Search

In a recent prospective double-blind placebo-controlled trial, a combination of aspirin and dipyridamole was not associated with a reduction in the rate of restenosis within the 1st 6 months after coronary angioplasty. The purpose of this study was to determine whether clinical, anatomic or procedural factors were predictive of the observed restenosis rates in that prospective trial. A total of 247 patients and 280 segments underwent follow-up angiography and quantitative coronary angiographic analysis between 4 and 7 months after coronary angioplasty. Two baseline clinical characteristics--angina class and duration of angina in months--were related to the rate of restenosis by univariate analysis. Patient-related stepwise logistic regression analysis identified severity of angina as the only clinical predictor of restenosis. Three univariate baseline anatomic characteristics--percent diameter stenosis before angioplasty, stenosis greater than 10 mm in length and calcific stenosis--and two early postangioplasty characteristics--residual percent diameter stenosis and residual mean pressure gradient--were predictive of restenosis. Of these, only two--length of stenosis and residual percent diameter stenosis--were independently related to restenosis by multivariate analysis and only the former is identifiable before the procedure. It is concluded that in prospective studies in contrast to retrospective studies, few clinical and anatomic factors appear to be predictive of restenosis after coronary angioplasty.

During the past decade, large, placebo-controlled, randomized trials have demonstrated that the incidence of coronary events can be reduced by treating hyperlipidemia. In studies with angiographic end points, marked lowering of total and low-density-lipoprotein cholesterol with comparable increases in high-density-lipoprotein cholesterol retards the progression of coronary atherosclerosis and favors regression. In the Cholesterol-Lowering Atherosclerosis Study (CLAS), such therapy also prevented the appearance and worsening of atherosclerotic lesions in coronary bypass grafts. In the recently reported Familial Atherosclerosis Treatment Study (FATS), in which coronary lesions were measured quantitatively, treatment induced clear regression of coronary atherosclerosis and also markedly decreased coronary events. The beneficial effect on coronary lesions in these studies appears to be proportional to the degree of lipid lowering. In addition, new evidence suggests that aspirin and calcium antagonists might prevent the development of early coronary lesions. The identification and aggressive treatment of patients with high serum cholesterol levels can have a major impact on the development and evolution of coronary atherosclerosis.

In this study, two alternative methods of assessing left ventricular (LV) sequential wall motion and ejection fraction (EF) were used in 28 consecutive patients in whom an unstable clinical condition (unstable angina pectoris or severe LV dysfunction) precluded the use of high volume contrast cineventriculography. A new approach, direct small volume contrast digital ventriculography, was compared to radionuclide blood pool ventriculography considered as a "standard" and reliable technique. The qualitative analysis of regional LV contraction by three independent observers showed a complete agreement in 64% of segments studied in the left anterior oblique (LAO) projection and in 69% in the right anterior oblique (RAO) projection; a one-degree disagreement was observed in 13% and 19% respectively, and a discrepancy of two degrees or more in 23% and 12% respectively. Left ventricular ejection fraction calculated from both techniques correlated relatively well (r = 0.82). The radionuclide examination still remains the fastest, easiest and most objective way to appraise global LV function in high risk patients. However, optimal analysis of segmental wall motion requires invasive digital contrast left ventriculography. In future, a more general use of non-ionic contrast media including their intravenous injection and the advent of portable digital devices should permit their widespread use as a safe, rapid and reliable procedure even in the intensive care unit.

In order to assess if coronary artery disease progression occurs as a slow, continuous process or at bouts, the coronary angiograms of 44 patients catheterized three times were reviewed. A previously developed logistic model, taking into account time interval between the angiograms, age, occurrence of unstable angina, and extent score of coronary artery disease, was used to compute a probability of progression from the second to the third angiogram. Two groups of patients were considered: those with (n = 15) and those without (n = 29) progression from the first to the second angiogram (PROGRESSION 1-2). A simulation provided in each group the distribution of the expected number of patients with progression from the second to the third catheterization. In the group without PROGRESSION 1-2, the observed number of progressions from the second to the third angiogram was in agreement with the expected one. However, in the group with PROGRESSION 1-2, the progression from the second to the third angiogram was more frequent than expected (p = 0.068). These results suggest that, in many patients, coronary artery disease progression is continuous over several years.

A patient with Prinzmetal angina and ST segment elevation in the anterior ECG leads became asymptomatic after a 50% left anterior descending coronary artery stenosis was bypassed. However, seven years later Prinzmetal angina recurred but with ST segment elevation in the inferior ECG leads. Although the coronary bypass graft had remained patent, the proximal and distal left anterior descending coronary artery was occluded. No significant stenosis was present in the right coronary artery. Perhexiline maleate controlled his symptoms but when the drug was stopped because of side effects an acute inferior myocardial infarction occurred.

We studied the progression of atherosclerotic coronary lesions in 38 patients who had previously undergone angiography and were later hospitalized for an episode of unstable angina pectoris, and in 38 matched patients with stable angina who had also undergone prior catheterization. Patients with unstable angina and those with stable angina were similar in terms of age (mean, 49 and 50 years, respectively), number of risk factors (1.5 per patient in both groups), interval between studies (mean +/- S.D., 44 +/- 31 and 35 +/- 31 months, respectively), number of diseased vessels on the first angiogram (1.52 in both groups), and initial ejection fraction (65 and 63 per cent, respectively). Progression of coronary lesions was demonstrated in 29 of the 38 patients with unstable angina, as compared with 12 of the 38 with stable angina (P less than 0.0005). Progression to 70 per cent or more stenosis was recorded in 21 of the patients with unstable angina but in only 5 of those with stable angina (P less than 0.0005). Also more frequent in the patients with unstable angina were multifocal progression (11 vs. 2, P less than 0.01) and progression of the left main or preseptal left anterior descending artery or both (9 vs. 1, P less than 0.01). Thus, we have demonstrated by angiography that unstable angina is associated with progression in the extent and severity of coronary atherosclerosis.

To examine the role of antiplatelet therapy in the prevention of arterial restenosis after percutaneous transluminal coronary angioplasty (PTCA), we conducted a randomized, double-blind, placebo-controlled study in 376 patients. The active treatment consisted of an oral aspirin-dipyridamole combination (330 mg-75 mg) given three times daily, beginning 24 hours before PTCA. Eight hours before PTCA, the oral dipyridamole was replaced with intravenous dipyridamole at a dosage of 10 mg per hour for 24 hours, and oral aspirin was continued. Sixteen hours after PTCA, the initial combination was reinstituted. Treatment was continued in patients with a successfully dilated vessel until follow-up angiography four to seven months after PTCA--or earlier, if symptoms dictated. Of 249 patients who underwent follow-up angiography, 37.7 percent of patients receiving the active drug had restenosis in at least one segment, as compared with 38.6 percent of patients taking placebo (P not significant). The number of stenotic segments was virtually the same in the two groups. Among the 376 randomized patients, there were 16 periprocedural Q-wave myocardial infarctions--13 in the placebo group and 3 in the active-drug group (6.9 percent vs. 1.6 percent, P = 0.0113). Although the use of this antiplatelet regimen before and after PTCA did not reduce the six-month rate of restenosis after successful coronary angioplasty, it markedly reduced the incidence of transmural myocardial infarction during or soon after PTCA. Thus, the short-term use of antiplatelet agents in relation to PTCA can be recommended.

Originally described in Japan, 'apical hypertrophic cardiomyopathy' has now been reported in many other countries. A series of eight patients who present with the classic 'spade-like' left ventricular angiographic pattern are reported; five of them also had hypertension. Thus, this angiographic pattern may not be specific for apical hypertrophic cardiomyopathy and may be seen in acquired heart disease.

Atherosclerosis is the most frequent cause of occlusion of aortocoronary saphenous vein grafts between 5 and 10 years after coronary artery bypass surgery. The typical atherosclerotic plaque appears between 1 and 3 years after operation and, at a mean of 5 years, histologic changes of atherosclerosis are present in 21% of grafts and in 27% of patients. Only approximately 60% of saphenous vein grafts remain patent at repeat angiography between 10 and 12 years after bypass surgery; 45% of patent grafts show atherosclerotic changes at angiography and 43% of patients show evidence of atherosclerosis in one or more saphenous vein grafts. We do not know whether the development or the progression of these atherosclerotic changes can be modified; however, the data currently available suggest that the administration of platelet inhibitors and/or of lipid lowering agents offer two promising avenues of investigation in patients undergoing aortocoronary saphenous vein bypass surgery. Until this has been carefully studied, the internal mammary artery should remain the preferred conduit for aortocoronary bypass grafting, whenever possible.

We have demonstrated that selective digital left ventricular angiography using small amounts of contrast material minimized both symptoms and hemodynamic alterations and provided good images for assessment of regional ventricular function. However, comparisons of ejection fraction (EF), end-systolic volume (ESV), and end-diastolic volume (EDV) from digital angiography, at 10 frames per second, with measurements derived from conventional angiography, showed only a fair correlation between the two methods. Using a new generation of digital equipment and an acquisition time of 30 frames per second, we studied the correlation between digital and conventional angiography in 29 patients with coronary artery disease for a wide spectrum of left ventricular functions. Ventricular volumes and EF were calculated by computer using the area-length method. The correlation coefficient (r) between both the methods was 0.93 for EF, 0.95 for ESV and 0.89 for EDV. Thus digital left ventricular angiography provides an accurate evaluation of left ventricular function and can with advantage replace conventional angiography for this purpose.

In two series of consecutive patients who underwent coronary artery grafting with the saphenous vein or the internal mammary artery (IMA), angiographic studies were conducted two weeks and one year after operation. The early patency rate was 91.8% in 184 vein grafts and 97.4% in 38 IMA grafts. Late patency was 93.1% in 143 vein grafts and 90.9% in 33 IMA grafts. Thus, the cumulative patency rate at one year was 84.9% for vein grafts and 88.3% for IMA grafts. The incidence of severe narrowing at the site of anastomosis was 2.2% in vein grafts and 7.9% in IMA grafts; the rate of occlusion of the distal limb of the recipient coronary artery was, respectively, 4.3 and 7.9%. Diffuse reduction in the caliber of grafts at one year was less frequent with IMA grafts (12.7 versus 6.6%). On the other hand, blood flow was significantly higher in vein grafts: 67.4 versus 45.2 ml per minute (p less than 0.001). Blood flow in IMA grafts whose caliber was larger than that of the recipient coronary artery was significantly higher than flow in IMA grafts with a caliber equal or inferior to that of the coronary artery: 63.1 versus 32.7 ml per minute (p less than 0.001). Although cumulative patency rates at one year were comparable in both series, because only one-third of the IMAs were larger than their recipient coronary arteries, flow was somewhat restricted in the other two-thirds. This suggests that the IMA does not constitute the better bypass conduit and, unless it is of large caliber, preferably should be used in the grafting of small coronary arteries or those with limited runoff.

The importance of the coronary collateral circulation as a cause of false negative exercise tests was studied in 37 patients who had a 90 percent or greater isolated stenosis of the luminal diameter in one major coronary artery. Sixteen patients had large collateral vessels and 21 patients had either minimal or no collateral circulation. Myocardial scintigraphy was performed in 22 of the 37 patients. The final treadmill time was similar in both groups (521 +/- 192 versus 554 +/- 144 seconds [mean +/- standard error of the mean]). The presence and depth of S-T segment depression was not influenced by the degree of collateralization. The sensitivity of the exercise electrocardiogram was greater for patients with disease in the left anterior descending than in the right or left circumflex coronary arteries (95 versus 60 percent, p < 0.03). Among the 22 patients with thallium-201 scintigrams, myocardial perfusion defects were more common in patients without collateral circulation (100 versus 40 percent, p < 0.01) and involved more myocardial segments (p < 0.005). The overall sensitivity of exercise electrocardiography for the detection of single vessel stenosis 90 percent or greater was similar to that of myocardial scintigraphy (81 versus 73 percent). In conclusion, large intercoronary collateral vessels are not a cause of false negative exercise electrocardiograms in patients with single vessel disease but are a common cause of false negative scintigrams. Large collateral vessels may limit the quantity and location of myocardial ischemia, but exercise electrocardiography and thallium-201 scintigraphy may detect different aspects of ischemia.

We examined 82 patients 10 years after saphenous-vein aortocoronary bypass surgery to determine their angiographic status and to relate those findings to the risk factors for coronary-artery disease. Of 132 grafts shown to be patent 1 year after surgery, only 50 were unaffected at 10 years. The remainder were narrowed (43) or occluded (39). Disease progression in coronary arteries without grafts was also frequent, both in vessels that were normal (15 of 32) and in those with minor stenosis (25 of 53). New lesions did not develop in 15 patients, whereas they did in 67--in the grafts, the native vessels, or both. There was no significant difference between the two groups in the incidence of hypertension, diabetes, or smoking, whereas plasma levels of very-low-density lipoproteins (VLDLs) and low-density lipoproteins (LDLs) were higher, and high-density lipoprotein (HDL) levels were lower in those with new disease than in those without. Univariate analysis showed that plasma cholesterol and triglyceride levels were significantly higher at the time of surgery and at the 10-year examination in those with new lesions. Multivariate analysis indicated that among the lipoprotein indexes, levels of HDL cholesterol and plasma LDL apoprotein B best distinguished the two groups. The findings indicate that atherosclerosis in these patients was a progressive disease, frequently affecting both the grafts and the native vessels, and that the course of such disease may be related to the plasma lipoprotein levels.

Initial results, complications, restenosis rates and clinical outcomes were compared in 78 patients undergoing multilesion and 128 patients undergoing multivessel percutaneous transluminal coronary angioplasty (PTCA). Multilesion PTCA was defined as a procedure in which a proximal PTCA site had to be crossed to dilate a distal severe narrowing and multivessel PTCA as multiple dilatations without having to cross 1 severe narrowing to dilate another. The clinical and angiographic features of the 2 groups were similar. More sites per patient were attempted among those who underwent multilesion PTCA. Primary success rate per lesion was 86% (236 of 274) among those who underwent multivessel and 73% (155 of 211) among those who underwent multilesion PTCA (p less than 0.001). A success rate of 81% (101 of 124) for proximal lesions among those with multilesion PTCA was not significantly worse than that for those with multivessel PTCA; however, lesions distal to proximal sites had a success rate of only 62% (54 of 87), worse than either those with proximal stenoses or multivessel PTCA (p less than 0.005). Arterial diameter, severity of stenosis or procedural variables did not account for this difference. Complication rates were similar in the 2 groups. Despite a poorer success rate among patients with multilesion PTCA, clinical improvement to functional class 0 or 1 occurred in more than 70% of patients in both groups and was equal in patients with and without successful distal dilatations. Restenosis rates per lesion in patients with multivessel (31%) and multilesion (30%) PTCA were similar.(ABSTRACT TRUNCATED AT 250 WORDS)

The respective diagnostic values of M mode and 2D echocardiography and pulsed and continuous wave Doppler were assessed in bioprosthetic valve dysfunction. The results of the ultrasonic investigations were compared with the operative findings and anatomo pathological appearances in 56 cases of dysfunction. Only cases with surgical confirmation were included. Doppler examinations were carried out in 13 cases. Echocardiographic imaging alone cannot resolve all the diagnostic problems posed: specific signs are rare and were only observed in one out of 7 cases of periprosthetic leak, 7 out of 10 cases of valvular stenosis and 20 out of 36 cases (55 per cent) of valve tear. In cases of valve tear, 2D echocardiography was falsely normal in 15 per cent of cases and gave equivocal results in 30 per cent of cases because it was not possible to visualise the three cusps of the bioprostheses. Doppler echocardiography does not have the same limitations and gives an immediate and accurate assessment of valve function. It is particularly useful for the diagnosis of stenosis and valve tear in which the diagnostic specificity and sensitivity attain 100 per cent (exact diagnosis in all 11 cases of valve tear). At present, continuous wave Doppler seems to be the most reliable diagnostic tool for qualitative and quantitative assessment of primary degeneration of valvular prostheses.

Repeat coronary angiography was performed within 6 months after successful percutaneous transluminal coronary angioplasty (PTCA) in 178 of our first 181 patients (98%). The remaining 3 patients were symptom free, had negative treadmill exercise test results and were considered not to have had restenosis. A second follow-up angiogram was performed in 107 patients (59%), including all patients with persistent or recurrent anginal symptoms, between 7 and 18 months after PTCA. Fifty-one of the 181 patients (28%) had restenosis on 51 of 205 successfully dilated segments (25%). The stenosis was greater than or equal to 70% in 49 of these 51 segments; it was 65% and 55%, respectively, in the 2 remaining patients. Restenosis was documented angiographically at a median time of 4.7 +/- 4 months. However, 47 patients (92%) had restenosis documented within 6 months, 2 between 7 and 12 months and 2 between 13 and 18 months after PTCA. Stepwise logistic regression analysis selected the following factors as independent predictors of restenosis after PTCA: variant angina, multivessel disease, severity of residual stenosis and less reduction in the diameter of the stenosis on the angiogram immediately after PTCA. Of these 4 factors, the degree of residual stenosis immediately after PTCA was by far the most significant. It is concluded that restenosis occurs in approximately 25% of patients, almost always within the first 6 months, after successful PTCA. The degree of residual stenosis after PTCA is the most important predictor of restenosis. Increased experience and improved instrumentation may eventually lead to less residual stenosis and better late results after PTCA.

Digital subtraction and computer enhancement of left ventriculography allow the injection of small amounts of contrast medium into the left ventricle. Image quality measurements of cardiac volumes, and ejection fraction and evaluation of regional wall motion were compared following digital subtraction and cine ventriculography in 30 patients undergoing coronary arteriography for suspected or proven ischemic heart disease. At concentrations of 13% to 19% (iodine contents: 2.0 to 5.0 g) meglumine sodium diatrizoate used for digital subtraction ventriculography, no alterations of ventricular pressures were noted; premature ventricular contraction and cineventriculography in 30 patients undergoing coronary arteriography for suspected wall motion by two independent observers showed complete agreement between digital and cineventriculography in 141 of 150 segments (94%), including 114 normal segments; digital ventriculography led to underestimation of four segments and to overestimation of five. Left ventricular ejection fraction and volumes calculated using both techniques correlated relatively well (ejection fraction: r = 0.86; end systolic volume: r = 0.88; end diastolic volume: r = 0.665). Thus, intraventricular injection of low concentrations of contrast medium provides good digital angiographic images and may eventually replace cine ventriculography for invasive assessment of left ventricular performance. However, ECG gating and shorter exposure times will be required for accurate measurement of ventricular volumes and ejection fractions.

Postoperative angiographic studies were carried out at 1 month, 1 year, and 10 years in two groups of patients: 238 patients with saphenous vein (SV) grafts and 40 patients with internal mammary artery (IMA) grafts. Cumulative patency was better in IMA grafts, both at 1 year (88.5% vs 76.4%) and at 10 years (84.1% vs 52.8%). Atheromatous changes in patent grafts at 10 years were frequent in SV grafts (29/66 or 43.9%) and uncommon in IMA grafts (1/19 or 5.2%; p less than .02). Attrition rate (11.8%) during the first year in IMA grafts (representing our initial experience with IMA grafts) was comparable to that of SV grafts (15.2%) in a group of patients operated on after 2 years of experience. Therefore, early attrition rate may be related to both experience and type of conduit. Later, at 10 years, the conduit itself appears to be the dominant factor. Furthermore, patients who received IMA grafts had a better survival rate at 10 years (84.3% vs 70%) than those who underwent SV bypass grafting.

An accurate and objective knowledge of the evolution of the aorta-to-coronary grafts is essential in order to establish the rationale of the role of this surgery in the treatment of the coronary artery disease. Serial angiographies of the venous grafts were performed 15 days, one year and approximately 3 years after operation in 74 patients (101 grafts). The graft occlusion rate was 10% in the initial study, more than 20% in the second examination and 6% in the third examination. Moreover, a significant number of pervious grafts have shown, between 2 weeks and one year, a diffuse or segmentary reduction of their lumen. Nevertheless, besides a few grafts with severe stenoses which became occluded, these changes did not progress between one and three years. Therefore, sub-intimal fibrous hyperplasia, responsible for the structure changes of the grafts, does not seem to be a slowly evolutive pathologic process but seems rather to stabilize itself after one year.

The authors have compared myocardial perfusion, i.e. the coronary blood flow per unit of myocardial mass, in 9 patients with cardiomyopathy and 5 normal subjects, both at rest and during coronary sinus pacing-induced tachycardia at a rate of 150 beats/mn. In the cardiomyopathies, myocardial perfusion was found to be decreased at rest, and to remain abnormally low during induced tachycardia despite the evidence for a significant coronary reserve. During pacing there were, in addition to induced chest pain, indirect signs of sub-endocardial ischaemia which could explain the angina of effort found in certain cardiomyopathies, especially those of the obstructive hypertrophic type.

Sequential control angiographic examinations were performed at 2 weeks, 1 year, 5 to 7 years, and 10 to 12 years after aortocoronary saphenous vein bypass surgery in 82 unselected patients. Graft modifications consisting of wall irregularities and obstructive lesions of various severity and shapes that were found to develop after the first year were attributed to atherosclerosis. The incidence of these late changes increased from 16% during the interval between 1 year and 5 to 7 years to 36.4% during the subsequent interval between 7 and 12 years (p less than .01). These changes were not influenced by the severity of early diffuse or localized intimal hyperplasia. They were not related to classical risk factors except for low-density lipoprotein and low-density beta-lipoprotein cholesterol. Graft closure increased 2.5-fold from the interval between 1 year and 5 to 7 years to the following period between 7 and 12 years, 10.2% to 26.1% (p less than .02); thus the mean yearly attrition rate augmented from 2% to 5.3%. Late graft closure may result from early localized stenosis most likely related to improper surgical techniques, but the most frequent cause appears to be atherosclerosis. Graft patency at 10 to 12 years is 63.3%.

A new coronary artery occlusion was found in 98 of 313 consecutive patients (31%) with coronary artery disease treated medically who underwent catheterization twice, 39 +/- 25 months apart. Multivariate logistic regression displayed 8 independent predictors of new occlusion. Four were available at the time of the second angiogram: the interval between the 2 studies (p = 0.005), a decrease in ejection fraction (p less than 0.01), the appearance of bundle branch block (p less than 0.01), and an interim myocardial infarction (p less than 0.05). Four other predictors were found at the time of the first angiogram: 2 angiographic characteristics, 1 related to the severity (presence of an 80% or greater luminal diameter narrowing of an artery supplying a non-akinetic left ventricular segment [p less than 0.005]) and 1 to the extent (count of the lesions narrowed 75% or less in luminal diameter in a 15-segment coding system [p less than 0.05]) of coronary artery disease, and 2 risk factors: smoking status (p less than 0.05) and male sex (p less than 0.05). The 140 male smokers with at least 80% diameter stenosis or at least 4 segments with moderate (75% or less) stenosis were at a higher risk of occlusion than the 173 other patients after intervals of less than 2 years (13 of 53 vs 7 of 74, p less than 0.01), 2 to 4 years (23 of 40 vs 10 of 47, p less than 0.005) and more than 4 years (27 of 47 vs 18 of 54, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

The influence of dietary or pharmacological intervention on coronary atherosclerosis can best be assessed by performing serial coronary arteriography on patients at high risk for coronary disease progression who are randomised into controlled trials. Changes in coronary artery lesion diameter of less than 20% cannot be accurately assessed by visual interpretation, because of inter- and intra-observer variability. The introduction of quantitative, computer-assisted measurements of coronary lesions has reduced variability and greatly improved the precision of measurements. Both cholestyramine and colestipol-niacin have been shown to reduce the rate of progression of coronary atherosclerosis; however, in both studies coronary lesions were assessed visually and no quantitative measurements were reported. A marked reduction in serum cholesterol appears to be the intervention that is most likely to prevent the progression or induce regression of coronary atherosclerosis. Quantitative angiographic measurement techniques should be used in clinical trials designed to assess cholesterol-lowering interventions.

Among 500 patients who received aortocoronary saphenous vein grafts at the Montreal heart Institute between September 1969 and August 1972, the condition in 88% of survivors with respect to angina pectoris was improved 1 year after surgery and 47% were still better after 12 years. One year after grafting, 202 patients underwent follow-up angiography; symptoms of angina had lessened in 89% who had at least one graft patent but in only 57.5% of those with all grafts occluded. This difference was still obvious 12 years after surgery. Loss of improvement decreased at a mean annual rate of 3.7%. Of the 59 angina-free patients at 1 year who had angiographic follow-up at 10 to 12 years, angina developed subsequently in 30 (51%); 25 (83%) of these were found to have obstructive changes that reduced the lumen by at least 50% in grafts or in ungrafted coronary arteries, compared with only 13 (45%) of the 29 angina-free patients who did not have angina subsequently. Improvement in the degree of angina and its recurrence after bypass surgery are closely related to graft patency and subsequent development of atherosclerosis in the grafts or in the native coronary arteries.

Control angiographic studies were carried out 54 to 88 months after aortocoronary saphenous vein bypass surgery (70 +/- 10 months) in 100 unselected patients who were known to have at least one patent graft 6 to 18 months following the operation. Only 17 of the 159 grafts were found occluded during this interval of 5 years, giving an average yearly attrition rate of 2.1% after the first year. The mean yearly attrition rate was 0.7% in our second series of near consecutive patients operated on after 2 years of experience and modifications of surgical techniques, and it compares favorably with the 2.4% yearly attrition rate found in our first series of patients (P < 0.05). Of the 37 grafts having localized stenoses at 1 year, eight became occluded (21.6%), and four became worse. Grafts with localized stenoses were more prone to late occlusion, whereas no late occlusion was observed in normally appearing grafts at 1 year. Diffuse graft narrowing noted during the first year showed no further change during the subsequent 5 years, and it did not appear to lead to late occlusion. Finally, in 14 grafts, localized narrowing developed after the first year, at a yearly rate of 1.5%. Atherosclerosis appears to be the most likely etiology, being found in two of these instances at reoperation.

Clinical and angiographic features were identified that influences early mortality in 807 patients who underwent aortocoronary bypass grafting alone among the first 1000 consecutive patients subjected to aortocoronary bypass operations at the Montreal Heart Institute. The early mortality was 4.7% and was related to the patient's age, the duration of the illness from its first clinical manifestation, certain types of clinical presentation, electrocardiographic findings, the number of obstructed arteries and the ejection fraction. The influence of the number of obstructed arteries appeared to be independent of other factors, including the number of grafts and the degree of correction. Early mortality was not influenced by risk factors such as lipid abnormalities, hypertension or diabetes, by the history of previous myocardial infarction or the number of grafts.

Both the Veterans Administration Cooperative Study and the European Coronary Surgery Study have provided only brief accounts of graft patency rates in their surgically treated patients. In the Veterans Administration Cooperative Study, at an average of 1 year after operation, 69% of the grafts were patent among 208 patients; 88% of patients had at least one patent graft, and 58% had all grafts patent. In the European Coronary Surgery Study, angiographic examination of the grafts was performed within 9 months of operation in 84 patients, and showed a patency rate of 90%; in 223 patients, the examination was performed at between 9 and 18 months, and showed a 77% patency rate. In the Coronary Artery Surgery Study (CASS), graft patency rates were evaluated within 60 days of operation in 129 patients, a median of 18 months after operation in 121 patients, and a median of 5 years after operation in 197 patients. Cumulative vein graft patency (per distal anastomosis) was 90% early, 82% at 18 months, and 82% at 5 years. At least one graft anastomosis was patent early in 97% of patients, at 18 months in 96% of patients, and at 5 years in 97% of patients; all graft anastomoses were patent early in 81% of patients, at 18 months in 70% of patients, and at 5 years in 67% of patients. The incidence of vein graft stenosis of 50% or more was 10% at 18 months and 8% at 5 years after operation. The excellent results reported in CASS were associated with marked improvement in quality of life and excellent survival 5 years after operation in surgically treated patients, as previously reported.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in the native coronary circulation were evaluated 5 to 7 years (72 +/- 10 months) after aortocoronary bypass surgery in 108 patients; 104 had had previous angiographic controls between 6 and 18 months following surgery. Coronary artery narrowings were graded on a scale of 0 to 6, 0 being normal, grade 1 and 2, < or = 50%; grade 3, 51-75%; grade 4, 76-90%; grade 5, 91-99% narrowing and grade 6 total occlusion. Progression of disease was significant when a preexisting stenosis increased at least 1 grade or a new lesion > 50% developed. Nongrafted vessels were compared to arteries with patent or occluded grafts. During the first year following surgery, the rate of progression was much higher in grafted arteries with patent or occluded grafts than in nongrafted arteries 157 and 53% vs 9.5% respectively, P < 0.001). During the subsequent period of approximately 5 years, however, grafted arteries did not change, whereas the rate of progression in nongrafted arteries increased from 9.5 to 46%. At 5 to 7 years after surgery, grade 1 and 2 (< or = 50%) narrowings progressed slightly more frequently in grafted arteries because of surgically related events. However, for narrowings > 50% and for new lesions, there was no difference in the rate of progression between grafted and nongrafted vessels. In conclusion, the rate of progression of atherosclerosis in nongrafted coronary arteries is important. At 5 to 7 years after surgery, there is little or no difference in the severity of the disease in the proximal segments of grafted and nongrafted coronary arteries.

To characterize the clinical and angiographic factors associated with progression of coronary atherosclerosis, 313 consecutive medically treated patients who had had two coronary arteriograms 3 to 119 months (mean 39 +/- 25) apart were studied. One hundred eighty-one patients underwent recatheterization for stable angina, 52 for unstable angina and 80 for various other reasons. In addition to the conventional angiographic features present at the first angiographic study (number of diseased vessels 1.5 +/- 0.8, ejection fraction 59 +/- 11%), an extent score was defined based on the number of coronary segments with 5 to 75% narrowings from a 15 segment coding system. Multivariate logistic regression identified four independent predictors of progression of coronary artery disease: the interval between studies (p less than 0.0001), unstable angina (p less than 0.0001), a high extent score (p = 0.0001) and young age (p = 0.0026). In a subset of 74 patients aged 50 years or younger with, at the time of the first evaluation, an extent score of 4 or more, the probability of progression between 2 and 4 years and after 4 years was, respectively, 80 and 90% compared with 50% for the other patients. Risk stratification for progression of coronary artery disease can thus be obtained.

We studied the incidence of reversibility of coronary obstructions in a consecutive series of 313 patients with nonoperated coronary artery disease catheterized twice 3 to 118 (mean 38) months apart. Recanalization was observed in three patients and regression from an initial less than 100% obstruction in six patients. Progression in a different location occurred in six of the nine patients who demonstrated one recanalized or one regressive lesion. We conclude that true regression is an infrequent event in the natural history of medically treated patients with coronary artery disease; moreover, the pathophysiology and clinical relevance of angiographic regression remain poorly defined.

To assess the interrelation of clinical and procedural factors responsible for restenosis, 119 patients undergoing coronary arteriography were studied a mean of 5.8 +/- 3 months after successful multiple percutaneous transluminal coronary angioplasty. In all clinical, angiographic and procedural variables, the 119 patients undergoing repeat catheterization were similar to the 87 patients that did not. Overall, restenosis occurred in 74 (34%) of 215 lesions. Sixty-three patients had no restenosis, 44 had at least one restenosis and 12 had restenosis at all angioplasty sites. The statistical distribution of restenoses did not follow a binomial model, suggesting that restenosis is more than a lesion-specific phenomenon. Of all the clinical and procedural variables assessed by multivariate logistic regression analysis, only percent stenosis before angioplasty (p less than 0.01), diabetes mellitus (p less than 0.01) and percent stenosis after angioplasty (p less than 0.05) were predictive of restenosis in the entire group. Patients with no restenosis and patients with restenosis at all sites were not different with respect to procedural variables; however, patients with restenosis at all sites more often (p less than 0.05) had diabetes and recent onset angina. In contrast, patients with no restenosis differed from patients with isolated restenosis with respect to procedural variables: severity of stenosis before and after angioplasty, balloon/artery lumen ratio and maximal inflation pressure. Thus, procedural factors may be more related to isolated restenosis, but patient-related factors such as diabetes and recent onset angina may play a more important role in patients with multiple restenoses.

Twenty-two patients underwent coronary artery grafting with a circular vein graft comprising four or five distal coronary anastomoses. Postoperative angiographic evaluation showed patency in 90 (95.7 percent) of the 94 coronary anastomoses fashioned in this manner. All four occlusions occurred in the one patient whose graft comprised five anastomoses and was occluded beyond the first anastomosis on the right coronary artery (RCA). Eleven of the 94 anastomoses were made onto arteries with limited runoff. Blod flow averaged 214 ml. per minute (range 130 to 320) in the main portion of the graft and 59 ml. per minute (range 35 to 100) in the most distal segment. Flow doubled (averaged 403 ml. per minute) in the 11 grafts injected with papaverine. The technique of circular vein grafting is described in detail and potential pitfalls are outlined. The reasons for the high early patency rate are believed to be the following: (1) high flow in the proximal segment of the graft insuring patency of said segment, (2) termination on the left anterior descending (LAD) coronary artery providing good distal flow and patency. (3) diamond-shaped side-to-side anastomoses (SSA's) preventing angulation of the graft at these crucial points, and (4) nearly equidistant anchoring at the site of the multiple anastomoses giving the graft a smooth, even contour.

The authors have studied by pulsed and continuous Doppler ultrasonography 108 pericardial prostheses in a good functional state implanted for less than five years to patients without any clinical and echographic signs of heart failure. The pulsed Doppler ultrasonography allowed to exclude the possible dysfunction of the prostheses; continuous Doppler ultrasonography allowed the measurement of the maximal transprosthetic velocities and to deduce the corresponding maximal and middle gradients by means of simplified Bernouilli's equation. Using three types of bioprostheses (Carpentier-Edwards, Ionescu and Mitroflow) the following problems were investigated: Normal ranges of maximal transprosthetic velocity and gradients. At the aortic level the maximal velocity ranges from 1.60 to 2.83 +/- 14 m/s and the maximal gradients from 10 for size 27-29 to 32 +/- 3.3 mmHg for size 19. At the mitral level the maximal velocity ranges from 0.80 to 2 m/s and the mean gradients from 1 for size 33 to 7 mmHg for size 25. The mean half-life of decrease is 100 +/- 28 ms. Thus all aortic bioprostheses appear to be stenosing, which is not the case for the mitral ones, size 31 and 33. Factors governing the maximal transprosthetic velocity and the gradients: these determining factors are the size, the type and the age of the bioprosthesis (r = 0.59 for the correlation between maximal velocity and size, r = 0.53 between size and mean aortic gradient). The accessory factors are the age and the functional condition of the myocardium. All these factors have to be considered and neutralized for allowing a valid comparison of various types of prostheses. Comparison of the three pericardial prostheses studied: in patients without signs of myocardial dysfunction of prosthetic origin and with comparable basal conditions, comparison of maximal velocity and of the gradient points to a significant superiority of the Mitroflow at the aortic level and of the Ionescu and Mitroflow at the mitral level. It should be noted in the end that the great similarity of the results obtained in the present study by Doppler ultrasonography with the previously reported hemodynamic data confirms the important role of the Doppler method in the evaluation of valvular bioprostheses.

This prospective nonrandomized study was performed to evaluate the safety and efficacy of, as well as patient tolerance for, a new low osmolality contrast medium, ioxaglate (Hexabrix), in 90 adult patients of both sexes who were referred to our cardiac catheterization laboratory for angiocardiography including selective coronary arteriography. Ioxaglate did not cause any major adverse effects; side effects were rare and mild. Hemodynamic changes were minimal, even in patients with severe coronary artery disease, and no arrhythmias were seen. The radiographic quality of angiograms was scored as good to excellent for each examination, and was equal to that of films performed using a conventional contrast medium. Ioxaglate may be the contrast medium of choice for angiocardiography, especially in patients at high risk, i.e., those with severe coronary artery disease or severe left ventricular dysfunction.