C-reactive protein as a marker for acute coronary syndromes

BACKGROUND: For several years, acute coronary syndromes have been perceived as causing the most hospital admissions, and even hospital mortality. The syndrome of unstable angina frequently progresses to acute myocardial infarction but its pathogenesis is poorly understood, and prognosis determination is still problematic. We tested the hypothesis that measurement of the C-reactive protein in patients admitted for chest pain could be a marker for acute coronary syndromes. METHODS AND RESULTS: We studied 110 patients admitted with suspected ischaemic heart disease, but without elevated serum creatine-kinase levels at the time of hospital admission. Patients were subsequently divided into two groups based on their final diagnosis: group 1 comprised patients with unstable angina; group 2 patients with acute myocardial infarction. We measured the C-reactive protein at the time of hospital admission. The concentration of C-reactive protein was elevated in 59% of the patients with a final diagnosis of acute myocardial infarction, and in 5% of the patients with a final diagnosis of unstable angina, (P < 0.001). CONCLUSION: This study indicates that C-reactive protein levels measured at the time of admission in patients with suspected ischaemic heart disease could be a marker for acute coronary syndromes, and helpful in identifying patients at high risk for acute myocardial infarction. Measurement of C-reactive protein may have practical clinical significance in the management of patients hospitalized for suspected acute coronary syndromes.     

The importance of ambulatory ECG monitoring for determining the prognosis of patients with stable stenocardia]

149 patients with coronary artery disease and stable angina pectoris underwent coronary angiography and had coronary artery stenosis over 50 per cent. All the patients were also subjected to 24-h Holter monitoring at primary examination and 12-18 months after it. Typical ischemic ST changes were defined by transient horizontal or descending ST depressions > 1.0 mV (measured 80 ms after the J point) lasting at least for a minute. 75 (50.3 per cent) patients had episodes of silent myocardial ischemia. The course of the disease was assessed in follow-up period of 12-18 months. Four variants of the course were determined: cardiac events (16 patients), the disease progression (33 patients), a stable course (75 patients), clinical remission (25 patients). A significant correlation between the occurrence, the slope and duration of silent ischemia, the data of selective coronary angiography and clinical course of ischemic heart disease was established. Cardiac events occurred in 87.5% of the patients with silent myocardial ischemia who had total ischemic burden 30 minutes or more and/or ST-segments decrease 3.0 mm and more during heart rate less than 100 beat-min. The stable course was registered in patients with silent ischemia or without it with similar frequency. Clinical remission of angina pectoris in the patients with silent ischemia was observed rarely. The results of this study demonstrate that silent ischemia is an important prognostic factor.     

Unstable angina: are we able to recognize high-risk patients?

It is difficult to identify characteristics of patients with unstable angina that are predictive of a high likelihood of developing clinical events. However, several features have been recognized. Patients with a clinical history of previous stable exertional angina symptoms who began to experience rest pain appear to be at risk and tend to have more extensively underlying coronary disease. When the ischemic episodes are accompanied by rates, a new or worsening mitral regurgitation murmur, or hypotension, there is a high likelihood of significant coronary artery disease and one should triage these patients to early cardiac catheterization and prompt revascularization. An angiographic feature that carries a high risk is a lesion in the proximal left anterior descending or in the left main coronary artery. Certain typical ECG patterns are very suggestive for a critical narrowing in these coronary arteries. If chest pain and ST-segment changes recur on vigorous medical management, early invasive evaluation should be strongly considered. Even so, the left ventricular function is very important prognostically. According to serologic tests, the level of C-reactive protein and serum amyloid A protein suggesting that there may be active inflammation predicts an early poor outcome. However, these serologic abnormalities do not have much clinical value. An increased platelet activation and a reduced fibrinolytic capacity play a role in the pathogenesis of unstable angina, but thrombolytic therapy does not improve the prognosis in patients with unstable angina.     

The use of empiric clinical data in the evaluation of practice guidelines for unstable angina

OBJECTIVE: To determine the applicability to emergency department (ED) clinical practice of a nationally disseminated practice guideline on the disposition of patients with a diagnosis of unstable angina, and to determine the potential impact of the guideline on hospital admissions and demand for intensive care beds. DESIGN: Application of guideline criteria for ED disposition decisions to a validation sample derived from a prospective clinical trial. SETTING: Five hospitals, including 2 urban general teaching hospitals, 2 urban tertiary care university hospitals, and 1 suburban university-affiliated community hospital. PATIENTS: A consecutive sample of 457 patients who presented with symptoms suggestive of acute cardiac ischemia and who had "unstable angina" or "rule out unstable angina" diagnosed by ED physicians. Greater than 90% of eligible patients were enrolled in the clinical trial; follow-up data sufficient for assignment of a definitive diagnosis were obtained for 99% of subjects. MAIN OUTCOME MEASURES: Acute myocardial infarction and unstable angina, based on blind review of initial and follow-up clinical data, including cardiac enzyme levels and electrocardiograms. After completion of the trial, without knowledge of final diagnosis or outcome, the investigators classified patients into risk groups specified by the unstable angina guideline. RESULTS: Of subjects with an ED diagnosis of unstable angina, only 6% (n=28) met the guideline's criteria corresponding to low risk for adverse events and were therefore suitable for discharge directly to home. Fifty-four percent (n=247) met the intermediate-risk criteria; 40% (n=182) met the high-risk criteria and were identified as requiring admission to an intensive care unit. Actual ED disposition differed from guideline recommendations in 2 major areas: only 4% (1/28) of low-risk patients were discharged to home with outpatient follow-up, and only 40% (72/182) of high-risk patients were admitted to an intensive care unit. CONCLUSIONS: Although the guideline was intended to reduce hospitalization by identifying a low-risk group, the small size of this group among ED patients suggests that little reduction in hospitalization can be expected. Indeed, the guideline may increase demand for the limited number of intensive care beds to accommodate patients with unstable angina considered high-risk but currently placed elsewhere. These results emphasize the need to use empiric data from target clinical settings to assess the likely actual impact of guidelines on clinical care prior to national dissemination.     

Saikosaponin b2 induces differentiation without growth inhibition in cultured B16 melanoma cells

Some patients of ischemic heart disease have low uptake in 123I-labeled beta methyl-iodophenyl penta-decanoic acid (BMIPP) SPECT in spite of normal uptake in thallium-201 (Tl) SPECT. To investigate their clinical significance, we performed both T1 and BMIPP myocardial SPECT in 26 cases with stable angina (n = 16) and unstable angina (n = 10), and compared with clinical backgrounds electrocardiogram (ECG) and left ventriculography (LVG). In 11 patients of them, the uptake of BMIPP was moderately reduced. We divided 26 cases into two groups according to uptake of BMIPP (normal/reduced). The two groups had no differences in length of angina attack and duration of disease, but they had a significant difference in the abnormality of either ECG or LVG. Three to six months after PTCA, we examined LVG in 18 cases, 12 of 16 cases with the abnormality of LVG showed the improvement of wall motion. We concluded the reduced uptake of BMIPP with normal uptake of Tl was related to more severe ischemia in cases with unstable angina.     

Agreement between administrative files and written medical records: a case of the Department of Veterans Affairs

OBJECTIVES: This study examined the reliability of Department of Veterans Affairs' health information databases concerning patient demographics, use of care, and diagnoses. METHODS: The Department of Veterans Affairs' Patient Treatment files for Main, Bed-section (PTF) and Outpatient Care (OCF) were compared with medical charts and administrative records (MR) for a random national sample of 1,356 outpatient visits and 414 inpatient discharges to Department of Veterans Affairs' facilities between July 1 and September 30, 1995. Records were uniformly abstracted by a focus group of utilization review nurses and medical record coders blinded to administrative file entries. RESULTS: Reliability was adequate for demographics (kappa approximately 0.92), length of stay (agreement=98%), and selected diagnoses (kappa ranged 0.39 to 1.0). Reliability was generally inadequate to identify the treating bedsection or clinic (kappa approximately 0.5). Compared with medical charts, Patient Treatment Files/Outpatient Care Files reported an additional diagnosis per discharge and 0.8 clinic stops per outpatient visit, resulting in higher estimates of disease prevalence (+39% heart disease, +19% diabetes) and outpatient costs (+36% per unique outpatient per quarter). CONCLUSIONS: In the absence of pilot work validating key data elements, investigators are advised to construct health and utilization data from multiple sources. Further validation studies of administrative files should focus on the relation between process of data capture and data validity.     

Diagnostic significance of a change in the contractile function of the interventricular septum in ischemic heart disease (based on echocardiographic data)

Echocardiography was conducted in 169 patients with ischemic heart disease (atherosclerotic and postinfarction cardiosclerosis, angina pectoris, unstable angina pectoris, myocardial infarction) to determine the diagnostic importance of changes in the contractile function of the interventricular septum (IVS). It is shown that no essential changes in IVS contractility detectable by echocardiography are encountered in patients with ischemic heart disease in a period clear of exacerbation. During an attack of angina pectoris, a decrease of the mean normalized rate of IVS systolic displacement is recorded, which suggests indirectly a lesion of the left anterior descending artery. IVS contractile function increases in the pre-infarction period, which is a compensatory reaction to the changes in the contractile function of the left ventricle.     

Continuous ECG monitoring. A valuable technique in acute myocardial infarction

Early diagnosis of acute myocardial infarction is important to enable myocardial injury to be limited by means of various treatments. Monitoring of vessel patency with vector cardiography or continuous 12-lead ECG recording is a form of surveillance that has been widely accepted in Sweden. In post-reperfusion therapy monitoring, there is approximately 80 per cent agreement between monitoring ST-segment changes and acute coronary cardiography. For risk stratification of patients with unstable angina or non-Q-wave infarction, ST-segment monitoring manifests great predictive power which is further enhanced by its combination with the measurement of highly specific markers of myocardial injury. Computerised techniques for continuous monitoring of multiple ECG leads have contributed much to our understanding of the dynamics of acute coronary heart disease. Valuable prognostic information is available in real time, early identification of myocardial injury is possible, and treatment strategies can be based upon more reliable grounds.     

The pathophysiological basis of the destabilization of the clinical course in ischemic heart disease

The role of the coagulative blood system in initiation of acute coronary events was investigated on patients with different clinical forms of ischemic heart disease (IHD). The obtained results indicate that unstable angina (UA) and myocardial infarction (MI) are two independent forms of the acute IHD with distinct qualitative peculiarities. The most common feature of UA was an increase in the functional activity of platelets both in cases proceeded in MI and in uncomplicated cases. It means that these changes may be treated as the main pathogenic factor if UA but not as a mechanism of its transformation to MI. But high degree of the risk of MI development appears if these changes are combined with preceding significant disturbances in the haemostatic balance as a result of inhibition of the activity of anticoagulative and fibrinolytic blood systems. These data show that differentiation of the diagnosis between UA and MI in its initial stage and the choice of the treatment principles should be based on the careful investigation of the coagulative potential of blood and of its most important components.     

Temporal association of Amblyomma americanum with the presence of Ehrlichia chaffeensis reactive antibodies in white-tailed deer

In order to improve the diagnostic procedure for patients with chest pain suspected of having acute ischemic heart disease we elaborated a mathematical model to predict ischemic risk and then compared its predictive capacity with that of the physician. From September 1989 to December 1992, 564 patients with a chief symptom of chest pain were seen at our Emergency Room (ER). Sixty-two percent of them were male, mean age was 58 +/- 13 years, and none had acute myocardial infarction or unstable angina. Clinical and historical data, serial sampling of enzymes and ECG patterns were collected for 4 hours after admission to the ER. At that point a decision was made to hospitalize or discharge that patient. Follow-up was completed within 2 months. At the end of follow-up, we observed that the physician's assessment resulted in 35% true positive, 55% true negative, 4.7% false positive, and 5.3% false negative judgments for acute ischemic heart disease.(ABSTRACT TRUNCATED AT 250 WORDS)     

Diagnosis of coronary vasospasm in patients with clinical presentation of unstable angina pectoris using ergonovine echocardiography

Although coronary vasospasm can contribute to the development of unstable angina, the definite diagnostic method has not been established. The purpose of this study was to determine if ergonovine echocardiography (detection of regional wall motion abnormality during bedside ergonovine challenge) after angiographic confirmation of insignificant fixed disease would be useful and safe in detecting coronary vasospasm in patients with unstable angina. After control of chest pain with medications in patients admitted to the coronary care unit under the tentative diagnosis of unstable angina, diagnostic coronary angiography was performed. All patients with normal or insignificant fixed disease underwent ergonovine echocardiography after discontinuation of medications for 4+/-1 days. Among 208 consecutive patients enrolled for this study, 75% (156 of 208) showed significant fixed disease in the angiography. Ergonovine echocardiography was performed in 52 patients with insignificant disease, and coronary vasospasm was documented in 33 (63%, 33 of 52). No serious procedure-related arrhythmia or myocardial infarction occurred. Esophageal motility disorder and hypertrophic cardiomyopathy were diagnosed in 6 and 3 patients, respectively. Chest pain of undetermined etiology was the final diagnosis at discharge in 10 patients (5%, 10 of 208); among them chest pain redeveloped in 2 patients, and repeated ergonovine echocardiography revealed positive results. Our data suggest that among patients with the clinical presentation of unstable angina, coronary vasospasm is the main cause of myocardial ischemia in a considerable number of patients with a normal or near-normal angiogram, and ergonovine echocardiography after confirmation of absence of significant fixed disease is useful and safe for noninvasive diagnosis of coronary vasospasm in this setting.     

A new clinical classification for hospital prognosis of unstable angina pectoris

Unstable angina represents a heterogeneous spectrum of clinical entities between chronic stable angina and acute myocardial infarction. To facilitate prognostication of in-hospital outcome, we prospectively tested on a priori unstable angina classification scheme based on information available at the time of acute presentation. Prospective database enrollment at the time of emergency room presentation was performed and patients were classified into 1 of the following categories: class IA, acceleration of previous exertional angina without electrocardiographic (ECG) changes; class IB, acceleration of previous exertional angina with ECG changes; class II, new-onset exertional angina; class III, new-onset rest angina; class IV, protracted rest angina with ECG changes. The study consisted of 1,387 consecutive patients with unstable angina. Baseline demographics and aggregate in-hospital major cardiac event rates were recorded (myocardial infarction, refractory angina, and death). There was a significant increasing trend in cardiac events from class I to IV (p < 0.0001). Class IA patients had the lowest aggregate event rate at 2.7% (p = 0.0005). Paired chi-square tests of adjacent categories showed no differences in event rates for class IB and II (p = 0.3). A significantly higher rate of adverse events was seen for class III patients (20.1%, p < 0.0001). Class IV patients demonstrated the highest rate of in-hospital adverse events (42.8%, p < 0.0001). We conclude that this easily deduced, universally applicable categorization of unstable angina is highly prognostic of in-hospital adverse cardiac events and hence could have potential use for triage decisions regarding hospital admission and intensity of therapy.     

Activation of the antibacterial properties and neutrophil myeloperoxidase and acid phosphatase in patients with unstable angina pectoris

Neutrophils are very important in pathogenesis of ischemic disease. They take part in the biomorphology of thrombus and also in the damage of myocardium ischemia in a course of unstable angina pectoris. We evaluated the functional status of neutrophils in peripheral blood, by measurement of bactericidal activity and activity of granulocyte's enzymes: myeloperoxidase (MPO) and acid phosphatase in the patients with unstable angina pectoris. We studied a group of 43 people at the age from 34 to 74 years. The blood for investigation was obtained during the first five hours from the moment of hospitalization. The control group were 40 healthy people. The number of granulocytes was significantly higher in patients with unstable angina pectoris and granulocytes were metabolically activated which was shown in the bigger activity of granulocyte's enzymes like MPO and acid phosphatase than in the control group. The activation of neutrophils is developed by many factors in the course of unstable angina pectoris. They take part in the processes of thrombogenesis and thrombolysis and they are a very important origin for active oxygen metabolites, which are responsible for damage of myocardium ischemia.     

Unstable angina: good long-term outcome after a complicated early course

OBJECTIVES: This study was performed to investigate the long-term outcome of patients with unstable angina within subgroups of the Braunwald classification. BACKGROUND: Long-term follow-up studies of patients with unstable angina are rare and date from more than two decades ago. This study was performed to establish the prognosis of different subgroups of patients with unstable angina (Braunwald criteria) during a 7-year follow-up period. METHODS: We registered a well defined group of 417 consecutive patients, admitted to the hospital for suspected unstable angina. The definite diagnosis was unstable angina in 282 patients (68%) and evolving myocardial infarction in 26; in 109 patients (26%), the symptoms were attributed to other or nonspecific causes. Patients with definite unstable angina were subclassified according to the Braunwald classification. Survival, survival without infarction and survival without infarction or intervention were determined for each class. RESULTS: After a median follow-up period of 94 months, the mortality rate in the first year was 6% and 2% to 3% in the following years. The frequency of revascularization was 47% in the first year, and that for myocardial infarction was 11% in the first year and 1% to 3% thereafter. The Braunwald classification appeared to be appropriate for risk stratification in the first year. However, at 7 years the event rates in all classes were similar. In particular, the Braunwald classification had no long-term impact on mortality or infarction rates. However, patients with acute angina at rest or postinfarction angina and patients with extensive anginal treatment had high intervention rates. CONCLUSIONS: To our knowledge, this study is the first to demonstrate that despite a complicated course during the first year, current management results in good long-term outcome in patients with unstable angina.     

Validity of the recording of ischaemic heart disease and chronic obstructive pulmonary disease in the Saskatchewan health care datafiles

The internal validity of the recording of information about ischaemic heart disease (IHD) and chronic obstructive pulmonary disease (COPD) in the administrative health care datafiles of the Canadian province of Saskatchewan is investigated. Comparisons between hospital data and medical charts for acute myocardial infarction and chronic airways obstruction patients showed excellent diagnostic agreement: 97 per cent and 94 per cent, respectively. Appropriate physician service claims were identified for 89 per cent of hospitalizations for IHD and COPD and exact concordance between diagnoses in the two datafiles varied between 15 per cent for acute/sub-acute IHD and 80 per cent for asthma; including any physician diagnosis within the same broad category (IHD or COPD) increased concordance to 79-94 per cent for IHD and 64-88 per cent for COPD. Contextual information related to the hospitalizations was clinically and epidemiologically realistic.     

Use of a program package for comparison of radiographic images of tissues during treatment

Repeated courses of laser therapy given to patients with ischemic heart disease, angina of effort class I-IV for 2 years brought about stabilization of coronary insufficiency and improvement of clinical and functional conditions. Microcirculatory picture of the bulbar conjunctiva, coronary reserve improved. The treatment had also a hypotensive effect.     

Seven zinc-finger transcription factors are expressed sequentially during the development of anthers in petunia

BACKGROUND: Little is known about the value of heart rate variability in patients with symptomatic coronary artery disease with a preserved left ventricular function. We hypothesized that in these patients heart rate variability might be a helpful adjunct to conventional parameters to predict clinical events. METHODS: In a prospective 2-year follow-up study ambulatory electrocardiographic recordings were performed in 263 consecutive male patients (mean age 56+/-8 years) with stable angina pectoris and a mean left ventricular ejection fraction of 71%+/-12%. Clinical events consisted mainly of coronary events such as percutaneous transluminal angioplasty or coronary artery bypass graft operation. RESULTS: Low measures of standard deviation of normal R-R intervals, standard deviation of the mean R-R intervals of 5 minutes, and two spectral components of heart rate variability were found in patients who had had an event compared with patients with no event. Adjusted for severity of angina, the presence of a previous myocardial infarction, and the use of beta-blockers in a logistic regression model this relation remained statistically significant for SDNN. Healthy volunteers appeared to have the highest measures of heart rate variability. CONCLUSION: In patients with ischemic heart disease and normal or near normal ventricular function decreased heart rate variability is associated with adverse clinical events.     

Aggression and sexual offense in Asperger''s syndrome

PURPOSE: To determine the accuracy of adolescents' self-report of health insurance coverage, using parents' report as a comparison standard. METHODS: Two separate samples of urban, school-based adolescents and their parents completed self-administered questionnaires about type of health insurance coverage. Sample 1 included 123 and Sample 2 included 93 adolescent-parent pairs. Percent agreement and the kappa statistic were determined for each of the sample groups, and for males versus females and older (> 14 years) versus younger (< or = 14 years) adolescents. RESULTS: In Sample 1, 33% of adolescent respondents responded "don't know" to the question about type of insurance coverage, and 4% left the question blank; in Sample 2, 3% answered "don't know," with none leaving the question blank. For Sample 1, we found a 57% rate of agreement of adolescents with their parents, and a corresponding kappa of .21. Females and older subjects demonstrated greater accuracy, with kappa's all in the range .13-.29. In Sample 2, 73% of subjects agreed with parents' report, with a kappa of .48. Females and older subjects also demonstrated greater accuracy, with the highest kappa of .59 demonstrated by older females. Excluding those responding with "don't know," we found overall percent agreement with parents of 87% in Sample 1 and 73% in Sample 2; the corresponding kappas were .47 and .51. Females demonstrated higher agreement with parents in both samples. The results stratifying by age were inconsistent. In Sample 1, privately insured subjects were more accurate reporters than those either on medical assistance or uninsured. In Sample 2, no differences were seen by type of insurance. CONCLUSIONS: Many adolescents do not know their health insurance coverage status. However, for those who did claim to know, acceptable rates of accuracy using both percent agreement and the kappa statistic were demonstrated. Further research is needed to determine how information about insurance is communicated to adolescents and how this knowledge affects access to and use of health services.     

Elderly patients receive less aggressive medical and invasive management of unstable angina: potential impact of practice guidelines

BACKGROUND: The Agency for Health Care Policy and Research (AHCPR) released a practice guideline on the diagnosis and management of unstable angina in 1994. OBJECTIVE: To examine practice variation across the age spectrum in the management of patients hospitalized with unstable angina 2 years before release of the AHCPR guideline. DESIGN: Retrospective cohort. SETTING: Urban academic hospital. PATIENTS: All nonreferral patients diagnosed as having unstable angina who were hospitalized directly from the emergency department to the intensive care or telemetry unit between October 1, 1991, and September 30, 1992. MEASUREMENTS: Percentage of eligible patients receiving medical treatment concordant with 8 important AHCPR guideline recommendations. RESULTS: Half of the 280 patients were older than 66 years; women were older than men on average (70 vs 64 years; P<.001). After excluding those with contraindications to therapy, patients in the oldest quartile (age, 75.20-93.37 years) were less likely than younger patients to receive aspirin (P<.009), beta-blockers (P<.04), and referral for cardiac catheterization (P<.001). Overall guideline concordance weighted for the number of eligible patients declined with increasing age (87.4%, 87.4%, 84.0%, and 74.9% for age quartiles 1 to 4, respectively; chi2, P<.001). Increasing age, the presence of congestive heart failure at presentation, a history of congestive heart failure, previous myocardial infarction, increasing comorbidity, and elevated creatinine concentration were associated with care that was less concordant with AHCPR guideline recommendations; only age and congestive heart failure at presentation remained significant in the multivariate analysis (odds ratios, 1.28 per decade [95% confidence interval, 1.02-1.61] and 3.16 [95% confidence interval, 1.57-6.36], respectively). CONCLUSIONS: Older patients were less likely to receive standard therapies for unstable angina before release of the 1994 AHCPR guideline. Patients presenting with congestive heart failure also received care that was more discordant with guideline recommendations. The AHCPR guideline allows identification of patients who receive nonstandard care and, if applied to those patients with the greatest likelihood to benefit, could lead to improved health care delivery.     

Access to coronary catheterisation: fair shares for all?

OBJECTIVE: To determine the effects of patient's sex and area's material deprivation on utilisation rates of coronary catheterisation and angiography in the investigation of ischaemic heart disease. DESIGN: Retrospective analysis of routinely collected hospital statistics. SETTING: Acute hospitals throughout Northern Ireland. SUBJECTS: 24,179 episodes of patients discharged from hospital with a primary diagnosis of ischaemic heart disease and 1270 episodes relating to patients with an underlying diagnosis of ischaemic heart disease who had either coronary catheterisation or angiography. MAIN OUTCOME MEASURES: Age standardised admission rates for heart disease and age standardised utilisation rates for catheterisation or angiography, or both, for 566 electoral wards ranked by Townsend "deprivation" scores. RESULTS: Catheterisation-angiography rates in men were over fivefold those of women, ranging from 85.5/100,000 v 16/100,000 in patients from "well off" areas to 123/100,000 v 22/100,000 for patients from deprived areas. After admission rates for heart disease were controlled for, the overall rate ratio for women was 0.48 (95% confidence interval 0.38 to 0.60). After differential admission rates for heart disease and other potential clinical confounders were controlled for, the investigation rates of patients from the least and most "deprived" areas were not significantly different (rate ratio 1.04 (0.87 to 1.25)). CONCLUSION: Although investigation rates were significantly lower in women than in men, further clinical data would be required before labelling this underutilisation as evidence of bias. There was no significant difference in invasive investigation rates for heart disease in areas of varying deprivation or affluence.