James G. Jollis

Diagnostic performance of 64-multidetector row coronary computed tomographic angiography for evaluation of coronary artery stenosis in individuals without known coronary artery disease: results from the prospective multicenter ACCURACY (Assessment by Coronary Computed Tomographic Angiography of Individuals Undergoing Invasive Coronary Angiography) trial.

OBJECTIVES The purpose of this study was to evaluate the diagnostic accuracy of electrocardiographically gated 64-multidetector row coronary computed tomographic angiography (CCTA) in individuals without known coronary artery disease (CAD). BACKGROUND CCTA is a promising method for detection and exclusion of obstructive coronary artery stenosis. To date, no prospective multicenter trial has evaluated the diagnostic accuracy of 64-multidetector row CCTA in populations with intermediate prevalence of CAD. METHODS We prospectively evaluated subjects with chest pain at 16 sites who were clinically referred for invasive coronary angiography (ICA). CCTAs were scored by consensus of 3 independent blinded readers. The ICAs were evaluated for coronary stenosis based on quantitative coronary angiography (QCA). No subjects were excluded for baseline coronary artery calcium score or body mass index. RESULTS A total of 230 subjects underwent both CCTA and ICA (59.1% male; mean age: 57 +/- 10 years). On a patient-based model, the sensitivity, specificity, and positive and negative predictive values to detect > or =50% or > or =70% stenosis were 95%, 83%, 64%, and 99%, respectively, and 94%, 83%, 48%, 99%, respectively. No differences in sensitivity and specificity were noted for nonobese compared with obese subjects or for heart rates < or =65 beats/min compared with >65 beats/min, whereas calcium scores >400 reduced specificity significantly. CONCLUSIONS In this prospective multicenter trial of chest pain patients without known CAD, 64-multidetector row CCTA possesses high diagnostic accuracy for detection of obstructive coronary stenosis at both thresholds of 50% and 70% stenosis. Importantly, the 99% negative predictive value at the patient and vessel level establishes CCTA as an effective noninvasive alternative to ICA to rule out obstructive coronary artery stenosis. (A Study of Computed Tomography [CT] for Evaluation of Coronary Artery Blockages in Typical or Atypical Chest Pain; NCT00348569).

Discordance of Databases Designed for Claims Payment versus Clinical Information Systems: Implications for Outcomes Research

Insurance claims data are being used increasingly to study clinical outcomes and quality of care [1-4]. Each year, hospital-specific mortality rates, adjusted by clinically modified International Classification of Diseases (ICD-9-CM) codes from Medicare bills, are released by the Health Care Financing Administration (HCFA) [1-3]. Using ICD-9-CM data to adjust for illness severity, threefold differences for surgeon-specific mortality in Philadelphia were found by Williams and colleagues [4]. Many of the Patient Outcomes Research Teams (PORTs), supported by the Agency for Health Care Policy Research, are using ICD-9-CM coded Medicare discharge abstracts to examine the process of medical care, including physician- and hospital-specific performance [5-7]. The potential advantages of using insurance claims data sets for clinical research have been described in many previous publications [8]. They include 1) large samples of geographically dispersed patients; 2) longitudinal records; 3) data already collected and available; and 4) defined sampling frames. The question remains: Are data collected to obtain insurance reimbursement a valid proxy for data collected for clinical care and research purposes? Such validity is essential to identify clinically relevant populations and to adjust for illness severity and differences in outcomes [9]. Six reabstracting studies have attempted to answer this question with respect to analysis of patients discharged after acute myocardial infarction [10-15]. These studies selected patients with the ICD-9-CM code 410, the code for acute myocardial infarction. By examining medical records, they found that clinical criteria for an acute myocardial infarction were met in 43% to 87% of records where the code was used at discharge. Errors resulted when the physician listed the acute myocardial infarction incorrectly, when a myocardial infarction occurred in a previous admission, or when myocardial infarction was ruled out (if it was the admitting diagnosis). A substantial limitation of five of these studies was that they selected patients based on claims data. Thus, the groups selected for review were only those patients with an ICD-9-CM code for myocardial infarction. Using this design, it was only possible to obtain estimates of disagreement in one direction; patients who had a condition coded in the clinical data set, but not in the claims data set, could not be examined. A second limitation of the previous studies is that their comparison gold standard was based on retrospective review of information recorded in the discharge summary or medical chart. Medical record data are limited by the unstructured way in which they are collected. Inaccuracies in these sources cannot be identified in such a study, and it is possible that in some disagreements with ICD-9-CM codes, the medical record is incorrect. Our study examined the suitability of billing data compared with clinical data (prospectively collected for cardiology research and patient care) for use in clinical outcomes research. The descriptors for coronary artery disease that we examined were those listed as important determinants of prognosis by an expert panel from the American College of Cardiology [16]. Methods Insurance Claims Data The administrative or insurance claims information comprised all discharge abstracts from Duke University Medical Center between July 1985 and May 1990 containing any procedure code for coronary arteriography. All discharged patients, regardless of insurance status or age, were routinely classified by ICD-9-CM codes recorded by trained medical record technicians based on the attending physicians listed discharge diagnoses, the discharge summary, and selected information from the progress notes and from the test result sections of the hospital chart [17]. These records contained up to 30 diagnostic codes and 9 procedure codes. After the technician had assembled the ICD-9-CM codes, the discharge abstract and the chart were returned to the attending physician for final approval by signature; ICD-9-CM codes were not generated for patients having outpatient cardiac catheterization unless they were subsequently admitted for further evaluation or treatment. The records for the subgroup of Medicare patients in this study were sent by Duke Hospital to the North Carolina Medicare intermediary and, thus, reflect the Duke Hospital data contained in the Health Care Financing Administration data sets. Clinical Database Data The clinical information consisted of important diagnostic and prognostic information about coronary artery disease routinely collected on standardized data forms by the cardiology fellow doing the cardiac catheterization for suspected ischemic heart disease. Information collected included details from the patient history, physical examination, laboratory studies, and cardiac catheterization, as previously described [18]. Each new fellow entering the catheterization laboratory was given a 3-hour training session on variable definitions and use of the data forms and was given an operations manual covering these details. In addition, all data were reviewed for accuracy by the attending angiographer associated with the case; additional consistency, range check, and other quality control measures were done during the data entry process by trained research technicians. This information was stored in the Duke Databank for Cardiovascular Disease, a completely separate and independent system from the hospital administrative records described above. Records Matching and Variable Definitions Records from the administrative and clinical files were matched by unique, patient hospital identification numbers and hospitalization dates. Only the first matching clinical record for each patient was included in the analysis. Twelve clinical variables were mapped to ICD-9-CM codes according to an algorithm developed by the Patient Outcomes Research Team for chronic ischemic heart disease (Table 1) (Romano PS, Roos LL. Unpublished observations). The variables studied were selected if they met two criteria: 1) They were considered to be determinants of prognosis for coronary artery disease according to an expert panel from the American College of Cardiology; 2) they could be mapped to diagnoses contained in the ICD-9-CM coding system [16, 17]. The definitions of the clinically identified conditions appear in the Appendix. Table 1. International Classification of Diseases-9-CM and Clinical Detail Map Appendix.Glossary of Terms Data Analysis Based on the clinical condition and the ICD-9-CM map described above, two-by-two tables were constructed to assess the agreement between the data sources. For the claims data, a condition was considered to be absent if it was not coded. For the clinical data, patients with missing data were excluded from the analysis for the specific missing condition. Kappa statistics were generated for each condition to measure agreement while controlling for chance agreement [19]. Confidence intervals and test statistics for proportions were calculated by the normal approximation. For the diagnoses of acute myocardial infarction, congestive heart failure, angina, and unstable angina, we reviewed a random sample of 15 clinical-positive and claims-negative charts as well as 15 claims-positive and clinical-negative charts for each diagnosis to illustrate the major reasons for disagreement. In addition to the comparisons made in the overall data sets, subsets defined by age, fiscal year, and sex were compared to determine if the coding accuracy varied according to these factors. Results The study group consisted of 12 937 consecutive patients having inpatient cardiac catheterization between July 1985 and May 1990. Although each record represented the first cardiac catheterization in the claims records, from the perspective of the clinical records, 89% involved the first catheterization, 8% involved the second catheterization, and the remaining 3% involved the third or subsequent catheterization. The patients had a mean age of 58.8 years, 34% were women, and the racial composition was 88% white, 10% black, and 2% other. At cardiac catheterization, the mean left ventricular ejection fraction was 52%. The distribution of the number of diseased major epicardial vessels (zero, one, two, or three) was 23%, 26%, 23%, and 28%, respectively. Overall, the study group characteristics were similar to those of other large angiographic registries except for the greater proportion of women and the higher mean age [20, 21]. Measures of Agreement Specific measures of agreement between clinical database and ICD-9-CM variables are listed in Table 2 in descending order of value (the agreement rate adjusted for chance agreement). Kappas ranged from 0.83 for diabetes mellitus to 0.09 for unstable angina. Of the 12 conditions, only 3 (diabetes, acute myocardial infarction, and hypertension) were identified by the claims data more than 50% of the time that they were identified by the clinical data. Table 2. Comparison of Agreement by Condition Ranked by Kappa Value In the clinical data set, two conditions were graded according to severity, congestive heart failure, and mitral regurgitation. With increasing severity levels, the claims data were more likely to identify the presence of these conditions. Claims data identified 31% of clinically identified congestive heart failure that was New York Heart Association class I and II and identified 45% of class III and IV heart failure (P < 0.0001) [22]. Similarly, claims data identified 40% of grades I and II mitral regurgitation and identified 69% of grades III and IV mitral regurgitation (P < 0.0001). When all diagnoses were considered together, the overall agreement of ICD-9-CM codes with clinical data was 0.75 (99% CI, 0.75 to 0.76). The proportion of conditions in the clinical data set identified by claims data was 0.39 (99% CI, 0.38 to 0.39) (Table 3). Stratified by fisc

Outcome of Acute Myocardial Infarction According to the Specialty of the Admitting Physician

BACKGROUND In order to limit costs, health care organizations in the United States are shifting medical care from specialists to primary care physicians. Although primary care physicians provide less resource-intensive care, there is little information concerning the effects of this strategy on outcomes. METHODS We examined mortality according to the specialty of the admitting physician among 8241 Medicare patients who were hospitalized for acute myocardial infarction in four states during a seven-month period in 1992. Proportional-hazards regression models were used to examine survival up to one year after the myocardial infarction. To determine the generalizability of our findings, we also examined insurance claims and survival data for all 220,535 patients for whom there were Medicare claims for hospital care for acute myocardial infarction in 1992. RESULTS After adjustment for characteristics of the patients and hospitals, patients who were admitted to the hospital by a cardiologist were 12 percent less likely to die within one year than those admitted by a primary care physician (P<0.001). Cardiologists also had the highest rate of use of cardiac procedures and medications, including medications (such as thrombolytic agents and beta-blockers) that are associated with improved survival. CONCLUSIONS Health care strategies that shift the care of elderly patients with myocardial infarction from cardiologists to primary care physicians lower rates of use of resources (and potentially lower costs), but they may also cause decreased survival. Additional information is needed to elucidate how primary care physicians and specialists should interact in the care of severely ill patients.

American Society of Echocardiography Consensus Statement on the Clinical Applications of Ultrasonic Contrast Agents in Echocardiography

UNLABELLED ACCREDITATION STATEMENT: The American Society of Echocardiography (ASE) is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The ASE designates this educational activity for a maximum of 1 AMA PRA Category 1 Credit.trade mark Physicians should only claim credit commensurate with the extent of their participation in the activity. The American Registry of Diagnostic Medical Sonographers and Cardiovascular Credentialing International recognize the ASEs certificates and have agreed to honor the credit hours toward their registry requirements for sonographers. The ASE is committed to resolving all conflict-of-interest issues, and its mandate is to retain only those speakers with financial interests that can be reconciled with the goals and educational integrity of the educational program. Disclosure of faculty and commercial support sponsor relationships, if any, have been indicated. TARGET AUDIENCE This activity is designed for all cardiovascular physicians, cardiac sonographers, and nurses with a primary interest and knowledge base in the field of echocardiography; in addition, residents, researchers, clinicians, sonographers, and other medical professionals having a specific interest in contrast echocardiography may be included. OBJECTIVES Upon completing this activity, participants will be able to: 1. Demonstrate an increased knowledge of the applications for contrast echocardiography and their impact on cardiac diagnosis. 2. Differentiate the available ultrasound contrast agents and ultrasound equipment imaging features to optimize their use. 3. Recognize the indications, benefits, and safety of ultrasound contrast agents, acknowledging the recent labeling changes by the US Food and Drug Administration (FDA) regarding contrast agent use and safety information. 4. Identify specific patient populations that represent potential candidates for the use of contrast agents, to enable cost-effective clinical diagnosis. 5. Incorporate effective teamwork strategies for the implementation of contrast agents in the echocardiography laboratory and establish guidelines for contrast use. 6. Use contrast enhancement for endocardial border delineation and left ventricular opacification in rest and stress echocardiography and unique patient care environments in which echocardiographic image acquisition is frequently challenging, including intensive care units (ICUs) and emergency departments. 7. Effectively use contrast echocardiography for the diagnosis of intracardiac and extracardiac abnormalities, including the identification of complications of acute myocardial infarction. 8. Assess the common pitfalls in contrast imaging and use stepwise, guideline-based contrast equipment setup and contrast agent administration techniques to optimize image acquisition.

The relation between the volume of coronary angioplasty procedures at hospitals treating Medicare beneficiaries and short-term mortality.

BACKGROUND Previous studies have found that hospitals at which more procedures, such as coronary-artery bypass grafting (CABG) and other vascular surgery, are performed have lower rates of mortality related to these procedures than hospitals where fewer such procedures are performed. METHODS We examined the relation between the number of percutaneous transluminal coronary angioplasty (PTCA) procedures performed at hospitals (volume) and short-term mortality in a population of 217,836 Medicare beneficiaries 65 years of age or older who underwent angioplasty in the United States from 1987 through 1990. RESULTS The unadjusted in-hospital mortality among patients who underwent PTCA increased from 2.5 percent among the 10 percent of patients treated in hospitals with the highest volume of such procedures to 3.9 percent among the 10 percent of patients treated in hospitals with the lowest volume. The rate of bypass surgery after PTCA also increased, from 2.8 percent among patients in the highest-volume hospitals to 5.3 percent among those in the lowest-volume hospitals. Higher rates of mortality and CABG persisted in all the groups of patients treated in hospitals that performed fewer than 100 angioplasty procedures per year in Medicare beneficiaries; this volume in Medicare beneficiaries can be extrapolated to an overall annual volume of 200 to 400 angioplasty procedures. In a logistic-regression model, the volume of PTCA procedures at a hospital was found to be a highly significant predictor of in-hospital mortality (P < 0.001). These results suggest that if the hospitals with the lowest volume had achieved the experience and technical results of the highest-volume hospitals, 381 fewer patients would have undergone CABG and there would have been 300 fewer in-hospital deaths in the population we studied. CONCLUSIONS Hospitals that perform more PTCA procedures have lower short-term mortality rates after the procedure. These data provide evidence in support of the regionalization of angioplasty services.

Relationship Between Physician and Hospital Coronary Angioplasty Volume and Outcome in Elderly Patients

BACKGROUND With the expectation that physicians who perform larger numbers of coronary angioplasty procedures will have better outcomes, the American College of Cardiology/ American Heart Association guidelines recommend minimum physician volumes of 75 procedures per year. However, there is little empirical data to support this recommendation. METHODS AND RESULTS We examined in-hospital bypass surgery and death after angioplasty according to 1992 physician and hospital Medicare procedure volume. In 1992, 6115 physicians performed angioplasty on 97,478 Medicare patients at 984 hospitals. The median numbers of procedures performed per physician and per hospital were 13 (interquartile range, 5 to 25) and 98 (interquartile range, 40 to 181), respectively. With the assumption that Medicare patients composed one half to one third of all patients undergoing angioplasty, these median values are consistent with an overall physician volume of 26 to 39 cases per year and an overall hospital volume of 196 to 294 cases per year. After adjusting for age, sex, race, acute myocardial infarction, and comorbidity, low-volume physicians were associated with higher rates of bypass surgery (P < .001) and low-volume hospitals were associated with higher rates of bypass surgery and death (P < .001). Improving outcomes were seen up to threshold values of 75 Medicare cases per physician and 200 Medicare cases per hospital. CONCLUSIONS More than 50% of physicians and 25% of hospitals performing coronary angioplasty in 1992 were unlikely to have met the minimum volume guidelines first published in 1988, and these patients had worse outcomes. While more recent data are required to determine whether the same relationships persist after the introduction of newer technologies, this study suggests that adherence to minimum volume standards by physicians and hospitals will lead to better outcomes for elderly patients undergoing coronary angioplasty.

Outcomes of Coronary Artery Bypass Graft Surgery in 24 461 Patients Aged 80 Years or Older

BACKGROUND Coronary artery bypass graft surgery is increasingly common in patients of age > or = 80 years. Single-institution reviews have cited a wide range of mortality results after bypass surgery in this age group, in part because of limited sample sizes. Using claims data, we examined recent national trends in the use and outcomes of bypass surgery in the very elderly. METHODS AND RESULTS From an examination of Medicare data from 1987 through 1990, we identified 24,461 patients of age > or = 80 years who underwent bypass surgery. We compared surgical outcomes in these patients with those in Medicare patients of age 65 to 70 years. We found that the national use of bypass surgery in patients of age > or = 80 years increased 67% between 1987 and 1990. Compared with patients of age 65 to 70 years, the very elderly had significantly longer postoperative hospital stays (mean, 14.3 versus 10.4 days), higher charges (mean,

A comparison of administrative versus clinical data: coronary artery bypass surgery as an example

48,200 versus

Impact of Heart Failure on Patients Undergoing Major Noncardiac Surgery

38,000), and greater costs (mean,

Cost-effectiveness of transesophageal echocardiography to determine the duration of therapy for intravascular catheter-associated Staphylococcus aureus bacteremia

27,200 versus