Victor S. Behar

The role of the exercise test in the evaluation of patients for ischemic heart disease.

A cohort of 1472 patients who underwent both exercise stress testing and coronary angiography within six weeks was examined. The data indicated that a combination of exercise parameters is both diagnostically and prognostically important. Almost all patients (> 97%) who had positive exercise tests at Stage I or Stage II had significant coronary artery disease. More than half of these (> 60%) had three vessel disease and over 25% had significant narrowing (> 50%) of the left main coronary artery. Patients who achieved Stage IV or greater exercise durations with either negative or indeterminate ST-segment response had less than a 15% prevalence of three vessel disease and less than a 1% prevalence of left main coronary artery disease. A low risk subgroup (75% of all nonoperated patients) was identified with a twelve month survival greater than 99%. A high risk subgroup (11% of all nonoperated patients) was identified with a twelve month survival of less than 85%. The exercise test is a noninvasive, reproducible method to assess the presence and extent of anatomic disease and the prognosis when significant disease has been defined. It should be used in conjunction with other noninvasive tests to determine optimal management in patients evaluated for ischemic heart disease.

Prognostic value of a coronary artery jeopardy score

The prognostic value of a coronary artery jeopardy score was evaluated in 462 consecutive nonsurgically treated patients with significant coronary artery disease, but without significant left main coronary stenosis. The jeopardy score is a simple method for estimating the amount of myocardium at risk on the basis of the particular location of coronary artery stenoses. In patients with a previous myocardial infarction, higher jeopardy scores were associated with a lower left ventricular ejection fraction. When the jeopardy score and the number of diseased vessels were considered individually, each descriptor effectively stratified prognosis. Five year survival was 97% in patients with a jeopardy score of 2 and 95, 85, 78, 75 and 56%, respectively, for patients with a jeopardy score of 4, 6, 8, 10 and 12. In multivariable analysis when only jeopardy score and number of diseased vessels were considered, the jeopardy score contained all of the prognostic information. Thus, the number of diseased vessels added no prognostic information to the jeopardy score. The left ventricular ejection fraction was more closely related to prognosis than was the jeopardy score. When other anatomic factors were examined, the degree of stenosis of each vessel, particularly the left anterior descending coronary artery, was found to add prognostic information to the jeopardy score. Thus, the jeopardy score is a simple method for describing the coronary anatomy. It provides more prognostic information than the number of diseased coronary arteries, but it can be improved by including the degree of stenosis of each vessel and giving additional weight to disease of the left anterior descending coronary artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Survival in medically treated coronary artery disease.

SUMMARY In1214symptomatic medically treated patients with coronaryartery disease, 57noninvasive baseline clinical characteristics and24catheterization descriptors wereanalyzed byamultivariable analysis technique todetermine thecharacteristics that wereindependent predictors ofsurvival and,inparticular, to determine whether noninvasive characteristics contributed prognostic information inaddition tocatheterizationfindings. Whenthenoninvasive characteristics were analyzed, 31characteristics were significant (p< 0.05) univariate predictors ofsurvival, butonly12contained significant independent prognostic information. Five- and7-year survival ratesin197patients whohadnone oftheindependently significant noninvasive characteristics wereboth90%.Nineteen variables weresignificant whenthecatheterization descriptors were analyzed individually. Onlysevenwereindependently significant whenthey wereanalyzed jointly. Whenall81 baseline characteristics wereanalyzed jointly, sevennoninvasive characteristics (history ofperipheral vascular disease, NewYorkHeartAssociation class IVheart failure, nonspecific intraventricular conduction defect, progressive chest pain, nocturnal pain, premature ventricular complexes on theresting ECG,andleft bundle branch block) andsixinvasive characteristics (left-main stenosis, arteriovenous oxygen difference, number of diseased vessels, abnormal left ventricular contraction, left ventricular end-diastolic pressureandanterior asynergy) wereindependently significant. Different survival rates may occurinsubsets that areuniform with respect toonly oneortwoimportant characteristics (e.g., coronaryanatomyandventricular function) because ofdifferences inother important baseline characteristics. Bothnoninvasive andinvasive characteristics mustbe takeninto account todefine prognosisincoronarydisease fully. EARLY STUDIESofpatients withclinically diagnosed coronary artery disease identified clinical characteristics suchasage,sex, previous myocardial

Graded Exercise Stress Tests in Angiographically Documented Coronary Artery Disease

Graded exercise stress tests performed on 650 consecutive patients with proven or suspected coronary disease undergoing evaluation by cardiac catheterization were correlated with clinical, hemodynamic, and angiographic findings. Among 451 patients with significant coronary stenosis, 332 (74%) had interpretable stress tests and 65% of these were positive (sensitivity). The rate of “false positives’ was 8%.The clinical syndrome of typical angina identified significant coronary disease in 89% of the patients, and 58% of that group had a positive exercise test defined by objective electrocardiographic criteria.Patients were not eliminated from this study because of recent digitalis ingestion. Although a higher frequency of uninterpretable exercise tests was found in this group (40%), the test results reflected more severe coronary disease. None of the patients with “false positive’ tests were taking digitalis. It is concluded that recent digitalis ingestion should not be considered a contraindication for exercise stress testing.Among the patients with interpretable exercise tests, the angiographic severity of coronary artery disease correlates strongly with the frequency of positive tests (40%, 66%, and 76%, with 70% or greater occlusion of one, two or three vessels respectively). Left main coronary stenosis of 70% or greater was associated with more severe ST segment changes, inability to achieve target heart rate during stress, and a lower maximum heart rate during exercise. The angiographic occurrence of collateral vessels was related to the extent of coronary disease and was associated with a higher percentage of positive exercise tests; no protective effect of collateral circulation could be demonstrated. Patients with abnormal resting hemodynamics or left ventricular asynergy had no significant difference in the frequency of positive tests after adjustment for the angiographic severity of disease.

Functional improvement of jeopardized myocardium following intracoronary streptokinase infusion in acute myocardial infarction.

The effect of reperfusion on regional left ventricular performance following acute myocardial infarction in man was determined. Intracoronary streptokinase was administered in 24 patients within 6 h of the onset of symptoms. 15 patients (62%) were successfully recanalized during the initial study. Mean percent radial shortening (%RS) in both the jeopardized and compensatory regions were determined using 23 radii from the centroid of diastolic and systolic angiographic silhouettes. Sequential measurements were obtained during repeat cardiac catheterization studies at 24 h in 19 patients and before discharge from the hospital (16 +/- 11 d) in 15 patients. At the time of the predischarge study, each acutely reperfused patient showed improvement in %RS in the jeopardized region (P = 0.01) with 56% returning to the normal range. Despite the uniform improvement in the contractile function of the jeopardized region in each reperfused patient, the global ejection fraction showed no improvement or a decrease at the time of the chronic study in 44%. This was due to a decrease in the compensatory wall motion in the uninvolved segments between the acute and chronic study in each case. Neither the %RS nor the ejection fraction changed significantly at the time of the chronic study in the patients who could not be acutely recanalized. These data indicate (a) significant salvage of jeopardized myocardium associated with recovery of contractile function in patients reperfused during the first 6 h of chest pain following acute myocardial infarction; (b) no improvement in regional or global left ventricular performance in patients who could not be reperfused acutely; and (c) the ejection fraction is strongly influenced by changes in the compensatory wall motion of the uninvolved segments and does not accurately reflect changes in the contractile function of the jeopardized myocardium.

A comparison of real-time, two dimensional echocardiography and cineangiography in detecting left ventricular asynergy.

SUMMARYLeft ventricular wall motion was assessed in 105 consecutive patients both invasively, using biplane cineangiography, and noninvasively, by a real-time, phased-array, two-dimensional echocardiography system. Ventricular wall motion in five anatomic areas of the ventricle (anterolateral, posterolateral, apical, septal, and inferior) was analyzed by both methods in a double-blind manner. Twodimensional echocardiographic images were deemed adequate for analysis in 82% of the regions (430 of 525). Fifty-five discrepancies were noted in the comparison of the remaining 430 regions.The reasons for discrepancies in interpretation between the two methods were established for 54 during retrospective review: 33 were due to echocardiography (inadequate target visualization, observer error, or tangential echo views). Fifteen were related to angiography (overlay of silhouettes or observer error), and six were due to other reasons including definition problems or spatial orientation difficulties.Both real-time, two-dimensional echocardiography and cineangiography have advantages and disadvantages. The techniques used together could provide more complete information concerning ventricular wall movement than is now currently available.

Mitral valve prolapse. Two-dimensional echocardiographic and angiographic correlation.

SUMMARY In order to define baseline descriptive criteria for the diagnosis of mitral valve prolapse with cross-sectional echocardiography, 49 patients undergoing catheterization were examined by a real-time, two-dimensional phased array echocardiographic imaging system. Angiography was used to separate patients into two distinct groups: 15 with normal mitral valve function and 34 with definite mitral valve prolapse. Systolic mitral leaflet and annulus motion were then observed in each patient and similarities and differences were noted between the two groups of patients. Correlative M-mode echocardiographic data were available in 37 patients.Certain two-dimensional echocardiographic findings restrited to the angiographically proven mitral valve prolapse group were defined: 1) posteriorly displaced coaptation of the leaflets, 2) systolic superior movement of one or both mitral leaflets above the level of the mitral ring, and 3) a systolic curling motion of the posterior mitral ring on its adjacent myocardium. One or more of these abnormalities were found in all 34 patients with angiographic mitral valve prolapse. When mitral valve prolapse does occur, the results of two-dimensional echocardiography would suggest that both leaflets are usually involved.

Prognostic implications of ventricular arrhythmias during 24 hour ambulatory monitoring in patients undergoing cardiac catheterization for coronary artery disease

The prognostic importance of ventricular arrhythmias detected during 24 hour ambulatory monitoring was evaluated in 395 patients with and 260 patients without significant coronary artery disease. Ventricular arrhythmias were found to be strongly related to abnormal left ventricular function. A modification of the Lown grading system (ventricular arrhythmia score) was the most useful scheme for classifying ventricular arrhythmias according to prognostic importance. When only noninvasive characteristics were considered, the score contributed independent prognostic information, and the complexity of ventricular arrhythmias as measured by this score was inversely related to survival. However, when invasive measurements were included, the ventricular arrhythmia score did not contribute independent prognostic information. Furthermore, ejection fraction was more useful than the ventricular arrhythmia score in identifying patients at high risk of sudden death.

Outcome in medically treated coronary artery disease. Ischemic events: nonfatal infarction and death.

In this study we extended the characterization of outcome in 1214 medically treated patients with coronary disease by considering nonfatal infarction and death together as ischemic events. At 7 years, the cumulative event rate was 47% (18% for nonfatal infarction as the initial event and 29% for death as the initial event). In multivariable analysis of 81 baseline descriptors, 11 (six clinical and five catheterization) were independent predictors of events. Progressive chest pain, number of diseased vessels, left main stenosis and left ventricular (LV) function were the most important predictors. Progressive pain was a more important predictor of total events than of survival alone. In patients with one-, two- or three-vessel disease and normal LV function, nonfatal infarction accounted for at least 50% of initial events. In patients with left main disease or severe LV dysfunction, death was the predominant event. These results have important implications for interpreting the natural history of coronary artery disease.

Detection and exclusion of interatrial shunts by two-dimensional echocardiography and peripheral venous injection.

Two-dimensional echocardiography (2-D echo) was used with peripherally injected contrast material to detect interatrial shunts in 33 patients. Group 1 consisted of 11 patients having classic clinical findings of atrial septal defect. Group 2 consisted of 12 patients with problems requiring that atrial shunting be excluded. Group 3 (control group) consisted of 10 patients undergoing cardiac catheterization for chest pain. Confirmation of the 2-D echo findings was provided by cardiac catheterization in 32 patients and postmortem examination in one. Right-to-left atrial shunts were detected in all 11 patients in group 1, although seven had no right-to-left shunt calculable by oximetry. Four patients in Group 2 had right-to-left atrial shunts. None of the patients in Group 3 had atrial shunts. In the 15 patients with atrial shunts, the degree of right-to-left shunting could be qualitatively assessed as small, moderate, or large. There were no false-negative or false-positive results by contrast 2-D ech