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Abstract
Background Patients who experience in-hospital ST-segment elevation myocardial infarction (iSTEMI) represent a uniquely high-risk cohort owing to delays in diagnosis, prolonged time to reperfusion and increased mortality. Quality initiatives aimed at improving the care of this vulnerable, yet understudied population are needed.
Methods This study included consecutive patients with iSTEMI treated with percutaneous coronary intervention (PCI) between 1 January 2011 and 15 July 2019 at a single, tertiary referral centre. A comprehensive iSTEMI protocol (CSP) was implemented on 15 July 2014, incorporating: (1) cardiology fellow activation of the catheterisation lab using standardised criteria, (2) nursing chest pain protocol, (3) improved electronic access to electrocardiographic studies, (4) checklist for initial triage and management, (5) 24/7/365 catheterisation lab readiness and (6) radial-first PCI approach. Key metrics and clinical outcomes were compared before and after CSP implementation.
Results Among 125 total subjects, the post-CSP cohort (n=81) was younger, had more males and were more likely to be hospitalised for cardiac-related reasons relative to the pre-CSP cohort (n=44) who were more likely hospitalised for operative-related aetiologies. After CSP adoption, median ECG-to-first-device-activation time decreased from 113 min to 64 min (p<0.001), goal ECG-to-first-device-activation time increased from 36% to 76% of patients (p<0.001), administration of guideline-directed medical therapy prior to PCI increased from 27.3% to 65.4% (p<0.001), trans-radial access increased from 16% to 70% (p<0.001) and rates of discharge home increased from 56.8% to 76.5% (p=0.04). Statistically insignificant numerical reductions were observed post-CSP in in-hospital mortality (18.2% vs 9.9%, p=0.30), 30-day mortality (15.9% vs 12.3%, p=0.78) and 1-year mortality (27.3% vs 21.0%, p=0.57).
Conclusions The implementation of a CSP was associated with marked enhancements in key care metrics among patients with iSTEMI. Among a larger cohort, the use of a CSP yielded a significant reduction in ECG-to-first-device-activation time in a particularly vulnerable population at high risk of death.
- Percutaneous Coronary Intervention
- Acute Coronary Syndrome
- Myocardial Infarction
- Quality of Health Care
- Delivery of Health Care
Data availability statement
No data are available.
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- Percutaneous Coronary Intervention
- Acute Coronary Syndrome
- Myocardial Infarction
- Quality of Health Care
- Delivery of Health Care
WHAT IS ALREADY KNOWN ON THIS TOPIC
Patients who develop in-hospital ST-segment elevation myocardial infarction (iSTEMI) represent a uniquely high-risk population with a greater degree of illness relative to their out-of-hospital counterparts. These events are under-recognised, and few systems exist which promote recognition, triage and management of iSTEMI, ultimately leading to delays in diagnosis and treatment.
WHAT THIS STUDY ADDS
In this observational, cohort analysis of 125 adults who developed iSTEMI at a tertiary referral centre, the implementation of a comprehensive iSTEMI protocol was associated with significant reductions in median and goal ECG-to-first-device-activation times and increases in guideline-directed medical therapy use prior to percutaneous coronary intervention and trans-radial access rates. The strengths of our analysis are the inclusion of the largest population of patients with iSTEMI studied yet and the implementation of a novel initiative previously demonstrated to benefit other cohorts.
HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY
The utilisation of such a protocol can serve as a framework for institutions to optimise quality metrics and to fuel additional research to ultimately improve survival in this vulnerable group at high risk of death.
Introduction
ST-segment elevation myocardial infarction (STEMI) management centres around timely reperfusion with percutaneous coronary intervention (PCI) as the preferred treatment method.1 2 Since 2006 when the American College of Cardiology began urging door-to-balloon times of ≤90 min, STEMI outcomes at PCI-capable hospitals have significantly improved, particularly with the use of out-of-hospital protocolised systems of care.3 4
Despite this, patients who experience in-hospital STEMI (iSTEMI) still represent approximately 5% of STEMI presentations overall and comprise a unique population with demographics and outcomes disparate from those with out-of-hospital STEMI.5 Relative to their out-of-hospital counterparts, these patients are generally older with a higher burden of comorbidities, more often hospitalised with concomitant non-cardiac conditions including surgical indications, less likely treated with PCI and more likely to experience adverse outcomes including bleeding, cardiac arrest, cardiogenic shock (CS) and death.6–10 Importantly, despite recent focus on optimising care processes for out-of-hospital STEMI, few systems exist which promote recognition, triage and management of iSTEMI, ultimately leading to delays in diagnosis and treatment.11 While implementation of quality improvement programmes has improved iSTEMI recognition6 and reduced symptom-to-first device activation time,7 time to reperfusion remains significantly delayed as guideline recommendations are infrequently achieved in this cohort. Moreover, the impact of quality improvement protocols on the incidence of bleeding, cardiac arrest, CS and mortality remains unknown.
We have previously demonstrated the complementary impact on mortality of guideline-directed medical therapy, use of trans-radial access (TRA) for primary PCI and lower ECG-First-Device-Activation (ECG-to-FDA) time among patients with STEMI.12 The utility of a system of care delivery focused on improving these key STEMI metrics applies to additional high-risk cohorts, including women, African Americans and patients with CS.13 14 As such, we aimed to assess the impact of a comprehensive STEMI protocol (CSP), centred on systematically targeting these tenets of STEMI care, on care metrics and outcomes among patients with iSTEMI. We present the following article in accordance with the Strenghtening the Reporting of Observational Studies in Epidemiology (STROBE) checklist.
Methods
Study design and population
This observational, cohort-based study included consecutive adult patients with iSTEMI treated with PCI at a single tertiary care centre within a multihospital regional STEMI system between 1 January 2011 and 15 July 2019. No exclusionary criteria were applied. Baseline data, procedural characteristics, care and process metrics, adverse events, in-hospital outcomes and 30-day and 1-year mortality were prospectively collected and retrospectively adjudicated according to the standards of the American College of Cardiology National Cardiovascular Data Registry CathPCI Registry by trained data abstractors.15 Patients and the public were not involved in the design, conduct, reporting or dissemination plans of our research.
Comprehensive STEMI protocol
Our original CSP has previously been described.12–14 16 The CSP used in this study incorporated three additional modifications to the initial CSP as listed in steps 1–3 below. Implementation of the in-hospital CSP commenced on 15 July 2014 with the intention of minimising STEMI care variability by (1) cardiology fellow activation of the catheterisation lab using standardised criteria; (2) implementing a nursing chest pain protocol; (3) improving access to ECGs in the electronic medical record (EMR); (4) using a STEMI Safe Handoff Checklist to standardise the early triage of patients including proper antiplatelet administration; (5) ensuring 24/7/365 catheterisation laboratory availability to avoid patient delays and (6) employing a ‘radial-first’ approach to PCI as clinically appropriate.
Enhancements towards ECG accessibility in our CSP included the acquisition of more ECG machines for swifter use, mandatory patient identification allowing for more rapid transfer to the EMR, an auto-interpret feature to facilitate initial identification of a STEMI (acknowledging the existence of false positives and negatives), and immediate preliminary results available in the EMR instead of a 24- to 48-hour delay for official interpretation. A critical value protocol was included such that the ECG technician would escalate concerning findings to the floor nurse, who would in turn notify the primary team or activate an emergency medical response team to assess the patient. All ECG technicians underwent training by the ECG laboratory director (a licensed physician). Floor nurses completed a 16-hour dysrhythmia course broken up into multiple sessions and repeat this annually.
The STEMI Safe Handoff Checklist: (1) outlines the key roles of cardiovascular nurses and physicians when performing high-acuity assessments; (2) provides guidance on appropriately indicated antiplatelet administration; and (3) notifies the catheterisation laboratory team of factors that may increase the risk of PCI-related complications.13
Study outcomes
The main objective of this study was to compare key metrics and outcomes pre- and post-CSP among those with iSTEMI, with patients treated during 1 January 2011–14 July 2014 defined as the control group and those managed between 15 July 2014 and 15 July 2019 as the CSP group.
The primary process metric was ECG-to-FDA time as defined for iSTEMI as the time from the first ECG confirming STEMI to first intracoronary device activation. Secondary outcomes included administration of appropriate medications (aspirin, a P2Y12 inhibitor including clopidogrel, ticagrelor or prasugrel, and an anticoagulant including unfractionated or low-molecular-weight heparin) prior to arterial sheath insertion, use of TRA for PCI and discharge home after PCI. The primary clinical outcomes were in-hospital, 30-day and 1-year mortality. Posthospital discharge home and survival status were confirmed by review of the EMRs, and patients were censored using the last available follow-up date.
Statistical analysis
Continuous variables are presented as mean±SD or median (IQR), as appropriate, and assessed using two-tailed Student t-tests or Mann-Whitney-U test according to the distribution of the data. Categorical variables are denoted as counts (percentages) and compared using χ2 or Fisher’s exact tests. To compare mortality risk between groups, Kaplan-Meier life tables and the log-rank test were employed. Quality control charts with statistical process control were created in order to visually depict the variability in ECG-to-FDA times; this method provides evidence of statistical change by using time series analysis to graphically present data variability.17 Multivariable logistic and linear regression models were generated to assess the impact of the CSP on various key process metrics and to account for confounding. Analyses were performed using R V.3.6.3 (R Foundation for Statistical Computing, Vienna, Austria).
Results
Of 125 patients with iSTEMI, patients in the CSP group (n=81, 64.8%) were younger with a more frequent history of smoking and heart failure relative to controls (n=44, 35.2%) (table 1). Among the control group indications for hospitalisation, 36.3% were cardiac, 45.5% were postoperative, and 18.2% were non-cardiac in aetiology. In the CSP group, 56.8% were cardiac, 18.5% were postoperative, and 24.7% were non-cardiac.
Baseline characteristics of patients with iSTEMI before and after CSP implementation
Impact of CSP on metrics and outcomes of iSTEMI
Compared with controls, patients in the CSP group had significant improvements in median ECG-to-FDA time (113.5 (80, 194) vs 64 (52, 88) min, p<0.001), ECG-to-FDA time ≤90 min (36.4% vs 76.5%, p<0.001), administration of appropriate medication prior to PCI (27.3% vs 65.4%, p<0.001) and use of TRA for PCI (14.6% vs 70.4%, p<0.001). Use of mechanical circulatory support was similar between groups (table 2). Figure 1 depicts the trends in ECG-to-FDA times before and after CSP implementation, which demonstrates a 44% relative risk reduction in ECG-to-FDA time and a 40% absolute increase in the percentage of patients who achieved goal ECG-to-FDA time ≤90 min.
Control chart of temporal trends in ECG-to-FDA times for patients with iSTEMI across the date of CSP implementation. After CSP implementation, a 44% risk reduction in ECG-to-FDA time and 40% increase in percentage of patients who achieved goal ECG-to-FDA time of 90 min were observed. Time intervals on the x-axis were averaged over 1 week. CSP, comprehensive STEMI protocol; FDA, first device activation; iSTEMI, in-hospital ST-segment elevation myocardial infarction; Cl, mean control limit; LCL, lower control limit; UCL, upper control limit.
Procedural features of patients with iSTEMI before and after CSP implementation
While no difference in length of hospitalisation was observed between groups, CSP patients were more often discharged home relative to controls (56.8% vs 76.5%, p=0.04) (table 3). Groups had similar rates of reinfarction, stroke, heart failure hospitalisation and major bleeding. Non-significant reductions in in-hospital mortality (18.2% vs 9.9%, p=0.3), 30-day mortality (15.9% vs 12.3%, p=0.78) and 1-year mortality (27.3% vs 21.0%, p=0.57) were observed between controls and CSP patients, respectively (table 3).
Clinical outcomes of patients with iSTEMI before and after CSP implementation
Discussion
This is the largest study to date assessing the impact of an in-hospital comprehensive STEMI protocol on quality metrics and clinical outcomes in patients with iSTEMI. In this contemporary analysis, we found that institutional implementation of a six-step CSP was associated with marked and sustained improvements in ECG-to-FDA time, administration of proper antiplatelet medications preprocedurally and use of TRA for PCI, which ultimately led to a greater rate of patients being discharged home. Our study demonstrates the value of a system-wide initiative in improving key process metrics in a uniquely vulnerable iSTEMI cohort.
The CSP led to significant reductions in overall, goal and variability in ECG-to-FDA times across the study duration, thereby contributing to more optimal STEMI care delivery in patients with iSTEMI. The sustainability of these process improvements lends credence to involving nursing staff in the protocolisation of assessing patient-reported chest pain as well as streamlining digital ECG access. These effects of the CSP in patients with iSTEMI, as we previously demonstrate in separate unique cohorts,8–10 reinforce the notion that optimal STEMI care must be multifaceted (addressing various processes and care tenets) and multidisciplinary (involving multiple healthcare team members with complementary expertise including ECG technicians, nursing staff, emergency department physicians and the cardiovascular team).
This study is the first to integrate TRA as the preferred PCI vascular access approach into a CSP among those with iSTEMI. Compared with the transfemoral approach, TRA confers fewer bleeding complications and overall improved outcomes including all-cause mortality and length of hospitalisation in patients with out-of-hospital STEMI.13–15 18 19 Our decision to implement TRA into the CSP stems from updated guideline recommendations. It stands to reason that the well-established benefits of TRA in preventing major bleeding extend to the in-hospital population, but that the complexity of iSTEMI as a clinical event with competing risks may have overshadowed any statistically significant reduction in major bleeding that TRA could offer in this population. We demonstrate the feasibility of adopting TRA in patients with iSTEMI and urge all centres to strive for this standard as a means to further eliminate avoidable untoward factors in STEMI care.
Our study builds on prior efforts which demonstrate that optimising in-hospital care metrics using a multipronged approach is a critical first step to improving clinical outcomes in a high-risk iSTEMI cohort. Though several institutions have established systems of care for the management of out-of-hospital STEMI, there remains a heightened need for the standardisation of practice in treating postadmission STEMI. A recent review summarised the three major causes of treatment delays in these patients which include delays in ECG acquisition, ECG interpretation and activation of the catheterisation laboratory.11 Prior similar studies further demonstrate the feasibility of reducing ECG-to-FDA time by implementing an institutional protocol for patients with iSTEMI, and beyond that, affirm the notion that mitigating such delays and ultimately improving process and care metrics requires multidisciplinary and multilevelled efforts.2 3 Garberich and colleagues modified a previously established out-of-hospital STEMI protocol for inpatient events and included a toolkit with a checklist, transfer and clinical data forms, standing orders, ancillary medications and laboratory supplies; this ultimately led to improved iSTEMI recognition, time to reperfusion and mortality at 1 year.6 Dai and colleagues designed a protocol inclusive of a STEMI-specific response team and monthly review of such cases; this led to significant improvements in time to recognition and treatment.7 Importantly like ours, these protocols incorporated non-cardiologists by training and empowering various members of the healthcare team though our protocol stressed the early recognition, communication and education of ECG technicians and nursing personnel while expanding the role of the cardiovascular medicine fellows in iSTEMI activation. The significance of a team approach in optimising care for patients with iSTEMI cannot be overstated.
Despite marked improvement in quality metrics, the adoption of CSP failed to derive statistically significant mortality benefits likely due to: (1) the degree of illness and higher burden of comorbidities among patients with iSTEMI and/or (2) an analysis underpowered to demonstrate statistical significance. Additionally, the relatively high incidence of CS preceding PCI in these groups possibly impacted survival despite timely intervention. It is tenable that iSTEMI leading to CS constituted a specific disease pattern such as more proximal culprit occlusion, higher angiographic disease burden or larger infarct size. More granular insight into the procedural characteristics and clinical outcomes of the STEMI-CS cohort will further elucidate any possible discrepancies that may have arisen and are being masked in our study. Notwithstanding, it is evident that a standardised, multipronged STEMI protocol confers advantages in care delivery for hospitalised patients who experience STEMI.
Our iSTEMI protocol may serve as a framework for further efforts to study outcomes across a longer duration and among additional patients including those who develop iSTEMI at non-PCI capable hospitals who may benefit greatly from a protocolised STEMI systems of care.
Limitations
Our study has several limitations. Study subjects were selected from a single STEMI referral centre within a regional hospital system, and therefore, while no patients were excluded, our findings may warrant validation in separate patient populations. The study results originate from a high-volume centre with aggressive reperfusion strategies that may not reflect clinical practice at lower-volume institutions. For instance, immediate access to ECG interpretation and catheterisation lab activation likely led to the observed improvements seen in care metrics. In addition, despite similar comorbidities between groups, a historical control group was used with no random assignment to iSTEMI treatment protocols which may have introduced undetected confounding. Although this study is the largest with respect to the number of post-CSP patients, the limited sample size may have restricted our ability to draw discrete conclusions and that this analysis was underpowered to achieve a significant association between the CSP and clinical outcomes including mortality. Deaths may also be under-reported if not reflected in the institutional EMRs. Lastly, the pre–post study design introduces confounding bias as temporal changes in population risk may exist outside of the CSP.
Conclusions
The implementation of a CSP was associated with marked improvements in key quality and care metrics among patients with iSTEMI including overall, goal and variability in time to reperfusion, use of proper antiplatelet medications before PCI and utilisation of TRA during PCI. The adoption of systems-based solutions holds promise in reducing in-hospital mortality among this vulnerable population at high risk of death. Developing systems of care aimed at addressing the modifiable time delays in the care of patients with iSTEMI is vital and must be prioritised by hospitals globally.
Data availability statement
No data are available.
Ethics statements
Patient consent for publication
Ethics approval
The study protocol was approved by the Cleveland Clinic Institutional Review Board, and patient informed consent was waived.
Acknowledgments
The authors appreciate the hard work and dedication displayed by the members of our research team and by the healthcare workers who strived to uphold the highest standards in treating patients within the scope of the STEMI protocol.
References
Footnotes
Twitter @Cnkanaan, @GrantReedMD
Contributors CK, NK, RMN and UK conceived and designed the study; CK, NK, RMN, AnK, CPH and KK collected, analysed and interpreted the data; CK, NK, RMN, AnK, CPH, AmK, ML and UK drafted and critically revised the manuscript; GR, AmK, AML, JK, RP, KZ, RN, SK and UK supervised the study; CK, NK and UK are responsible for the overall content and serve as guarantors. All authors read and approved the final manuscript.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.