Chain elongation in the isoprenoid biosynthetic pathway

PURPOSE: To investigate the associations between specific preoperative 12-lead electrocardiogram (ECG) abnormalities, perioperative ischemia, and postoperative myocardial infarction or cardiac death in major vascular surgery. METHODS: Two prospective studies on perioperative myocardial ischemia performed in two tertiary university hospitals were combined to include 405 patients. All preoperative ECGs were analyzed according to the Sokolow-Lyon criteria for left ventricular hypertrophy by investigators who were blinded to the patients' perioperative clinical course. Perioperative myocardial ischemia was detected by continuous ECG recording, and postoperative cardiac complications included myocardial infarction and cardiac death. RESULTS: A total of 19 postoperative cardiac complications occurred (two cardiac deaths and 17 myocardial infarctions). Voltage criteria for left ventricular hypertrophy (78 patients, 19%) and ST segment depression greater than 0.5 mm (98 patients, 24.2%) on preoperative ECGs were both significantly associated with postoperative myocardial infarction or cardiac death (odds ratio, 4.2 and 4.7; p = 0.001 and 0.0005, respectively) and with longer intraoperative and postoperative myocardial ischemia. In each of the two study groups, a preoperative ECG abnormality that involved voltage criteria, ST segment depression, or both (134 patients, 33.1%) was more predictive of postoperative cardiac complications than any other preoperative clinical variable, including a history of myocardial infarction or angina pectoris, diabetes mellitus, pathologic Q-wave by ECG, or preoperative myocardial ischemia. The combined duration of intraoperative and postoperative ischemia and the preoperative ECG with either voltage criteria or ST segment depression were the only independent factors associated with adverse cardiac events by multivariate analysis (p < or = 0.0001 and p = 0.02, respectively). CONCLUSION: Left ventricular hypertrophy and ST segment depression on preoperative 12-lead ECGs are important markers of increased risk for myocardial infarction or cardiac death after major vascular surgery.     

Asymptomatic myocardial ischemia before and after surgical revascularization in patients with multivessel occlusive coronary disease

INTRODUCTION: The objective of this study was to examine the occurrence of asymptomatic myocardial ischemia prior to and after myocardial revascularization in patients with multivessel occlusive coronary disease. Asymptomatic ischemia can be described as real ischemia without anginal pain or other ischemic symptoms in patients with coronary disease or coronary artery spasm. Our study examined silent ischemia after myocardial revascularization. Early detection of silent ischemia is important for prevention of cardiac incidents. MATERIAL AND METHODS: We have examined patients with multivessel coronary disease with occurrence of continued preoperative silent ischemia. All patients have undergone ECG examination, exercise stress test and Holter-monitoring prior to and after myocardial revascularization. RESULTS: The investigation comprised 27 patients and their average age was 54.5 years. All patients with silent ischemia had a multivessel occlusive coronary disease and have undergone myocardial revascularization managed with triple or quadruple aortocoronary bypass surgery. Exercise stress test was performed postoperatively in elder patients, as well as ECG and Holter-monitoring. Silent ischemia was established in 21.6% of patients, while in 87.5% untreated diabetes mellitus was diagnosed. Silent ischemia most often occurred in the early morning hours and it was frequently associated with heart rhythm disturbances (VES) whereas these rhythm disturbances depended on the length of the ischemic episode. Intermittent 2nd degree atrioventricular block was found in one patient. CONCLUSION: Silent myocardial ischemia occurred in 21% of patients after myocardial revascularization. It is most often detected in the early morning hours and is associated with ventricular rhythm disorders. Silent ischemia is easily detected by simple examination procedures providing adequate therapy and prevention of cardiac incidents.     

Dobutamine stress echocardiography: clinical utility and predictive value at various infusion rates

Dobutamine stress echocardiography has increasingly been used to assess patients for coronary artery disease. Despite the popularity of this test, the optimal dose of dobutamine has not been established. The objective of this study was to assess the accuracy of dobutamine stress echocardiography at various infusion doses and its utility as a predictor of perioperative risk in patients undergoing a noncardiac surgical procedure. One hundred thirteen consecutive patients underwent dobutamine stress echocardiography, subsequent cardiac catheterization and/or a noncardiac surgical procedure. Three patient groups were analyzed on the basis of peak dobutamine infusion rates (17 +/- 4, 29 +/- 2, and 40 +/- 0 micrograms/kg/min, respectively). The three groups were comparable with regard to age, sex, ejection fraction, and severity of coronary artery disease. In group I, the sensitivity and specificity of dobutamine stress echocardiography were 74% and 33%, respectively, with a positive predictive value of 78%. In group II, the sensitivity and specificity improved to 84% and 78%, with a positive predictive value of 89%. In group III, the sensitivity and specificity were 86% and 80%, respectively, with a positive predictive value of 86%. In the noncardiac surgical group there was only one nonfatal cardiac complication among the 50 patients with a dobutamine echocardiogram, which was negative for evidence of inducible ischemia. In conclusion, this study demonstrates that dobutamine stress echocardiography should use an infusion rate of > or = 30 micrograms/kg/min to optimize diagnostic accuracy relative to angiographic coronary artery disease. A test that shows no evidence of new, inducible ischemia predicts a low risk of perioperative cardiac events in patients undergoing noncardiac surgery, even at an infusion rate as low as 20 microns/kg/min.     

Cardiac outcome in patients with subarachnoid hemorrhage and electrocardiographic abnormalities

OBJECTIVE: Approximately 25% of patients with subarachnoid hemorrhage (SAH) have electrocardiographic (ECG) abnormalities consistent with myocardial ischemia or myocardial infarction (MI), and their cardiac prognosis remains unclear. The objective of this study was to determine the cardiac and all-cause mortality rate of a series of patients with SAH with ECG changes consistent with ischemia or MI. METHODS: Using an existing database of patients with SAH and predetermined ECG criteria for ischemia or MI, a study group of patients with abnormal ECG results within 3 days of presentation and before aneurysm surgery was identified. Database patients without abnormal ECG results served as a control group. Cardiac mortality, defined as death resulting from arrhythmia, congestive heart failure, or cardiogenic shock, was assessed by chart review. RESULTS: Of 439 patients with SAH in the database, 58 met the criteria for the study group. Forty-one of these patients were treated neurosurgically. No deaths resulting from cardiac causes occurred, and 20 patients died as a result of noncardiac causes. In a multivariable analysis, age older than 65 years and Hunt and Hess grade of at least 3 were predictive of all-cause mortality. ECG abnormalities, however, were not a statistically significant predictor. CONCLUSION: In patients with SAH and ECG readings consistent with ischemia or MI, the risk of death resulting from cardiac causes is low, with or without aneurysm surgery. The ECG abnormalities are associated with more severe neurological injury but are not independently predictive of all-cause mortality.     

Candida glabrata prosthesis infection following pyelonephritis and septicaemia

A 48-year-old woman with no cardiovascular risk factors was admitted to the hospital because of acute dyspnea. At 27-year-old, she developed Hodgkin's disease, that was successfully treated with splenectomy, combined chemotherapy (nitrogen mustard, vincristine, procarbazine, prednisone-MOPP regimen) and radiotherapy (4500 rads). At 43-year-old the lymphoma relapsed and she had further chemotherapy with doxorubicin, bleomycin, vinblastina and dacarbazine. After this treatment, she had an episode of pulmonary edema, attributed to doxorubicin acute cardiotoxicity. She responded to digitalis and diuretics and was discharged with an electrocardiogram (ECG) showing left bundle branch block and a normal echocardiogram. The patient enjoyed good health for several years and 4 months before the present admission the ECG and echocardiogram were unchanged. On this admission there were signs of left ventricular failure with acute pulmonary edema, and a new soft apical murmur (3-4 Levine). The patient required endotracheal intubation and high doses of diuretics, digitalis and vasodilators. The cardiac enzymes were negative, the serial ECGs confirmed left bundle branch block, while the echocardiogram showed moderate to severe mitral regurgitation, akinesia of the interventricular septum and inferior wall with dilation of the left ventricle. A previous silent myocardial infarction was suspected. After recovery, she underwent cardiac catheterization confirming akinesia of the interventricular septum and inferior wall with moderate mitral regurgitation, while coronary angiography showed a critical ostial stenosis of the right coronary artery. In view of a dipyridamole-thallium scan negative for myocardial viability, reperfusion was not attempted. With changes in radiotherapeutic techniques, the incidence of radiation-induced heart disease (pericarditis, myocarditis, conduction abnormalities and, rarely, occlusive coronary artery disease) is declining. Nevertheless, after irradiation of the chest and mediastinum a longterm cardiological follow-up is useful in selecting patients at higher risk of radiation-induced coronary artery disease, who will eventually require coronary angiography and reperfusion intervention.     

Long-term prognostic value of dobutamine-atropine stress echocardiography in 1737 patients with known or suspected coronary artery disease: A single-center experience

BACKGROUND: The purpose of this study was to assess the long-term value of dobutamine-atropine stress echocardiography (DSE) for prediction of late cardiac events in patients with proven or suspected coronary artery disease. METHODS AND RESULTS: Clinical data and DSE results were analyzed in 1734 consecutive patients undergoing DSE between 1989 and 1997. Seventy-four patients who underwent revascularization within 3 months of DSE and 1 patient lost to follow-up were excluded; the remaining 1659 (median age, 62 years; range, 14 to 99 years) were followed up for 36 months (range, 6 to 96 months). Wall motion abnormalities at rest and the presence and extent of stress-induced wall motion abnormalities (ischemia) were scored for each patient. Cardiac events were related to clinical and ECG data and DSE results. Four hundred twenty-eight cardiac events occurred in 366, documented cardiac death in 108 (total death, 247), nonfatal infarction in 128, and late revascularization in 192 patients. In a multivariable Cox proportional-hazards model, the ratio of documented cardiac death or (re)infarction was increased in the presence of stress-induced ischemia (hazard ratio, 3.3; 95% CI, 2.4 to 4.4) and extensive rest wall motion abnormalities (hazard ratio, 1.9; 95% CI, 1.3 to 2.6). The number of ischemic segments was predictive for late cardiac events. A normal DSE carried a relatively good prognosis, with an annual event rate of cardiac death or infarction of 1.3% over a 5-year period. CONCLUSIONS: In a large group of patients, DSE has an added value for predicting late cardiac events during long-term follow-up, improving the separation between high- risk and very-low-risk patients.     

Value of QT dispersion in the interpretation of exercise stress test in women

BACKGROUND: Exercise testing in women is associated with a high incidence of false-positive ECG changes and should be combined with an imaging study. The QT dispersion (QTD), recorded as the difference between maximum and minimum QT intervals on a 12-lead ECG, is sensitive to myocardial ischemia and may improve the accuracy of exercise testing in women. METHODS AND RESULTS: Exercise ECGs were analyzed in 64 women who had undergone exercise ECG and coronary angiography for clinical indications: 20 patients with normal exercise stress test and nonsignificant (< or = 50% diameter narrowing of a major epicardial coronary artery) coronary artery disease (CAD) on angiography (true-negative; TN group), 20 patients with positive exercise stress tests (> or = 1 mm ST-segment depression or reversible perfusion defects) and significant CAD (true-positive; TP group), and 24 patients with positive exercise stress tests but no significant CAD (false-positive; FP group). The exercise QTD was 45+/-15 ms in TN, 80+/-23 ms in TP (P<.0001 versus TP), and 41+/-14 ms in FP (P=NS versus TN and <.0001 versus TP) groups. A stress QTD of > 60 ms had a sensitivity of 70% and specificity of 95% for the diagnosis of significant CAD compared with 55% (P<.05) and 63% (P<.01), respectively, for > or = 1 mm ST-segment depression during stress. When QTD of > 60 ms was added to ST-segment depression as a condition for positive test, the specificity increased to 100%. CONCLUSIONS: Exercise QTD is an easily measurable ECG variable that significantly increases the accuracy of exercise testing in women.     

Intravenous diltiazem and acute renal failure after cardiac operations

BACKGROUND: Perioperative administration of intravenous diltiazem to patients undergoing cardiac procedures has been shown to decrease the incidence of ischemia and arrhythmias. However, after adopting this practice in our cardiac surgery program, we perceived an increased incidence of postoperative renal dysfunction. METHODS: A directed record review of postoperative renal function was conducted for consecutive patients undergoing cardiac operation for the time periods before and after adoption of prophylactic intravenous diltiazem (0.1 mg.kg-1.h-1 for 24 hours). The two groups were compared using chi 2 and two-sample t tests. The risk of development of postoperative renal failure was modeled with logistic regression. RESULTS: Diltiazem-treated patients (n = 271) were similar to the control patients (n = 143) in terms of age (64 versus 61 years; p = 0.14), ejection fraction (0.46 versus 0.47; p = 0.61), baseline serum creatinine level (1.2 versus 1.1 mg/dL; p = 0.27), prevalence of comorbid conditions, and surgical characteristics. The prevalence of left main coronary artery disease was lower in the diltiazem group than the control group (39% versus 52%; p = 0.01). During the 7-day postoperative period, the average peak serum creatinine level was higher in the diltiazem group (1.7 +/- 0.9 mg/dL; mean +/- 1 standard deviation) than the control group (1.5 +/- 0.5 mg/dL; p = 0.003). The incidence of acute renal failure requiring dialysis was 4.4% in the diltiazem group versus 0.7% in the control group (p = 0.04). There was no difference in length of hospitalization or mortality. The risk of acute renal failure was strongly associated with intravenous diltiazem (adjusted odds ratio [AOR] 6.3; p = 0.08), age (AOR 2.5 per 10 years; p = 0.07), baseline serum creatinine (AOR 4.8 per 1 mg/dL; p = 0.02), the presence of left main coronary disease (AOR 5.3; p = 0.02), and the presence of cerebrovascular disease (AOR 4.5; p = 0.05). CONCLUSIONS: Our retrospective analysis suggests that prophylactic use of intravenous diltiazem in patients undergoing cardiac operations was associated with increased renal dysfunction. Further studies of the risk and benefits of intravenous diltiazem in this setting should be undertaken.     

Usefulness of percutaneous transluminal coronary angioplasty in silent myocardial ischemia

The usefulness of percutaneous transluminal coronary angioplasty (PTCA) was assessed in patients with exercise-induced asymptomatic myocardial ischemia (silent ischemia) and compared with exercise-induced symptomatic myocardial ischemia (symptomatic ischemia). Patients with single vessel coronary artery disease (51 with angina pectoris, 40 with old myocardial infarction) and evidence of stress-induced ischemia on thallium-201 single photon emission computed tomography (SPECT) underwent successful PTCA. Thirty-seven percent of angina patients and 60% of infarction patients showed asymptomatic exercise-induced ischemia. There was no significant difference in population characteristics between silent and symptomatic patients. Patients with silent angina had significantly higher percentage thallium uptake and washout rate than symptomatic patients. After PTCA, both percentage diameter stenosis and percentage thallium uptake were improved in all patients with angina irrespective of the presence or absence of symptoms. There were no significant differences in percentage thallium uptake and washout rate between patients with silent and symptomatic infarction. After PTCA, percentage diameter stenosis, percentage thallium uptake, and washout rate improved in all infarction patients irrespective of the symptoms. Zero percent of silent angina patients, 12% of symptomatic angina patients, 12% of silent infarction patients, 19% of symptomatic infarction patients had cardiac events during about 4.5 years after PTCA. The incidence of cardiac events did not significantly differ in any patient group. PTCA improved myocardial perfusion in all patients, and the incidence of cardiac events did not differ between the silent and symptomatic groups. Revascularization with PTCA is suitable for patients with silent as well as symptomatic ischemia.     

Perioperative cardiac evaluation for noncardiac surgery noninvasive cardiac testing

Prognostic risk stratification to identify perioperative and long-term cardiac risk in selected patients undergoing noncardiac surgery is part of good clinical practice. Exercise variables associated with significant increased risk include poor functional capacity (eg, <4 metabolic equivalents), marked exercise-induced ST segment shift or angina at low workloads, and inability to increase or actually decrease systolic blood pressure with progressive exercise. Approximately 40% of patients tested before peripheral vascular surgery will have an abnormal exercise electrocardiogram (ECG). The predictive value for a perioperative event, ie, death or myocardial infarction, ranges from 5% to 25% for a positive test and 90% to 95% for a negative test. Whereas exercise cardiac imaging is the modality of choice in patients with a noninterpretable exercise ECG, pharmacological stress imaging should be used in the 30% to 50% of patients who require perioperative noninvasive risk stratification and are unable to perform an adequate level of exercise to test cardiac reserve. Myocardial perfusion variables predictive of increased cardiac events include severity of the perfusion defect, number of reversible defects, extent of fixed and reversible defects, increased lung uptake of thallium-201, and marked ST segment changes associated with angina during the test. The reported sensitivity and specificity of dobutamine-induced echocardiographic wall motion abnormalities in patients with peripheral vascular disease is similar to myocardial perfusion scintigraphy, but the confidence limits are wider due to the smaller sample size in these more recent studies. In conclusion, noninvasive cardiac testing should be used selectively in patients undergoing noncardiac surgery; the results provide useful estimates of short- and long-term risk of cardiac events, and the magnitude of abnormal response on noninvasive testing should be used to formulate decisions regarding the need for coronary angiography and subsequent revascularization.     

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.     

Characteristics of medical care related to autopsy authorization in a pediatric hospital

Patients with atypical chest pain frequently lack significant coronary artery disease (CAD) and are, therefore, at low risk for future adverse cardiovascular events. We hypothesized that in this group of patients, stress echocardiography could identify those at risk for cardiac events. We retrospectively reviewed (mean follow-up 23.0 +/- 7.2 months) the prognostic value of stress echocardiography for major (cardiac death, myocardial infarction, congestive heart failure, and unstable angina) and total (major events plus coronary revascularization) cardiac events in 661 patients with atypical chest pain, normal global left ventricular (LV) systolic function, and no history of CAD. A positive stress echocardiogram was defined as the development of new or worsening wall motion abnormalities with exercise stress (80%) or dobutamine (20%). A total of 41 cardiac and 16 major events were noted. The event-free survival for total cardiac events was 97% for a normal stress echocardiogram and 93% for a normal stress electrocardiogram (ECG) at 30 months. A positive stress ECG predicted an event-free rate of 86% compared with 74% for stress-induced wall motion abnormalities and 42% if stress-induced LV dysfunction accompanied the wall motion abnormalities. A strategy recommending invasive studies based on positive stress echocardiogram results increased the per-patient cost, but led to greater savings per cardiac event predicted and provided incremental prognostic value for future cardiac events beyond clinical and stress electrocardiographic data. Thus, stress echocardiography in low-risk patients for CAD appears to be more cost effective than a stress ECG.     

Silent myocardial ischemia in Kawasaki disease: evaluation of percutaneous transluminal coronary angioplasty by dobutamine stress testing

BACKGROUND: Myocardial ischemia and myocardial infarction are the most serious complications of coronary artery lesions in children with Kawasaki disease (KD). Therefore, early detection and treatment of myocardial ischemia in patients with KD is essential. We studied the effectiveness of percutaneous transluminal coronary angioplasty (PTCA) in patients with silent myocardial ischemia detected by dobutamine stress 99mTc myocardial scintigraphy (TMS), body surface mapping (BMS), and signal-averaged ECG late potentials (ELP). METHODS AND RESULTS: Eight of 76 asymptomatic patients with a coronary stenosis >25% and a positive dobutamine stress test were considered to have silent myocardial ischemia. All eight patients had >95% stenoses demonstrated by coronary angiography (CAG) just before PTCA. After PTCA, CAG showed that all of the coronary artery stenoses had been reduced to <50%. Additionally, intravascular ultrasonography (IVUS) performed in five patients before and after PTCA demonstrated adequate dilation of the coronary stenosis after PTCA. All eight patients underwent dobutamine stress TMS, BMS, and ELP 2 to 3 months after PTCA, which demonstrated no regions of myocardial ischemia. Approximately 6 months later, CAG was performed in all eight patients, and only one patient had developed restenosis. CONCLUSIONS: PTCA effectively dilates stenotic coronary arteries in children with KD. Moreover, dobutamine stress TMS, BMS, and ELP are useful for detecting silent myocardial ischemia and estimating the effectiveness of PTCA. Furthermore, IVUS is useful for evaluating the severity of coronary artery lesions before and after PTCA in patients with KD.     

Arrhythmogenic marker for the sudden unexplained death syndrome in Thai men

BACKGROUND: Between 1981 and 1988, the Centers for Disease Control and Prevention reported a very high incidence of sudden death among young male Southeast Asians who died unexpectedly during sleep. The pattern of death has long been prevalent in Southeast Asia. We carried out a study to identify the clinical markers for patients at high risk of developing sudden unexplained death syndrome (SUDS) and long-term outcomes. METHODS AND RESULTS: We studied 27 Thai men (mean age, 39.7+/-11 years) referred because they had cardiac arrest due to ventricular fibrillation, usually occurring at night while asleep (n=17), or were suspected to have had symptoms similar to the clinical presentation of SUDS (n=10). We performed cardiac testing, including EPS and cardiac catheterization. The patients were then followed at approximately 3-month intervals; our primary end points were death, ventricular fibrillation, or cardiac arrest. A distinct ECG abnormality divided our patients who had no structural heart disease (except 3 patients with mild left ventricular hypertrophy) into two groups: group 1 (n=16) patients had right bundle-branch block and ST-segment elevation in V1 through V3, and group 2 (n=11) had a normal ECG. Group 1 patients had well-defined electrophysiological abnormalities: group 1 had an abnormally prolonged His-Purkinje conduction time (HV interval, 63+/-11 versus 49+/-6 ms; P=.007). Group 1 had a higher incidence of inducible ventricular fibrillation (93% for group 1 versus 11% for group 2; P=.0002) and a positive signal-averaged ECG (92% for group 1 versus 11% for group 2; P=.002), which was associated with a higher incidence of ventricular fibrillation or death (P=.047). The life-table analysis showed that the group 1 patients had a much greater risk of dying suddenly (P=.05). CONCLUSIONS: Right bundle-branch block and precordial injury pattern in V1 through V3 is common in SUDS patients and represents an arrhythmogenic marker that identifies patients who face an inordinate risk of ventricular fibrillation or sudden death.     

Early diagnosis of acute myocardial infarction by either electrocardiogram or a logistic regression model: portability of a predictive instrument of acute cardiac ischemia to a small rural coronary care unit

OBJECTIVE: To test the ability of a logistic regression model (LRM) that predicts acute cardiac ischemia to make an early diagnosis of acute myocardial infarction (AMI); the ability of the LRM to predict AMI was also compared with the presenting electrocardiogram (ECG). SETTING: A small rural Irish coronary care unit. METHODS: Clinical and ECG data required by the LRM to predict acute coronary ischemia were recorded in 600 consecutive patients admitted with suspected AMI. Estimates of the LRM were ranked into equal deciles in declining probability of acute cardiac ischemia (pACI), and presenting ECGs were placed into one of seven categories. RESULTS: At presentation 50% of AMI patients were in the two LRM deciles with the highest pACI, and 49% of AMI patients had ECGs with greater than 2 mm ST elevation associated with reciprocal changes. ECG categories had a 76% sensitivity for the early diagnosis of AMI and the LRM had an 84% sensitivity. The specificity, accuracy and positive predictive value for the ECG categories were 92%, 84% and 85%, respectively. The specificity, accuracy and positive predictive value of the LRM were 84%, 84% and 75%, respectively. The areas under the receiver operating characteristic curve of the LRM and ECG categories were almost identical (91% and 90%, respectively). CONCLUSION: AMI can be diagnosed early with comparable accuracy either by placing presenting ECGs into one of seven categories, or by the LRM. The best method and 'cut-off' point for the diagnosis of AMI varies according to clinical circumstances. Categorizing ECGs requires more skill in ECG interpretation, but takes less time. The previously reported performances of the LRM were replicated, confirming portability of its use into different clinical settings and patient populations.     

Survival and incidence of myocardial infarction in men with ambulatory ECG-detected frequent and complex ventricular arrhythmias. 10 year follow-up of the 'Men born 1914' study in Malm?, Sweden

AIM: To assess to what extent do frequent or complex ventricular arrhythmias, detected during 24 h ambulatory electrocardiographic recording (ECG), influence prognosis with regard to survival and incidence of ischaemic heart disease. METHODS AND RESULTS: The study subjects were the 456 randomly selected men born in 1914, the population-based cohort study of 1982-83, in Malm?, Sweden. The main outcome measures were total mortality and incidence of cardiac event (myocardial infarction and death from ischaemic heart disease). Frequent or complex ventricular arrhythmias (Lown classes 2-5) were detected in 49% of the men with (n = 77), and in 35% of those without, a history of myocardial infarction or angina pectoris at baseline, P = 0.019. Independent of clinically evident coronary artery disease at baseline, and after adjustment for traditional atherosclerotic risk factors and use of digitalis or beta-blocker therapy, frequent or complex ventricular arrhythmias were associated with an increased mortality from ischaemic heart disease (relative risk (RR), 2.1; 95% confidence interval (CI), 1.2-3.9) and an increased cardiac event rate (RR, 1.6; 95% CI, 1.0-2.5)). Men free from both ischaemic-type ST depression and frequent or complex ventricular arrhythmias (used as the control group) had the lowest ischaemic heart disease death rate, 5.9 per 1000 person-years. The combination of ST depression and frequent or complex ventricular arrhythmias was associated with an ischaemic heart disease death rate of 20.9 per 1000 person-years. The cardiac event rate in these two groups was 15.6 and 76.1 per 1000 person-years, respectively (adjusted RR, 2.3; CI, 1.1-4.6). CONCLUSIONS: In elderly men without a history of myocardial infarction and angina pectoris, frequent or complex ventricular arrhythmias during ambulatory ECG recording is associated with an increased incidence of myocardial infarction and mortality. Men who, during ambulatory ECG recording, also demonstrate ST-segment depression have an even less favourable prognosis.     

Value of dobutamine stress echocardiography in determining the prognosis of patients with known or suspected coronary artery disease

Although the accuracy of dobutamine stress echo (DSE) for detecting coronary artery disease (CAD) has been established, its role in determining prognosis is less well defined. The purpose of this study was to evaluate the prognostic significance of DSE in patients with known or suspected CAD. Follow-up was obtained on 291 patients an average of 15 months after clinically indicated DSE. Studies were stratified with respect to resting and inducible wall motion abnormalities into 1 of 4 responses: normal, ischemic, fixed, and mixed. Hard end points of nonfatal myocardial infarction and cardiac death were tabulated for outcome. Statistically significant differences in the incidence of hard cardiac end points were noted for 2 of 4 DSE responses. A normal DSE was associated with a statistically lower likelihood of a hard cardiac event than was a DSE demonstrating resting or inducible abnormalities (p = 0.001). DSE with a mixed response (resting abnormality with additional inducible ischemia) was associated with a higher likelihood of cardiac events by multivariate analysis (p = 0.003). By multiple logistic regression analysis of dobutamine response, age, and cardiac risk factors, only a mixed response on DSE was independently associated with the occurrence of a hard cardiac event in the follow-up period. In addition, left ventricular dysfunction on the resting echocardiogram was associated with a worse prognosis in patients with major noncardiac disease. We conclude that dobutamine response is an independent predictor of cardiac events compared with traditional risk factor analysis and that DSE can identify high- and low-risk subsets of patients with known or suspected CAD.     

Efficacy of cobalt chelates in the rabbit eye model for epithelial herpetic keratitis

STUDY OBJECTIVE: Accurate diagnosis in emergency department patients with possible myocardial ischemia is problematic. Two-dimensional echocardiography has a high sensitivity for identifying patients with myocardial infarction (MI); however, few studies have investigated its diagnostic ability when used acutely in ED patients with possible myocardial ischemia. Therefore we investigated the ability of ED echocardiography for predicting cardiac events in patients with possible myocardial ischemia. METHODS: Echocardiography was performed within 4 hours of ED presentation in 260 patients with possible myocardial ischemia, and was considered positive if there were segmental wall motion abnormalities or the ejection fraction was less than 40%. ECGs were considered abnormal if there was an ST-segment elevation or depression of greater than or equal to 1 mm, or ischemic T-wave inversion. Cardiac events included MI and revascularization. RESULTS: Of the 260 patients studied, 45 had cardiac events (23 MI, 19 percutaneous transluminal angioplasty, 3 coronary bypass surgery). The sensitivity of echocardiography for predicting cardiac events was 91% (95% confidence interval 79% to 97%]), which was significantly higher than the ECG (40% [95% CI 27% to 55%]: P < .0001), although specificity was lower (75% [95% CI 69% to 81%] versus 94% [95% CI 90% to 97%]; P < .001). Addition of the echocardiography results to baseline clinical variables and the ECG added significant incremental diagnostic value (P < .001). With use of multivariate analysis, only male gender (P < .03, odds ratio [OR] 2.4 [1.1 to 5.3]), and a positive echocardiographic finding (P < .0001, OR 24 [9 to 65]) predicted cardiac events. Excluding patients with abnormal ECGs (N = 30) did not affect sensitivity (85%) or specificity (74%) of echocardiography. CONCLUSION: Echocardiography performed in ED patients with possible myocardial ischemia identifies those who will have cardiac events, is more sensitive than the ECG, and has significant incremental value when added to baseline clinical variables and the ECG.     

Apolipoprotein A, fibrinogen, age, and history of stroke are predictors of death in dialysed diabetic patients: a prospective study in 412 subjects

BACKGROUND: Diabetic patients with end-stage renal failure (ESRD) have a high cardiovascular morbidity and mortality. The underlying mechanisms are not completely elucidated. The aim of our study was to define predictors of death in diabetic patients with end-stage renal disease. PATIENTS AND METHODS: We performed a prospective study in 35 dialysis centres in Germany between 1985 and 1994. To evaluate predictors and risk factors in this population we examined 412 diabetic patients at the time of admission to dialysis treatment (peritoneal dialysis (PD) or haemodialysis (HD)). Classification of the type of diabetes was done according the criteria of the National Diabetes Data Group [1,2]. Items assessed at the time of admission were coronary artery disease (CAD), peripheral occlusive disease (POD), and stroke. CAD was defined as a history of myocardial infarction with the corresponding changes in the ECG or luminal narrowing by more than 50% in at least one coronary artery upon coronarangiography; POD was defined as claudication and/or brachial-tibial ratio (BTR) less than 0.9 or a history of amputation. Assessment of the nutritional state comprised body mass index, skinfold thickness of the upper arm and lateral thorax area, and urea concentration. Cholesterol, HDL, LDL, apolipoprotein A (ApoA-I) and B (ApoB), triglycerides, lipoprotein(a) (Lp(a)), and fibrinogen were measured. As an index of disturbed cardiac innervation beat-to-beat variation was measured. Outcome measurements were causes of death (i.e. cardiac and non-cardiac) and time of survival. RESULTS: One hundred and eighty of 412 (44%) patients died during the observation period. Patients who died were older (61 +/- 12 versus 53 +/- 15 years P < 0.0001), had lower skin fold thickness (13.1 +/- 6.0 versus 15.1 +/- 7.3 mm P < 0.04), lower ApoA-I (100 +/- 35 versus 111 +/- 32 mg/dl P < 0.005) and higher fibrinogen (515 +/- 146 versus 451 +/- 155 mg/dl P < 0.02). Type II diabetic patients had a lower mean survival time than type I (34 versus 66 months P < 0.0006). The mode of renal replacement therapy (PD or HD) had no adverse effect on survival time. Survivors less frequently had a history of CAD, POD and stroke than non-survivors. In multivariate analysis ApoA-I, fibrinogen, age and stroke were independent predictors of cardiac and non-cardiac death in diabetic patients with end-stage renal failure. Lipid values and nutritional state did not independently predict the overall and cardiovascular mortality. CONCLUSION: This study in dialysed diabetic patients identifies several predictors of death, some of which are susceptible to intervention.     

Frequency and severity of asymptomatic coronary disease in patients with different causes of stroke

BACKGROUND AND PURPOSE: We sought (1) to compare the frequency and severity of asymptomatic coronary artery disease (CAD) in patients with different causes of brain ischemia and (2) to determine profiles of patients with brain ischemia who are at highest risk of asymptomatic CAD. METHODS: Sixty-nine patients with transient ischemic attack or stroke and without overt CAD underwent a cardiac stress test and a diagnostic evaluation to determine the cause of brain ischemia. The frequency of abnormal cardiac stress tests was compared in patients with large-artery cerebrovascular disease versus other causes of brain ischemia (90% of whom had penetrating artery disease or cryptogenic stroke). Additionally, the frequencies of vascular risk factors, resting electrocardiographic abnormalities, and cause of stroke (large-artery disease versus other causes) were compared in patients with abnormal stress tests versus patients with normal stress tests. RESULTS: The frequency of abnormal stress tests was 50% (15 of 30) in patients with large-artery cerebrovascular disease versus 23% (9 of 39) in patients with other causes of brain ischemia (P = .04). Moreover, 60% of abnormal stress tests (9 of 15) in patients with large-artery cerebrovascular disease suggested severe underlying CAD that was confirmed in 7 of 7 patients who underwent coronary angiography. On the other hand, less than 25% of abnormal stress tests (2 of 9) in patients with other causes of brain ischemia suggested severe underlying CAD. Features that were more common in patients with abnormal stress tests were smoking (P = .006), large-artery cerebrovascular disease (P = .02), veteran status (P = .02), and left ventricular hypertrophy (P = .07). CONCLUSIONS: Patients with penetrating artery disease or cryptogenic stroke have a significantly lower frequency of asymptomatic CAD than patients with large-artery cerebrovascular disease. Large-artery cerebrovascular disease, smoking, veteran status, and possibly left ventricular hypertrophy may be useful features for identifying patients with transient ischemic attack or stroke who are at highest risk of harboring asymptomatic CAD.