Noninvasive assessment of cardiac diabetic neuropathy by carbon-11 hydroxyephedrine and positron emission tomography

OBJECTIVES: The purpose of this investigation was to evaluate the sympathetic nervous system of the heart by positron emission tomographic (PET) imaging in patients with diabetes mellitus with and without diabetic autonomic neuropathy. BACKGROUND: The clinical assessment of cardiac involvement in diabetic autonomic neuropathy has been limited to cardiovascular reflex testing. With the recent introduction of radiolabeled catecholamines such as carbon (C)-11 hydroxyephedrine, the sympathetic innervation of the heart can be specifically visualized with PET imaging. METHODS: Positron emission tomographic imaging was performed with C-11 hydroxyephedrine and rest myocardial blood flow imaging with nitrogen-13 ammonia. Three patient groups were studied, including healthy volunteers as control subjects, diabetic patients with normal autonomic function testing and diabetic patients with varying severity of autonomic neuropathy. Homogeneity of cardiac tracer retention as well as absolute tracer retention was determined by relating myocardial tracer retention to an arterial C-11 activity input function. RESULTS: Abnormal regional C-11 hydroxyephedrine retention was seen in seven of eight patients with autonomic neuropathy. Relative tracer retention was significantly reduced in apical, inferior and lateral segments. The extent of the abnormality correlated with the severity of conventional markers of autonomic dysfunction. Absolute myocardial tracer retention index measurements showed a 45 +/- 21% decrease in distal compared with proximal myocardial segments in autonomic neuropathy (0.069 +/- 0.037 min-1 vs. 0.13 +/- 0.052 min-1, p = 0.02). CONCLUSIONS: This study demonstrates a heterogeneous pattern of neuronal abnormalities in patients with diabetic cardiac neuropathy. The extent of this abnormality correlated with the severity of neuropathy assessed by conventional tests. Future studies in larger groups of patients are required to define the relative sensitivity of this imaging approach in detecting cardiac neuropathy and to determine the clinical significance of these scintigraphic findings in comparison with conventional markers of autonomic innervation.     

The heart at necropsy in centenarians

Cardiac findings at necropsy are described in 6 patients aged 100 to 103 years of age. Although 4 had considerably narrowed coronary arteries at necropsy, none had apparent clinical evidence of myocardial ischemia or congestive heart failure during life.     

Massive myocardial calcification in the perinatal period

Massive myocardial calcification (MMC) in the perinatal period is an unusual finding considered to be a unique tissue reaction. This report summarizes the clinical and pathologic findings of seven cases of perinatal MMC. All patients presented clinical evidence of myocardial damage. In two cases arrhythmia was detected in utero. Four cases presented with hydrops, one of which was associated with major heart malformation. One case was a trisomy 13. Three cases had polyhydramnios. Our results demonstrate that calcification follows progressive stages from patches of calcified myocardial cells (stage I), to coagulative and colliquative myocytolysis with clusters of interstitial mononucleated cells (stage II), to collapsing fibrosis with granulation tissue and multinucleated regenerative myocardial cells (stage III), and finally to fibrous scars containing entrapped remaining myocardial cells (stage IV). Literature review and our findings suggest that perinatal MMC results from different conditions inducing hypoxic-ischemic damage that later is followed by progressive scarring if the patient survives the acute stage. The lesion may represent the human counterpart of the so-called dystrophic cardiac calcinosis in mice. This disease is related to an abnormality at the Dyscalc locus of proximal chromosome 7 (syntenic with human chromosome 19q13 and 11p15).     

Prevalence of myocardial ischemia as depicted by regional wall motion abnormality in blacks

Coronary artery disease with subsequent myocardial ischemia is a common cause of morbidity and mortality in the United States, and data are scarce on the prevalence of the disease in blacks. Regional wall motion abnormality correlates either directly or indirectly with myocardial ischemia. This study examines the two-dimensional (2-D) echocardiography of patients > or = 45 years for men and > or = 55 years at Metropolitan Nashville General Hospital, Nashville, Tennessee. A total of 601 2-D echocardiographic studies were performed on patients who presented with symptoms and signs of cardiovascular disease. Of these, 377 (62.7%) met the age criteria and formed the study group; 92 were excluded for various reasons, leaving 285 (75%) in the analysis group. A total of 80 (28.1%) patients had regional wall motion abnormality while 205 (71.9%) did not. On analysis of the 80 patients with regional wall motion abnormality, the segment of the heart commonly affected was the septal area, although more than one segment of the myocardium was affected in all of the patients. A total of 36 (45%) patients had normal left ventricular size. In relation to race, blacks had a higher prevalence of regional wall motion abnormality compared with whites (29.2% versus 26.2%, respectively), but the difference was not statistically significant. These prevalence rates indicate the importance of looking for this abnormality during echocardiographic evaluation of a patient. The presence of regional wall motion abnormality on 2-D echocardiography in the presence of other cardiovascular risk factors necessitates further investigation and management to minimize later complications of coronary artery disease.     

Changes in hemostasis in ischemic heart disease

The relationship between changes in blood coagulation, the occurrence and severity of risk factors of ischemic heart disease and the clinical condition of the patient was investigated. The at risk group of patients 42.2% had more than 3 pathological parameters. Intravascular blood coagulation was not activated in any of the patients. In patients with acute myocardial infarction (MI), 62.2% had more than 3 pathological parameters on the first day of MI development. Demonstrable activation of intravascular blood coagulation was found in 28.2% of these patients. On day 5 of MI, activation of intravascular blood coagulation was recorded in 57.7% of the patients treated by classical approach and in 15.4-30.8% of the patients on thrombolytic treatment. In the at risk group, primary hemostasis and the fibrinolytic system were more affected, in patients with MI the whole hemostatic mechanism was involved. On day 5 of MI, in patients with classical therapy pathological laboratory findings still persisted or were even more deteriorated, particularly increases in fibrinogen level. At that time, in patients on thrombolytic therapy no substantial changes of initial values were recorded. No correlation was found to exist between changes in hemostasis and the risk profile or between changes in hemostasis and the clinical severity of MI. The obtained results justify the administration of antithrombotic substances, especially in patients with unstable angina pectoris. On observing time constraints, administration of thrombolytics is justified in MI. (Fig. 9, Ref. 25.)     

Heart involvement in hepatolenticular degeneration

The case of a 10-year-old boy with a mild abdominal form of hepatolenticular degeneration, showing clinical, laboratory and histological manifestations of heart involvement is reported. The microscopical examination of myocardial fragments collected by intracavitary puncture biopsy, using hematoxylin-eosine and the histochemical method with rubeanic acid, showed a medium degree of myocardial damage and the presence of copper deposition in the tissue. Copper concentration on a myocardial biopsy fragment was almost 10 times the normal heart content. Comments are made on the relationship of the clinical, laboratory and pathological findings with the degree of copper storage on the myocardium.     

Myocardial damage after minimally invasive coronary artery bypass grafting on the beating heart

BACKGROUND: In conventional coronary artery bypass grafting, the rate of perioperative myocardial infarction is reported in the 2% to 6% range; however, significantly higher rates are observed if sensitive myocardial marker proteins are used to detect perioperative myocardial damage. For minimally invasive direct coronary artery bypass grafting, few data are available concerning myocardial marker protein release. METHODS: Fifteen consecutive patients (11 male, 4 female; mean age, 59.6 +/- 8.5 years) received minimally invasive direct coronary artery bypass grafting procedures via minithoracotomy on the beating heart. Electrocardiography and transesophageal and transthoracic echocardiography as well as determination of creatine kinase-MB mass concentration and cardiac troponin I level were used for ischemic monitoring. RESULTS: One patient had a perioperative myocardial infarction according to standard criteria and died despite mechanical circulatory support. Determination of cardiac troponin I level showed small but definitive ischemic damage in 4 of 9 patients (44%) who presented transient ischemic signs intraoperatively or postoperatively. In 2 of these 4 patients pathologic findings could be detected on angiographic restudies. CONCLUSIONS: Subclinical myocardial injury is a common event in minimally invasive coronary artery bypass grafting on the beating heart. Cardiac troponin I could serve as an adequate diagnostic tool for diagnosis of perioperative myocardial infarction in minimally invasive direct coronary artery bypass grafting.     

Frequent nut consumption and risk of coronary heart disease in women: prospective cohort study

OBJECTIVE: To examine the relation between nut consumption and risk of coronary heart disease in a cohort of women from the Nurses' Health Study. DESIGN: Prospective cohort study. SETTING: Nurses' Health Study. SUBJECTS: 86 016 women from 34 to 59 years of age without previously diagnosed coronary heart disease, stroke, or cancer at baseline in 1980. MAIN OUTCOME MEASURES: Major coronary heart disease including non-fatal myocardial infarction and fatal coronary heart disease. RESULTS: 1255 major coronary disease events (861 cases of non-fatal myocardial infarction and 394 cases of fatal coronary heart disease) occurred during 14 years of follow up. After adjusting for age, smoking, and other known risk factors for coronary heart disease, women who ate more than five units of nuts (one unit equivalent to 1 oz of nuts) a week (frequent consumption) had a significantly lower risk of total coronary heart disease (relative risk 0.65, 95% confidence interval 0.47 to 0.89, P for trend=0.0009) than women who never ate nuts or who ate less than one unit a month (rare consumption). The magnitude of risk reduction was similar for both fatal coronary heart disease (0.61, 0.35 to 1.05, P for trend=0.007) and non-fatal myocardial infarction (0.68, 0.47 to 1.00, P for trend=0.04). Further adjustment for intakes of dietary fats, fibre, vegetables, and fruits did not alter these results. The inverse association persisted in subgroups stratified by levels of smoking,use of alcohol, use of multivitamin and vitamin E supplements, body mass index, exercise, and intake of vegetables or fruits. CONCLUSIONS: Frequent nut consumption was associated with a reduced risk of both fatal coronary heart disease and non-fatal myocardial infarction. These data, and those from other epidemiological and clinical studies, support a role for nuts in reducing the risk of coronary heart disease.     

The quality of vital perinatal statistics data, with special reference to prenatal care

OBJECTIVES: Most patients with severe pulmonary emphysema referred for lung volume reduction surgery (LVRS) have a long-standing history of cigarette smoking. Coronary artery disease (CAD) predisposes to perioperative cardiac complications. Since symptoms and signs of myocardial ischemia are often absent in patients with severe ventilatory impairment even during exercise, we investigated the prevalence of CAD in candidates for LVRS by angiography. DESIGN: We prospectively studied the prevalence of CAD by angiography and assessed the CAD risk factor profile in 41 candidates for LVRS (26 men, 15 women; mean age, 66+/-6.8 years; range, 52 to 76 years), who had no current symptoms or a history of myocardial ischemia. RESULTS: In six patients (15%), asymptomatic but significant coronary lesions (> 70% stenosis) were detected. In five patients, these findings altered the clinical management. Patients with CAD had significant higher cholesterol levels, tended to have smoked more, and had more often additional vascular risk factors. CONCLUSIONS: We found a high prevalence of angiographically significant but clinically silent CAD in this particular population of heavy smokers with advanced emphysema.     

Pathology of acute myocardial infarction with particular reference to occlusive coronary thrombi

Analysis of the pathological findings in 500 cases of fatal acute myocardial infarction showed that in 469 this was localized to one transmural area of the left ventricle; in 31 there was diffuse subendocardial necrosis. In the former occlusive coronary thrombus was found in the related artery in 95 per cent of cases. Variation in the percentage of occlusions found was noted between different prosectors and when coronary artery calcification was present. Only 4 of the 31 patients with subendocardial necrosis had recent occlusion; triple vessel disease was common in this group suggesting general failure of coronary perfusion. It is essential in necropsy studies of the relation of coronary thrombosis to myocardial infarction to be sure that muscle necrosis is present, to distinguish the two forms of myocardial necrosis, and to employ a meticulous dissection technique with decalcification of the arteries when necessary.     

Coronary surgery on the beating heart under extracorporeal circulation in high-risk patients. An acceptable compromise?

Coronary artery surgery with cardioplegia in high risk patients carries a risk of myocardial ischaemia and, without cardiopulmonary bypass, is not always technically feasible. The authors assessed an alternative, surgery on the beating heart with haemodynamic assist by cardiopulmonary bypass in 43 consecutive patients with poor left ventricular function (mean ejection fraction: 0.26), evolving myocardial ischaemia or acute myocardial infarction, old age (mean: 79.5 years) and comorbid conditions. Results were assessed mainly on clinical criteria. In addition, 9 patients had pre- and post-cardiopulmonary bypass measurements of markers of myocardial ischaemia (troponine Ic) and systemic inflammation (interleukines 6 and 10, elastase). In 6 cases, right atrial biopsy was analysed for expression of messenger ribonucleic acid coding for heat shock protein (HSP) 70; the data were compared with those of patients operated under warm blood cardioplegia. There was one cardiac death and one myocardial infarction. Myocardial conservation was confirmed by the minimal increase in troponine Ic levels and the significant increase in HSP 70 in RNA suggesting myocardial adaptation to stress. On the other hand, the minimal concentrations of mediators of inflammation were not significantly changed. In selected high risk patients, coronary revascularisation on the beating heart under cardiopulmonary bypass could be a valuable alternative. It conserves the potentially deleterious effects of cardiopulmonary bypass but peroperative global myocardial ischaemia, an important factor in the aggressivity of cardiac surgery, is eliminated.     

Management of risk factors after coronary heart disease in European countries

BACKGROUND: Despite clinical and epidemiological evidence of benefits from sustained management of vascular risk factors following coronary heart disease, the implication of physicians in secondary prevention remains limited. In 1994, several European scientific societies published jointly guidelines for the prevention of coronary heart disease in clinical practice, ranking as the highest priority the reduction of risk factors in coronary patients. METHODS: The European Society of Cardiology launched at the same period a study on the prevalence and management of vascular risk factors of coronary patients in Europe, the EUROASPIRE project. Six months after a coronary event 3,569 patients, from a total population of 4,863 affected individuals recruited in hospitals of 9 European countries, were interviewed and examined to estimate the levels and management of their vascular risk factors. RESULTS: At least six months after discharge, one patient out of five kept on smoking, one out of four was still obese, one out of two had high blood pressure levels and 44% total cholesterolemia over 5.5 mmol/L. More than 8 smoking patients out of 10 attempted to stop smoking and 8 obese patients out of 10 attempted to lose weight. More than 40% of patients, treated or not for hypertension, had systolic blood pressure levels over 140 mm Hg, and almost one patient out of two, treated or not treated for dyslipemia, a total cholesterolemia over 5.5 mmol/L. CONCLUSIONS: Given the high prevalence of vascular risk factors in coronary patients, efficient secondary prevention aiming at the reduction of the levels of these risk factors, may have a major impact on the decrease of morbidity and mortality of these patients. Thus, joined European efforts to elaborate, diffuse and evaluate secondary prevention strategies towards physicians and patients should be rapidly developed to facilitate the achievement of such benefits for coronary patient health.     

Working hours as a risk factor for acute myocardial infarction in Japan: case-control study

OBJECTIVE: To clarify the extent to which working hours affect the risk of acute myocardial infarction, independent of established risk factors and occupational conditions. DESIGN: Case-control study. SETTING: University and general hospitals and routine medical examinations at workplaces in Japan. SUBJECTS: Cases were 195 men aged 30-69 years admitted to hospital with acute myocardial infarction during 1990-3. Controls were 331 men matched at group level for age and occupation who were judged to be free of coronary heart diseases at routine medical examinations in the workplace. MAIN OUTCOME MEASURES: Odds ratios for myocardial infarction in relation to previous mean daily working hours in a month and changes in mean working hours during previous year. RESULTS: Compared with men with mean working hours of >7-9 hours, the odds ratio of acute myocardial infarction (adjusted for age and occupation) for men with working hours of >11 hours was 2.44 (95% confidence interval 1.26 to 4.73) and for men with working hours of <=7 hours was 3.07 (1.77 to 5.32). Compared with men who experienced an increase of <=1 hour in mean working hours, the adjusted odds ratio of myocardial infarction for men who experienced an increase of >3 hours was 2.53 (1.34 to 4. 77). No appreciable change was observed when odds ratios were adjusted for established and psychosocial risk factors for myocardial infarction. CONCLUSION: There was a U shaped relation between the mean working hours and the risk of acute myocardial infarction. There also seemed to be a trend for the risk of infarction to increase with greater increases in mean working hours.     

The effect of the mean platelet volume on the short-term prognosis of acute myocardial infarct

INTRODUCTION AND OBJECTIVES: The increase of mean platelet volume in the late phase of myocardial infarction is an independent predictor for recurrent myocardial infarction and death, but the association between this finding and the short-term prognosis after acute myocardial infarction is unknown. The goals of this study were to assess the influence of mean platelet volume on the risk of death, recurrent ischemic events or cardiac heart failure during the in-hospital phase of myocardial infarction and to analyse the relationship between mean platelet volume and several demographic and clinical variables registered on admission. MATERIAL AND METHODS: A population of 1,082 patients with acute myocardial infarction were distributed in two groups according to the platelet volume measured on admission: group 1, mean platelet volume > 9 fl (n = 443) and group 2, mean platelet volume < or = 9 fl (n = 639). The difference between both groups on the end-point of this study were assessed by univariate and multivariate statistical methods. An univariate analysis was also applied to assess the relationship between platelet volume and the baseline variables. RESULTS: A mean platelet volume > 9 fl was associated with a significant increase of risk for the combined end-point considered (OR = 1.37; p = 0.026). By univariate analysis, an increased platelet volume was related to a higher risk of cardiac failure (OR = 1.46; p = 0.01) and a non-significant increase in the incidence of recurrent ischemic events (OR = 1.35; p = 0.07). In addition, a large platelet volume was also associated with a higher prevalence of prior myocardial infarction, arterial hypertension and diabetes mellitus. CONCLUSIONS: The results of this study suggest that the increase of mean platelet volume on admission is an independent risk factor for cardiac heart failure and is associated with a non significant higher rates of ischemic events during the recovery phase of acute myocardial infarction.     

Comparison of coronary angiographic findings in acute and chronic first presentation of ischemic heart disease

BACKGROUND: It is generally assumed that the clinical manifestations of ischemic heart disease occur randomly on the same underlying pathological process. Therefore, coronary angiographic findings should be similar whether the first presentation of ischemic heart disease is acute myocardial infarction or uncomplicated chronic stable angina. METHODS AND RESULTS: We studied 102 patients (men < or = 60 years old, women < or = 65 years old) presenting with either acute myocardial infarction as first manifestation of coronary artery disease with a concomitant coronary angiogram (55 patients; mean age, 50.2 years) or stable angina for at least 2 years with no history, ECG, or left ventriculographic evidence of any acute event and with an angiogram performed at least 2 years after initial symptoms (47 patients; mean age at symptom onset, 51.7 years). These angiograms were evaluated blindly for severity (number of vessels diseased, stenoses > or = 50%, occlusions), extent of disease (with an index derived by assigning a score of 0-3 per segment, depending on the proportion of lumen length irregularity and dividing the sum by the number of visualized segments), and pattern (discrete: three or fewer loci of disease never involving more than 50% of the length of any segment or diffuse: anything exceeding this). Patients with unheralded myocardial infarction had fewer vessels diseased, fewer stenoses and occlusion, and a lower extent index than those with uncomplicated stable angina (mean +/- SD of 1.3 +/- 0.8 versus 2.1 +/- 0.8, p < 0.001; 2.1 +/- 1.8 versus 3.9 +/- 1.8, p < 0.001; 0.6 +/- 0.6 versus 1.0 +/- 0.9, p < 0.02; and 0.6 +/- 0.5 versus 1.2 +/- 0.5, p < 0.001, respectively). A discrete pattern was present in 54.5% of patients with unheralded infarction and in only 8.5% of those with uncomplicated angina (p < 0.001). CONCLUSIONS: These very different angiographic findings suggest that unheralded acute myocardial infarction and uncomplicated chronic stable angina do not occur randomly on a common atherosclerotic background but rather that additional factors, such as a varying propensity to thrombosis, may predispose to one or the other of these two clinical syndromes.     

At risk of first or recurring heart disease

OBJECTIVES: The self-reported prevalence of risk factors for heart disease among Canadians with and without heart disease is estimated. The characteristics associated with these risk factors are examined in order to identify groups to be targeted for primary and secondary prevention. DATA SOURCE: The data are from the household component of the 1994/95 National Population Health Survey (NPHS). ANALYTICAL TECHNIQUES: For the population aged 20 and older with and without heart disease, bivariate and multiple regression analyses were used to determine associations between four risk factors (smoking, high blood pressure, diabetes, and inactivity) and demographic characteristics and socioeconomic status. MAIN RESULTS: According to the NPHS, 4.4% of people aged 20 and older reported that they heart disease. However, many more adults had risk factors for this disease. As well, about one-quarter of those without heart disease and half of those with heart disease had two or more risk factors. To some extent, many of these risks are modifiable. The groups particularly at risk were people older than 35, those with less than high school graduation, those in households with inadequate income, people who consumed three or more drinks a day, and residents of the Atlantic provinces, Quebec and Ontario.     

Cardiac death prediction and impaired cardiac sympathetic innervation assessed by MIBG in patients with failing and nonfailing hearts

BACKGROUND: Although cardiac sympathetic nerve dysfunction is related to poor clinical outcome, a critical sympathetic dysfunction level for predicting cardiac death is still unclear. The current study was designed to investigate which indices derived from metaiodobenzylguanidine (MIBG) imaging have prognostic value compared with clinical and cardiac function variables, and to determine the threshold of cardiac MIBG activity for identifying patients likely to suffer cardiac death in both failing and nonfailing hearts. METHODS AND RESULTS: Myocardial I-123-MIBG activity was quantified as a heart-to-mediastinum ratio in 414 consecutive patients, 173 (42%) of whom had symptomatic heart failure. After cardiac function measurements, patients were followed up with an end-point of cardiac or noncardiac death. During a mean follow-up period of 22 months, 37 cardiac deaths occurred: 23 resulted from heart failure, 9 were sudden cardiac deaths, and 5 were fatal myocardial infarctions. Multivariate analysis using the Wald chi2 and the Cox proportional hazard model revealed that late heart-to-mediastinum ratio, the use of nitrates, early heart-to-mediastinum ratio, and left ventricular ejection fraction were independent predictors of cardiac death; late heart-to-mediastinum ratio, New York Heart Association (NYHA) class, the presence of previous myocardial infarction, and age were independent predictors of heart failure and sudden cardiac death. Late heart-to-mediastinum ratio was the most powerful predictor of overall cardiac death among the variables. The Kaplan-Meier analysis showed that a late heart-to-mediastinum ratio of 1.74 or less, age greater than 60 years, the presence of myocardial infarction, and NYHA functional class 3 or 4 strongly indicated poor clinical outcomes. Furthermore, the more powerful incremental prognostic values were obtained by using MIBG imaging in combination with conventional clinical variables. CONCLUSIONS: Impaired cardiac sympathetic innervation assessed by MIBG activity has the greatest potential for predicting cardiac death and may be useful for identifying a threshold level for selecting patients at risk for death by heart failure, sudden cardiac death, and fatal myocardial infarction.     

Silent ST-T changes in an epidemiologic cohort study--a marker of hypertension or coronary heart disease, or both: the Reykjavik study

OBJECTIVES: We sought to evaluate the prognostic value and clinical characteristics associated with electrocardiographic (ECG) ST-T changes among men without other manifestations of coronary heart disease. BACKGROUND: Recent achievements in secondary prevention and treatment of coronary heart disease have highlighted the importance of early diagnosis of both symptomatic and silent forms of the disease. The prognostic and clinical importance of ST-T changes in men with no other manifestations of coronary heart disease is still unclear. Do they reflect silent coronary heart disease or hypertension, or both, and what is their independent contribution to prognosis? METHODS: The subjects were 9,139 men born in the years 1907 to 1934 and followed up for 4 to 24 years. On initial visit they were assigned to different categories of coronary heart disease on the basis of Rose chest pain questionnaire, hospital records, 12-lead ECG, history and physical examination. RESULTS: The prevalence of silent ST-T changes among men without overt coronary heart disease was strongly influenced by age, increasing from 2% at age 40 years to 30% at age 80 years. Men with such ST-T changes were older and had higher serum triglyceride levels and worse glucose tolerance than men without such changes or other evidence of coronary heart disease. Their blood pressure was higher, and they more often had an enlarged heart or left ventricular hypertrophy and more often took antihypertensive medication, digitalis or diuretic drugs. Serum cholesterol levels were not different between the two groups. After adjustment for other risk factors, these silent ST-T changes had a risk ratio of 2.0 for death from coronary heart disease and 1.6 for subsequent myocardial infarction or angina pectoris. CONCLUSIONS: Silent ST-T changes that are ischemic by the Minnesota code are probably both a marker of silent coronary heart disease and high blood pressure. They define a distinct group of patients with highly abnormal risk factor profile. Although not specific for coronary heart disease and often transient, they are associated with the development of every clinical manifestation of coronary heart disease and are independent predictors of reduced survival.     

Cardiac troponin T in the diagnosis and follow up of suspected myocarditis

BACKGROUND AND OBJECTIVE: Results of routine laboratory tests for demonstrating myocardial damage in patients suspected of having myocarditis are often negative. This study was undertaken to ascertain (1) whether measuring Tropinin T (cTnT) in these patients can sensitively determine myocardial cell death, (2) to what extent this correlates with the findings of endomyocardial biopsy, and (3) whether measurement of cTnT can provide noninvasive assessment of the course of myocarditis. PATIENTS AND METHODS: 80 consecutive patients (52 men, 28 women) with clinically suspected myocarditis were investigated. The main clinical symptoms were heart failure (n = 45), angina pectoris (n = 25) or cardiac arrhythmias (n = 10). In most patients the symptoms had developed in temporal relation to a viral infection. Coronary heart disease was excluded in all by coronary angiography. Interventricular septal endomyocardial biopsies were examined histologically and immunohistologically. cTnT was measured with a highly sensitive sandwich-immunoassay. RESULTS: An increased level of cTnT (> 0.1 ng/ml) was demonstrated in 28 of the 80 patients (35%). Myocarditis was diagnosed histologically in only 5 patients, but immunohistologically in 26 of 28 (93%) with a raised cTnT level and in 23 of 52 (44%) with a normal cTnT level. The cTnT level was more frequently elevated in patients with a brief rather than a long history of myocarditis. After 6 months the cTnT level was elevated in only 4 of 28 patients with myocarditis, but the myocardial biopsy showed persisting myocarditis in 14 patients. CONCLUSION: Measurement of cTnT is a very sensitive way of demonstrating myocardial cell damage in patients clinically suspected of having myocarditis. Immunohistological analysis can often provide positive results even if the histological findings are unremarkable. The sensitivity in diagnosing of cTnT is greatest when the patient is tested shortly after the onset of symptoms.