Effect of Austrian COVID-19 lockdowns on acute myocardial infarction frequency and long-term mortality: a multicentre observational study

OBJECTIVES

The aim of this study was to find out if the decrease in acute myocardial infarction (AMI) admissions during the first COVID-19 lockdowns (LD), which was described by previous studies, occurred equally in all LD periods (LD1, LD2, LD2021), which had identical restrictions. Further, we wanted to analyse if the decrease of AMI admission had any association with the 1-year mortality rate.

DESIGN AND SETTING

This study is a prospective observational study of two centres that are participating in the Vienna ST-elevation myocardial infarction network.

PARTICIPANTS

A total of 1732 patients who presented with AMI according to the 4th universal definition of myocardial infarction in 2019, 2020 and the LD period of 2021 were included in our study. Patients with myocardial infarction with non-obstructive coronary arteries were excluded from our study.

MAIN OUTCOME MEASURES

The primary outcome of this study was the frequency of AMI during the LD periods and the all-cause and cardiac-cause 1-year mortality rate of 2019 (pre-COVID-19) and 2020.

RESULTS

Out of 1732 patients, 70% (n=1205) were male and median age was 64 years. There was a decrease in AMI admissions of 55% in LD1, 28% in LD2 and 17% in LD2021 compared with 2019.There were no differences in all-cause 1-year mortality between the year 2019 (11%; n=110) and 2020 (11%; n=79; p=0.92) or death by cardiac causes [10% (n=97) 2019 vs 10% (n=71) 2020; p=0.983].

CONCLUSION

All LDs showed a decrease in AMI admissions, though not to the same extent, even though the regulatory measures were equal. Admission in an LD period was not associated with cardiac or all-cause 1-year mortality rate in AMI patients in our study.

On detection of spontaneous pulse by photoplethysmography in cardiopulmonary resuscitation

OBJECTIVE

This work investigates the potential of photoplethysmography (PPG) to detect a spontaneous pulse from the finger, nose or ear in order to support pulse checks during cardiopulmonary resuscitation (CPR).

METHODS

In a prospective single-center cross-sectional study, PPG signals were acquired from cardiac arrest victims who underwent CPR. The PPG signals were analyzed and compared to arterial blood pressure (ABP) signals as a reference during three distranaisco; Date: 2/2/2020; Time:18:44:23inct phases of CPR: compression pauses, on-going compressions and at very low arterial blood pressure. Data analysis was based on a qualitative subjective visual description of similarities of the frequency content of PPG and ABP waveform.

RESULTS

In 9 patients PPG waveforms corresponded to ABP waveforms during normal blood pressures. During ABP in the clinically challenging range of 60 to 90 mmHg and during chest compressions and pauses, PPG continued to resemble ABP, as both signals showed similar frequency components as a result of chest compressions as well as cardiac activity. Altogether 1199 s of PPG data in compression pauses were expected to show a spontaneous pulse, of which 732 s (61%) of data were artifact-free and showed the spontaneous pulse as visible in the ABP.

CONCLUSIONS

PPG signals at all investigated sites can indicate pulse presence at the moment the heart resumes beating as verified via the ABP signal. Therefore, PPG may provide decision support during CPR, especially related to preventing and shortening interruptions for unnecessary pulse checks. This could have impact on CPR outcome and should further be investigated.

Age-dependent effect of targeted temperature management on outcome after cardiac arrest

BACKGROUND

In elder patients after out-of-hospital cardiac arrest, diminished neurologic function as well as reduced neuronal plasticity may cause a low response to targeted temperature management (TTM). Therefore, we investigated the association between TTM (32-34°C) and neurologic outcome in cardiac arrest survivors with respect to age.

MATERIAL AND METHODS

This retrospective cohort study included patients 18 years of age or older suffering a witnessed out-of-hospital cardiac arrest with presumed cardiac cause, which remained comatose after return of spontaneous circulation. Patients were a priori split by age into four groups (<50 years (n = 496); 50-64 years (n = 714); 65-74 years (n = 395); >75 years (n = 280)). Subsequently, within these groups, patients receiving TTM were compared to those not treated with TTM.

RESULTS

Out of 1885 patients, 921 received TTM for 24 hours. TTM was significantly associated with good neurologic outcome in patients <65 years of age whereas showing no effect in elders (65-74 years: OR: 1.49 (95% CI: 0.90-2.47); > 75 years: OR 1.44 (95% CI 0.79-2.34)).

CONCLUSION

In our cohort, it seems that TTM might not be able to achieve the same benefit for neurologic outcome in all age groups. Although the results of this study should be interpreted with caution, TTM was associated with improved neurologic outcome only in younger individuals, patients with 65 years of age or older did not benefit from this treatment.

Outcome of in- and out-of-hospital cardiac arrest survivors with liver cirrhosis

Background

Organ failure increases mortality in patients with liver cirrhosis. Data about resuscitated cardiac arrest patients with liver cirrhosis are missing. This study aims to assess aetiology, survival and functional outcome in patients after successful cardiopulmonary resuscitation (CPR) with and without liver cirrhosis.

Methods

Analysis of prospectively collected cardiac arrest registry data of consecutively hospital-admitted patients following successful CPR was performed. Patient’s characteristics, admission diagnosis, severity of disease, course of disease, short- and long-term mortality as well as functional outcome were assessed and compared between patients with and without cirrhosis.

Results

Out of 1068 patients with successful CPR, 47 (4%) had liver cirrhosis. Acute-on-chronic liver failure (ACLF) was present in 33 (70%) of these patients on admission, and four patients developed ACLF during follow-up. Mortality at 1 year was more than threefold increased in patients with liver cirrhosis (OR 3.25; 95% CI 1.33–7.96). Liver cirrhosis was associated with impaired neurological outcome (OR for a favourable cerebral performance category: 0.13; 95% CI 0.04–0.36). None of the patients with Child–Turcotte–Pugh (CTP) C cirrhosis survived 28 days with good neurological outcome. Overall nine (19%) patients with cirrhosis survived 28 days with good neurological outcome. All patients with ACLF grade 3 died within 28 days.

Conclusion

Cardiac arrest survivors with cirrhosis have worse outcome than those without. Although one quarter of patients with liver cirrhosis survived longer than 28 days after successful CPR, patients with CTP C as well as advanced ACLF did not survive 28 days with good neurological outcome.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-017-0322-1) contains supplementary material, which is available to authorized users.

Improvements in the quality of advanced life support and patient outcome after implementation of a standardized real-life post-resuscitation feedback system

BACKGROUND

Educational aspects in the training of advanced life support (ALS) represent a key role in critical care management of patients with out-of-hospital cardiac arrest (OHCA) and received special attention in guidelines of various international societies. While a positive association of feedback on ALS performance in training conditions is well established, data on the impact of a real-life post-resuscitation feedback on both ALS quality and outcome remain scarce and inconclusive. We aimed to elucidate the impact of a standardized post-resuscitation feedback on quality of ALS and improvements in patient outcome, in a real-life out-of-hospital setting.

METHODS

We prospectively enrolled and analyzed 2209 patients presenting with OHCA receiving resuscitation attempts by the municipal emergency medical service (EMS) of Vienna over a two-year period. A standardized post-resuscitation feedback protocol was delivered to the respective EMS-team to elucidate its impact on the quality of ALS.

RESULTS

We observed that both chest compression rates and ratios were in accordance to recommendations of recent guidelines. While interruptions of chest compressions longer than 30s declined during the observation period (-6.5%) rates of the recommended chest compressions during defibrillator-charging periods increased (+8.9%). Since the percentage of ROSC and 30-day survival remained balanced, the frequencies of both survival until hospital discharge (+6.3%) and favorable neurological outcome (+16%) in survivors significantly increased during the observation period.

CONCLUSION

Improvements in the quality of advanced life support as well the patient outcome were observed after the implementation of a standardized post-resuscitation feedback protocol.

Non-occlusive mesenteric ischaemia in out of hospital cardiac arrest survivors

BACKGROUND AND AIM OF THE STUDY

Non-occlusive mesenteric ischaemia (NOMI) is characterised by hypoperfusion of the intestines without evidence of mechanical obstruction, potentially leading to extensive ischaemia and necrosis. Low cardiac output appears to be a major risk factor. Cardiopulmonary resuscitation aims at restoring blood flow after cardiac arrest. However, post restoration of spontaneous circulation, myocardial stunning limits immediate recovery of sufficient cardiac function. Since after successful cardiopulmonary resuscitation patients are often ventilated and sedated, NOMI might be underdiagnosed and potentially life-saving treatment delayed.

MATERIAL AND METHODS

A prospectively maintained multi-purpose cohort of out of hospital cardiac arrest survivors, who had successful restoration of spontaneous circulation, was used for this retrospective database analysis. Patients' charts were screened for clinical, radiological or pathological evidence of NOMI and clinical data were collected.

RESULTS

Between 2000 and 2014, 1780 patients who were successfully resuscitated after out of hospital cardiac arrest were screened for NOMI. Twelve patients (0.68 %) suffered from NOMI and six of those died (50 %). Patients suffering from NOMI tended to have a longer duration until restoration of spontaneous circulation (27 vs. 20 min, p=0.128) and had significantly higher lactate (14 mmol/l vs. 8 mmol/l, p=0.002) and base deficit levels at admission (-17 vs. -10, p=0.012). Median leukocyte counts in NOMI patients peaked at the day of diagnosis.

CONCLUSION

NOMI is a rare but life-threatening and potentially curable complication following successful cardiopulmonary resuscitation. Lactate and base deficit at admission could help to identify patients at risk for developing NOMI who might benefit from increased clinical attention.

The effect of percutaneous coronary intervention in patients suffering from ST-segment elevation myocardial infarction complicated by out-of-hospital cardiac arrest on 30 days survival

AIM OF THE STUDY

To question the beneficial effects of the recommended early percutaneous coronary intervention (PCI) after out-of-hospital cardiac arrest on 30-day survival with favourable neurological outcome.

METHODS

Prospectively collected data of 1277 out of hospital cardiac arrest patients between 2005 and 2010 from a registry at a tertiary care university hospital were used for a cohort study.

RESULTS

In 494 (39%) arrest patients ST-segment elevation was identified in 249 (19%). Within 12h after restoration of spontaneous circulation catheter laboratory investigations were initiated in 197 (79%) and PCI in 183 (93%) (78% got PCI in less than 180 min). Adjustment for a cumulative time without chest compressions <2 min, initial shockable rhythm, cardiac arrest witnessed by healthcare professionals, and a higher core temperature at time of hospitalization reduced the effect of PCI on favourable neurological outcome at 30 days (OR 1.40; 95% CI, 0.53-3.7) compared to the univariate analysis (OR 2.52; 95% CI, 1.42-4.48).

CONCLUSION

This cohort study failed to demonstrate the beneficial effects of PCI as part of post-resuscitation care on 30-day survival with a favourable neurological outcome.

The beneficial effect of mild therapeutic hypothermia depends on the time of complete circulatory standstill in patients with cardiac arrest

AIM

Mild therapeutic hypothermia has shown to improve long-time survival as well as favorable functional outcome after cardiac arrest. Animal models suggest that ischemic durations beyond 8 min results in progressively worse neurologic deficits. Based on these considerations, it would be obvious that cardiac arrest survivors would benefit most from mild therapeutic hypothermia if they have reached a complete circulatory standstill of more than 8 min.

METHODS

In this retrospective cohort study we included cardiac arrest survivors of 18 years of age or older suffering a witnessed out-of-hospital cardiac arrest, which remain comatose after restoration of spontaneous circulation. Data were collected from 1992 to 2010. We investigated the interaction of 'no-flow' time on the association between post arrest mild therapeutic hypothermia and good neurological outcome. 'No-flow' time was categorized into time quartiles (0, 1-2, 3-8, >8 min).

RESULTS

One thousand-two-hundred patients were analyzed. Hypothermia was induced in 598 patients. In spite of showing a statistically significant improvement in favorable neurologic outcome in all patients treated with mild therapeutic hypothermia (odds ratio [OR]: 1.49; 95% confidence interval [CI]: 1.14-1.93) this effect varies with 'no-flow' time. The effect is significant in patients with 'no-flow' times of more than 2 min (OR: 2.72; CI: 1.35-5.48) with the maximum benefit in those with 'no-flow' times beyond 8 min (OR: 6.15; CI: 2.23-16.99).

CONCLUSION

The beneficial effect of mild therapeutic hypothermia increases with cumulative time of complete circulatory standstill in patients with witnessed out-of-hospital cardiac arrest.

Post-resuscitation care at the emergency department with critical care facilities--a length-of-stay analysis

AIM OF THE STUDY

An emergency department providing critical care will have an effect on outcome and intensive-care-units' resources by avoiding unnecessary or futile intensive-care admissions and thereby save hospital expenses. The study focussed on this result.

METHODS

The study employed a retrospective analysis of prospectively collected data of out-of-hospital cardiac arrest patients with return of spontaneous circulation, comatose on arrival. Outcomes and length of stay of patients who either stayed at the 'emergency department only' or were 'transferred in addition to an intensive care unit' were compared. Linear regression with log length of stay as outcome and 'emergency department only' as predictor with covariates was used for modelling.

RESULTS

From 1991 to 2008, out of 1236 patients (age 57 ± 15 years, female 31%), the 'emergency department only' group (n=349 (28%)) survived to discharge in 81(23%) cases, with a median length-of-stay in critical care of 1.7 (interquartile range 0.8; 3.1) days. The patients 'transferred in addition to an intensive care unit' (n=887 (72%)), with a survival rate of 55% (n=486, p<0.001) stayed 10 (5; 18) days (p<0.001). The length-of-stay in hospital was significantly shorter if patients were treated in the 'emergency department only' independent of other cardiac-arrest-related factors (regression coefficient -1.42, confidence interval -1.60 to -1.24).

CONCLUSIONS

An emergency department with critical care prevents admissions to intensive care units in 28% of patients with out-of-hospital cardiac arrest. It saves intensive-care-unit resources and shortens length of stay for comatose out-of-hospital cardiac-arrest survivors, regardless of their outcome.