A multicentre analysis of troponin use in clinical practice.

BACKGROUND: The role of troponin quantification in evaluation of patients with suspected acute coronary syndrome is established, but with cost implications. Emerging high-sensitivity troponin and novel multi-marker assays herald further resource implications. AIMS: The objective of this study was to quantify recent trends in troponin usage and costs in a cross-section of hospitals. METHODS: A cross-sectional survey seeking data on troponin usage and costs from six tertiary referral, public access teaching hospitals for consecutive years between 2003 and 2009 was carried out. RESULTS: A median annual increase in the volume of troponin assays requested was identified in all six hospitals, with an average median annual increase of 6.9 % across hospitals (interquartile range 3.4, 10.1 %). This annual increase was not accompanied by a corresponding increase in volume of patients presenting to the Emergency Department (ED) with chest pain. The majority (44-67 %) of troponin requests originated in the ED of hospitals. The median annual spend on troponins per hospital was 115,612 (interquartile range 80,452, 140,918). An analysis of results of assays performed in one centre found that the majority (91 %) of troponin assays performed were in the normal range. CONCLUSIONS: An annual increase in troponin requests without a corresponding increase in patient activity raises the possibility of increasingly indiscriminate troponin testing. The cumulative direct and indirect costs of inappropriate testing are significant. Corrective strategies are necessary to improve patient selection and testing protocols, particularly in the advent of the high-sensitivity troponin assays and novel multi-marker strategies.

Gender differences in the management and outcome of acute myocardial infarction in unselected patients in the thrombolytic era.

This study compares the clinical features, management, and outcome in men and women from a consecutive, unselected series of patients with acute myocardial infarction (AMI) who were admitted to a university cardiac center over a 3-year period. It is a retrospective observational study of 1,059 admissions with AMI identified through the Hospital In-Patient Enquiry (HIPE) registry, validated according to Minnesota Manual criteria, and followed for a period of up to 5 years (median 36 months). Women comprised 40% of all admissions, had a higher hospital mortality (24% vs. 16%, p<0.001), and were less likely to receive thrombolysis (23% vs. 33%, p<0.01), admission to coronary care (65% vs. 77%, p<0.001), or subsequent invasive or noninvasive investigations (55% vs. 63%, p<0.01). However, women with AMI were older than men with AMI (71 vs. 65 years, p<0.001). After adjusting for age, differences that remained significant were prevalence of hypertension (odds ratio [OR] 2.12, 95% confidence intervals [CI] 1.56 to 2.88) and cigarette smoking (OR 0.47, 95% CI 0.35 to 0.65), management in coronary care (OR 0.66, 95% CI 0.49 to 0.88), and hospital mortality (OR 1.48, 95% CI 1.07 to 2.04). Excess mortality occurred predominantly in women <65 years old (18% vs. 8%, OR [multivariate] 2.35, 95% CI 1.19 to 4.56), among whom multivariate analysis demonstrated a significantly lower thrombolysis rate (OR 0.48, 95% CI 0.27 to 0.86). In this group, lack of thrombolysis independently predicted hospital mortality (OR 5.37, 95% CI 1.45 to 19.82). Female gender was not an independent predictor of mortality following AMI (OR 1.42, 95% CI 0.90 to 2.26). Thus, among unselected patients, female gender is associated with, but not an independent predictor of, reduced survival after AMI. Gender differences in mortality are greatest in younger patients, who are less likely to receive thrombolysis and in whom lack of thrombolysis is independently associated with mortality after AMI.

Characteristics and outcomes in patients with acute myocardial infarction with ST-segment depression on initial electrocardiogram.

BACKGROUND: Acute myocardial infarction (AMI) with nonreciprocal ST-segment depression is said to have a poor prognosis, and early diagnosis and treatment are problematic. The aim of this study was to determine the proportion of unselected consecutive patients admitted to a university center with AMI with nonreciprocal ST-segment depression and to characterize these patients in terms of clinical features, treatment, and short- and long-term prognoses. METHODS AND RESULTS: Admission electrocardiographic data on 852 consecutive admissions with AMI were analyzed. Nonreciprocal ST-depression was an admitting feature in 95 (11%) patients, the majority of whom had ST depression >3 mm. These were older (70.3 vs 66.8 years, P <.05), more likely to have had myocardial infarction (40% vs 25%, P <.01), and to have left ventricular failure (56% vs 42%, P <.5), cardiogenic shock (15% vs 9% P =.06), and atrial fibrillation (34% vs 19%, P <.01). Hospital mortality rate was significantly higher (31% vs 17%, P <.01). Patients were less likely to undergo thrombolysis (17% vs 31%, P <.01), angiography (22% vs 35%, P <.05), or percutaneous revascularization (5% vs 9%, P <.01). Patients with ST depression undergoing coronary angiography were more likely to have 3-vessel disease (71% vs 47%, P <.05). Mortality rate at follow-up (median 36 months) was significantly higher in patients with ST depression (56% vs 32%, P <.001). Analysis by individual electrocardiography demonstrated ST-segment depression to be the third most frequent presentation after ST elevation (n = 327) and T-wave changes (n = 258), in whom hospital mortality rates were 24% and 9%, respectively. In multivariate analysis, previous myocardial infarction was an independent predictor of nonreciprocal ST depression at initial examination (odds ratio 2.04 [1.25 to 3.34], P <.005). No electrocardiographic presentation was an independent predictor of death in the hospital after AMI. CONCLUSIONS: In unselected cases of AMI, patients with ST-segment depression make up a significant minority (11%), who are likely to be older with a high prevalence of previous myocardial infarction and multivessel disease, and who have a poor prognosis.

Hospital mortality of acute myocardial infarction in the thrombolytic era.

OBJECTIVE: To examine the management and outcome of an unselected consecutive series of patients admitted with acute myocardial infarction to a tertiary referral centre. DESIGN: A historical cohort study over a three year period (1992-94) of consecutive unselected admissions with acute myocardial infarction identified using the HIPE (hospital inpatient enquiry) database and validated according to MONICA criteria for definite or probable acute myocardial infarction. SETTING: University teaching hospital and cardiac tertiary referral centre. RESULTS: 1059 patients were included. Mean age was 67 years; 60% were male and 40% female. Rates of coronary care unit (CCU) admission, thrombolysis, and predischarge angiography were 70%, 28%, and 32%, respectively. Overall in-hospital mortality was 18%. Independent predictors of hospital mortality by multivariate analysis were age, left ventricular failure, ventricular arrhythmias, cardiogenic shock, management outside CCU, and reinfarction. Hospital mortality in a small cohort from a non-tertiary referral centre was 14%, a difference largely explained by the lower mean age of these patients (64 years). Five year survival in the cohort was 50%. Only age and left ventricular failure were independent predictors of mortality at follow up. CONCLUSIONS: In unselected consecutive patients the hospital mortality of acute myocardial infarction remains high (18%). Age and the occurrence of left ventricular failure are major determinants of short and long term mortality after acute myocardial infarction.

Management and outcome of acute myocardial infarction in older patients in the thrombolytic era.

OBJECTIVE: Acute myocardial infarction (AMI) is an important cause of mortality and morbidity in older patients. The aim of this study was to determine the proportion of unselected admissions with AMI that is older than 75 years and to examine management and outcomes in this group. DESIGN: An historical cohort study of consecutive unselected admissions with AMI identified using the Hospital In Patient Enquiry (HIPE) database and validated according to MONICA criteria for definite or probable AMI. SETTING: An acute cardiac unit in a university teaching hospital/cardiac tertiary referral center. RESULTS: Of 1059 patients, 606 (57%) were older than 65 years and 309 (29.2%) were older than 75 years. Mean age in this group was 80.5 years. Hospital mortality was almost twice as high as in patients younger than 75 years (28% vs 15%, P < .001), and age was an independent predictor of short- and long-term mortality following AMI. Women constituted a significantly higher proportion of older patients. Family history of AMI and cigarette smoking were less prevalent in older patients. Mean cholesterol was lower and comorbidities were higher. Other baseline characteristics, including previous AMI, did not differ. However older patients were less likely to receive thrombolysis (13% vs 36%, P < .001), aspirin (76% vs 86%, P < .01), or beta-blockers (25% vs 51%, P < .001) and were less likely to undergo cardiac catheterization or revascularization. Only 53% were admitted to coronary care. CONCLUSION: Patients more than age 75 comprise almost one-third of patients with AMI and have a poor prognosis. Although age is an independent predictor of mortality following AMI, suboptimal management may contribute to the high mortality in these patients.

Histopathologic changes in asymptomatic relatives of patients with idiopathic dilated cardiomyopathy.

Echocardiographic screening of asymptomatic relatives of patients with idiopathic dilated cardiomyopathy identifies a subset with left ventricular enlargement who are assumed to have early familial idiopathic dilated cardiomyopathy. This study shows for the first time that the myocardium in such relatives demonstrates abnormal cellularity.

Detection of coronary artery disease using dobutamine stress echocardiography in patients with an abnormal resting electrocardiograph.

PURPOSE: We assessed the value of dobutamine stress echocardiography for the detection of coronary artery disease in patients with chest pain and an abnormal resting electrocardiograph (ECG). METHODS: Dobutamine stress echocardiography was performed in a standard fashion. Significant coronary artery disease was defined as a >50% luminal diameter stenosis on coronary angiography. RESULTS: The sensitivity, specificity, positive and negative predictive value of dobutamine stress echocardiography for the detection of coronary artery disease in 218 patients were 89, 50, 95 and 32%, respectively. The sensitivity for detection of multi-, double- and single vessel disease were 97, 82 and 81%, respectively. The sensitivity for the detection of coronary artery disease in a subgroup of 69 patients by treadmill exercise testing was 37%. CONCLUSION: Dobutamine stress echocardiography is better than exercise ECG for the detection of significant coronary artery disease. The negative predictive value of dobutamine stress echocardiography in this patient group is low.

Long-term clinical outcome following coronary artery bypass grafting for isolated stenosis of the left anterior descending coronary artery.

AIMS: To detail the clinical and angiographic profile, and long-term outcome in consecutive patients with isolated stenosis of the left anterior descending coronary artery undergoing bypass surgery. METHODS: A retrospective study of all patients (n = 301) (January 1984-December 1990) and undergoing coronary artery bypass grafting for isolated left anterior descending disease, in the Irish Republic, was performed. Survival was compared with that of an exact age- and gender-matched cohort. RESULTS: Mean age was 53 (+/- 9.3) years. There were 238 (79%) males. In 241 (80%) patients an internal thoracic arterial bypass graft was used. Operative mortality was 1.3%. Of the 280 (93%) patients alive (16 cardiac deaths) at 7.1 (+/- 1.9) years, 105 (35%) had angina, 26 (9%) suffered an interval myocardial infarction, and repeat revascularization was required on 29 (10%). Female gender (P = 0.002), pre-operative myocardial infarction (P = 0.02), significant diagonal disease (P = 0.04) and postoperative myocardial infarction (P = 0.0001) were independently associated with survival. Females were more likely to develop congestive cardiac failure (P = 0.01) or postoperative angina (P = 0.03) than their male counterparts. CONCLUSIONS: Survivorship (97%) and event-free survival (96%) at 5 years following coronary artery bypass grafting for isolated left anterior descending coronary artery disease is excellent and equivalent to an age-matched and gender-matched cohort.

Alcohol consumption and idiopathic dilated cardiomyopathy: a case control study.

BACKGROUND: Alcohol has been implicated as a risk factor for idiopathic dilated cardiomyopathy (DCM), but a causal relation has not been established. The objective of this study was to determine the association between alcohol consumption and DCM. METHODS: Questionnaires detailing average weekly intake of alcohol, total lifetime consumption, and alcohol abuse were administered in a cohort of well-defined patients with DCM and a randomly selected, population-based control group. RESULTS: Significantly more of the 100 patients with DCM than the 211 members of the control group drank greater than the recommended weekly intake of alcohol (40% vs 24%; p < 0.01) and were alcohol abusers according to the CAGE questionnaire (27% vs 16%; p < 0.05). The average total lifetime consumption measured in units of alcohol was also significantly greater in cases than in the control group (31,200 vs 7,904; p < 0.01). Patients with familial DCM were not significantly more likely to consume alcohol above recommended limits or to be alcohol abusers compared with nonfamilial cases. CONCLUSIONS: This study confirms previous suspicion of a causal association between alcohol and DCM, with significantly more patients than members of the control group either abusing alcohol or drinking it in excess of recommended limits.

Fatal stent thrombosis following successful treatment or coronary artery rupture in an octogenarian.

Primary intracoronary stenting of a calcified left anterior descending coronary artery stenosis was complicated by within-stent coronary artery rupture and subsequent cardiac tamponade. Despite pericardiocentesis and sealing of the perforation by additional stent placement, subsequent stent thrombosis resulted in anterior myocardial infarction and fatal cardiogenic shock.

Dobutamine stress echocardiography in the detection of coronary artery disease in a clinical practice setting.

UNLABELLED: In this prospective study, patients referred for coronary angiography for detection of disease underwent dobutamine stress echocardiography to define its value in a clinical practice setting. RESULTS: Of 219 patients studied, 170 (78%) had significant coronary artery disease. The overall sensitivity and specificity of dobutamine stress echocardiography for coronary artery disease were 82 and 65%, respectively. The sensitivity was 88% for detection of triple-vessel disease, 83% for double-vessel disease, and 74% for single-vessel disease. Positive and negative predictive values for coronary artery disease were 89 and 51%, respectively. Dobutamine stress echocardiography correctly identified only 72 of 138 patients with significant stenosis of the left anterior descending coronary artery. In 219 patients, 345 of 657 major epicardial vessels had significant disease. Dobutamine stress echocardiography could only correctly identify the vessel involved in 188. Triple-vessel disease was present in 65 patients. Dobutamine stress echocardiography correctly categorised 18% (n = 12) of these. The remainder were incorrectly classified as having double-vessel disease or single-vessel disease (n = 45), or no disease at all (n = 8). CONCLUSION: Dobutamine stress echocardiography performs well. However, lower specificity may lead to unwarranted referrals for coronary angiography, and the low NPV give false reassurance as to the absence of disease.

Dobutamine stress echocardiography in the detection of coronary artery disease: importance of the pretest likelihood of disease.

Although the accuracy of dobutamine stress echocardiography for the detection of coronary artery disease in a high-risk population is known, it has not been well defined for lower risk groups. Two probability groups, high (>75%; n = 199) and intermediate (>10% but < or =75%; n = 118), were studied. Dobutamine stress echocardiography was performed in a standard fashion. Significant coronary artery disease was defined as a >50% luminal diameter stenosis on coronary angiography. The positive predictive accuracy of dobutamine stress echocardiography for the detection of coronary artery disease was greater in the high-probability group (96% vs 86%), as was the sensitivity (89% vs 78%), whereas the negative predictive value was greater in the intermediate-probability group (50% vs 23%), as was the specificity (63% vs 50%). Dobutamine stress echocardiography does have a diagnostic role in the evaluation of patients with an intermediate probability of coronary artery disease.

Idiopathic dilated cardiomyopathy: familial prevalence and HLA distribution.

OBJECTIVES: To compare HLA distribution in familial and non-familial dilated cardiomyopathy, because a serum marker that could identify families at risk of developing dilated cardiomyopathy should be of use in screening for the disease. PATIENTS: 100 patients with dilated cardiomyopathy. METHODS: 200 first degree relatives from 56 of the proband families were screened for dilated cardiomyopathy by echocardiography. The HLA profile of the patients with dilated cardiomyopathy, as well as of the familial and non-familial subgroups, was compared with that of 9000 normal controls. RESULTS: The familial prevalence of dilated cardiomyopathy in this patient group was "definite" in 14 of 56 (25%) and "possible" in 25 of 56 (45%). The HLA-DR4 frequency in the 100 patients with dilated cardiomyopathy was similar to that in the 9000 controls (39% v 32%). However, the DR4 subtype was significantly more common in the 25 probands with a familial tendency to dilated cardiomyopathy than in the 31 probands with non-familial dilated cardiomyopathy (68% v 32%; P < 0.05). CONCLUSIONS: The present finding supports an HLA linked predisposition to familial dilated cardiomyopathy. The HLA type DR4 was significantly more common in familial than in non-familial cases. The DR4 halotype was associated with two thirds of the families at risk for dilated cardiomyopathy.

Safety of dobutamine stress echocardiography in 474 consecutive studies.

BACKGROUND: With expanding applications and increasingly aggressive stress protocols, concerns about the safety of dobutamine stress echocardiography (DSE) have arisen. The purpose of this study was to analyse prospectively the safety, adverse event profile and complication rate of DSE. METHODS: Prospective data were recorded in a consecutive series of 474 patients undergoing DSE. Dobutamine was administered intravenously in graded infusion, each stage over 3 min, at 10, 20, 40 and, if required, 50 micrograms/kg/min. Atropine (1 mg) was administered thereafter if the response remained suboptimal. RESULTS: The mean dose of dobutamine was 42 micrograms/kg/min, with 111 patients (23%) receiving 50 micrograms/kg/min. Atropine was required for 27 patients (6%). No patient died or suffered a myocardial infarction. Sustained ventricular tachycardia occurred in one patient, angina pectoris in 127 (27%), non-sustained ventricular tachycardia in eight (2%) and supraventricular tachycardia in 19 (4%). Profound bradycardia requiring cessation of the test occurred in one patient. Pulmonary oedema developed in one patient. A hypotensive response requiring cessation of the test was seen in one patient. Test termination because the patient complained of nausea, tremor or headache was not required. CONCLUSION: DSE is safe. Side effects are rare and when they occur, are usually minor. Ischaemic pain is effectively treated by termination of the test and sublingual administration of nitrates.

Evaluation of patients with diabetes mellitus for coronary artery disease using dobutamine stress echocardiography.

BACKGROUND: There is a high prevalence of coronary artery disease (CAD) in patients with diabetes mellitus. Detection of inducible ischaemia using treadmill exercise testing may be limited by the relatively poor inherent predictive accuracy of the test. The purpose of this study was to determine the value of dobutamine stress echocardiography (DSE) for the detection of CAD in patients with diabetes mellitus. METHODS: Patients with diabetes mellitus referred for cardiac assessment were considered eligible for study. DSE was performed in a standard fashion. Significant CAD was defined as a > 50% luminal diameter stenosis on coronary angiography. RESULTS: A total of 52 patients (mean age 59 years) with diabetes mellitus were studied prospectively using DSE. Risk factors for CAD included hypertension in 19, family history in 21, hypercholesterolaemia in 14, history of smoking in 38. The sensitivity, specificity, positive and negative predictive values of DSE for detection of CAD were 82, 54, 84 and 50% respectively. CONCLUSION: The specificity of DSE for CAD in patients with diabetes mellitus is low. Whether this reflects an underdetection of small vessel disease by contrast coronary angiography or whether it relates to test performance is unclear.