Isolated stenosis of left anterior descending or right coronary artery: Relation between site of stenosis and ventricular dysfunction and therapeutic implications

Indications for coronary arterial bypass surgery in single vessel coronary artery disease are unresolved. To determine the extent of myocardium at risk with stenosis (70 percent or more) of a single coronary artery, left ventricular angiograms of 200 patients with stenosis confined to either the left anterior descending or right coronary artery and of 15 normal control subjects were assessed. Among patients without myocardial infarction, ejection fraction was unchanged (p > 0.05 versus normal values) in (1) those with stenosis of the proximal (above first septal branch, n = 19), mid (between septal and first diagonal branches, n = 14) and distal (within 2 cm distal to diagonal branch, n = 15) left anterior descending coronary artery, and (2) those with stenosis of the proximal (above acute marginal branch, n = 16) and distal (between acute marginal and posterior descending branches, n = 16) right coronary artery. In contrast, ejection fraction was depressed (p < 0.001 versus normal values) In left anterior descending arterial stenosis with anterior myocardial Infarction: proximal (38 ± 10 percent, n = 33), mid (46 ± 12 percent, n = 24; p < 0.01 versus proximal), and distal (56 ± 9 percent, n = 15; p < 0.01 versus mid). Ejection fraction was similar with proximal and distal stenosis of the right coronary artery and inferior Infarction: 54 ± 11 percent versus 55 ± 9 percent, p > 0.05; both p < 0.05 versus normal value. Shortening velocity was assessed in three anterior (I to III, base to apex) and three inferior (IV to VI, apex to base) equidistant hemichords perpendicular to the long axis, 30 ° right anterior oblique view. With anterior Infarction and left anterior descending stenosis, shortening of hemichords I to V, I to IV and II to III with proximal, mid and distal stenosis, respectively, was depressed (p < 0.05 versus normal value). Septal excursion and thickening on M mode echocardiography with proximal left anterior descending stenosis and infarction were depressed (p < 0.05 versus mid and distal stenosis with infarcts). Hemichordal shortening with Inferior infarction was similarly depressed (p > 0.05) with proximal and distal stenoses.In conclusion, stenosis of the left anterior descending coronary artery is a heterogenous disease, the extent of jeopardized myocardium is highly dependent on the site of stenosis, and the criteria for surgery cannot be applied uniformly. When the surgical goal is myocardial preservation, these data provide an objective rationale for bypass of stenosis of the proximal left anterior descending coronary artery. In stenosis confined to the right coronary artery, left ventricular preservation alone should not be considered an indication for coronary bypass grafting.     

Effect of coronary occlusion site on angiographic and clinical outcome in acute myocardial infarction patients treated with early coronary intervention

In acute myocardial infarction that is treated with thrombolysis, proximal coronary artery occlusion is associated with worse prognosis, irrespective of the infarcted artery. Primary percutaneous coronary intervention (PCI) is currently the treatment of choice for ST-segment elevation acute myocardial infarction. Therefore, we evaluated the prognostic significance of proximal versus distal coronary artery occlusion in patients with acute myocardial infarction that was treated with primary PCI. Between 1994 and 2001, patients with a first acute myocardial infarction that was treated with primary PCI were analyzed. A lesion was considered proximal if it was located proximal to the first diagonal branch in the left anterior descending coronary artery (LAD), the first marginal obtuse branch in the left circumflex coronary artery, and the first right acute marginal branch in the right coronary artery. Lesions distal of these side branches were considered distal. In total, 1,468 patients were analyzed. Left ventricular ejection fraction (LVEF) for proximal LAD lesions was lower than that for distal ones (37 +/- 11% vs 42 +/- 11%, p <0.0001). Adjusted relative risk of 3-year mortality for proximal versus distal LAD was 4.04 (95% confidence interval 1.95 to 8.38). In patients with infarcts related to the right or left circumflex coronary artery, no significant association between lesion location and LVEF or mortality was seen. No difference was seen in adjusted 3-year mortality between distal LAD and non-LAD-related infarcts (p = 0.145). In conclusion, our analysis shows that, even in patients with acute myocardial infarction that is treated with primary PCI, infarcts related to the proximal LAD have the worst 3-year survival and lowest residual LVEF compared with distal LAD or non-LAD-related infarcts.     

Impact of late coronary artery reperfusion on left ventricular function one month after acute myocardial infarction (results from the ISAM study)

To evaluate the impact of late reperfusion of an infarct-related coronary artery on left ventricular (LV) function in the month after myocardial infarction, findings from 368 patients in the Intravenous Streptokinase in Myocardial Infarction study are presented. All patients had a late peaking in the creatine kinase-MB serum time-activity curve, suggesting absence of early reperfusion. Contrast angiography was performed 1 month after the acute event. The infarct-related coronary artery was patent in 74 of 116 (64%) streptokinase-treated patients and 141 of 252 (56%) patients treated with anticoagulant therapy (placebo group). In all baseline variables, including the actually developed enzymatic and electrocardiographic infarct sizes, there were no differences between the patent- or occluded-artery groups. A patent infarct artery 1 month after infarction was associated with significantly better LV function regardless of the vessel involved and whether or not patients had been treated with streptokinase. Ejection fraction in patients with patent versus occluded artery was 56 +/- 13 versus 50 +/- 14 (p less than 0.0005). Most benefit was noted in patients in whom the proximal left anterior descending coronary artery was affected: ejection fraction was 52 +/- 14 versus 36 +/- 12% (p less than 0.0005). Our data confirm that restoration of adequate flow through an infarct-related coronary artery beyond the time window for actual salvage of ischemic myocardium has a definite beneficial effect on LV function.     

Differential effects on right ventricular function of transient right, left anterior descending and left circumflex coronary occlusions during percutaneous transluminal coronary angioplasty

Right ventricular function was studied by means of a thermodilution catheter before, during and after percutaneous transluminal angioplasty of the proximal right (group 1, n = 8), left anterior descending (group 2, n = 8) or left circumflex (group 3, n = 8) coronary artery. All patients had evidence of myocardial ischemia, with single-vessel disease affecting the proximal segment of one of the three major coronary arteries; no patient had had a previous myocardial infarction and all had normal cardiac function at baseline study. Cardiac index decreased during balloon inflation. Mean pulmonary artery pressure was unaffected in group 1 but increased in group 2 (from 19 +/- 5 to 31 +/- 11 mm Hg, p less than 0.01) and in group 3 (from 19 +/- 2 to 22 +/- 5 mm Hg, p less than 0.05). Right ventricular ejection fraction decreased from 62 +/- 9% to 52 +/- 10% (p less than 0.01) in group 1 and from 64 +/- 7% to 44 +/- 10% (p less than 0.005) in group 2, and returned to normal within 2 min after balloon deflation in both groups. In group 3, right ventricular ejection fraction was unchanged during balloon inflation (58 +/- 5% at baseline, 58 +/- 9% at 60 s, p = NS). Therefore, brief occlusion of the proximal segments of the left anterior descending or right coronary artery results in marked alteration of right ventricular performance that is probably caused by right ventricular free wall ischemia in the right coronary group and by the concomitant effects of septal ischemia and increased right ventricular afterload in the left anterior descending artery group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Histologically proven myocarditis in patients with biventricular dysfunction and severe asymptomatic coronary artery disease

The aim of our study was to investigate the pathogenesis of the global biventricular dysfunction observed in patients with critical coronary artery stenosis, but no evidence of myocardial ischemia or infarction. From January 1992 to January 1997, among consecutive patients undergoing invasive cardiac study including biventricular endomyocardial biopsy because of progressive heart failure (NYHA functional class III-IV) associated with biventricular dysfunction and no history of myocardial ischemic events, 7 patients had severe coronary artery disease (three vessel 4 patients; two vessel 1 patient, proximal occlusion of left anterior descending artery 2 patients). At two-dimensional echocardiography left and right ventricular end-diastolic diameter were 73 +/- 10.5 and 39 +/- 7 mm, respectively, left ventricular ejection fraction was 0.23 +/- 6.5 and right ventricular ejection fraction was 0.29 +/- 7.2. Histology showed extensive lymphocytic infiltrates with focal myocytolysis meeting the Dallas criteria for myocarditis in all patients. Two patients with active inflammation received prednisone and azathioprine in addition to conventional drug therapy for heart failure. At 6-month follow-up cardiac volume and function improved in immunosuppressed patients (left ventricular ejection fraction from 15 to 50% and from 20 to 38%, respectively) while they remained unchanged in conventionally treated patients. In conclusion, global biventricular dysfunction in patients with severe asymptomatic coronary artery disease and no evidence of previous myocardial infarction may be caused by myocarditis rather than by myocardial ischemia or hibernation.     

Diagnostic value of stress echocardiography under dobutamine and myocardial scintigraphy for restenosis at 6 months after angioplasty of the left anterior descending artery

This study compared prospectively the diagnostic value of dobutamine echocardiography and exercise myocardial scintigraphy for restenosis at 6 months after angioplasty of the left anterior descending artery. Forty-one patients aged 58 +/- 10 years, admitted to hospital for myocardium infarction (N = 22) or unstable angina (N = 19), with single vessel disease, were treated by angioplasty of one lesion of the left anterior descending artery after initial evaluation of the left ventricular ejection fraction by echocardiography. At 6 months, left ventricular function was reassessed by echocardiography, dobutamine echocardiography and exercise myocardial scintigraphy (Thallium 201) performed without treatment. Coronary angiography was performed at the same time and showed 8 restenosis (19.5%). Overall, in this series, dobutamine echo and scintigraphy had respectively a sensitivity of 37.5% and 75%, and a specificity of 97% and 70% (p < 0.02). Nine patients had left ventricular dysfunction unchanged compared with the initial measurement without viability in the territory of the left anterior descending artery with low dose dobutamine (group 1); thirty-two patients had improved or normal left ventricular ejection fraction with myocardial viability (group 2). In group 1, no cases of restenosis were detected by dobutamine echocardiography but_of them had myocardial scintigraphic evidence of ischaemia. In group 2, the sensitivity of the two techniques was comparable but dobutamine echo was more specific than scintigraphy (96 versus 75%, p = 0.03). In conclusion, dobutamine echocardiography may be indicated in the diagnosis of restenosis of the left anterior descending artery and in cases of viability in its territory. In its absence, myocardial scintigraphy seems to be preferable.     

Left ventricular wall motion at rest in patients with organic coronary artery disease vs coronary spasm

Left ventricular ejection fractions and regional ejection changes obtained from left ventriculograms at rest were analyzed in 15 normal subjects, in 17 patients with isolated, organic left anterior descending coronary artery disease, and in 11 patients with isolated left anterior descending coronary artery spasm. Patients with coronary artery spasm did not have significant organic lesions at the site of spasm. All patients with organic coronary artery disease and coronary artery spasm had a history of angina pectoris without myocardial infarction. No significant differences in ejection fraction were observed among the three groups. The regional ejection change of the anterolateral and apical wall supplied by the left anterior descending coronary artery was significantly decreased in patients with organic coronary artery disease compared with those in normal subjects (anterolateral 39.5 +/- 10.3% vs 48.4 +/- 7.7%, p less than 0.05; apical 48.4 +/- 8.8% vs 55.6 +/- 7.8%, p less than 0.05). However, the anterolateral and apical wall motion was not impaired in patients with coronary artery spasm. Thus, patients with organic coronary artery disease had impairment of left ventricular wall motion, while those with coronary artery spasm did not, although both groups of patients had symptoms of angina. These results suggest that patients with organic coronary artery disease may have had coronary blood flow disturbances through stenosed vessels and chronic active ischemia that produced left ventricular impairment.     

Effects of acute, transient coronary occlusion on global and regional right ventricular function in humans.

OBJECTIVES. The aim of this study was to investigate the changes in right ventricular function during acute coronary occlusion produced by inflating a coronary angioplasty balloon catheter. BACKGROUND. Alterations in right ventricular function are well known to occur in patients with acute myocardial infarction or ischemic cardiomyopathy. However, the changes in right ventricular function resulting from acute, transient coronary occlusion of each of the major coronary arteries have been scantily studied, perhaps because of serious limitations of currently available technology. METHODS. A newly designed, mobile, multiwire gamma camera, in combination with generator-produced tantalum-178, affords high count rate first-pass radionuclide angiography and is thus ideal for studying right ventricular function at the bedside. Accordingly, 46 patients underwent first-pass radionuclide angiography at baseline and during transient coronary occlusion induced by a coronary angioplasty balloon catheter. RESULTS. A significant, albeit modest, decrease in global right ventricular ejection fraction occurred during occlusion of the left anterior descending (from 42.9 +/- 9.3% to 39 +/- 8.7%, p < 0.05) and left circumflex (from 44 +/- 9.1% to 38.8 +/- 7.9%, p = 0.03) coronary arteries, but diagonal artery occlusion caused no significant change in right ventricular ejection fraction. Occlusion of the right coronary artery proximal (but not distal) to the acute marginal branch caused a significant decrease in right ventricular ejection fraction (from 42.6 +/- 4.7% to 35.7 +/- 7.2%, p < 0.01). Although occlusion of the left anterior descending, left circumflex and proximal right coronary arteries all caused significant deterioration in regional right ventricular function, only proximal right coronary occlusion caused right ventricular dilation (p < 0.005). CONCLUSIONS. Significant impairment of right ventricular function occurs during transient occlusion of the left anterior descending, left circumflex and proximal right coronary arteries, but only occlusion of the latter causes acute right ventricular dilation, probably as a result of ischemia.     

Anterior left ventricular wall echoes in coronary artery disease. Linear scanning with a single element transducer

The feasibility and usefulness of obtaining anterior left ventricular wall echoes were studied using a linear cardiac scan with a single element tranducer and M mode recordings. One hundred four patients were examined: 50 with acute myocardial infarction and 54 who underwent left ventricular angiography and coronary cineangiography for evaluation of chest pain. Of the 54 patients with cardiac catheterization studies, 11 had no evidence of cardiac disease, 42 had 50 percent or greater obstruction in one or more of the three major coronary arteries and one had aortic insufficiency. Anterior left ventricular wall echo motion toward the transducer or absence of motion during ejection was called abnormal, and motion away from the transducer during ejection was interpreted as normal. Abnormal motion was seen in four of four patients with an isolated lesion of the anterior descending coronary artery, in one of three with an isolated lesion of the right coronary artery and in neither of two with an isolated lesion of the left circumflex artery. Of the 20 patients with obstructive coronary artery disease by arteriography and abnormal left ventricular wall echo motion, 18 had obstruction of the left anterior descending artery with or without other disease. Correlation of the anterior left ventricular echograms with the left ventricular angiograms was poor, with agreement in only 66 percent (33 of 50) of cases. Twenty-five of 26 patients with acute infarction and abnormal anterior left ventricular wall echo motion had electrocardiographic changes indicative of anterior or lateral wall infarction, or both. Twenty-five of 34 patients with electrocardiographic changes indicative of anterior wall infarction had an abnormal anterior wall motion echo. This study shows that obtaining the anterior left ventricular wall echo is feasible and useful in patients with coronary artery disease since abnormal anterior left ventricular wall motion is closely associated with anterior wall ischemia or infarction in these patients.     

Is the prognosis of non-thrombolysed inferior infarction benign?

Between 1978 and 1983, 2,970 coronary angiographies were performed at the Cardiology Clinic of Necker Hospital; 220 survivors of an initial Q-wave inferior infarction who had not received thrombolytic therapy were selected. The ejection fraction was 55 +/- 11 per cent, and the indexed end diastolic left ventricular volume was 108 +/- 29 ml/m2. The left anterior descending artery was diseased in 57 per cent of cases. The incidence of multivessel disease was 67 per cent. Two hundred and eleven patients (96%) were followed up for 79 +/- 22 months. The prevalence of cardiovascular events was: cardiac deaths: 22 (10%), recurrent infarction: 20 (9%), angina requiring coronary bypass surgery: 60 (28%), cardiac failure: 22 (10%). The 10 year actuarial survival was significantly lower in patients with an ejection fraction less than 45 per cent (46% vs 91%) and in patients with triple vessel disease (62% vs 92% and 88%). The survival was not lower in patients with stenosis of the left anterior descending artery.     

Coronary angiographic significance of left anterior fascicular block during acute myocardial infarction

The clinical and angiographic significance of isolated left anterior fascicular block occurring during the early stage of acute myocardial infarction was studied in 141 consecutive patients who underwent cardiac catheterization before hospital discharge. Left anterior fascicular block occurred in 15 of the 62 patients with an anterior wall infarction and in 13 of the 79 with an inferior infarction. None of the clinical characteristics differed among patients with or without left anterior fascicular block. The number of coronary vessels with significant stenosis, the Friesinger and the Gensini scores for severity of stenosis and the ejection fraction were also similar in the two groups. Patients with left anterior fascicular block had more severe narrowing of the coronary artery supplying the infarct zone (88 +/- 21 versus 70 +/- 35%, p less than 0.001) and tended to have less developed collateral circulation (collateral score 0.7 +/- 0.8 versus 1 +/- 0.8, p = 0.10). A significant stenosis of the left anterior descending coronary artery was found as frequently in patients with as in those without left anterior fascicular block (64 versus 65%); 29% of the patients with inferior wall infarction and left anterior fascicular block had left anterior descending coronary artery stenosis compared with 47% of the patients without this conduction disturbance (no significant difference). When the infarction was located anteriorly, a significant stenosis of the proximal segment of the left anterior descending coronary artery was present in 47% of the patients with and in 45% of the patients without left anterior fascicular block.(ABSTRACT TRUNCATED AT 250 WORDS)     

Thrombolysis and coronary occlusion: effects upon the non-infarct zone.

Regional wall motion was examined by angiography after 3 weeks in 154 patients taking part in the Thrombolysis in Coronary Occlusion (TICO) Trial. Coronary patency rate was greater after administration of recombinant tissue plasminogen activator, (rt-PA 62/77pts 81%) than after a placebo (P 49/77pts 64% P = 0.02), particularly for the left anterior descending artery compared with the right coronary artery (LAD 27/28 96% vs RCA 28/40 70% P = 0.006). Left ventricular ejection fraction (LVEF) was preserved after rt-PA (rt-PA 59 +/- 14% vs P 53 +/- 15% P = 0.01), predominantly because of more effective non-infarct zone contraction (rt-PA 0.52 +/- 1.16 SD/cord vs P 1.01 +/- 1.07 SD/cord P = 0.008). Infarct zone scores differed little (rt-PA 2.88 +/- 0.95 SD/cord vs P 3.16 +/- 1.11 SD/cord P = 0.09). Left ventricular ejection fraction and non-infarct zone function were best preserved after rt-PA compared with the placebo, particularly in patients with single vessel disease and in patients in whom the infarct-related artery was the left anterior descending vessel.     

Natural history of severe proximal coronary artery disease as documented by coronary cineangiography

Studying the natural history of patients with severe proximal coronary arterial lesions may assist evaluation of coronary revascularization surgery. We reviewed the mortality statistics of 469 patients with 80 to 100 percent occlusive lesions in the proximal coronary tree as diagnosed by selective angiography. Only patients with normal or moderately impaired left ventricular function were included in the study; patients with severe cardiomegaly, congestive heart failure or severe left ventricular impairment by left ventriculography were excluded. Follow-up periods ranged from 6 to 11 years for 178 patients with single vessel disease, 177 with double vessel disease and 114 with triple vessel disease. Patients with isolated disease of the left anterior descending artery had a 4 percent average yearly attrition rate or a 6 year mortality rate of 25.5 percent (17 of 69). Those with isolated disease of the right coronary artery demonstrated only a 2.3 percent yearly attrition rate or a 14 percent mortality rate in 6 years (11 of 77). Patients with double and triple vessel disease had, respectively, 41.5 and 63 percent 6 year mortality rates.Survival was related to the number of vessels involved. Patients with single vessel disease of the left anterior descending artery had a significant annual mortality rate. The prognosis improved when good angiographic collateralization was present, particularly in single vessel disease with total occlusion. Functional disability, classified according to the New York Heart Association criteria, was related to mortality rates and proved a useful indicator in large patient groups. Prior myocardial infarction, location of the lesion above or below the major septal perforator in left anterior descending artery disease, and left main trunk lesions did not alter the prognosis significantly.     

Clinical and angiographic profile and follow-up of myocardial bridges: a study of 21 cases

Myocardial bridging describes an angiographic entity, which is any degree of systolic narrowing of a coronary artery observed in at least one angiographic projection. Among the cineangiograms of 3200 patients reviewed, there were 21 cases (19 males) of myocardial bridges--incidence of 0.6 percent. Of these, seven had hypertrophic cardiomyopathy, six had atherosclerotic coronary artery disease and remaining eight had no evidence of either. All 21 patients had myocardial bridges in proximal or mid left anterior descending coronary artery. In addition, one case of hypertrophic cardiomyopathy had whole posterior descending coronary artery under a myocardial bridge. Another case of hypertrophic cardiomyopathy had a short normal segment of 5 mm inside a long myocardial bridge of 35 mm (tandem myocardial bridges). The length of the bridges varied from 10 to 35 mm (mean 24.5 +/- 4.5 mm) and diameter stenosis during systole varied from 40-90 percent (mean 70 +/- 8%). Two patients had large saccular coronary aneurysms proximal to the muscle bridge. Four of the eight patients who had neither hypertrophic cardiomyopathy nor coronary artery disease presented with acute anterior wall myocardial infarction and three of them had regional wall motion abnormality of left descending territory. Of the six patients who had coronary artery disease, one had 60 percent left descending artery lesion and two had recanalized segments proximal to the bridge. Five of the above six patients had significant stenosis of other coronary vessels. Four patients were lost to follow-up (mean period 3.4 +/- 2 years). In the coronary artery disease group, one patient underwent coronary artery bypass graft surgery for 3-vessel disease including graft to left descending artery and one developed inferior wall myocardial infarction. The patients in the hypertrophic cardiomyopathy group and "no hypertrophic cardiomyopathy-no coronary artery disease" group were free of events at last follow-up. Long-term prognosis of isolated myocardial bridges appears to be excellent. Degree of systolic narrowing or length of myocardial bridge does not correlate with event rates on follow-up.     

Scintigraphic anatomy of coronary artery disease in digital thallium-201 myocardial images.

One hundred and eight patients with single and multiple vessel coronary artery disease confirmed by arteriography were evaluated by exercise thallium-201 (201Tl) myocardial scintigraphy to determine the scintigraphic appearances of specific coronary stenoses. In general proximal stenoses caused more widespread, but not necessarily more severe, myocardial tracer deficit than distal stenoses. In particular, proximal dominant right coronary artery disease was specifically associated with extensive inferior wall tracer deficit in the anterior scintigram, whereas proximal left circumflex disease caused similar tracer depletion best visualised in the left lateral scintigram. A triad of uptake defects was caused by left anterior descending coronary artery disease: viz. apical tracer deficit (anterior view) in 71% lesions, septal tracer deficit (left anterior oblique view) in 83% of lesions, and anterolateral wall tracer deficit (left lateral projection) in 72% of lesions. The last defect has been termed a 'diagonal window' because it was associated with independent disease of the main diagonal branch of the left anterior descending coronary artery or with disease in the main left anterior descending artery situated proximal to this branch. Diagonal window tracer deficit was the most useful scintigraphic sign distinguishing proximal from distal disease in the left anterior descending coronary artery. False negative scintigraphic defects occurred more commonly in patients with triple vessel disease and in association with well-developed coronary collateral vessels. Certain scintigraphic patterns of 201Tl myocardial accumulation appear invaluable in the noninvasive localisation of stenoses within specific coronary arteries and thus may be useful in predicting life-threatening coronary artery disease which should be confirmed by definite coronary arteriography. The digital 201Tl myocardial scintigram also provides an independent functional guide to the interpretation of coronary arteriograms and may be helpful in the planning of aortocoronary bypass graft surgery.     

Coronary Artery Surgery Study (CASS): comparability of 10 year survival in randomized and randomizable patients

The Coronary Artery Surgery Study (CASS) includes 780 patients with mild or moderate stable angina pectoris or asymptomatic survivors of a myocardial infarction who were randomized to either medical or surgical therapy and 1,319 patients who were eligible for randomization but were not randomized (randomizable patients). There were no substantial aggregate differences observed in any of the survival comparisons after 10 years of follow-up study between the randomized and randomizable patients assigned to the medical (79% versus 80%) or surgical (82% versus 81%) groups or in patient subgroups stratified according to coronary artery disease extent and left ventricular ejection fraction. Cox regression analyses were done with independent variables known to be predictors of survival, including surgical versus medical therapy and randomized versus randomizable group, to test the null hypothesis of a mortality difference between medical versus surgical assignment according to group assignment (randomized versus randomizable). In no case did the initial group category enter as a significant predictor of survival. The results in the randomizable group reinforce those in the randomized group with respect to the medical versus surgical comparison. Two subgroups are identified with a significant surgical advantage: 1) patients with proximal left anterior descending coronary artery stenosis greater than or equal to 70% and an ejection fraction less than 0.50, and 2) patients with three vessel coronary artery disease and an ejection fraction less than 0.50. In both groups, coronary bypass surgery had a statistically significant beneficial effect on survival (p less than 0.05). After a decade of follow-up, the CASS randomizable patients confirm conclusions reached on the basis of the CASS randomized trial.     

Coronary angiography and left ventriculography in survivors of transmural and nontransmural myocardial infarction

Recent studies have suggested a similar prognosis for patients with transmural myocardial infarction and nontransmural myocardial infarction despite a smaller infarct size in the latter patients estimated by creatine phosphokinase (CPK). Thirty-one patients with transmural myocardial infarction and 17 patients with nontransmural myocardial infarction as defined by electrocardiographic criteria underwent coronary angiography and left ventriculography from 10 to 24 days after they had an acute myocardial infarction. Forty-three of these 48 patients were asymptomatic following their myocardial infarction. When compared to patients with nontransmural myocardial infarction, those with transmural myocardial infarction had greater peak CPK levels, 1,090 +/- 210 versus 290 +/- 60 IU (p less than 0.01). There was no difference in prevalence of single, double or triple vessel coronary artery disease, mean number of coronary arteries 50 per cent narrowed (2.0 +/- 0.2 versus 2.0 +/- 0.2), near total or total occlusions, coronary score (Friesinger) (7.9 +/- 0.6 versus 8.2 +/- 0.7), left ventricular ejection fraction (48 +/- 2 versus 53 +/- 4), or per cent of akinetic-dyskinetic myocardial segments (66 of 242 [27 per cent] versus 32 of 132 [24 per cent]) between two groups. The similar extent of coronary artery narrowing and degree of left ventricular dysfunction may explain the similar prognosis for patients with transmural myocardial infarction and those with nontransmural myocardial infarction despite differences in enzymatically estimated acute infarct size.     

Preponderance of acute proximal left anterior descending coronary arterial lesions in fatal myocardial infarction: A clinicopathologic study

To determine whether an acute lesion in a specific segment of the cororiary tree is more likely than other obstructions to cause fatal myocardial infarction, 77 autopsy patients Who died of acute myocardial infarction were studied. Multiple coronary stenoses were present in 92 percent of these patients, arid the proximal left anterior descending coronary artery before the first septal perforator accounted for only 23 percent of the critical narrowings (greater than 70 percent of luminal diameter). In contrast, acute thrombotic coronary events associated with fatal myocardial infarction occurred most often in the proximal left anterior descending artery, accounting for 61 percent of acute lesions; this rate compared with 8 percent of acute lesions occurring in the mid or distal left anterior descending artery, 18 percent of those in the right, 6 percent of those in the left circumflex and 7 percent of those in the left main coronary artery. Of the autopsy patients, 32 (40 percent) had 77 prior nonfatal myocardial infarcts of which only 17 (22 percent) were anteroseptal infarcts related to occlusion of the proximal left anterior descending coronary artery. The amount of infarcted myocardium in the hearts with acute proximal left anterior descending coronary arterial lesions was somewhat more extensive but not significantly different from that of hearts with other acute coronary lesions.

Fifty survivors of myocardial infarction who underwent cardiac catheterization were studied for comparison. In those patients, proximal left anterior descending coronary disease accounted for 17 percent of critical narrowings and only 22 percent of nonfatal infarcts. These findings suggest that an acute proximal left anterior descending coronary arterial lesion is more likely to result in fatal myocardial infarction than are critical obstructions elsewhere in the coronary arterial tree. Because the quantity of the infarct does not appear to be sufficient to explain these differences, qualitative differences in anteroseptal myocardium are suggested.     

Natural history of left anterior descending coronary artery obstruction: significance of location of stenoses in medically treated patients

We examined the prognostic significance of an obstructive lesion in the proximal left anterior descending (LAD) coronary artery. Five-year or longer follow-up data were examined from 311 patients with greater than 70% obstruction of the LAD treated without surgery. Mortality was compared in subsets with lesions proximal to and distal to the first septal perforating artery. Survival curves were worse in patients with proximal than with distal LAD disease (p less than 0.05); lesion location remained a significant determinant of survival when ejection fraction, age, and sex were controlled using a Cox regression model. However, when patient subsets were examined, survival with proximal LAD disease was worse than with distal obstruction only in the presence of an associated right coronary artery lesion and an ejection fraction of less than 40% (p less than 0.01). Patients with proximal LAD plus right coronary lesions had a 5-year mortality rate (34.08 +/- 8.9%) that was not significantly (p greater than 0.05) different from that of a group of 66 patients with greater than 50% narrowing of the left main coronary artery (24.02 +/- 4.3%). Thus, proximal LAD disease is more significant than is a distal lesion only in the presence of right coronary obstruction. This two-vessel combination results in a mortality rate as high as that associated with left main coronary artery obstruction.     

Quantification of carotid atheroma, by vascular ultrasonics and spectral analysis, after myocardial infarction. Apropos of 80 cases

A prospective study of carotid artery atheroma by vascular echotomography and spectral analysis was performed in 40 patients with myocardial infarction and 40 control subjects. Carotid artery atheroma was commoner in the group of patients with myocardial infarction (72.5% +/- 6.8%), earlier (9 years), more commonly bilateral (37.5% +/- 7.6%) and more stenotic (32.5% +/- 7.4%) than in the control group (p less than 0.000a, p less than 0.0001 and p less than 0.002, respectively). The severity of carotid artery atheroma correlated with the site of coronary artery disease; the following significant relationships were found: stenosing 40% and/or bilateral carotid atherosclerosis and left anterior descending disease (p less than 0.02); carotid atherosclerosis and double or triple vessel disease (p less than 0.05). The authors conclude that detection of carotid artery atheroma after myocardial infarction is valuable for two reasons: it gives an indication as to the severity of the coronary disease; carotid endarterectomy may be considered at the same time as coronary artery bypass surgery.