Abnormalities of left ventricular long-axis function predict the onset of hypertension independent of blood pressure: a 7-year prospective study.

Increased blood pressure and left ventricular (LV) mass predict the onset of the clinically manifest hypertension, but little is known regarding the possible predictive value of LV function. The present study was designed to evaluate the association between echocardiographic LV long-axis systolic, and diastolic function and hypertension onset. We prospectively followed 244 normotensive adults with a family history of hypertension (HTN), with echocardiography for 7 years. M-mode derived atrioventricular plane displacement of the mitral and tricuspid annuli (MAVPD and TAVPD respectively), and LV circumferential fractional shortening were calculated. Diastolic function of the left and right ventricle were assessed using Doppler indices of the mitral and tricuspid inflow. During follow-up, 79 subjects developed hypertension (H group) and 165 subjects remained normotensive (N group). H group subjects had diminished MAVPD (13.8+/-3.4 vs 15.0+/-3.1 mm; P=0.007), lower mitral E/A ratio, and longer mitral E-wave deceleration time as compared to N group. In multivariate Cox model MAVPD and mitral E/A ratio predicted the onset of hypertension independent of LV mass index, blood pressure, pre-hypertensive status at baseline, age, sex and body mass index. During follow-up, H subjects experienced a significant decline in MAVPD and mitral E/A ratio, whereas the indices of right ventricular function and LV circumferential shortening remained intact. In conclusion, alterations in LV long-axis systolic and diastolic function, as measured by MAVPD and E/A ratio predict the onset of hypertension. These parameters declined during the development of hypertension.

Metabolic syndrome, diabetes and cardiovascular events: current controversies and recommendations.

Metabolic syndrome is now present in up to 40% of the United States adult population and is associated with a nearly a two fold increase in cardiovascular events, independent of the presence of diabetes mellitus. The concept of the metabolic syndrome as clinical syndrome has recently been challenged, however, and controversy exists as to whether the metabolic syndrome adds to cardiovascular risk above and beyond the sum of its independent metabolic components. Given the epidemic of obesity in both industrialized and third world countries, this issue is of great importance. The current article puts this controversy into perspective and explores the association of metabolic syndrome with both accelerated cardiovascular risk and the risk of development of type 2 diabetes. The pathophysiology of the increased risk of cardiovascular disease in diabetes associated with metabolic syndrome is discussed and the importance of early recognition of metabolic syndrome and potential role of addressing insulin resistance is stressed. Clearly more data is needed, but it is safe to say that metabolic syndrome is a worldwide epidemic in association with central obesity and underlying insulin resistance, which will propel a marked increase in cardiovascular events and diabetes mellitus in the years to come. Further research is needed to understand the role of more aggressive therapy in preventing type 2 diabetes and cardiovascular events in the population.

Impact of troponin T determinations on hospital resource utilization and costs in the evaluation of patients with suspected myocardial ischemia.

The evaluation and triage of patients with suspected myocardial ischemia in the emergency department remains challenging and costly. Previous studies of cardiac troponins have focused predominantly on patients with chest pain and have not randomized patients to different diagnostic strategies. Eight hundred fifty-six patients with suspected myocardial ischemia were prospectively randomized to receive a standard evaluation, including serial electrocardiographic and creatine phosphokinase-MB determinations (controls) or a standard evaluation with the addition of serial troponin T determinations (troponin group). The primary end points were length of stay and hospital charges. Significant reductions in length of hospital stay were seen in troponin T patients both with (3.6 vs 4.7 days; p = 0.01) and without (1.2 vs 1.6 days; p = 0.03) acute coronary syndromes compared with controls. Total hospital charges were reduced in a similar fashion in troponin patients with and without acute coronary syndromes ($15,004 vs $19,202; p = 0.01, and $4,487 vs $6,187; p = 0.17, respectively) compared with controls. Troponin patients without acute coronary syndromes had fewer hospital admissions (25% vs 31%; p = 0.04), whereas troponin patients with acute coronary syndromes had shorter telemetry and coronary care unit lengths of stay (3.5 vs 4.5 days; p = 0.03) compared with controls. Thus, utilization of troponin T in a broad spectrum of emergency department patients with suspected myocardial ischemia improves hospital resource utilization and reduces costs.

Age and history of cardiac disease as risk factors for cardiac complications after peripheral vascular surgery in diabetic patients.

OBJECTIVE: To examine the relationship of age and clinical factors to postoperative cardiovascular events in a cohort of diabetic patients undergoing peripheral vascular surgery. PATIENTS AND METHODS: In this cohort study, 316 diabetic patients were followed up prospectively after femoral-to-distal artery bypass surgery. The major end points of the study were all-cause mortality and cardiac morbidity (cardiac events defined as nonfatal myocardial infarction, unstable angina, and congestive heart failure). RESULTS: The overall postoperative cardiac event rate was 17.1% (54/316), with a 7.6% (24/316) rate of postoperative death or nonfatal myocardial infarction. Older diabetic patients (> or = 65 years) had a complication rate of 19.9% (43/216) compared with an 11.0% (11/100) complication rate in younger diabetic patients (< 65 years) (P = .02). Younger diabetic patients with a clinical history of coronary artery disease had an event rate of 18.2% (39/216) compared with an event rate of 2.4% (1/42) in younger diabetic patients without known cardiac disease (P = .02). In contrast, event rates were similar (20.7% [150/208] vs 18.2% [66/108]) in older diabetic patients with or without prior evidence of cardiac disease. CONCLUSION: Advanced age and clinical evidence of coronary artery disease are important determinants of postoperative outcome in diabetic patients undergoing peripheral vascular surgery.

Failure of a brief educational program to improve interpretation of pulmonary artery occlusion pressure tracings.

OBJECTIVE: To determine whether a brief educational program can reduce variability of interpretation of pulmonary artery occlusion pressure (PAOP) tracings. DESIGN: Prospective, observational study. PARTICIPANTS: Twenty-three intensive care nurses and 18 physicians. INTERVENTIONS: Participants interpreted PAOP tracings before and 1 week after receiving a single, brief educational session and/or written materials ("in-service") designed to reduce interobserver variability of PAOP interpretation. Differences between two reference values before and after in-service (mean population and Chief of Critical Care's readings) were compared for both groups. RESULTS: There were no significant differences in the variabilities in PAOP interpretations before and after in-service in either group. CONCLUSIONS: We conclude that this specific educational program was ineffective in reducing variability of interpretation of PAOP tracings. These data suggest that more comprehensive educational tools and/or sustained programs may be required to improve performance of critical care personnel in PAOP interpretation.

Myocardial ischemia and weaning failure in patients with coronary artery disease: an update.

OBJECTIVE: To determine the frequency and effects of weaning-related myocardial ischemia on weaning outcomes in patients with coronary artery disease. DESIGN: Prospective cohort study. SETTING: Medical and cardiac intensive care units of a 300-bed teaching community hospital. MEASUREMENTS AND MAIN RESULTS: Three-lead ST segments, heart rate-systolic blood pressure products, and respiratory rate/tidal volume ratios were obtained for patients with coronary artery disease just before and during their initial trials of weaning from mechanical ventilation. ST segments were interpreted by a blinded cardiologist. Eighty-three patients with a mean age of 72.4 +/- 1.1 years (mean +/- SEM), a mean Acute Physiology and Chronic Health Evaluation II score of 16.4 +/- 0.8, and a mean duration of mechanical ventilation of 4.6 +/- 0.9 days were studied. Eight patients showed electrocardiographic evidence of ischemia during weaning, and seven of these patients failed to be liberated on their first day of weaning. The presence of ischemia significantly increased the risk of weaning failure (risk ratio, 2.1; 95% confidence interval, 1.4-3.1). The rate-pressure product for the group as a whole increased significantly during weaning, from 11.9 +/- 0.4 to 13.5 +/- 0.5 mm Hg x beats/min x 10(3) (p < .01). The increase in rate-pressure product tended to be greater in patients who became ischemic (12.8 +/- 0.9 to 17.3 +/- 2.0 mm Hg x beats/min x 10(3)) than in patients who were not ischemic during weaning (11.8 +/- 0.4 to 13.0 +/- 0.5 mm Hg x beats/min x 10(3); p = .05). The rate/volume ratio did not change significantly during weaning, but the rate/volume ratios after both 1 min (65.6 +/- 4.6 vs. 98.0 +/- 9.4 breaths/min/L; p < .05) and 30 mins (68.6 +/- 4.3 vs. 91.1 +/- 8.9 breaths/min/L; p < .05) of unassisted breathing were lower in successful than in unsuccessful patients. CONCLUSION: Electrocardiographic evidence of myocardial ischemia occurs frequently and is associated with significantly increased risk of first-day weaning failure in patients with coronary artery disease.

The Goldman algorithm revisited: prospective evaluation of a computer-derived algorithm versus unaided physician judgment in suspected acute myocardial infarction.

BACKGROUND: It has been nearly a decade since Goldman's computer-driven algorithm to predict myocardial infarction was validated. Despite the potential to avoid admission of patients without acute myocardial infarction (AMI) to the coronary care unit (CCU), the routine use of computer-generated protocols has not been widely adopted. METHODS: Two hundred consecutive patients admitted to a university-affiliated community hospital with the suspected diagnosis of AMI as determined by physicians without the aid of the Goldman protocol underwent a blinded prospective evaluation to assess the performance of the Goldman algorithm in predicting the presence of AMI. Over the same time period, the Goldman algorithm was applied by retrospective chart review in 762 patients with non-AMI admitting diagnoses. Prospective history, physical examination, and electrocardiographic data were obtained within 24 hours of admission to the CCU by a physician blinded to each patient's clinical course. Retrospective chart reviews were conducted for 762 patients with chest pain given with non-AMI diagnoses. RESULTS: The diagnosis of AMI was confirmed in 68.5% (137/200) of patients with suspected AMI admitted to the CCU. In prospective parallel evaluations the Goldman algorithm predicted the presence of AMI in 167 (83.5%) of these 200 patients. All 137 confirmed patients with AMI were correctly identified by the Goldman algorithm. All major in-hospital complications occurred in the 137 patients who were diagnosed as having AMI. Of the 762 patients with chest pain with non-AMI diagnoses, only 27 (3.5%) sustained an AMI. The Goldman algorithm predicted the presence of AMI in 85% (23/27) of these patients. Adherence to the use of Goldman's algorithm in the triage of chest pain could have prevented 16.5% of CCU admissions for AMI. CONCLUSIONS: Routine adherence to the Goldman algorithm for the evaluation of patients with acute chest pain could have decreased the number of CCU admissions for suspected AMI by 16. 5%. Because major in-hospital complications occurred only in patients with AMI, this strategy would result in significant cost savings to our health care system without jeopardizing patient safety.

Analysis of observer variability in measurement of pulmonary artery occlusion pressures.

The goal of this study was to determine inter- and intraobserver variability in measurement of pulmonary artery occlusion pressure (Ppao), comparing values recorded by critical care nurses and those measured by physician specialists. Critical care nurses (CCNs) obtained contiguous pulmonary artery and occlusion pressure paper tracings, up to twice a day, between June 1997 and March 1998. All tracings were interpreted on two separate occasions, in blinded fashion, by our Chiefs of Critical Care (CCMD) and Cardiology (CARD). Their values of Ppao were compared with those that had been recorded by CCNs. One hundred and forty-seven measurements of Ppao were performed on 40 patients with a mean age of 62.5 +/- 2.2 yr and a mean APACHE II score of 21.5 +/- 0.8. Either or both physician readers found 34 tracings as not satisfactory for Ppao interpretation. Intraobserver agreement of Ppao measurements, determined by correlation coefficients, was 0.91 for the CCMD and 0. 87 for the CARD. Correlation coefficients for interobserver comparisons were 0.83 for CCMD-CARD, 0.66 for CARD-CCN, and 0.67 for CCMD-CCN. Clinically significant differences were observed between CCMD-CARD (range of differences, -11 to 12 mm Hg), CARD-CCN (-13 to 15 mm Hg), and CCMD- CCN (-11 to 15 mm Hg). When Ppao readings were categorized as low (< 5 mm Hg), normal (5-15 mm Hg), and high (> 15 mm Hg), kappa values were 0.57 for CARD-CCMD, 0.51 for CARD-CCN, and 0.41 for CCMD-CCN comparisons. Interobserver variability was not explained by positive pressure ventilation or by the presence of (> 4 mm Hg) ventricular waves. The absolute values of interobserver differences in tracings with respiratory phasic variations (RPV) >/= 8 mm Hg were significantly greater than for tracings with variations < 8 mm Hg (p < 0.05, except CCMD-CCN, p = 0.10). Intraobserver differences also tended to be higher for tracings with RPV >/= 8 mm Hg (p = 0.06 and 0.05). When selected tracings were presented to 23 CCNs and 18 physicians, variability of Ppao interpretation was twice as great for tracings with large RPVs as compared with those with minimal RPVs. These data suggest that observer variability of Ppao interpretation is of potential clinical importance and that the degree of variability is associated with the magnitude of respiratory phasic variation of intrathoracic pressures. Although this could represent a local aberration, this study highlights a factor (respiratory phasic variation of Ppao) responsible for significantly increased intra- and interobserver variabilities.

Long-term prognostic value of preoperative dipyridamole thallium imaging and clinical indexes in patients with diabetes mellitus undergoing peripheral vascular surgery.

The objective of this study is to assess the prognostic impact of preoperative dipyridamole thallium imaging and clinical variables on the long-term outcome of diabetic patients undergoing peripheral vascular surgery. Complete follow-up was obtained in 101 consecutive patients with diabetes mellitus undergoing routine dipyridamole thallium scintigraphy before vascular surgery (mean 4.2 +/- 3.2 years, range 1 month to 11 years). Low risk was defined by diabetes alone with a normal resting electrocardiogram. High risk was defined as a history of angina, myocardial infarction, congestive heart failure, or resting electrocardiogram abnormalities. There were 71 deaths in 98 patients discharged alive from the hospital (median survival 4.4 years). Age, the presence of resting electrocardiogram abnormalities, and an abnormal thallium scan were independent predictors of late death. After adjusting for age >70 years and thallium abnormalities, high-risk patients had a death rate 4.8 times (95% confidence interval 1.7 to 13.4, p <0.002) greater than low-risk patients. The presence of >2 reversible thallium defects was useful in further risk stratification of both low- and high-risk patients. Low-risk patients with >2 reversible defects had a median survival of 4.0 years compared with 9.4 years in those with < or =2 reversible defects (p <0.001). Similarly, high-risk patients with < or =2 reversible defects had an intermediate median survival rate of 4.7 years compared with 1.8 years in the group with >2 reversible defects (p <0.001). Therefore, advanced age and the presence of resting electrocardiographic or thallium abnormalities identifies a subset of diabetic patients with a poor long-term outcome after vascular surgery. Combined clinical and thallium variables may identify a population in whom intensive medical or surgical interventions may be warranted to reduce both perioperative and late cardiac events.

Myocardial infarction complicating gastrointestinal hemorrhage.

OBJECTIVE: To determine the frequency of and risk factors for myocardial infarction (MI) in patients admitted to an intensive-care unit (ICU) with gastrointestinal (GI) hemorrhage and to ascertain the effects on mortality and lengths of stay. MATERIAL AND METHODS: Demographic, laboratory, and outcome data were determined for all patients admitted to a medical ICU with GI hemorrhage between April 1996 and January 1997. Serial creatine kinase with isoenzyme levels and electrocardiograms were interpreted blindly by a senior cardiologist. RESULTS: For 83 consecutive admissions to the ICU because of GI hemorrhage, the patients' mean (+/- standard error) age was 65.0 +/- 1.7 years and APACHE II (acute physiology and chronic health evaluation) score was 15.7 +/- 0.8. In-hospital death occurred in 16 patients (19%). Patients who did not survive had a lower admission systolic blood pressure (99.2 +/- 4.5 versus 115.0 +/- 4.0 mm Hg; P = 0.01) than did those who survived. Eleven of 83 patients (13%) fulfilled both enzymatic and electrocardiographic criteria for MI. Ten patients (12%) had electrocardiographic evidence of myocardial ischemia but did not meet criteria for MI. Patients with MI were older (74.4 +/- 4.0 versus 61.7 +/- 2.0 years; P < 0.05), had a higher acuity of illness (APACHE II score, 21.6 +/- 3.0 versus 14.6 +/- 0.7; P < 0.05), and had more coronary risk factors (2.3 +/- 0.3 versus 1.4 +/- 0.1; P < 0.05) in comparison with those without MI or ischemia. Patients with MI also had longer ICU (8.6 +/- 2.4 versus 3.3 +/- 0.4 days; P < 0.05) and hospital (16.3 +/- 3.4 versus 9.1 +/- 0.8 days; P < 0.05) lengths of stay. Patients older than 65 years had a threefold increased risk (risk ratio, 4.0; 95% confidence interval, 0.9 to 17.4) and those with two or more risk factors for coronary artery disease had a ninefold increased risk of MI (risk ratio, 10.2; 95% confidence interval, 1.4 to 76.1) in comparison with those who were younger or who had fewer coronary risk factors, respectively. MI complicating GI hemorrhage did not significantly affect the risk of in-hospital mortality (risk ratio, 1.5; 95% confidence interval, 0.5 to 4.4). CONCLUSION: MI occurs frequently in patients with GI hemorrhage admitted to an ICU. Age more than 65 years and two or more risk factors for coronary artery disease identify patients who are at greatest risk for occurrence of MI, which is associated with longer ICU and hospital stays.

Detecting and differentiating white from red coronary thrombus by angiography in angina pectoris and in acute myocardial infarction.

To determine the ability to detect thrombus by angiography, angioscopy was performed before angiography in patients undergoing interventional procedures and the data collected in a blinded fashion. These data demonstrated that the sensitivity of angiography to detect white thrombus was 50% and the specificity was 95%, whereas the sensitivity and specificity to detect red thrombus was 100%, respectively; the positive and negative predictive value of detecting thrombus in general was 89% and 83%, respectively.

Types of anesthesia and cardiovascular outcomes in patients with congestive heart failure undergoing vascular surgery.

BACKGROUND. Whether regional anesthesia is preferable to general anesthesia for patients with congestive heart failure (CHF) undergoing noncardiac surgery remains controversial. The purpose of this study was to determine whether anesthetic technique affects postoperative cardiac outcome in patients with CHF; we hypothesized that cardiac outcomes would be superior with regional anesthesia compared with general anesthesia. DESIGN. 106 patients with prior or persistent CHF, undergoing femoral to distal artery bypass surgery, were randomized to general anesthesia (29 patients) or regional anesthesia (epidural, 42 patients, or spinal anesthesia, 35 patients). The primary end point was death or adverse cardiac events (myocardial infarction, unstable angina, or CHF). RESULTS. There was no statistically significant difference between groups in incidence of combined cardiac events, death, myocardial infarction, death or myocardial infarction combined, unstable angina, or CHF. CONCLUSION. Although larger studies are required to establish equivalence of the anesthetic strategies, this large single center study preliminarily indicates that regional anesthesia may not be superior to general anesthesia in patients with heart failure undergoing femoral to distal artery bypass surgery. (c)1999 by CHF, Inc.

Evaluating a new graphical ordinal logit method (GOLDminer) in the diagnosis of myocardial infarction utilizing clinical features and laboratory data.

OBJECTIVE: We used a new graphical ordinal logit method (GOLDminer) to assess a single cardiac troponin T (cTnT) analysis at the time of admission (first generation monoclonal; Roche BMC Corp., Indianapolis, Indiana), the character of chest pain, and electrocardiographic (ECG)findings in predicting the likelihood of acute myocardial infarction (AMI) in patients presenting with suspected myocardial ischemia. The final diagnosis of AMI was based on serial ECG findings and evolution of CKMB isoenzyme levels in conjunction with clinical findings. SUBJECTS: The study population consisted of 293 consecutive patients who presented at a mean of six hours after onset of chest pain or associated symptoms warranting a "rule-out" for AMI assessment to a university-affiliated community hospital. RESULTS: The odds-ratio for an elevated cTnT (> 0. 1 ng/ml) in AMI was 22.2:1. There was an association between typical chest pain and cTnT (chi square = 78.23, p < .0001) and between abnormal ECG findings and cTnT (chi square = 108, p < .0001). The cTnT yielded diagnostic benefit in addition to chest pain characteristics and ECG findings in AMI. We present the odds-ratios for the combined features in GOLDminer plots. CONCLUSION: We demonstrate how the odds-ratios for AMI are obtained after scaling continuous to ordinal the values for a single cTnT determination alone and with other features in patients presenting with chest pain.

Diagnosis of myocardial infarction: integration of serum markers and clinical descriptors using information theory.

OBJECTIVE: We examine the use of information theory applied to a single cardiac troponin T (cTnT) (first generation monoclonal; Boehringer Mannheim Corp., Indianapolis, Indiana) used with the character of chest pain, electrocardiography (ECG) and serial ECG changes in the evaluation of acute myocardial infarction (AMI). We combined a single measure of cTnT (blinded to the investigators) with a creatine kinase MB isoenzyme (CK-MB) measurement to discover the best decision value for this test in a study of 293 consecutive patients presenting to the emergency department with symptoms warranting exclusion of AMI. METHODS: The decision value for determining whether cTnT is positive or negative was determined independently of the final diagnosis by examining the information in the cTnT and CKMB data. Using information theory, an autocorrelation matrix with a one-to-one pairing of the CKMB and troponin T was constructed. The effective information, also known as Kullback entropy, assigned the values for troponin T and for CKMB that have the lowest frequency of misclassification error. The Kullback entropy is determined by subtracting the data entropy from the maximum entropy of the data set in which the information has been destroyed. The assignment of the optimum decision values was made independently of the clinical diagnoses without the construction of a receiver-operator characteristic curve (ROC). The final diagnosis of AMI was independently determined by the clinicians and entered into the medical record. RESULTS: The decision value for cTnT was 0.1 ng/ml as determined by the the information in the data. The method was validated within the same study by mapping the results so obtained into the diagnoses obtained independently by the clinicians using all of the methods at their disposal. The cTnT was different in AMI (n = 60) compared with non-AMI patients (n = 233) (2.08 +/- 0.21 vs. 0.07 +/- 0.10; p < .0001). CONCLUSION: Information theory provides a strong framework and methodology for determining the decision value for cTnT which minimizes misclassification errors at 0.1 ng/ml. The result has a strong correlation with other features in detecting AMI in patients presenting with chest pain.

Angioscopy of culprit coronary lesions in unstable angina pectoris and correlation of clinical presentation with plaque morphology.

This study demonstrates that plaque disruption and thrombus are absent in a considerable number of patients with unstable angina and that culprit lesion morphologies as assessed by angioscopy may differ among the various clinical subsets of patients. Although plaque disruption and thrombus undoubtedly play an important role in the pathogenesis of unstable angina, alternative mechanisms may be responsible for ischemia in some patients.

Outcomes research is the fifth discipline of the fifth generation of managed care: utility of a single troponin-T.

OBJECTIVE: The fifth generation of managed care is disease management. Diseases have measurable risk in providing laboratory and medical services. The link between managing services and managing risk can be aided by leveraging the laboratory. We wish to remodel laboratory services to fit the needs of the use, thereby using the laboratory for competitive advantage by redesigning a desired output using a formal structured process. Outcomes research is the systems framework for the remodeling process through the link of laboratory output to clinical and financial outcomes. A process redesign model connects the use of laboratory tests to improved medical services by leveraging resources to achieve measurable improvement over current results. This view of outcomes research seeks both competitive advantage and measurable improvements in quality. METHODOLOGY: This approach is illustrated by the patient presenting with chest pain (CP). A majority of the patients rule out for acute myocardial infarction (AMI), including patients with indigestion, shortness of breath, and other clinical findings. This is the basis for an emergency department (ED) CP observation unit to reduce coronary care unit admission rates. When the Goldman algorithm for discharging low-risk patients with CP from the ED using only clinical features and electrocardiographic findings proved difficult to implement, we turned to measuring the diagnostic efficiency of a new cardiac marker to replace the evolutionary changes in creatine kinase (CK) isoenzyme MB. The physicians making the decision were blinded to the results of the study. We fitted the expected characteristics of the test to the expected results for our program. The test was done on the presenting specimen of 293 evaluable patients with a median of 6.5 hours from the time of onset of CP to the time the specimen was drawn. The result was compared with the evolutionary pattern of CK-MB. RESULTS: The sensitivity of the test at presentation to the ED was 85% compared with < 50% for the presenting CK-MB, the false negative results taken earlier than 3 hours or 10 days after the onset of symptoms. Troponin-T effectively identifies non Q-wave AMI much earlier than the CK-MB. This study led to a prospective randomized clinical trial to demonstrate an improved medical and financial benefit from an early rule in or rule out of severe coronary artery ischemia. CONCLUSION: The study supports our hypothesis that the laboratory can systematically redesign its technology strategy and participate in the construction of a clinical pathway for the discharge from ED or admitting decisions with a test 98% sensitive for identifying patients with serious coronary ischemia by 3.5 hours after the onset of symptoms.

Angioscopic assessment of coronary lesions underlying thrombus.

This study examines the characteristics of coronary lesions in which thrombus is found as assessed by angioscopy before percutaneous transluminal coronary angioplasty in patients with various coronary syndromes. Our findings demonstrate that the plaque underlying intracoronary thrombus is usually yellow and/or disrupted, and support in vitro observations that lipid-rich plaques are highly thrombogenic and that disruption of these plaques is associated with in situ thrombosis.

Variability in the measurement of intracoronary ultrasound images: implications for the identification of atherosclerotic plaque regression.

BACKGROUND AND HYPOTHESIS: Serial coronary angiography cannot reliably detect the small changes in arterial dimensions. Measurement of arterial dimensions by intracoronary ultrasound (ICUS) may be a superior method to determine the extent of atherosclerotic burden since it directly images the diseased portion of the vessel. METHODS: To quantify inter- and intraobserver variability of ICUS measurements, 27 images of atherosclerotic coronary lesions were measured by two study physicians and repeated 14 days later. RESULTS: Interobserver correlation coefficients for external elastic lamina, lumen, and effective plaque area were 0.96, 0.99, and 0.91, respectively. Intraobserver correlation coefficients for external elastic lamina, lumen, and effective plaque area were 0.99, 0.99, and 0.97, respectively. To determine progression or regression in effective plaque area, a minimal difference of 2.77 mm2 (which represents a 23% change in plaque area) is needed. CONCLUSIONS: Direct visualization of the extent of atherosclerosis by ICUS can be accomplished with a low degree of inter- and intraobserver variability. ICUS may be a preferable alternative to angiography in atherosclerosis regression trials.

Angioscopic predictors of early adverse outcome after coronary angioplasty in patients with unstable angina and non-Q-wave myocardial infarction.

BACKGROUND: Clinical and angiographic criteria have a limited ability to predict adverse outcome in patients with unstable angina who are undergoing percutaneous transluminal coronary angioplasty (PTCA). We investigated whether the use of angioscopy can improve prediction of early adverse outcome after PTCA. METHODS AND RESULTS: Angioscopic characterization of the culprit lesion was performed before PTCA in 32 patients with unstable angina and 10 with non-Q-wave infarction. Seven patients (17%) had an adverse outcome (myocardial infarction, repeat PTCA, or need for coronary artery bypass graft surgery) within 24 hours after PTCA. Six of 18 patients with a yellow culprit lesion had an adverse outcome compared with 1 of 24 in whom the culprit lesion was white (P = .03). Six of 20 patients with plaque disruption suffered an adverse outcome compared with 1 of 22 with nondisrupted plaques (P = .04). Six of 17 patients with intraluminal thrombus had an adverse outcome, whereas only 1 of 25 patients without thrombus suffered an adverse outcome (P = .01). Yellow color, disruption, and thrombus at the culprit lesion site were associated with an eightfold increase in risk of adverse outcome after PTCA. The prediction of PTCA outcome based on characteristics of the plaque that were identifiable by angioscopy was superior to that estimated by the use of angiographic variables. CONCLUSIONS: In patients with unstable angina and non-Q-wave infarction, angioscopic features of disruption, yellow color, or thrombus at the culprit lesion site can identify patients at high risk of early adverse outcome after PTCA. Angioscopy was superior to angiography for prediction of PTCA outcome.