Development of Systems of Care for ST-Elevation Myocardial Infarction Patients

Outcomes of medically managed patients with myocardial infarction

AIMS

The purpose of this study was to compare outcomes associated with medical management of ST-elevation myocardial infarction and non-ST-elevation myocardial infarction patients presenting to hospitals with and without onsite catheterization facilities.

METHODS

All patients (n=25,921) with ST-elevation myocardial infarction (n=10,563) or non-ST-elevation myocardial infarction (n=15,358) in Alberta, Canada between April 2010-March 2016 were categorized according to availability of catheterization facilities at the hospital they presented to and their management strategy (medically managed without coronary angiography or medically managed after coronary angiography).

RESULTS

Overall, 51% presented to hospitals without catheterization facilities; and 34% were managed medically (18% without coronary angiography, and 16% after coronary angiography). Rates of medical management were higher at hospitals without versus those with catheterization facilities (43% vs. 24%, p<0.01). However, both the rate of presentation to hospitals without catheterization facilities (70% non-ST-elevation myocardial infarction, 24% ST-elevation myocardial infarction, p<0.01) and medical management (45% non-ST-elevation myocardial infarction, 18% ST-elevation myocardial infarction, p<0.01) differed by myocardial infarction type. The lack of catheterization facilities at the presenting hospital had no association with in-hospital mortality in patients medically managed without coronary angiography, but was associated with a lower risk of mortality among patients medically managed after coronary angiography. However, the latter benefit was restricted to non-ST-elevation myocardial infarction patients only (adjusted hazard ratio 0.43, 95% confidence interval: 0.25-0.76).

CONCLUSION

The availability of catheterization facilities at the hospital at which non-ST-elevation myocardial infarction and ST-elevation myocardial infarction patients presented influenced their likelihood of being medically managed, but was not associated with adverse short- or long-term mortality outcomes.

Routine diversion of patients with STEMI to high-volume PCI centres: modelling the financial impact on referral hospitals

OBJECTIVE

To quantify possible revenue losses from proposed ST-elevation myocardial infarction (STEMI) patient diversion policies for small hospitals that lack high-volume percutaneous coronary intervention (PCI) capability status (ie, 'STEMI referral hospitals').

BACKGROUND

Negative financial impacts on STEMI referral hospitals have been discussed as an important barrier to implementing regional STEMI bypass/transfer protocols. However, there is little empirical data available that directly quantifies this potential financial impact.

METHODS

Using detailed financial charges from Florida hospital discharge data, we examined the potential negative financial impact on 112 STEMI referral hospitals from losing all inpatient STEMI revenue. The main outcome was projected revenue loss (PRL), defined as total annual patient with STEMI charges as a proportion of total annual charges for all patients. We hypothesised that for most community hospitals (>90%), STEMI revenue represented only a small fraction of total revenue (<1%). We further examined the financial impact of the 'worst case' scenario of loss of all acute coronary syndrome (ACS) (ie, chest pain) patients.

RESULTS

PRLs were $0.33 for every $100 of patient revenue statewide for STEMI and $1.73 for ACS. At the individual hospital level, the 90th centile PRL was $0.74 for STEMI and $2.77 for ACS. PRLs for STEMI were not greater in rural areas compared with major metropolitan areas. Hospital revenue centres that would be most impacted by loss of patients with STEMI were cardiology procedures and intensive care units.

CONCLUSIONS

Loss of patient with STEMI revenues would result in only a small financial impact on STEMI referral hospitals in Florida under proposed STEMI diversion/rapid transfer protocols. However, spillover loss of patients with ACS would increase revenue loss for many hospitals.

Cardioprotective potential of annexin-A1 mimetics in myocardial infarction

Myocardial infarction (MI) and its resultant heart failure remains a major cause of death in the world. The current treatments for patients with MI are revascularization with thrombolytic agents or interventional procedures. These treatments have focused on restoring blood flow to the ischemic tissue to prevent tissue necrosis and preserve organ function. The restoration of blood flow after a period of ischemia, however, may elicit further myocardial damage, called reperfusion injury. Pharmacological interventions, such as antioxidant and Ca(2+) channel blockers, have shown premises in experimental settings; however, clinical studies have shown limited success. Thus, there is a need for the development of novel therapies to treat reperfusion injury. The therapeutic potential of glucocorticoid-regulated anti-inflammatory mediator annexin-A1 (ANX-A1) has recently been recognized in a range of systemic inflammatory disorders. ANX-A1 binds to and activates the family of formyl peptide receptors (G protein-coupled receptor family) to inhibit neutrophil activation, migration and infiltration. Until recently, studies on the cardioprotective actions of ANX-A1 and its peptide mimetics (Ac2-26, CGEN-855A) have largely focused on its anti-inflammatory effects as a mechanism of preserving myocardial viability following I-R injury. Our laboratory provided the first evidence of the direct protective action of ANX-A1 on myocardium, independent of inflammatory cells in vitro. We now review the potential for ANX-A1 based therapeutics to be seen as a "triple shield" therapy against myocardial I-R injury, limiting neutrophil infiltration and preserving both cardiomyocyte viability and contractile function. This novel therapy may thus represent a valuable clinical approach to improve outcome after MI.

Reperfusion strategies and systems of care in ST-elevation myocardial infarction

Approximately 330,000 ST-elevation myocardial infarctions (STEMI) occur yearly in the United States. Emergent reperfusion is the cornerstone of STEMI therapy and the key to restoration of coronary blood flow in an infarct-related vessel. Reperfusion methods include thrombolysis, primary percutaneous coronary intervention, or both methods combined. Selection of the appropriate reperfusion strategy is essential, along with having an efficient system of care capable of delivering these therapies. Timely reperfusion is highly dependent on a well-structured care system designed to meet the needs of each individual community. This article reviews the data behind different reperfusion strategies and introduces successful systems-of-care models.

Hospital process intervals, not EMS time intervals, are the most important predictors of rapid reperfusion in EMS Patients with ST-segment elevation myocardial infarction

OBJECTIVE

To assess the relationship of emergency medical services (EMS) intervals and internal hospital intervals to the rapid reperfusion of patients with ST-segment elevation myocardial infarction (STEMI).

METHODS

We performed a secondary analysis of a prospectively collected database of STEMI patients transported to a large academic community hospital between January 1, 2004, and December 31, 2009. EMS and hospital data intervals included EMS scene time, transport time, hospital arrival to myocardial infarction (MI) team activation (D2Page), page to catheterization laboratory arrival (P2Lab), and catheterization laboratory arrival to reperfusion (L2B). We used two outcomes: EMS scene arrival to reperfusion (S2B) ≤90 minutes and hospital arrival to reperfusion (D2B) ≤90 minutes. Means and proportions are reported. Pearson chi-square and multivariate regression were used for analysis.

RESULTS

During the study period, we included 313 EMS-transported STEMI patients with 298 (95.2%) MI team activations. Of these STEMI patients, 295 (94.2%) were taken to the cardiac catheterization laboratory and 244 (78.0%) underwent percutaneous coronary intervention (PCI). For the patients who underwent PCI, 127 (52.5%) had prehospital EMS activation, 202 (82.8%) had D2B ≤90 minutes, and 72 (39%) had S2B ≤90 minutes. In a multivariate analysis, hospital processes EMS activation (OR 7.1, 95% CI 2.7, 18.4], Page to Lab [6.7, 95% CI 2.3, 19.2] and Lab arrival to Reperfusion [18.5, 95% CI 6.1, 55.6]) were the most important predictors of Scene to Balloon ≤ 90 minutes. EMS scene and transport intervals also had a modest association with rapid reperfusion (OR 0.85, 95% CI 0.78, 0.93 and OR 0.89, 95% CI 0.83, 0.95, respectively). In a secondary analysis, Hospital processes (Door to Page [OR 44.8, 95% CI 8.6, 234.4], Page 2 Lab [OR 5.4, 95% CI 1.9, 15.3], and Lab arrival to Reperfusion [OR 14.6 95% CI 2.5, 84.3]), but not EMS scene and transport intervals were the most important predictors D2B ≤90 minutes.

CONCLUSIONS

In our study, hospital process intervals (EMS activation, door to page, page to laboratory, and laboratory to reperfusion) are key covariates of rapid reperfusion for EMS STEMI patients and should be used when assessing STEMI care.

An organized system of emergency care for patients with myocardial infarction: a reality?

An organized system of emergency care is an essential requirement for the modern treatment of ST-elevation acute myocardial infarction. There is a strong need to deliver reperfusion therapy as soon as possible, with primary percutaneous coronary intervention being the preferred option if performed in a timely manner and thrombolytic therapy, particularly in the prehospital setting, being a good alternative if the primary percutaneous coronary intervention-related delay exceeds the equipoise. In this situation, emergency medical services have a primary role in rescuing patients from cardiac arrest, performing prehospital diagnosis, triage and treatment and safely transporting them to the most appropriate cardiological center, including interhospital transfer. A complete reorganization of the healthcare systems in different countries is frequently needed to build an ST-elevation acute myocardial infarction system of care, focusing on fast transport, use of telemedicine and diversion protocols to skip the unsuited centers.

Delays in fibrinolysis as primary reperfusion therapy for acute ST-segment elevation myocardial infarction

BACKGROUND

In contemporary practice, the degree to which fibrinolytic therapy is administered in a timely fashion for ST-segment elevation myocardial infarction (STEMI) and its association with outcomes is not well-known. Our objective was to assess the performance of fibrinolytic therapy within the recommended 30-minute time frame for patients with STEMI.

METHODS

Patient characteristics associated with the timeliness of fibrinolytic therapy were evaluated. We also examined the association of timely fibrinolysis with key patient outcomes, including inpatient mortality, stroke, and cardiogenic shock. Logistic generalized estimating equations were used to account for baseline clinical factors and within-hospital clustering.

RESULTS

Between January 2007 and June 2008, 3,219 STEMI patients in 178 hospitals received primary fibrinolytic therapy. Median door-to-needle (DTN) time was 34.0 minutes (interquartile range 22.0-54.0 minutes). However, only 44.5% met the American College of Cardiology/American College of Cardiology guideline DTN time of < or =30 minutes. Patient characteristics associated with longer fibrinolysis times included female gender (+17.8% longer vs men, 95% CI 11.9-24.1) and age > or =75 (+12.0% longer vs age <55, 95% CI 1.8-23.2). Timely (vs delayed) fibrinolysis was associated with a decreased risk of a composite outcome of death, shock, or stroke (6.2% vs 8.8%, adjusted odds ratio 0.74, 95% CI 0.56-0.98).

CONCLUSIONS

Timely fibrinolytic therapy was associated with lower risk of a composite outcome of shock, death, or stroke, yet DTN times of < or =30 minutes were achieved in less than half of the patients studied. Thus, efforts to optimize regional systems of STEMI care should focus on shortening reperfusion times for patients who receive fibrinolysis, as well as those who receive primary percutaneous coronary intervention.

Percutaneous coronary intervention, comorbidities, and mortality among emergency department-admitted ST-elevation myocardial infarction patients in Florida

BACKGROUND

Risk of mortality following an ST-elevation myocardial infarction (STEMI) can be significantly reduced by prompt percutaneous coronary intervention (PCI). National guidelines specify primary PCI as the preferred recommended treatment for STEMI. In this study, we examined same-day PCI as an independent predictor of in-hospital mortality, after adjustment for comorbidities, other patient factors, and hospital PCI-volume using unselected surveillance data from Florida.

METHODS

We analyzed hospital discharge data for adults, 18+ years old, with a primary diagnosis of STEMI who were admitted to PCI-capable hospitals through the emergency department during 2001-2005 (n = 43,849). Hierarchical (multilevel) logistic regression models were used for analysis.

RESULTS

Overall, 4,143 STEMI patients (9.4%) did not survive to hospital discharge. In late 2005, the in-hospital mortality rates were 1.9% for those who received same-day PCI versus 13.0% for those who did not. After adjustment for multiple patient factors, same-day PCI was a significant predictor of in-hospital survival with a strong protective effect (adjusted OR = 0.35, 95% CI 0.31-0.38 P < 0.0001). Restriction of the analysis to those patients who survived the first day of admission did not appreciably change this result (adjust OR = 0.37, 95% CI 0.33-0.42, P < 0.0001). Hospital PCI-volume did not significantly impact mortality risk.

CONCLUSIONS

Same-day PCI markedly reduced the risk of in-hospital mortality among STEMI patients after multivariate adjustment. Serious comorbidities and complications, older age, and female gender continued to predict elevated risk of mortality after control for treatment status. Our results provide additional evidence in support of national clinical recommendations and aggressive treatment of STEMI.

Interhospital transfer of patients with ST-segment elevation myocardial infarction for percutaneous coronary intervention

We investigated in 277 consecutive patients, mean age 63 years, with ST-segment elevation acute myocardial infarction transferred from 25 community hospitals to a tertiary percutaneous coronary intervention (PCI) center from a median distance of 21 miles the incidences of in-hospital mortality, stroke, and recurrent myocardial infarction associated with transfer times. Of the 277 patients, 158 (57%) had thrombolytic therapy at the referring hospital. Of the 277 patients, 63 (23%) had adjunctive PCI, 119 (43%) had primary PCI, and 95 (34%) had rescue PCI. Of the 277 patients, 42 (15%) were hemodynamically unstable. Median transfer times were 102 minutes with primary PCI, 119 minutes with rescue PCI, and 144 minutes for adjunctive PCI (P < 0.0001 for adjunctive PCI versus primary PCI; P = 0.011 for adjunctive PCI versus rescue PCI). Median transfer time was 98 minutes for hemodynamically unstable patients and 121 minutes for hemodynamically stable patients (P = 0.005). In-hospital death occurred in eight of 277 patients (3%). In-hospital stroke occurred in three of 277 patients (1%). In-hospital recurrent myocardial infarction occurred in none of 277 patients (0%). There was no association of transfer times with in-hospital mortality or stroke. In-hospital mortality occurred in three of 112 patients (3%) who had bare metal stents and in five of 165 patients (3%) who had drug-eluting stents.

Regionalization of care for ST-segment elevation myocardial infarction: is it too soon?

Interest in regionalization of the care of acute ST-segment elevation myocardial infarction (STEMI) has gained momentum recently. Optimal treatment of STEMI involves balancing time to treatment and reperfusion options. Primary percutaneous coronary intervention, when performed in a timely fashion, has been shown to be more effective than fibrinolysis. However, numerous practical barriers prevent many STEMI patients from receiving primary percutaneous coronary intervention. In an effort to increase beneficial primary percutaneous coronary intervention administration to STEMI patients, health care leaders have proposed regionalized STEMI care networks with advanced emergency medical services (EMS) involvement. Constructing regionalized STEMI networks presents a policy challenge because this shift in STEMI care would require changes in current EMS and emergency medicine practices. Therefore, we present various perspectives and issues that decisionmakers and system organizers must address properly before deciding whether to adopt this new model of care. Reorganizing STEMI care in a manner analogous to how trauma and stroke care are currently triaged and treated appeals intuitively; however, given the absence of evidence that STEMI regionalization actually improves patient outcomes and is cost-effective, more research is needed to determine whether STEMI regionalization is an efficient model for providing evidence-based care. The concept of STEMI regionalization represents an effort to inform policy according to evidence-based medicine, but real-world quality, geospatial, financial, cost, business, resource, and practice barriers present obstacles to implementing this concept efficiently and effectively.