Growth in percutaneous coronary intervention capacity relative to population and disease prevalence

Pharmacoinvasive and Primary Percutaneous Coronary Intervention Strategies in ST-Elevation Myocardial Infarction (from the Mayo Clinic STEMI Network)

The effectiveness of a pharmacoinvasive strategy consisting of fibrinolysis and transfer for percutaneous coronary intervention (PCI) compared to primary PCI (PPCI) in patients presenting to non-PCI-capable hospitals with ST-elevation myocardial infarction (STEMI) is not well defined. We analyzed data from the Mayo Clinic STEMI database of patients treated with a pharmacoinvasive strategy (favored in those presenting early after symptom onset) or PPCI in a regional STEMI network from 2004 to 2012. A total of 364 and 1,337 patients were included in the pharmacoinvasive and PPCI groups, respectively. Patients in the PPCI group were older and more frequently had cardiogenic shock at the time of presentation (12.1% vs 7.7%, p = 0.018). Death from any cause occurred in 58 (16%) and 314 (23%) patients in the pharmacoinvasive and PPCI groups, respectively (median follow-up 3.9 and 4.4 years, respectively). In multivariate analyses adjusting for age, gender, and other variables for which the 2 groups differed at baseline, there was no significant difference between the 2 strategies for 30-day (hazard ratio 0.66, 95% confidence interval 0.36 to 1.21) or overall mortality (hazard ratio 0.84, 95% confidence interval 0.63 to 1.12). Shorter door-to-balloon time was associated with increased effectiveness of PPCI (p for trend = 0.015), but there was no difference between the 2 strategies even when considering only the patients with door-to-balloon time in the lowest quartile. In conclusion, fibrinolysis followed by transfer for PCI represents a reasonable alternative when PPCI is not readily available especially in patients presenting early after symptom onset.

Impact of a Rural Regional Myocardial Infarction System of Care in Wyoming

Background

Primary percutaneous coronary intervention (PCI) is the preferred reperfusion strategy for patients presenting with ST‐segment elevation myocardial infarction; however, to be effective, PCI must be performed in a timely manner. Rural regions are at a severe disadvantage, given the relatively sparse number of PCI hospitals and long transport times.

Methods and Results

We developed a standardized treatment and transfer protocol for ST‐segment elevation myocardial infarction in the rural state of Wyoming. The study design compared the time‐to‐treatment outcomes during the pre‐ and postintervention periods. Details of the program, changes in reperfusion strategies over time, and outcome improvements in treatment times were reported. From January 1, 2013, to December 31, 2014, 889 patients were treated in 11 PCI‐capable hospitals (4 in Wyoming, 7 in adjoining states). Given the large geographic distance in the state (median of 47 miles between patient and PCI center), 52% of all patients were transfers, and 36% were administered fibrinolysis at the referral facility. Following the intervention, there was a significant shift toward greater use of primary PCI as the dominant reperfusion strategy (from 47% to 60%, P=0.002), and the median total ischemic time from symptom onset to arterial reperfusion was decreased by 92 minutes (P<0.001). There was a similar significant reduction in median time from receiving center door to balloon of 11 minutes less than the baseline time (P<0.01).

Conclusions

Rural systems of care for ST‐segment elevation myocardial infarction require increased levels of cooperation between emergency medical services agencies and hospitals. This study confirms that total ischemic times can be reduced through a coordinated rural statewide initiative.

Incidence and In-Hospital Mortality of Acute Kidney Injury (AKI) and Dialysis-Requiring AKI (AKI-D) After Cardiac Catheterization in the National Inpatient Sample

Background

Acute kidney injury (AKI) and dialysis‐requiring AKI (AKI‐D) are common, serious complications of cardiac procedures.

Methods and Results

We evaluated 3 633 762 (17 765 214 weighted population) cardiac catheterization or percutaneous coronary intervention (PCI) hospital discharges from the nationally representative National Inpatient Sample to determine annual population incidence rates for AKI and AKI‐D in the United States from 2001 to 2011. Odds ratios for both conditions and associated in‐hospital mortality were calculated for each year in the study period using multiple logistic regression. The number of cardiac catheterization or PCI cases resulting in AKI rose almost 3‐fold from 2001 to 2011. The adjusted odds of AKI and AKI‐D per year among cardiac catheterization and PCI patients were 1.11 (95% CI: 1.10–1.12) and 1.01 (95% CI: 0.99–1.02), respectively. Most importantly, in‐hospital mortality significantly decreased from 2001 to 2011 for AKI (19.6–9.2%) and AKI‐D (28.3–19.9%), whereas odds of associated in‐hospital mortality were 0.50 (95% CI: 0.45–0.56) and 0.70 (95% CI: 0.55–0.93) in 2011 versus 2001, respectively. The population‐attributable risk of mortality for AKI and AKI‐D was 25.8% and 3.8% in 2001 and 41.1% and 6.5% in 2011, respectively. Males and females had similar patterns of AKI increase, although males outpaced females.

Conclusions

The Incidence of AKI among cardiac catheterization and PCI patients has increased sharply in the United States, and this should be addressed by implementing prevention strategies. However, mortality has significantly declined, suggesting that efforts to manage AKI and AKI‐D after cardiac catheterization and PCI have reduced mortality.

Characteristics of Early and Late Adopting Hospitals Providing Percutaneous Coronary Intervention in Taiwan

BACKGROUND

Studies in the United States suggested that the characteristics of hospitals providing percutaneous coronary intervention (PCI) differed from those not providing PCI. However, little is known on the differences between the characteristics of early-adopting hospitals and those of late-adopting hospitals, and on their potential impacts on PCI volume and access.

METHODS AND RESULTS

We used inpatient claims data from 1997 to 2012 from the Taiwan National Health Insurance program to identify the hospitals offering PCI. Geographic information systems (GIS) were used to determine the population access to PCI hospital. As of 2012, 88 hospitals were capable of providing PCI. On the basis of the year that the hospitals started providing PCI, 32 hospitals were designated as early adopters (before 1998), 23 as early majority (1998-2002), 24 as late majority (2003-2007), and 16 as laggards (2008-2012). Hospitals that adopted PCI later were smaller in size and closer to an existing PCI hospital and had lower PCI volumes performed and less bypass surgery support. The median PCI volumes in 2012 were n=706, 330, 138, and 81 in early adopters, early majority, late majority, and laggards, respectively. Despite the low volume of PCI performed in laggard hospitals, the percentage with ST-elevation myocardial infarction and acute myocardial infarction as principal discharge diagnosis was higher than their early-adopting hospital counterparts. The percentage of the Taiwanese population living within 40 km of PCI hospitals (appropriate access defined in this study) was 95.7% in 1997 and 98.0% in 2002, and this has remained unchanged since 2002.

CONCLUSIONS

The characteristics of early-adopting hospitals differed from those of late-adopting hospitals. Despite lower PCI volume performed in late-adopting hospitals, many of them are in remote areas and provide needed and timely services for patients with acute myocardial infarction.

Association of Emergency Department Length of Stay and Crowding for Patients with ST-Elevation Myocardial Infarction

Introduction

With the majority of U.S. hospitals not having primary percutaneous coronary intervention (pPCI) capabilities, the time spent at transferring emergency departments (EDs) is predictive of clinical outcomes for patients with ST-elevation myocardial infarction (STEMI). Compounding the challenges of delivering timely emergency care are the known delays caused by ED crowding. However, the association of ED crowding with timeliness for patients with STEMI is unknown. We sought to examine the relationship between ED crowding and time spent at transferring EDs for patients with STEMI.

Methods

We analyzed the Centers for Medicare and Medicaid Services (CMS) quality data. The outcome was time spent at a transferring ED (i.e., door-in-door-out [DIDO]), was CMS measure OP-3b for hospitals with ≥10 acute myocardial infarction (AMI) cases requiring transfer (i.e., STEMI) annually: Time to Transfer an AMI Patient for Acute Coronary Intervention. We used four CMS ED timeliness measures as surrogate measures of ED crowding: admitted length of stay (LOS), discharged LOS, boarding time, and waiting time. We analyzed bivariate associations between DIDO and ED timeliness measures. We used a linear multivariable regression to evaluate the contribution of hospital characteristics (academic, trauma, rural, ED volume) to DIDO.

Results

Data were available for 405 out of 4,129 hospitals for the CMS DIDO measure. These facilities were primarily non-academic (99.0%), non-trauma centers (65.4%), and in urban locations (68.5%). Median DIDO was 54.0 minutes (IQR 42.0,68.0). Increased DIDO time was associated with longer admitted LOS and boarding times. After adjusting for hospital characteristics, a one-minute increase in ED LOS at transferring facilities was associated with DIDO (coefficient, 0.084 [95% CI [0.049,0.119]]; p<0.001). This translates into a five-minute increase in DIDO for every one-hour increase in ED LOS for admitted patients.

Conclusion

Among patients with STEMI presenting to U.S. EDs, we found that ED crowding has a small but operationally insignificant effect on time spent at the transferring ED.

Percutaneous Coronary Intervention in the United States: Risk Factors for Untimely Access

OBJECTIVE

To determine how access to percutaneous coronary intervention (PCI) is distributed across demographics.

DATA SOURCES

Secondary data from the 2011 American Hospital Association (AHA) survey data combined with 2010 Census.

STUDY DESIGN

We calculated prehospital times from 32,370 ZIP codes to the nearest PCI center. We used a multivariate logit model to determine the odds of untimely access by the ZIP code's concentration of vulnerable populations.

DATA COLLECTION

We used ZIP code-level data on community characteristics from the 2010 Census and supplemented it with 2011 AHA survey data on service-line availability of PCI for responding hospitals.

PRINCIPAL FINDINGS

For approximately 306 million Americans, the median prehospital time to the nearest PCI center is 33 minutes. While 84 percent of Americans live within one hour of a PCI center, the odds of untimely access are higher in low-income (OR: 3.00; 95 percent CI: 2.39, 3.77), rural (8.10; 95 percent CI: 6.84, 9.59), and highly Hispanic communities (2.55; 95 percent CI: 1.86, 3.49).

CONCLUSIONS

While the majority of Americans live within 60 minutes of a PCI center, rural, low-income, and highly Hispanic communities have worse PCI access. This may translate into worse outcomes for patients with acute myocardial infarction.

Thirty-day Hospital Readmissions in Patients with Non-ST-segment Elevation Acute Myocardial Infarction

BACKGROUND

Limited data exist about relatively recent trends in the magnitude and characteristics of patients who are rehospitalized shortly after admission for a non-ST-segment elevation acute myocardial infarction (NSTEMI). This observational study describes decade-long trends (1999-2009) in the magnitude and characteristics of patients readmitted to the hospital within 30 days of hospitalization for an incident (initial) episode of NSTEMI.

METHODS

We reviewed the medical records of 2249 residents of the Worcester (Mass) metropolitan area who were hospitalized for an initial NSTEMI in 6 biennial periods between 1999 and 2009 at 3 central Massachusetts medical centers.

RESULTS

The average age of our study population was 72 years, 90% were white, and 46% were women. The proportion of patients who were readmitted to the hospital for any cause within 30 days after discharge for an NSTEMI remained unchanged between 1999 and 2009 (approximately 15%) in both crude and multivariable adjusted analyses. Slight declines were observed for cardiovascular disease-related 30-day readmissions over the 10-year study period. Women, elderly patients, those with multiple chronic comorbidities or a prolonged index hospitalization, and patients who developed heart failure during their index hospitalization were at higher risk for being readmitted within 30 days than respective comparison groups.

CONCLUSION

Thirty-day hospital readmission rates after hospital discharge for a first NSTEMI remained stable between 1999 and 2009. We identified several groups at higher risk for hospital readmission; further surveillance efforts and/or tailored educational and treatment approaches remain needed for these groups.

The effect of interhospital transfers, emergency medical services, and distance on ischemic time in a rural ST-elevation myocardial infarction system of care

BACKGROUND

Regional myocardial infarction systems of care have been shown to improve timely access to primary percutaneous coronary intervention (PCI). However, there is a relatively sparse research on rural "frontier" regions. Arrival mode, high rates of interhospital transfers, long transport times, low population density, and mostly volunteer emergency medical services (EMS) distinguish this region from metropolitan systems of care. We sought to assess the effect of interhospital transfers, distance, and arrival mode on total ischemic times for patients with ST-elevation myocardial infarctions undergoing primary PCI.

METHODS

We assessed patient data from our observational cohort of 395 patients with ST-elevation myocardial infarction with PCI as their primary treatment strategy. Data came from the 10 PCI hospitals participating in the Wyoming Mission: Lifeline program from January 2013 to September 2014. We performed both regression and tests of differences.

RESULTS

Median total ischemic time was nearly 2.7 times greater in transferred patients than those presenting directly (379 vs 140 minutes). Distance in miles traveled between patient's home and PCI facility was 2.5 times larger in transfer patients (51 vs 20 miles). Emergency medical services arrival was associated with 23% shorter total ischemic times than self-arrival.

CONCLUSIONS

Transfer patients from referral hospitals had significantly greater total ischemic time, and use of EMS was associated with significantly lower times. Transport distance was mixed in its effect. These findings suggest a continued focus on improving transitions between referral and receiving centers and enhancing coordination in rural systems of care to reduce the multiplier effect of transfers on total ischemic time.

Timeliness of interfacility transfer for ED patients with ST-elevation myocardial infarction

OBJECTIVES

Most US hospitals lack primary percutaneous coronary intervention (PCI) capabilities to treat patients with ST-elevation myocardial infarction (STEMI) necessitating transfer to PCI-capable centers. Transferred patients rarely meet the 120-minute benchmark for timely reperfusion, and referring emergency departments (EDs) are a major source of preventable delays. We sought to use more granular data at transferring EDs to describe the variability in length of stay at referring EDs.

METHODS

We retrospectively analyzed a secondary data set used for quality improvement for patients with STEMI transferred to a single PCI center between 2008 and 2012. We conducted a descriptive analysis of the total time spent at each referring ED (door-in-door-out [DIDO] interval), periods that comprised DIDO (door to electrocardiogram [EKG], EKG-to-PCI activation, and PCI activation to exit), and the relationship of each period with overall time to reperfusion (medical contact-to-balloon [MCTB] interval).

RESULTS

We identified 41 EDs that transferred 620 patients between 2008 and 2012. Median MCTB was 135 minutes (interquartile range [IQR] 114,172). Median overall ED DIDO was 74 minutes (IQR 56,103) and was composed of door to EKG, 5 minutes (IQR 2,11); EKG-to-PCI activation, 18 minutes (IQR 7,37); and PCI activation to exit, 44 minutes (IQR 34,56). Door-in door-out accounted for the largest proportion (60%) of overall MCTB and had the largest variability (coefficient of variability, 1.37) of these intervals.

CONCLUSIONS

In this cohort of transferring EDs, we found high variability and substantial delays after EKG performance for patients with STEMI. Factors influencing ED decision making and transportation coordination after PCI activation are a potential target for intervention to improve the timeliness of reperfusion in patients with STEMI.