The quality of care and long-term mortality of out of hospital cardiac arrest survivors after acute myocardial infarction: a nationwide cohort study

BACKGROUND

The long-terms outcomes of out of hospital cardiac arrest (OHCA) survivors are not well known.

METHODS

Using the Myocardial Ischaemia National Audit Project (MINAP) registry, linked to Office for National Statistics (ONS) mortality data, we analysed 661 326 England, Wales and Northern-Ireland AMI patients; 14 127 (2%) suffered OHCA and survived beyond thirty-days of hospitalisation. Patients dying within thirty-days of admission were excluded. Mean follow-up for patients included was 1 500 days. Cox regression models were fitted, adjusting for demographics and management strategy.

RESULTS

OHCA survivors were younger (in years) (64 (interquartile range [IQR] 54-72) vs. 70 (IQR 59-80), P < 0.001), more often underwent invasive coronary angiography (88% vs. 71%, P < 0.001) and percutaneous coronary intervention (72% vs. 45%, P < 0.001). Overall, risk of mortality for OHCA patients that survived past 30-days was lower than patients that did not suffer cardiac arrest (adjusted hazard ratio [HR] 0.91; 95% CI; 0.87-0.95, P < 0.001). 'Excellent care' according to the mean opportunity-based quality indicator (OBQI) score compared to 'Poor care', predicted reduced risk of long-term mortality post OHCA, for all-patients (HR: 0.77, CI; 0.76-0.78, P < 0.001), more for STEMI patients (HR: 0.73, CI; 0.71-0.75, P < 0.001), but less significantly in NSTEMI patients (HR: 0.79, CI; 0.78-0.81, P < 0.001).

CONCLUSIONS

Out of hospital cardiac arrest (OHCA) patients remain at significant risk of mortality in-hospital. However, if surviving over thirty-days post arrest, OHCA survivors have good longer-term survival up to ten-years compared to the general AMI population. Higher quality inpatient care appears to improve long-term survival in all OHCA patients, more so in STEMI.

The incidence and outcomes of out-of-hospital cardiac arrest in metropolitan versus rural locations: A systematic review and meta-analysis

BACKGROUND/AIMS

Rurality poses a unique challenge to the management of out-of-hospital cardiac arrest (OHCA) when compared to metropolitan (metro) locations. We conducted a systematic review of published literature to understand how OHCA incidence, management and survival outcomes vary between metro and rural areas.

METHODS

We included studies comparing the incidence or survival of ambulance attended OHCA in metropolitan and rural areas, from a search of five databases from inception until 9th March 2022. The primary outcomes of interest were cumulative incidence and survival (return of spontaneous circulation, survival to hospital discharge (or survival to 30 days)). Meta-analyses of OHCA survival were undertaken.

RESULTS

We identified 28 studies (30 papers- total of 823,253 patients) across 13 countries of origin. The definition of rurality varied markedly. There was no clear difference in OHCA incidence between metro and rural locations. Whilst there was considerable statistical heterogeneity between studies, the likelihood of return of spontaneous circulation on arrival at hospital was lower in rural than metro locations (OR = 0.53, 95% CI 0.40, 0.70; I² = 89%; 5 studies; 90,934 participants), as was survival to hospital discharge/survival to 30 days (OR = 0.52, 95% CI 0.38, 0.71; I² = 95%; 15 studies; 18,837 participants).

CONCLUSIONS

Overall, while incidence did not vary, the odds of OHCA survival to hospital discharge were approximately 50% lower in rural areas compared to metro areas. This suggests an opportunity for improvement in the prehospital management of OHCA within rural locations. This review also highlighted major challenges in standardising the definition of rurality in the context of cardiac arrest research.

Prolonged targeted temperature management reduces memory retrieval deficits six months post-cardiac arrest: A randomised controlled trial

BACKGROUND

Cognitive sequelae, most frequently memory, attention, and executive dysfunctions, occur commonly in out-of-hospital cardiac arrest (OHCA) survivors. Targeted temperature management (TTM) following OHCA is associated with improved cognitive function. However, the relationship between the duration of TTM and cognitive outcome remains unclear. We hypothesised that OHCA survivors that were subjected to prolonged TTM of 48 h (TTM48) would exhibit better cognitive functions compared to those subjected to standard TTM of 24 h (TTM24) six months post-OHCA.

METHODS

A predefined, cognitive post-hoc sub-study was conducted on the multicentre clinical trial: "Target Temperature Management for 48 vs. 24 h and Neurologic Outcome after out-of-hospital cardiac arrest: A Randomised Clinical Trial" (the TTH48 trial). OHCA survivors with perceived good cognitive outcome (CPC score ≤ 2) were invited to a neuropsychological assessment of memory, attention, and executive functions six months post-OHCA.

RESULTS

In total, 79 patients were included in the study. Multivariate regression analysis revealed that TTM48 was associated with a significant better performance on three of 13 cognitive tests specific to memory retrieval after adjusting for age at follow-up and time to return of spontaneous circulation. Overall, patients in the TTM24 group were almost three times more likely (RR = 2.9 (95% CI 1.1-7.4)), p = 0.02) to be cognitively impaired.

CONCLUSIONS

This study reports an association between the duration of TTM and cognitive outcome. In OHCA survivors with perceived good cognitive outcome (CPC ≤ 2), TTM48 was associated with reduced memory retrieval deficits and lower relative risk of cognitive impairment six months after OHCA compared to standard TTM24. ClinicalTrials.gov (identifier: NCT01689077).