Trends in clinical outcomes and survival following prehospital thrombolytic therapy given by ambulance clinicians for ST-elevation myocardial infarction in rural sub-arctic Norway

Informing Utstein-style reporting guidelines for prehospital thrombolysis: A scoping review

BACKGROUND

Rural Australians with acute myocardial infarction (AMI) face higher mortality rates due to limited access to specialised cardiac services. Paramedic-administered prehospital thrombolysis (PHT) has emerged as an alternative to primary percutaneous intervention (pPCI) for patients facing barriers or delays to cardiac care. There is variability in PHT practices among Australian ambulance services, lacking standardised definitions and outcome measures. The aim of this scoping review was to identify quality indicators and influencing factors associated with outcomes for patients receiving PHT.

METHODS

A systematic search of literature in SCOPUS and Academic Search Complete, CINAHL and Health Source: Nursing/Academic Edition databases via EBSCO (Health) was conducted following the Joanna Briggs Institute methodology. Peer-reviewed studies from the past decade were screened using search criteria relevant to prehospital thrombolysis and quality indicators. Data extraction was performed and themed using five domains from the Utstein-style template commonly known for standardised prehospital cardiac arrest reporting.

RESULTS

After removing duplicates, the search yielded 3596 articles with 28 empirical studies meeting inclusion criteria for the review. These were primarily retrospective cohort studies performed in Australia, Canada and the United States. The scoping review identified 24 clinical quality indicators and factors related to Emergency Medical Service (EMS) systems, AMI recognition and ambulance dispatch, patient variables, PHT processes and patient outcomes. These findings correlate to the Donabedian structure-process-outcome quality of care model and have utility to inform future PHT reporting guidelines for jurisdictional ambulance services.

CONCLUSIONS

Given the variability in prehospital practice across Australian ambulance services, standardised reporting on quality indicators for PHT is needed. The Utstein-style template used to report data on pre-hospital cardiac arrest, trauma and airway management could be used for quality improvement in PHT. This review presents 24 quality indicators representing system, recognition and response, patient, process, and outcomes related to PHT. These results could be used to inform a future Delphi study and Utstein-like reporting guideline for prehospital thrombolysis.

Exploring variation in timely reperfusion treatment in ST-segment elevation myocardial infarction in Norway: a national register-based cohort study

OBJECTIVES

This study aimed to investigate determinants of reperfusion within recommended time limits (timely reperfusion) for ST-segment elevation myocardial infarction patients, exploring the impact of geography, patient characteristics and socio-economy.

DESIGN

National register-based cohort study.

SETTING

Multilevel logistic regression models were applied to examine the associations between timely reperfusion and residency in hospital referral areas and municipalities, patient characteristics, and socio-economy.

PARTICIPANTS

7607 Norwegian ST-segment elevation myocardial infarction patients registered in the Norwegian Registry of Myocardial Infarction during 2015-2018.

MAIN OUTCOME MEASURES

The odds of timely reperfusion by primary percutaneous coronary intervention (PCI) or fibrinolysis.

RESULTS

Among 7607 ST-segment elevation myocardial infarction patients in Norway, 56% received timely reperfusion. The Norwegian goal is 85%. While 81% of the patients living in the Oslo hospital referral area received timely reperfusion, only 13% of the patients living in Finnmark did so.Patients aged 75-84 years had lower odds of timely reperfusion than patients below 55 years of age (OR 0.73, 95% CI 0.61 to 0.87). Patients with moderate or high comorbidity had lower odds than patients without (OR 0.81, 95% CI 0.68 to 0.95 and OR 0.61, 95% CI 0.44 to 0.84). More than 2 hours from symptom onset to first medical contact gave lower odds than less than 30 min (OR 0.63, 95% CI 0.54 to 0.72). 1-2 hours of travel time to a PCI centre (OR 0.39, 95% CI 0.31 to 0.49) and more than 2 hours (OR 0.22, 95% CI 0.16 to 0.30) gave substantially lower odds than less than 1 hour of travel time.

CONCLUSIONS

The varying proportion of patients receiving timely reperfusion across hospital referral areas implies inequity in fundamental healthcare services, not compatible with established Norwegian health policy. The importance of travel time to PCI centre points at the expanded use of prehospital pharmacoinvasive strategy to obtain the goals of timely reperfusion in Norway.

Survival in Patients with Paramedic-Identified ST-Segment Elevation Myocardial Infarction

BACKGROUND

Field identification and treatment of ST-segment elevation myocardial infarction (STEMI) by paramedics is an important component of care for these patients. There is a paucity of studies in the setting of paramedic-identified STEMI. This study investigated mortality and factors associated with mortality in a large state-wide prehospital STEMI sample. Methods: Included were adult STEMI patients identified and treated with reperfusion therapy by paramedics in the field between January 2016 and December 2018 in Queensland, Australia. 30-day and one-year all-cause mortality was compared between two prehospital reperfusion pathways: prehospital fibrinolysis versus direct referral to a hospital for primary percutaneous coronary intervention (direct percutaneous coronary intervention [PCI] referral). For prehospital fibrinolysis patients, factors associated with failed fibrinolysis were investigated. For direct PCI referral patients, factors associated with mortality were examined. Results: The 30-day mortality was 2.2% for prehospital fibrinolysis group and 1.8% for direct PCI referral group (p = 0.661). One-year mortality for the two groups was 2.7% and 3.2%, respectively (p = 0.732). Failed prehospital fibrinolysis was observed in 20.1% of patients receiving this therapy, with male gender and history of heart failure being predictors. For direct PCI referral group, low left ventricular ejection fraction (LVEF) on admission and cardiogenic shock prior to PCI were predictors of both 30-day and one-year mortality. Aboriginal and Torres Strait Islander status, and impaired kidney function on admission, were associated with one-year but not 30-day mortality. Being overweight was associated with lower 30-day mortality. Conclusions: Mortality in STEMI patients identified and treated by paramedics was low, and the prehospital fibrinolysis treatment pathway was effective with a mortality rate comparable to that of patients undergoing primary PCI. Key words: prehospital; Queensland; cardiac reperfusion; STEMI.

Predictive value of high sensitivity C-reactive protein on progression to heart failure occurring after the first myocardial infarction

Background: High sensitivity C-reactive protein (hsCRP) predicts myocardial dysfunction after acute coronary syndromes. We aimed to study the association of hsCRP estimation at first acute myocardial infarction (AMI) with myocardial dysfunction and heart failure.

Methods: This research was carried out at the Department of Physiology and Department of Emergency Medicine, King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia. In this prospective study, 227 patients were studied. hsCRP levels were estimated when patients came to the emergency department at AMI, 7 days post AMI, and at 12 weeks of follow up after AMI. The outcome was change in myocardial functions, especially heart failure, 12 months after the attack.

Results: Based on a cutoff mean value of hsCRP levels at admission (10.05±12.68 mg/L), patients were grouped into high and low C-reactive protein (CRP.) The ejection fraction was significantly lower at follow up in the high CRP group (37.29±12.97) compared to the low CRP group (43.85±11.77, p<0.0198). hsCRP had significant inverse correlation with left ventricular ejection fraction (r=−0.283, p<0.01). About 38.1% patients showed heart failure, with 23.6% in the high CRP group and 14.5% in the low CRP group (OR 2.4, p=0.028). Receiver operating characteristic curve analysis showed that CRP levels at AMI had a specificity of 79% and sensitivity of 83% to predict heart failure.

Conclusion: A high hsCRP level measured at first AMI predicts myocardial dysfunction and heart failure. It is suggested that hsCRP plays an important role in the development of heart failure after myocardial infarction.