Robert F. Riley

Trends in Coronary Revascularization in the United States From 2001 to 2009 Recent Declines in Percutaneous Coronary Intervention Volumes

Background— There is speculation that the volume of percutaneous coronary interventions (PCIs) has been decreasing over the past several years. Published studies of PCI volume have evaluated regional or hospital trends, but few have captured national data. This study describes the use of coronary angiography and revascularization methods in Medicare patients from 2001 to 2009. Methods and Results— This retrospective study used data from the Centers for Medicare & Medicaid Services from 2001 to 2009. The annual number of coronary angiograms, PCI, intravascular ultrasound, fractional flow reserve, and coronary artery bypass graft (CABG) surgery procedures were determined from billing data and adjusted for the number of Medicare recipients. From 2001 to 2009, the average year-to-year increase for PCI was 1.3% per 1000 beneficiaries, whereas the mean annual decrease for CABG surgery was 5%. However, the increase in PCI volume occurred primarily from 2001 to 2004, as there was a mean annual rate of decline of 2.5% from 2004 to 2009; similar trends were seen with diagnostic angiography. The use of intravascular ultrasound and fractional flow reserve steadily increased over time. Conclusions— This study confirms recent speculation that PCI volume has begun to decrease. Although rates of CABG have waned for several decades, all forms of coronary revascularization have been declining since 2004.

The HEART Pathway Randomized Trial Identifying Emergency Department Patients With Acute Chest Pain for Early Discharge

Background—The HEART Pathway is a decision aid designed to identify emergency department patients with acute chest pain for early discharge. No randomized trials have compared the HEART Pathway with usual care. Methods and Results—Adult emergency department patients with symptoms related to acute coronary syndrome without ST-elevation on ECG (n=282) were randomized to the HEART Pathway or usual care. In the HEART Pathway arm, emergency department providers used the HEART score, a validated decision aid, and troponin measures at 0 and 3 hours to identify patients for early discharge. Usual care was based on American College of Cardiology/American Heart Association guidelines. The primary outcome, objective cardiac testing (stress testing or angiography), and secondary outcomes, index length of stay, early discharge, and major adverse cardiac events (death, myocardial infarction, or coronary revascularization), were assessed at 30 days by phone interview and record review. Participants had a mean age of 53 years, 16% had previous myocardial infarction, and 6% (95% confidence interval, 3.6%–9.5%) had major adverse cardiac events within 30 days of randomization. Compared with usual care, use of the HEART Pathway decreased objective cardiac testing at 30 days by 12.1% (68.8% versus 56.7%; P=0.048) and length of stay by 12 hours (9.9 versus 21.9 hours; P=0.013) and increased early discharges by 21.3% (39.7% versus 18.4%; P<0.001). No patients identified for early discharge had major adverse cardiac events within 30 days. Conclusions—The HEART Pathway reduces objective cardiac testing during 30 days, shortens length of stay, and increases early discharges. These important efficiency gains occurred without any patients identified for early discharge suffering MACE at 30 days. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique Identifier: NCT01665521.

Probing the Energy Landscape of Protein Folding/Unfolding Transition States

Previous molecular dynamics (MD) simulations of the thermal denaturation of chymotrypsin inhibitor 2 (CI2) have provided atomic-resolution models of the transition state ensemble that is well supported by experimental studies. Here, we use simulations to further investigate the energy landscape around the transition state region. Nine structures within approximately 35 ps and 3 A C(alpha) RMSD of the transition state ensemble identified in a previous 498 K thermal denaturation simulation were quenched under the quasi-native conditions of 335 K and neutral pH. All of the structures underwent hydrophobically driven collapse in response to the drop in temperature. Structures less denatured than the transition state became structurally more native-like, while structures that were more denatured than the transition state tended to show additional loss of native structure. The structures in the immediate region of the transition state fluctuated between becoming more and less native-like. All of the starting structures had the same native-like topology and were quite similar (within 3.5 A C(alpha) RMSD). That the structures all shared native-like topology, yet diverged into either more or less native-like structures depending on which side of the transition state they occupied on the unfolding trajectory, indicates that topology alone does not dictate protein folding. Instead, our results suggest that a detailed interplay of packing interactions and interactions with water determine whether a partially denatured protein will become more native-like under refolding conditions.

Managing Superior Vena Cava Syndrome as a Complication of Pacemaker Implantation: A Pooled Analysis of Clinical Practice

Background: Superior vena cava syndrome (SVCS) is a rare complication of pacemaker implantation. Numerous methods have been employed to treat this condition, ranging from anticoagulation and thrombolysis to surgical interventions and stenting. However, thus far only small case series have been reported and there is no currently accepted standard of care.

Performance of the EDACS-accelerated Diagnostic Pathway in a Cohort of US Patients with Acute Chest Pain.

BACKGROUND The Emergency Department Assessment of Chest pain Score-Accelerated Diagnostic Protocol (EDACS-ADP) is a decision aid designed to safely identify emergency department (ED) patients with chest pain for early discharge. Derivation and validation studies in Australasia have demonstrated high sensitivity (99%-100%) for major adverse cardiac events (MACE). OBJECTIVES To validate the EDACS-ADP in a cohort of US ED patients with symptoms suspicious for acute coronary syndrome (ACS). METHODS A secondary analysis of participants enrolled in the HEART Pathway Randomized Controlled Trial was conducted. This single-site trial enrolled 282 ED patients≥21 years old with symptoms concerning for ACS, inclusive of all cardiac risk levels. Each patient was classified as low risk or at risk by the EDACS-ADP based on EDACS, electrocardiogram, and serial troponins. Potential early discharge rate and sensitivity for MACE at 30 days, defined as cardiac death, myocardial infarction (MI), or coronary revascularization were calculated. RESULTS MACE occurred in 17/282 (6.0%) participants, including no deaths, 16/282 (5.6%) with MI, and 1/282 (0.4%) with coronary revascularization without MI. The EDACS-ADP identified 188/282 patients [66.7%, 95% confidence interval (CI): 60.8%-72.1%] as low risk. Of these, 2/188 (1.1%, 95% CI: 0.1%-3.9%) had MACE at 30 days. EDACS-ADP was 88.2% (95% CI: 63.6%-98.5%) sensitive for MACE, identifying 15/17 patients. Of the 2 patients identified as low risk with MACE, 1 had MI and 1 had coronary revascularization without MI. CONCLUSIONS Within a US cohort of ED patients with symptoms concerning for ACS, sensitivity for MACE was 88.2%. We are unable to validate the EDACS-ADP as sufficiently sensitive for clinical use.

Cost analysis of the History, ECG, Age, Risk factors, and initial Troponin (HEART) Pathway randomized control trial

Introduction: The HEART Pathway is a diagnostic protocol designed to identify low‐risk patients presenting to the emergency department with chest pain that are safe for early discharge. This protocol has been shown to significantly decrease health care resource utilization compared with usual care. However, the impact of the HEART Pathway on the cost of care has yet to be reported. Methods and Results: We performed a cost analysis of patients enrolled in the HEART Pathway trial, which randomized participants to either usual care or the HEART Pathway protocol. For low‐risk patients, the HEART Pathway recommended early discharge from the emergency department without further testing. We compared index visit cost, cost at 30 days, and cardiac‐related health care cost at 30 days between the 2 treatment arms. Costs for each patient included facility and professional costs. Cost at 30 days included total inpatient and outpatient costs, including the index encounter, regardless of etiology. Cardiac‐related health care cost at 30 days included the index encounter and costs adjudicated to be cardiac‐related within that period. Two hundred seventy of the 282 patients enrolled in the trial had cost data available for analysis. There was a significant reduction in cost for the HEART Pathway group at 30 days (median cost savings of

Diagnostic time course, treatment, and in-hospital outcomes for patients with ST-segment elevation myocardial infarction presenting with nondiagnostic initial electrocardiogram: A report from the American Heart Association Mission: Lifeline program

216 per individual), which was most evident in low‐risk (Thrombolysis In Myocardial Infarction score of 0‐1) patients (median savings of

HEART Pathway Accelerated Diagnostic Protocol Implementation: Prospective Pre-Post Interrupted Time Series Design and Methods

253 per patient) and driven primarily by lower cardiac diagnostic costs in the HEART Pathway group. Conclusions: Using the HEART Pathway as a decision aid for patients with undifferentiated chest pain resulted in significant cost savings.

Guidelines-based treatment of anaemic STEMI patients: practice patterns and effects on in-hospital mortality: a retrospective analysis from the NCDR.

BACKGROUND Prior studies indicate that a subset of patients diagnosed as having ST-segment elevation myocardial infarction (STEMI) will have an initial non-diagnostic electrocardiogram (ECG) during evaluation. However, the timing of diagnostic ECG changes in this group is unknown. Our primary aim was to describe the timing of ECG diagnosis of STEMI in patients whose initial ECG was non-diagnostic. Secondarily, we sought to compare the delivery of American College of Cardiology/American Heart Association guidelines-based care and in-hospital outcomes in this group compared with patients diagnosed as having STEMI on initial ECG. METHODS We analyzed data from 41,560 patients diagnosed as having STEMI included in the National Cardiovascular Data Registry ACTION Registry-GWTG from January 2007 to December 2010. We divided this study population into 2 groups: those diagnosed on initial ECG (N = 36,994) and those with an initial non-diagnostic ECG that were diagnosed on a follow-up ECG (N = 4,566). RESULTS In general, baseline characteristics and clinical presentations were similar between the 2 groups. For patients with an initial non-diagnostic ECG, 72.4% (n = 3,305) had an ECG diagnostic for STEMI within 90 minutes of their initial ECG. There did not appear to be significant differences in the administration of guideline-recommended treatments for STEMI, in-hospital major bleeding (P = .926), or death (P = .475) between these groups. CONCLUSIONS In a national sample of patients diagnosed as having STEMI, 11.0% had an initial non-diagnostic ECG. Of those patients, 72.4% had a follow-up diagnostic ECG within 90 minutes of their initial ECG. There did not appear to be clinically meaningful differences in guidelines-based treatment or major inhospital outcomes between patients diagnosed as having STEMI on an initial ECG and those diagnosed on a follow-up ECG.The 12-lead electrocardiogram(ECG) is one of the corner stones of the initial evaluation for acute myocardial infarction (AMI). However, ECG findings during AMI can vary substantially depending on the type, stage, and extent of infarction and timing of ECG acquisition.1–3 Several studies cited in the current American College of Emergency Physicians (ACEP) and American College of Cardiology (ACC)/American Heart Association (AHA) recommendations regarding serial ECG monitoring in patients being evaluated for acute coronary syndromes (ACS) indicate that a subset of patients ultimately diagnosed with ST-segment elevation myocardial infarction (STEMI) will have an initial non-diagnostic ECG.4,5 However, little has been reported about the timing of diagnostic ST-segment elevation in those with initial non-diagnostic ECGs. The primary aim of this study was to describe the timing of ECG diagnosis of STEMI in patients with an initial non-diagnostic ECG. The secondary objectives were to determine whether the delay in diagnosis of STEMI for patients with an initial non-diagnostic ECG resulted in differing administration of guidelines-recommended treatments and in-hospital outcomes compared to patients whose initial ECG was diagnostic. Given the importance of timely recognition of STEMI, further characterization of the diagnostic time course in patients with delayed ECG diagnosis, along with its association with treatment and outcomes, is warranted.

Chest Pain Risk Stratification: A Comparison of the 2-hour Accelerated Diagnostic Protocol (adapt) and the Heart Pathway

Background Most patients presenting to US Emergency Departments (ED) with chest pain are hospitalized for comprehensive testing. These evaluations cost the US health system >