobial agents (OR=12.21, 95% CI 5.13-29.08) remained associated with survival with CPC 1-2. In non-shockable patients, TH also significantly increased from 1 to 74%, immediate invasive coronary strategy from 8 to 51%, intraaortic balloon pump from 2 to 9% and vasopressors/inotropes from 56 to 84% during intensified period without concomitant increase in survival with CPC 1-2 (7% vs. 9%; p=0.27). After adjustment, only antimicrobial agents (OR=8.43, 95% CI: 1.05-67.72) remained associated with survival with CPC 1-2. CONCLUSION: Intensified postresuscitation treatment was associated with doubled survival in comatose survivors of OHCA with shockable rhythm. Such association could not be demonstrated in patients with non-shockable rhythm.

Irregularity test for very short electrocardiogram (ECG) signals as a method for predicting a successful defibrillation in patients with ventricular fibrillation.

A significant proportion of patients with ventricular fibrillation (VF) can only be defibrillated after a period of chest compressions and ventilation before the defibrillation attempt. In these patients, unsuccessful defibrillations increase the duration of heart arrest and reduce the possibility of a successful resuscitation, which could be avoided if a reliable prediction for the success of defibrillation could be made. A new method is presented for estimating the irregularity in very short electrocardiographic (ECG) recordings that enables the prediction of a successful defibrillation in patients with VF. This method is based on a recently developed determinism test for very short time series. A slight modification shows that the method can be used to determine relative differences in irregularity of the studied signals. In particular, ECG recordings of VF from patients who could be successfully defibrillated are characterized by a higher level of irregularity, indicating a chaotic nature of the dynamics of the heart, which is in agreement with previous studies on long ECG recordings showing that cardiac chaos was prevalent in healthy heart, whereas in severe congestive heart failure, a decrease in the chaotic behavior was observed.