Hospital variation in the use of noninvasive cardiac imaging and its association with downstream testing, interventions, and outcomes

Clinical Outcomes After Cardiac Stress Testing Among US Patients Younger Than 65 Years

Background

Scientific statements have championed the measurement of clinical outcomes after cardiac stress testing to better define their value. Using contemporary national data, we sought to describe the characteristics of patients who experience outcomes after stress testing.

Methods and Results

Using administrative claims from a large national private insurer, we conducted an observational cohort study of patients without cardiovascular disease aged 25 to 64 years who underwent stress testing from 2006 to 2011 and had at least 1 year of membership in the insurance company before and after testing. We used Kaplan–Meier time‐to‐event analyses to determine rates of acute myocardial infarction (AMI), elective coronary revascularization, and coronary angiography without revascularization in the year following testing. We used logistic regression to determine factors associated with outcomes, and stratified the cohort into quintiles based on likelihood of experiencing AMI and/or revascularization to describe the characteristics of patients at highest and lowest risk. Among 553 027 patients who underwent stress testing (mean age 50 years, 49% women, 73% white), 0.8% were hospitalized for AMI, 1.8% underwent elective coronary revascularization, and 2.5% underwent coronary angiography without revascularization within 1 year. Patients who were older, male, and white were more likely to undergo subsequent revascularization. Patients in the lowest likelihood quintile were young (mean age 40 years), frequently women (84.7%), had a low incidence of coexisting conditions (5.2% with diabetes mellitus), and had a 0.5% rate of AMI and/or revascularization.

Conclusions

The proportion of US patients younger than 65 who had AMI and/or coronary revascularization after stress testing was low. Assessing risk of subsequent outcomes may be useful in improving patient referrals for stress testing.

12-year Temporal Trend in Referral Pattern and Test Results of Stress Echocardiography in a Tertiary Care Referral Center with Moderate Volume Activities and Cath-lab Facility

Background

Data on stress echocardiography (SE) time-related changes in referral patterns and diagnostic yield for detection of inducible ischemia could enhance Echo Lab quality benchmarks and performance measures.

Aim

This study aims to evaluate temporal trends in SE test results among ambulatory patients with suspected or known coronary artery disease (CAD) in a tertiary care referral center with moderate (>100/year) volume SE activities and Cath-Lab facility.

Methods

From January 2004 to December 2015, 1954 patients (mean age 62 ± 12 years, 42% women, 27% with known CAD) underwent SE (1673 exercise SE, 86%, 246 pharmacological SE, 12%, 35 pacing SE, 2%). Time was grouped into three 4 year periods, where clinical data and test results were evaluated.

Results

Our series comprised low-to-intermediate pretest probability of CAD throughout the observation period (overall pretest probability of CAD 19% ± 15%). A progressive decline over time in the rate of pharmacological SE instead of a dramatic increment of exercise SE (79%-96%, P < 0.0001) was noted. The use of beta-blockers increased (from 43% to 66%, P < 0.0001), while the use of nitrates decreased (from 11% to 4%, P < 0.0001) over time. We noted a very uncommon occurrence of abnormal test results with a further decrease in the last period (from 11% to 3%, P < 0.0001).

Conclusions

We observed, over a 12-year period, a progressive decrease in the frequency of inducible myocardial ischemia among patients with known or suspected CADe referred to our Echo Lab for SE with Cath-Lab facility, and this trend was parallel to changes in SE referral practice. These findings are particularly relevant if we consider the practical implications on diagnostic SE accuracy and risk assessment.

Defining Quality in Cardiovascular Imaging: A Scientific Statement From the American Heart Association

The aims of the current statement are to refine the definition of quality in cardiovascular imaging and to propose novel methodological approaches to inform the demonstration of quality in imaging in future clinical trials and registries. We propose defining quality in cardiovascular imaging using an analytical framework put forth by the Institute of Medicine whereby quality was defined as testing being safe, effective, patient-centered, timely, equitable, and efficient. The implications of each of these components of quality health care are as essential for cardiovascular imaging as they are for other areas within health care. Our proposed statement may serve as the foundation for integrating these quality indicators into establishing designations of quality laboratory practices and developing standards for value-based payment reform for imaging services. We also include recommendations for future clinical research to fulfill quality aims within cardiovascular imaging, including clinical hypotheses of improving patient outcomes, the importance of health status as an end point, and deferred testing options. Future research should evolve to define novel methods optimized for the role of cardiovascular imaging for detecting disease and guiding treatment and to demonstrate the role of cardiovascular imaging in facilitating healthcare quality.

Cardiovascular Testing and Clinical Outcomes in Emergency Department Patients With Chest Pain

IMPORTANCE

Noninvasive testing and coronary angiography are used to evaluate patients who present to the emergency department (ED) with chest pain, but their effects on outcomes are uncertain.

OBJECTIVE

To determine whether cardiovascular testing-noninvasive imaging or coronary angiography-is associated with changes in the rates of coronary revascularization or acute myocardial infarction (AMI) admission in patients who present to the ED with chest pain without initial findings of ischemia.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort analysis used weekday (Monday-Thursday) vs weekend (Friday-Sunday) presentation as an instrument to adjust for unobserved case-mix variation (selection bias) between 2011 and 2012. National claims data (Truven MarketScan) was used. The data included a total of 926 633 privately insured patients ages 18 to 64 years who presented to the ED with chest pain without initial diagnosis consistent with acute ischemia.

EXPOSURES

Noninvasive testing or coronary angiography within 2 days or 30 days of presentation.

MAIN OUTCOMES AND MEASURES

The primary end points were coronary revascularization (percutaneous coronary intervention or coronary artery bypass graft surgery) and AMI admission at 7, 30, 180, and 365 days. The secondary end points were coronary angiography and coronary artery bypass grafting in those who underwent angiography.

RESULTS

The patients were ages 18 to 64 years with an average age of 44.4 years. A total of 536 197 patients (57.9%) were women. Patients who received testing (224 973) had increased risk at baseline and had greater risk of AMI admission than those who did not receive testing (701 660) (0.35% vs 0.14% at 30 days). Weekday patients (571 988) had similar baseline comorbidities to weekend patients (354 645) but were more likely to receive testing. After risk factor adjustment, testing within 30 days was associated with a significant increase in coronary angiography (36.5 per 1000 patients tested; 95% CI, 21.0-52.0) and revascularization (22.8 per 1000 patients tested; 95% CI, 10.6-35.0) at 1 year but no significant change in AMI admissions (7.8 per 1000 patients tested; 95% CI, -1.4 to 17.0). Testing within 2 days was also associated with a significant increase in coronary revascularization but no difference in AMI admissions.

CONCLUSIONS AND RELEVANCE

Cardiac testing in patients with chest pain was associated with increased downstream testing and treatment without a reduction in AMI admissions, suggesting that routine testing may not be warranted. Further research into whether specific high-risk subgroups benefit from testing is needed.

Clinical risk factors alone are inadequate for predicting significant coronary artery disease

OBJECTIVE

We sought to derive and validate a model for identifying suspected ACS patients harboring undiagnosed significant coronary artery disease (CAD).

METHODS

This was a secondary analysis of data from a randomized control trial (RCT). Patients randomized to the CTA arm of an RCT examining a CTA-based strategy for ruling-out acute coronary syndrome (ACS) constitute the derivation cohort, which was randomly divided into a training dataset (2/3, used for model derivation) and a test dataset (1/3, used for internal validation (IV)). ED patients from a different center receiving CTA to evaluate for suspected ACS constitute the external validation (EV) cohort. Primary outcome was CTA-assessed significant CAD (stenosis of ≥50% in a major coronary artery).

RESULTS

In the derivation cohort, 11.2% (76/679) of subjects had CTA-assessed significant CAD, and in the EV cohort, 8.2% of subjects (87/1056) had CTA-assessed significant CAD. Age was the strongest predictor of significant CAD among the clinical risk factors examined. Predictor variables included in the derived logistic regression model were: age, sex, tobacco use, diabetes, and race. This model exhibited an area under the receiver operating characteristic curve (ROC AUC) of 0.72 (95% CI: 0.61-0.83) based on IV, and 0.76 (95% CI: 0.70, 0.82) based on EV. The derived random forest model based on clinical risk factors yielded improved but not sufficient discrimination of significant CAD (ROC AUC = 0.76 [95% CI: 0.67-0.85] based on IV). Coronary artery calcium score was a more accurate predictor of significant CAD than any combination of clinical risk factors (ROC AUC = 0.85 [95% CI: 0.76-0.94] based on IV; ROC AUC = 0.92 [95% CI: 0.88-0.95] based on EV).

CONCLUSIONS

Clinical risk factors, either individually or in combination, are insufficient for accurately identifying suspected ACS patients harboring undiagnosed significant coronary artery disease.

ANMCO/GICR-IACPR/SICI-GISE Consensus Document: the clinical management of chronic ischaemic cardiomyopathy

Stable coronary artery disease (CAD) is a clinical entity of great epidemiological importance. It is becoming increasingly common due to the longer life expectancy, being strictly related to age and to advances in diagnostic techniques and pharmacological and non-pharmacological interventions. Stable CAD encompasses a variety of clinical and anatomic presentations, making the identification of its clinical and anatomical features challenging. Therapeutic interventions should be defined on an individual basis according to the patient's risk profile. To this aim, management flow charts have been reviewed based on sustainability and appropriateness derived from recent evidence. Special emphasis has been placed on non-pharmacological interventions, stressing the importance of lifestyle changes, including smoking cessation, regular physical activity, and diet. Adherence to therapy as an emerging risk factor is also discussed.

Noninvasive Testing in Emergency Department Patients with Low-Risk Chest Pain: Does the Evidence Support Current Guidelines?

Patients who present to the emergency department with chest pain but no evidence of ischemia on the electrocardiogram and negative cardiac markers are at very low risk. The newest American Heart Association/American College of Cardiology guidelines give noninvasive cardiac testing a IIa recommendation in this patient population. Here, we will review the existing literature that was cited in the American Heart Association/American College of Cardiology document, as well as several large, contemporary, comparative observational studies which were not included to address the following question: Do the benefits of noninvasive cardiac testing in this patient population outweigh the risks?

Impact of Glycoprotein IIb/IIIa Inhibitors Use on Outcomes After Lower Extremity Endovascular Interventions From Nationwide Inpatient Sample (2006-2011)

OBJECTIVE

The aim of our study was to study the impact of glycoprotein IIb/IIIa inhibitors (GPI) on in-hospital outcomes.

BACKGROUND

There is paucity of data regarding the impact of GPI on the outcomes following peripheral endovascular interventions.

METHODS

The study cohort was derived from Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS) database between the years 2006 and 2011. Peripheral endovascular interventions and GPI utilization were identified using appropriate ICD-9 Diagnostic and procedural codes. Two-level hierarchical multivariate mixed models were created. The study outcomes were: primary (in-hospital mortality and amputation studied separately) and secondary (composite of in-hospital mortality and postprocedural complications). Hospitalization costs were also assessed.

RESULTS

GPI utilization (OR, 95% CI, P-value) was independently predictive of lower amputation rates (0.36, 0.27-0.49, <0.001). There was no significant difference in terms of in-hospital mortality (0.59, 0.31-1.14, P 0.117), although GPI use predicted worse secondary outcomes (1.23, 1.03-1.47, 0.023). Following propensity matching, the amputation rate was lower (3.2% vs. 8%, P < 0.001), while hospitalization costs were higher in the cohort that received GPI ($21,091 ± 404 vs. 19,407 ± 133, P < 0.001).

CONCLUSIONS

Multivariate analysis revealed GPI use in peripheral endovascular interventions to be suggestive of an increase in composite end-point of in-hospital mortality and postprocedural complications, no impact on in-hospital mortality alone, significantly lower rate of amputation, and increase in hospitalization costs. © 2016 Wiley Periodicals, Inc.

Implementation of a Computerized Order Entry Tool to Reduce the Inappropriate and Unnecessary Use of Cardiac Stress Tests With Imaging in Hospitalized Patients

The rising use of imaging cardiac stress tests has led to potentially unnecessary testing. Interventions designed to reduce inappropriate stress testing have focused on the ambulatory setting. We developed a computerized order entry tool intended to reduce the use of imaging cardiac stress tests and improve appropriate use in hospitalized patients. The tool was evaluated using preimplementation and postimplementation cohorts at a single urban academic teaching hospital. All hospitalized patients referred for testing were included. The co-primary outcomes were the use of imaging stress tests as a percentage of all stress tests and the percentage of inappropriate tests, compared between the 2 cohorts. There were 478 patients in the precohort and 463 in the postcohort. The indication was chest pain in 66% and preoperative in 18% and was not significantly different between groups. The use of nonimaging stress tests increased from 4% in the pregroup to 15% in the postgroup (p <0.001). Among very low-risk chest pain patients, the use of nonimaging stress tests increased from 7% to 25% (p <0.001). Inappropriate testing did not change significantly between groups (12% vs 11%). Inappropriate tests were most often preoperative evaluations (83%). In conclusion, our computerized ordering tool significantly increased the use of nonimaging cardiac stress tests and reduced the use of imaging tests yet was not able to reduce inappropriate use. Our study highlights the differences in cardiac stress testing between hospitalized and ambulatory patients.

Comparison of In-Hospital Mortality, Length of Stay, Postprocedural Complications, and Cost of Single-Vessel Versus Multivessel Percutaneous Coronary Intervention in Hemodynamically Stable Patients With ST-Segment Elevation Myocardial Infarction (from Nationwide Inpatient Sample [2006 to 2012])

The primary objective of our study was to evaluate the in-hospital outcomes in terms of mortality, procedural complications, hospitalization costs, and length of stay (LOS) after multivessel percutaneous coronary intervention (MVPCI) in hemodynamically stable patients with ST-segment elevation myocardial infarction (STEMI). The study cohort was derived from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample database, years 2006 to 2012. Percutaneous coronary interventions (PCI) performed during STEMI were identified using appropriate International Classification of Diseases, Ninth Revision, diagnostic and procedural codes. Patients in cardiogenic shock were excluded. Hierarchical mixed-effects logistic regression models were used for categorical dependent variables such as in-hospital mortality and composite of in-hospital mortality and complications, and hierarchical mixed-effects linear regression models were used for continuous dependent variables such as cost of hospitalization and LOS. We identified 106,317 (weighted n = 525,161) single-vessel PCI and 15,282 (weighted n = 74,543) MVPCIs. MVPCI (odds ratio, 95% confidence interval [CI], p value) was not associated with significant increase in in-hospital mortality (0.99, 0.85 to 1.15, 0.863) but predicted a higher composite end point of in-hospital mortality and postprocedural complications (1.09, 1.02 to 1.17, 0.013) compared to single-vessel PCI. MVPCI was also predictive of longer LOS (LOS +0.19 days, 95% CI +0.14 to +0.23 days, p <0.001) and higher hospitalization costs (cost +$4,445, 95% CI +$4,128 to +$4,762, p <0.001). MVPCI performed during STEMI in hemodynamically stable patients is associated with no increase in in-hospital mortality but a higher rate of postprocedural complications and longer LOS and greater hospitalization costs compared to single-vessel PCI.

Association of Liability Concerns with Decisions to Order Echocardiography and Cardiac Stress Tests with Imaging

BACKGROUND

Professional societies have made efforts to curb overuse of cardiac imaging and decrease practice variation by publishing appropriate use criteria. However, little is known about the impact of physician-level determinants such as liability concerns and risk aversion on decisions to order testing.

METHODS

A web-based survey was administered to cardiologists and general practice physicians affiliated with two academic institutions. The survey consisted of four clinical scenarios in which appropriate use criteria rated echocardiography or stress testing as "may be appropriate." Respondents' degree of liability concerns and risk aversion were measured using validated tools. The primary outcome variable was tendency to order imaging, calculated as the average likelihood to order an imaging test across the clinical scenarios (1 = very unlikely, 6 = very likely). Linear regression models were used to evaluate the association between tendency to order imaging and physician characteristics.

RESULTS

From 420 physicians invited to participate, 108 complete responses were obtained (26% response rate, 54% cardiologists). There was no difference in tendency to order imaging between cardiologists and general practice physicians (3.46 [95% CI, 3.12-3.81] vs 3.15 [95% CI, 2.79-3.51], P = .22). On multivariate analysis, a higher degree of liability concerns was the only significant predictor of decisions to order imaging (mean difference in tendency to order imaging, 0.36; 95% CI, 0.09-0.62; P = .01).

CONCLUSION

In clinical situations in which performance of cardiac imaging is rated as "may be appropriate" by appropriate use criteria, physicians with higher liability concerns ordered significantly more testing than physicians with lower concerns.

A multi-center study of fidaxomicin use for Clostridium difficile infection

Purpose

Fidaxomicin use in real-world clinical practice, especially for severe Clostridium difficile infection (CDI), is mainly based on single-center observational studies. The purpose of this pharmacoepidemiology study was to assess outcomes of patients given fidaxomicin based on episode number and use of concomitant antibiotics.

Methods

Fidaxomicin use over time across included hospitals in the United States was assessed using a large inpatient drug utilization database. A multicenter retrospective chart review was also conducted of hospitalized patients with CDI that received fidaxomicin between 2011 and 2013. Fidaxomicin utilization and clinical outcomes were stratified by use of fidaxomicin for first or second episode (early episodes) versus greater than or equal to episodes (later episodes).

Results

The overall fidaxomicin use rate was 2.16 % which increased from 0.22 % in the last two quarters of 2011 to 3.16 % in the first two quarters of 2013. A total of 102 hospitalized patients that received fidaxomicin from 11 hospitals were identified in the multicenter study. Sixty-nine patients received fidaxomicin for early (68 % with severe CDI) and 33 received for later episodes. The majority of patients received other CDI therapy including 61 patients (88 %) for early episodes and 27 (82 %) for later episodes. Concomitant non-CDI antibiotics were received by 48 patients (47 %). Rates of clinical outcomes were similar regardless of CDI episode.

Conclusion

This study demonstrated a slow but steady increase in fidaxomicin utilization over time; most of which was combined with other systemic antibiotics. Antimicrobial stewardship teams should provide guidance on appropriate use of fidaxomicin to optimize therapy and assess the need to continue other antibiotics during CDI treatment.

Limited Hospital Variation in the Use and Yield of CT for Pulmonary Embolism in Patients Undergoing Total Hip or Total Knee Replacement Surgery

Purpose To evaluate the variation among U.S. hospitals in overall use and yield of in-hospital computed tomographic (CT) pulmonary angiography (PA) in patients undergoing total hip replacement (THR) or total knee replacement (TKR) surgery. Materials and Methods Patients in the Premier Research Database who underwent elective TKR or THR between 2007 and 2011 were enrolled in this HIPAA-compliant, institutional review board-approved retrospective observational study. The informed consent requirement was waived. Hospitals were categorized into low, medium, and high tertiles of CT PA use to compare baseline patient- and hospital-level characteristics and pulmonary embolism (PE) positivity rates. To further investigate between-hospital variation in CT PA use, a hierarchical logistic regression model that included hospital-specific random effects and fixed patient- and hospital-level effects was used. The intraclass correlation coefficient (ICC) was used to measure the amount of variability in CT PA use attributable to between-hospital variation. Results The cohort included 205 198 patients discharged from 178 hospitals (median of 734.5 patients discharged per hospital; interquartile range, 316-1461 patients) with 3647 CT PA studies (1.8%). The crude frequency of CT PA scans among the hospitals ranged from 0% to 6.2% (median, 1.6%); more than 90% of the hospitals performed CT PA in less than 3% of their patients. The mean hospital-level PE positivity rate was 12.3% (median, 9.1%); there was no significant difference in PE positivity rate across low through high CT PA use tertiles (11.3%, 11.9%, 12.9%, P = .37). After adjustment for hospital- and patient-level factors, the remaining amount of interhospital variation was relatively low (ICC, 9.0%). Conclusion Limited interhospital variation in use and yield of in-hospital CT PA was observed among patients undergoing TKR or THR in the United States. ^© RSNA, 2016 Online supplemental material is available for this article.

Association of Early Stress Testing with Outcomes for Emergency Department Evaluation of Suspected Acute Coronary Syndrome

BACKGROUND

Professional society guidelines suggest early stress testing (within 72 hours) after an emergency department (ED) evaluation for suspected acute coronary syndrome (ACS). However, there is increasing concern that current practice results in over-testing without evidence of benefit. We test the hypothesis that early stress testing improves outcomes.

METHODS

We analyzed prospectively collected data from 9 EDs on patients with suspected ACS, 1999-2001. We excluded patients with an ED diagnosis of ACS. The primary outcome was 30-day major adverse cardiac events (MACEs), including all-cause death, acute myocardial infarction, and revascularization. We used the HEART score to determine pretest ACS risk (low, intermediate, and high). To mitigate potential confounding, patients with and without early stress testing were matched within pretest risk strata in a 1:2 ratio using propensity scores.

RESULTS

Of 7127 potentially eligible patients, 895 (13%) received early stress testing. The analytic cohort included 895 patients with early stress testing matched to 1790 without early stress testing. The overall 30-day MACE rate in both the source and analytic population was 3%. There were no baseline imbalances after propensity score matching (P > 0.1 for more than 30 variables). There was no association between early stress testing and 30-day MACE [odds ratio, 1.0; 95% confidence interval (CI), 0.6-1.7]. There was no effect modification by pretest risk (low: odds ratio, 1.0; 95% CI, 0.2-3.7; intermediate: 1.2; 95% CI, 0.6-2.6; high: 0.4; 95% CI, 0.1-1.6).

CONCLUSIONS

Early stress testing is not associated with reduced MACE in patients evaluated for suspected ACS. Early stress testing may have limited value in populations with low MACE rate.

Practice-Level Variation in Outpatient Cardiac Care and Association With Outcomes

BACKGROUND

Utilization of cardiac services varies across regions and hospitals, yet little is known regarding variation in the intensity of outpatient cardiac care across cardiology physician practices or the association with clinical endpoints, an area of potential importance to promote efficient care.

METHODS AND RESULTS

We included 7 160 732 Medicare beneficiaries who received services from 5635 cardiology practices in 2012. Beneficiaries were assigned to practices providing the plurality of office visits, and practices were ranked and assigned to quartiles using the ratio of observed to predicted annual payments per beneficiary for common cardiac services (outpatient intensity index). The median (interquartile range) outpatient intensity index was 1.00 (0.81-1.24). Mean payments for beneficiaries attributed to practices in the highest (Q4) and lowest (Q1) quartile of outpatient intensity were: all cardiac payments (Q4 $1272 vs Q1 $581; ratio, 2.2); cardiac catheterization (Q4 $215 vs Q1 $64; ratio, 3.4); myocardial perfusion imaging (Q4 $253 vs Q1 $83; ratio, 3.0); and electrophysiology device procedures (Q4 $353 vs Q1 $142; ratio, 2.5). The adjusted odds ratios (95% CI) for 1 incremental quartile of outpatient intensity for each outcome was: cardiac surgical/procedural hospitalization (1.09 [1.09, 1.10]); cardiac medical hospitalization (1.00 [0.99, 1.00]); noncardiac hospitalization (0.99 [0.99, 0.99]); and death at 1 year (1.00 [0.99, 1.00]).

CONCLUSION

Substantial variation in the intensity of outpatient care exists at the cardiology practice level, and higher intensity is not associated with reduced mortality or hospitalizations. Outpatient cardiac care is a potentially important target for efforts to improve efficiency in the Medicare population.

In-Hospital Outcomes of Atherectomy During Endovascular Lower Extremity Revascularization

Contemporary data on clinical outcomes after utilization of atherectomy in lower extremity endovascular revascularization are sparse. The study cohort was derived from Healthcare Cost and Utilization Project nationwide inpatient sample database from the year 2012. Peripheral endovascular interventions including atherectomy were identified using appropriate International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic and procedural codes. The subjects were divided and compared in 2 groups: atherectomy versus no atherectomy. Two-level hierarchical multivariate mixed models were created. The coprimary outcomes were in-hospital mortality and amputation; secondary outcome was a composite of in-hospital mortality and periprocedural complications. Hospitalization costs were also assessed. Atherectomy utilization (odds ratio, 95% CI, p value) was independently predictive of lower in-hospital mortality (0.46, 0.28 to 0.75, 0.002) and lower amputation rates (0.83, 0.71 to 0.97, 0.020). Atherectomy use was also predictive of significantly lower secondary composite outcome of in-hospital mortality and complications (0.79, 0.69 to 0.90, 0.001). In the propensity-matched cohort, atherectomy utilization was again associated with a lower rate of amputation (11.18% vs 12.92%, p = 0.029), in-hospital mortality (0.71% vs 1.53%, p 0.001), and any complication (13.24% vs 16.09%, p 0.001). However, atherectomy use was also associated with higher costs ($24,790 ± 397 vs $22635 ± 251, p <0.001). Atherectomy use in conjunction with angioplasty (with or without stenting) was associated with improved in-hospital outcomes in terms of lower amputation rates, mortality, and postprocedural complications.

Coronary Atherectomy in the United States (from a Nationwide Inpatient Sample)

Contemporary real-world data on clinical outcomes after utilization of coronary atherectomy are sparse. The study cohort was derived from Healthcare Cost and Utilization Project Nationwide Inpatient Sample database from year 2012. Percutaneous coronary interventions including atherectomy were identified using appropriate International Classification of Diseases, 9th Revision diagnostic and procedural codes. Two-level hierarchical multivariate mixed models were created. The primary outcome was a composite of in-hospital mortality and periprocedural complications; the secondary outcome was in-hospital mortality. Hospitalization costs were also assessed. A total of 107,131 procedures were identified in 2012. Multivariate analysis revealed that atherectomy utilization was independently predictive of greater primary composite outcome of in-hospital mortality and complications (odds ratio 1.34, 95% confidence interval 1.22 to 1.47, p <0.001) but was not associated with any significant difference in terms of in-hospital mortality alone (odds ratio 1.22, 95% confidence interval 0.99 to 1.52, p 0.063). In the propensity-matched cohort, atherectomy utilization was again associated with a higher rate of complications (12.88% vs 10.99%, p = 0.001), in-hospital mortality +a ny complication (13.69% vs 11.91%, p = 0.003) with a nonsignificant difference in terms of in-hospital mortality alone (3.45% vs 2.88%, p = 0.063) and higher hospitalization costs ($25,341 ± 353 vs $21,984 ± 87, p <0.001). Atherectomy utilization during percutaneous coronary intervention is associated with a higher rate of postprocedural complications without any significant impact on in-hospital mortality.

Prognosis of Low-Risk Young Women Presenting to the Emergency Department With Chest Pain

Identification of patients at low risk presenting to the emergency department with chest pain is a continuing challenge. We examined a cohort of low-risk women with negative cardiac injury markers, electrocardiogram with normal results, and clinical stability. We hypothesized that these patients can be safely and accurately managed in a chest pain unit (CPU), may not require predischarge cardiac testing, and have an excellent short-term prognosis. The primary end point was major cardiovascular events during index admission or follow-up. Mean age of the 403 women was 42 ± 4.3 years (30 to 50 years). No patient had a cardiovascular event in the CPU, and none of the 321 patients followed for 6 months had a late cardiovascular event. Most (211, 52%) did not receive predischarge cardiac testing. The remaining 192 patients (48%) had predischarge exercise treadmill test, stress imaging, or cardiac catheterization. Of those patients who underwent treadmill testing, almost 90% had no exercise-induced chest pain and approximately 50% had functional capacity 8 to 14 METs. In addition, 166 patients (41%) were discharged from the CPU after <2 hours and 21% (n = 86) within 2 to 8 hours. In conclusion, this group of low-risk women was safely and accurately managed in the CPU and discharged promptly. There were no cardiac events on index admission or 6-month follow-up, and in most patients, predischarge cardiac testing was unnecessary.

Intravascular Ultrasound in Lower Extremity Peripheral Vascular Interventions

Purpose: To examine the impact of intravascular ultrasound (IVUS) utilization during lower limb endovascular interventions as regards postprocedural complications and amputation. Methods: The study cohort was derived from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample database between the years 2006 and 2011. Peripheral endovascular interventions were identified using appropriate ICD-9 procedure codes. Two-level hierarchical multivariate mixed models were created. The co-primary outcomes were in-hospital mortality and amputation; the secondary outcome was postprocedural complications. Model results are given as the odds ratio (OR) and 95% confidence interval (CI). Hospitalization costs were also assessed. Results: Overall, among the 92,714 patients extracted from the database during the observation period, IVUS was used in 1299 (1.4%) patients. IVUS utilization during lower extremity peripheral vascular procedures was independently predictive of a lower rate of postprocedural complications (OR 0.80, 95% CI 0.66 to 0.99, p=0.037) as well as lower amputation rates (OR 0.59, 95% CI 0.45 to 0.77, p<0.001) without any significant impact on in-hospital mortality. Multivariate analysis also revealed IVUS utilization to be predictive of a nonsignificant increase in hospitalization costs ($1333, 95% CI −$167 to +$2833, p=0.082). Conclusion: IVUS use during lower limb endovascular interventions is predictive of lower postprocedural complication and amputation rates with a nonsignificant increase in hospitalization costs.

Trends in referral patterns, invasive management, and mortality in elderly patients referred for exercise stress testing

INTRODUCTION

Scarce data are available on the temporal patterns in clinical characteristics and outcomes of elderly patients referred for exercise stress testing. We aimed to assess the trends in baseline characteristics, tests results, referrals for invasive management, and mortality in these patients.

METHODS

We evaluated 11,192 patients aged ≥65years who were referred for exercise stress testing between January 1998 and December 2013. Calendar years were grouped into four quadrennia (1998-2001, 2002-2005, 2006-2009, and 2010-2013), and trends in clinical characteristics of the patients, type and results of the tests, referrals for invasive management, and mortality across the different periods were assessed.

RESULTS

Despite a progressive decrease in the proportion of patients with non-interpretable baseline electrocardiograms or prior history of coronary artery disease, there was a gradual and marked increase in the use of cardiac imaging from 32.8% in 1998-2001 to 67.6% in 2010-2013 (p<0.001). In addition, despite a gradual decline in the probability of positive exercise stress testing both without imaging (from 18.9 to 13.6%, p<0.001) and with imaging assessment (from 40.2 to 29.7%, p<0.001), the cumulative rate of coronary revascularization at 1year increased (from 10.8 to 13.7%, p<0.001). One-year mortality also decreased progressively from 3% to 1.6% (p<0.001).

CONCLUSIONS

Among older adults referred for exercise stress testing, we observed a decline over time in the probability of inducible myocardial ischemia, an increase in the use of cardiac imaging and in the rate of coronary revascularization, and an improvement in the survival rate at 1year.

Risk stratification in non-ST elevation acute coronary syndromes: Risk scores, biomarkers and clinical judgment

Undifferentiated chest pain is one of the most common reasons for emergency department attendance and admission to hospitals. Non-ST elevation acute coronary syndrome (NSTE-ACS) is an important cause of chest pain, and accurate diagnosis and risk stratification in the emergency department must be a clinical priority. In the future, the incidence of NSTE-ACS will rise further as higher sensitivity troponin assays are implemented in clinical practice. In this article, we review contemporary approaches for the diagnosis and risk stratification of NSTE-ACS during emergency care. We consider the limitations of current practices and potential improvements.

Clinical guidelines recommend an early invasive strategy in higher risk NSTE-ACS. The Global Registry of Acute Coronary Events (GRACE) risk score is a validated risk stratification tool which has incremental prognostic value for risk stratification compared with clinical assessment or troponin testing alone. In emergency medicine, there has been a limited adoption of the GRACE score in some countries (e.g. United Kingdom), in part related to a delay in obtaining timely blood biochemistry results. Age makes an exponential contribution to the GRACE score, and on an individual patient basis, the risk of younger patients with a flow-limiting culprit coronary artery lesion may be underestimated. The future incorporation of novel cardiac biomarkers into this diagnostic pathway may allow for earlier treatment stratification. The cost-effectiveness of the new diagnostic pathways based on high-sensitivity troponin and copeptin must also be established. Finally, diagnostic tests and risk scores may optimize patient care but they cannot replace patient-focused good clinical judgment.

Comparison of Inhospital Outcomes and Hospitalization Costs of Peripheral Angioplasty and Endovascular Stenting

The comparative data for angioplasty and stenting for treatment of peripheral arterial disease are largely limited to technical factors such as patency rates with sparse data on clinical outcomes like mortality, postprocedural complications, and amputation. The study cohort was derived from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample database from 2006 to 2011. Peripheral endovascular interventions were identified using appropriate International Classification of Diseases, Ninth Revision (ICD-9) Diagnostic and procedural codes. Two-level hierarchical multivariate mixed models were created. The primary outcome includes inhospital mortality, and secondary outcome was a composite of inhospital mortality and postprocedural complications. Amputation was a separate outcome. Hospitalization costs were also assessed. Endovascular stenting (odds ratio, 95% confidence interval, p value) was independently predictive of lower composite end point of inhospital mortality and postprocedural complications compared with angioplasty alone (0.96, 0.91 to 0.99, 0.025) and lower amputation rates (0.56, 0.53 to 0.60, <0.001) with no significant difference in terms of inhospital mortality alone. Multivariate analysis also revealed stenting to be predictive of higher hospitalization costs ($1,516, 95% confidence interval 1,082 to 1,950, p <0.001) compared with angioplasty. In conclusion, endovascular stenting is associated with a lower rate of postprocedural complications, lower amputation rates, and only minimal increase in hospitalization costs compared with angioplasty alone.

Chest pain evaluation in the emergency department

Chest pain is a common complaint in the emergency department. Recognition of chest pain symptoms and electrocardiographic changes consistent with acute coronary syndrome (ACS) can lead to prompt initiation of goal-directed therapy. Cardiac troponin testing confirms the diagnosis of acute myocardial infarction, but does not reveal the mechanism of injury. When patients with chest pain rule out for ACS the use of advanced, noninvasive testing has not been found to be associated with better patient outcomes.

Temporal changes in the use and results of exercise echocardiography

AIMS

Limited data are available regarding changes over time in referral patterns and outcomes of non-invasive cardiac stress testing. Our aim was to evaluate the temporal changes in the use and results of exercise echocardiography in our area of reference.

METHODS AND RESULTS

A total of 12 339 patients referred to our unit for exercise echocardiography between 1997 and 2012 were included. We divided the 16-year period into four quadrennia and evaluated the changes in clinical data, results of the tests, referrals for invasive management and outcomes. We observed a gradual decrease in the frequency of detection of myocardial ischaemia from 35.3% in1997-2000 to 25.4% in 2009-12 (P < 0.001). There was also a progressive increase in the prevalence of cardiovascular risk factors and in the frequency of non-ischaemic chest pain and dyspnoea, while the proportion of patients with prior myocardial infarction and non-interpretable electrocardiograms declined. The rate of referral to coronary angiography within 6 months decreased from 24.8% in 1997-2000 to 19.6% in 2009-12 (P < 0.001), but the rate of coronary revascularization remained almost unchanged (13.1 to 11.7%, P for the trend = 0.16). We also observed a progressive decrease in the 1-year mortality rate from 3.4 to 1% (P < 0.001).

CONCLUSION

Over a 16-year period, there was a gradual decrease in the frequency of myocardial ischaemia among patients referred to our unit for exercise echocardiography, which was parallel to changes in their clinical profile. However, this was not accompanied by a significant reduction in the rate of coronary revascularization.

Comparative effectiveness of diagnostic testing strategies in emergency department patients with chest pain: an analysis of downstream testing, interventions, and outcomes

IMPORTANCE

Patients presenting to the emergency department (ED) with chest pain whose evaluation for ischemia demonstrates no abnormalities receive further functional or anatomical studies for coronary artery disease; however, comparative evidence for the various strategies is lacking and multiple testing options exist.

OBJECTIVE

To compare chest pain evaluation pathways based on their association with downstream testing, interventions, and outcomes for patients in EDs.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective analysis of health insurance claims data for a national sample of privately insured patients from January 1 to December 31, 2011. Individuals with a primary or secondary diagnosis of chest pain in the ED were selected and classified into 1 of 5 testing strategies: no noninvasive testing, exercise electrocardiography, stress echocardiography, myocardial perfusion scintigraphy, or coronary computed tomography angiography.

MAIN OUTCOMES AND MEASURES

The proportion of patients in each group who received a cardiac catheterization, coronary revascularization procedure, or future noninvasive test as well as those who were hospitalized for an acute myocardial infarction (MI) during 7 and 190 days of follow-up.

RESULTS

In 2011, there were 693 212 ED visits with a primary or secondary diagnosis of chest pain, accounting for 9.2% of all ED encounters. After application of the inclusion and exclusion criteria, 421 774 patients were included in the final analysis; 293 788 individuals did not receive an initial noninvasive test and 127 986 did, representing 1.7% of all ED encounters. Overall, the percentage of patients hospitalized with an MI was very low during both 7 and 190 days of follow-up (0.11% and 0.33%, respectively). Patients who did not undergo initial noninvasive testing were no more likely to experience an MI than were those who did receive testing. Compared with no testing, exercise electrocardiography, myocardial perfusion scintigraphy, and coronary computed tomography angiography were associated with significantly higher odds of cardiac catheterization and revascularization procedures without a concomitant improvement in the odds of experiencing an MI.

CONCLUSIONS AND RELEVANCE

Patients with chest pain evaluated in the ED who do not have an MI are at very low risk of experiencing an MI during short- and longer-term follow-up in a cohort of privately insured patients. This low risk does not appear to be affected by the initial testing strategy. Deferral of early noninvasive testing appears to be reasonable.

Diagnostic performance of reproducible chest wall tenderness to rule out acute coronary syndrome in acute chest pain: a prospective diagnostic study

OBJECTIVES

Acute chest pain (ACP) is a leading cause of hospital emergency unit consultation. As there are various underlying conditions, ranging from musculoskeletal disorders to acute coronary syndrome (ACS), thorough clinical diagnostics are warranted. The aim of this prospective study was to assess whether reproducible chest wall tenderness (CWT) on palpation in patients with ACP can help to rule out ACS.

METHODS

In this prospective, double-blinded diagnostic study, all consecutive patients assessed in the emergency unit at the University Hospital Zurich because of ACP between July 2012 and December 2013 were included when a member of the study team was present. Reproducible CWT on palpation was the initial step and was recorded before further examinations were initiated. The final diagnosis was adjudicated by a study-independent physician.

RESULTS

121 patients (60.3% male, median age 47 years, IQR 34-66.5 years) were included. The prevalence of ACS was 11.6%. Non-reproducible CWT had a high sensitivity of 92.9% (95% CI 66.1% to 98.8%) for ACS and the presence of reproducible CWT ruled out ACS (p=0.003) with a high negative predictive value (98.1%, 95% CI 89.9% to 99.7%). Conversely non-reproducible CWT ruled in ACS with low specificity (48.6%, 95% CI 38.8% to 58.5%) and low positive predictive value (19.1%, 95% CI 10.6% to 30.5%).

CONCLUSIONS

This prospective diagnostic study supports the concept that reproducible CWT helps to rule out ACS in patients with ACP in an early stage of the evaluation process. However, ACS and other diagnoses should be considered in patients with a negative CWT test.

TRIAL REGISTRATION NUMBER

ClinicalTrial.gov: NCT01724996.

Use of cardiac biomarker testing in the emergency department

IMPORTANCE

Cardiac biomarker testing is not routinely indicated in the emergency department (ED) because of low utility and potential downstream harms from false-positive results. However, current rates of testing are unknown.

OBJECTIVE

To determine the use of cardiac biomarker testing overall, as well as stratified by disposition status and selected characteristics.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective study of ED visits by adults (≥18 years old) selected from the 2009 and 2010 National Hospital Ambulatory Medical Care Survey, a probability sample of ED visits in the United States.

EXPOSURES

Selected patient, visit, and ED characteristics.

MAIN OUTCOMES AND MEASURES

Receipt of cardiac biomarker testing during the ED visit.

RESULTS

Of 44,448 ED visits, cardiac biomarkers were tested in 16.9% of visits, representing 28.6 million visits. Biomarker testing occurred in 8.2% of visits in the absence of acute coronary syndrome (ACS)-related symptoms, representing 8.5 million visits, almost one-third of all visits with biomarker testing. Among individuals subsequently hospitalized, cardiac biomarkers were tested in 47.0% of all visits. In this group, biomarkers were tested in 35.4% of visits despite the absence of ACS-related symptoms. Among all ED visits, the number of other tests or services performed was the strongest predictor of biomarker testing independent of symptoms of ACS. Compared with 0 to 5 other tests or services performed, more than 10 other tests or services performed was associated with 59.55 (95% CI, 39.23-90.40) times the odds of biomarker testing. The adjusted probabilities of biomarker testing if 0 to 5, 6 to 10, or more than 10 other tests or services performed were 6.3%, 34.3%, and 62.3%, respectively.

CONCLUSIONS AND RELEVANCE

Cardiac biomarker testing in the ED is common even among those without symptoms suggestive of ACS. Cardiac biomarker testing is also frequently used during visits with a high volume of other tests or services independent of the clinical presentation. More attention is needed to develop strategies for appropriate use of cardiac biomarkers.

Comparison of exercise electrocardiogram and exercise echocardiography in intermediate-risk chest pain patients

BACKGROUND

The novel exercise computer-assisted high-frequency QRS analysis (HF/QRS) has demonstrated improved sensitivity and specificity over the conventional ST/electrocardiogram-segment analysis (ST/ECG) in the detection of myocardial ischemia. The aim of the present study was to compare the diagnostic value of the validated exercise echocardiography (ex-Echo) with the novel exercise ECG (ex-ECG) including HF/QRS and ST/ECG analysis.

METHODS

A prospective cohort study was conducted in the emergency department of a tertiary care teaching Hospital. Patients with chest pain (CP), normal resting ECGs, troponins, and echocardiography, labeled as "intermediate-risk" for adverse coronary events, underwent the novel ex-ECG and ex-Echo. An ST-segment depression of at least 2 mV or at least 1 mV when associated with CP was considered as an index of ischemia, as well as a decrease of at least 50% in HF/QRS intensity, or new wall motion abnormalities on ex-Echo. Exclusion criteria were QRS duration of at least 120 milliseconds, poor echo-acoustic window, and inability to exercise. Patients were followed up to 3 months. The end point was the composite of coronary stenoses of 50% or greater at angiography or acute coronary syndrome, revascularization, and cardiovascular death on the 3-month follow-up.

RESULTS

Of 188 patients enrolled, 18 achieved the end point. The novel ex-ECG and ex-Echo showed comparable negative predictive value (97% vs 96%; P = .930); however, sensitivity was 83% vs 61%, respectively (P = .612), and specificity was 64% vs 92%, respectively,(P = .026). The areas on receiver operating characteristic analysis were comparable (ex-ECG: 0.734 [95% confidence interval, or CI, 0.62-0.85] vs ex-Echo: 0.767 [CI, 0.63-0.91]; C statistic, P = .167). On multivariate analysis, both ex-ECG (hazard ratio, 5; CI, 1-20; P = .017) and ex-Echo (HR, 12; CI, 4-40; P < .001) were predictors of the end point.

CONCLUSIONS

In intermediate-risk CP patients, the novel ex-ECG including HF/QRS added to ST/ECG analysis was a valuable diagnostic tool and might be proposed to avoid additional imaging. However, the novel test needs additional study before it can be recommended as a replacement for current techniques.