Patient delay and benefit of timely reperfusion in ST-segment elevation myocardial infarction

Association Between Patient and System Delays and In-Hospital Mortality in Primary PCI for STEMI: Findings from a Large, Nationwide Inpatients Sample

PURPOSE

System delay is associated with mortality in patients undergoing primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). However, the influence of patient delay has been relatively overlooked. We aimed to evaluate the influence of patient and system delays on STEMI patients undergoing primary PCI in China.

METHODS

STEMI patients registered at the Nationwide Chinese Cardiovascular Association Database-Chest Pain Center from January 2017 to September 2021 were screened. The exposures were total ischemic time (TIT), system delay and patient delay. The primary outcome was in-hospital mortality.

RESULTS

Among 458,260 patients from 2529 centers, median TIT, system delay and patient delay were 4.1, 1.5 and 2.1 hours, respectively. The adjusted odds ratio of in-hospital mortality increased by 2.2% (odds ratio [OR], 1.022, 95% confidence interval [CI], 1.017-1.027), 2.3% (1.023, 1.006-1.040) and 2.2% (1.022, 1.017-1.027) for every one-hour increase in TIT, system delay and patient delay, respectively.

CONCLUSIONS

Patient delay demonstrated a comparable impact to system delay on in-hospital mortality among STEMI patients undergoing primary PCI. Widespread primary PCI-capable center, improved awareness about myocardial infarction and regional transfer system are essential to shorten patient delay.

Survivorship With Incrementally Faster Times to Primary Percutaneous Coronary Intervention (SWIFT-PPCI): A Systematic Review and Meta-Analysis

In the United States, there are approximately 750,000 ST-elevation myocardial infarction cases each year. Streamlined care and rapid delivery for primary percutaneous coronary intervention (PPCI) is associated with improved survival. This systematic review and meta-analysis aimed to generate a practical estimate of mortality savings for every notional 30-minute decrease in the time to achieving PPCI. Included studies were those that provided a specific absolute risk reduction for a specific reduction in pre-PPCI time. The eligible studies evaluated the survival benefit from pre-PPCI time savings measured in any interval ending with PPCI and commencing with objectively recorded timing, such as initial emergency call, first medical contact, or hospital arrival. Study planning called for the reporting of data as individual study results, with a pooled effect estimate of relative risk calculated with random-effects meta-analysis. A total of 1,088 records were eligible for review; 52 were reviewed in full text, with 4 studies (total patient n = 235,814, overall mortality 4.7% to 7.8%) included in the final analysis. All 4 studies reported significant time-related survival benefit over the study focus window of 60 to 180 minutes pre-PPCI. The number of lives saved per 100 cases for each 30-minute pre-PPCI time savings ranged from 0.8 to 1.9. The overall effect estimate generated was 0.753 (95% confidence interval 0.712 to 0.796), with acceptable heterogeneity (I2 = 36%). In conclusion, a pooled effect calculation estimated a 24.7% relative risk reduction for each 30 minutes of time savings. For cases that underwent PPCI within 60 to 180 minutes of initial presentation with known baseline mortality risk, the time savings in 30-minute epochs can be leveraged to estimate a specific number of lives saved; this may be useful for those involved in the organization of medical care who make systemwide plans and individual patient triage decisions.

Types and effects of feedback for emergency ambulance staff: a systematic mixed studies review and meta-analysis

BACKGROUND

Extensive research has been conducted into the effects of feedback interventions within many areas of healthcare, but prehospital emergency care has been relatively neglected. Exploratory work suggests that enhancing feedback and follow-up to emergency medical service (EMS) staff might provide staff with closure and improve clinical performance. Our aim was to summarise the literature on the types of feedback received by EMS professionals and its effects on the quality and safety of patient care, staff well-being and professional development.

METHODS

A systematic review and meta-analysis, including primary research studies of any method published in peer-reviewed journals. Studies were included if they contained information on systematic feedback to emergency ambulance staff regarding their performance. Databases searched from inception were MEDLINE, Embase, AMED, PsycINFO, HMIC, CINAHL and Web of Science, with searches last updated on 2 August 2022. Study quality was appraised using the Mixed Methods Appraisal Tool. Data analysis followed a convergent integrated design involving simultaneous narrative synthesis and random effects multilevel meta-analyses.

RESULTS

The search strategy yielded 3183 articles, with 48 studies meeting inclusion criteria after title/abstract screening and full-text review. Interventions were categorised as audit and feedback (n=31), peer-to-peer feedback (n=3), postevent debriefing (n=2), incident-prompted feedback (n=1), patient outcome feedback (n=1) or a combination thereof (n=4). Feedback was found to have a moderate positive effect on quality of care and professional development with a pooled effect of d=0.50 (95% CI 0.34, 0.67). Feedback to EMS professionals had large effects in improving documentation (d=0.73 (0.00, 1.45)) and protocol adherence (d=0.68 (0.12, 1.24)), as well as small effects in enhancing cardiac arrest performance (d=0.46 (0.06, 0.86)), clinical decision-making (d=0.47 (0.23, 0.72)), ambulance times (d=0.43 (0.12, 0.74)) and survival rates (d=0.22 (0.11, 0.33)). The between-study heterogeneity variance was estimated at σ2=0.32 (95% CI 0.22, 0.50), with an I2 value of 99% (95% CI 98%, 99%), indicating substantial statistical heterogeneity.

CONCLUSION

This review demonstrated that the evidence base currently does not support a clear single point estimate of the pooled effect of feedback to EMS staff as a single intervention type due to study heterogeneity. Further research is needed to provide guidance and frameworks supporting better design and evaluation of feedback interventions within EMS.

PROSPERO REGISTRATION NUMBER

CRD42020162600.

Delays in first medical contact to primary interventional therapy and left ventricular remodelling in ST-segment elevation myocardial infarction

BACKGROUND

Early reperfusion and early evaluation of adverse cardiovascular events have become important aspects of treatment for ST-segment elevation myocardial infarction post-primary percutaneous coronary intervention (PPCI). However, emergency medical service (EMS) delays always occur, especially in developing countries.

AIMS

The aim of this study was to investigate the impact of EMS delays on short-term predictions of the severity of myocardial injury in STEMI patients after PPCI.

METHODS

A total of 151 STEMI patients who underwent successful PPCI and two postoperative cardiac magnetic resonance (CMR) imaging examinations (1 week and 4 months postoperatively) were retrospectively analysed. CMR cine and late gadolinium enhancement (LGE) images were analysed to evaluate left ventricular (LV) function, LV global longitudinal peak strain (GLS) and scar characteristics. The time from first medical contact to balloon (FMC2B) and door-to-balloon (D2B) time, expressed in minutes, were recorded and compared with the recommended timelines. Unadjusted and multivariable analyses were used to assess the impact of EMS delays on short-term left ventricular remodelling (ALVR).

RESULTS

EMS delays (FMC2B time > 90 min) led to larger infarct size (IS) and microcirculation obstruction (MVO) and poor recovery of the LV ejection fraction and GLS (all p < 0.05). Logistic regression analysis showed that an FMC2B time > 90 min (p = 0.028, OR = 2.661, 95% CI 1.112-6.367) and baseline IS (p = 0.016, OR = 1.079, 95% CI 1.015-1.148) were independent predictors of short-term ALVR.

CONCLUSION

Delays in FMC2B time were strongly associated with short-term ALVR; shorter ischaemic times may improve the cardiac function and prognosis of patients.

Exercise training and experimental myocardial ischemia and reperfusion: A systematic review and meta-analysis

Background

Despite the success of interventional coronary reperfusion strategies, morbidity and mortality from acute myocardial infarction are still substantial. Physical exercise is a well-recognized effective non-pharmacological therapy for cardiovascular diseases. Therefore, the objective of this systematic review was to analyze studies in animal models of ischemia-reperfusion in association with physical exercise protocols.

Search strategy

Articles published on the topic over a 13-year period (2010-2022) were searched in two databases (PubMed and Google Scholar) using the keywords exercise training, ischemia/reperfusion or ischemia reperfusion injury. Meta-analysis and quality assessment of the studies were performed using the Review Manager 5.3 program.

Results

From the 238 articles retrieved from PubMed and 200 from Google Scholar, after screening and eligibility assessment, 26 articles were included in the systematic review and meta-analysis. For meta-analysis comparing the group of previously exercised animals with the non-exercised animals and then submitted to ischemia-reperfusion, the infarct size was significantly decreased by exercise (p < 0.00001). In addition, the group exercised had increased heart-to-body weight ratio (p < 0.00001) and improved ejection fraction as measured by echocardiography (p < 0.0004) in comparison to non-exercised animals.

Conclusion

We concluded that the animal models of ischemia-reperfusion indicates that exercise reduce infarct size and preserve ejection fraction, associated with beneficial myocardial remodeling.

Metallothionein-2A Protects Cardiomyocytes from Hypoxia/reper-Fusion through Inhibiting p38

The reperfusion of coronary artery blood supply is often accompanied by myocardial hypoxia/reperfusion (H/R) injury, and induced cardiomyocytes apoptosis. The activation of p38 can induce apoptosis, thereby aggravating the myocardial H/R injury. Metallothionein-2A (MT2A) has the functions of anti-apoptosis and protective effect through p38. However, it is not clear that MT2A may protect cardiomyocytes from H/R injury through p38 signaling pathway. Here, we constructed an H/R model for H9c2 cardiomyocytes to explore the protective effect of MT2A on cardiomyocytes apoptosis during the process of H/R through p38 signal pathway. The results revealed that both endogenously overexpressed MT2A and exogenously added MT2A can inhibit the active expression of p-p38 and cleaved caspase-3 under H/R. Based on our results, H/R induced cardiomyocytes apoptosis and activation of p38. And, MT2A can inhibit the active expression of caspase-3 and p38. We found that MT2A can protect cardiomyocytes apoptosis from H/R injury through p38 signaling pathway.

Comparing Door-To-Balloon Time between ST-Elevation Myocardial Infarction Electrocardiogram and Its Equivalents

Background: In patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary interventions (pPCI), longer door-to-balloon (DTB) time is known to be associated with an unfavorable outcome. A percentage of patients with acute coronary occlusion present with atypical electrocardiographic (ECG) findings, known as STEMI-equivalents. We investigated whether DTB time for STEMI-equivalent patients was delayed. Methods: This is a retrospective study including patients arriving at an emergency department with the acute coronary syndrome in whom emergent pPCI was performed. ECGs were classified into STEMI and STEMI-equivalent groups. We compared DTB time, with its components, between the groups. We also investigated whether STEMI-equivalent ECG was an independent predictor of DTB time delayed for more than 90 min. Results: A total of 180 patients were included in the present study, and 23 patients (12.8%) presented with STEMI-equivalent ECGs. DTB time was significantly delayed in patients with STEMI-equivalent ECGs (89 (80–122) vs. 81 (70–88) min, p = 0.001). Multivariable logistic regression analysis showed that STEMI-equivalent ECG was an independent predictor of delayed DTB time (odds ratio: 4.692; 95% confidence interval: 1.632–13.490, p = 0.004). Conclusions: DTB time was significantly delayed in patients presenting with STEMI-equivalent ECGs. Prompt recognition of STEMI-equivalent ECGs by emergency physicians and interventional cardiologists might reduce DTB time and lead to a better clinical outcome.