The risk of reperfusion strategies in the treatment of patients with acute myocardial infarction.

Coronary reperfusion early after the onset of acute myocardial infarction can restore vessel patency, improve ventricular function and reduce short- and long-term mortality. A number of reperfusion methods have been used to achieve vessel patency in acute myocardial infarction, but each strategy varies considerably in its risk to the patient. Intravenous thrombolysis is associated with an 8% risk of major or minor bleeding and a less than 0.5% risk of intracranial bleeding. This latter risk has been reported to be 1.5% when 150 rather than 100 mg of intravenous recombinant tissue-type plasminogen activator (rt-PA) is used. Invasive procedures such as cardiac catheterization, coronary angioplasty and intraaortic balloon pumping significantly increased the risk of major bleeding at the vascular entry site (from 20 to 40%). Clinical factors such as older age, female gender, lower body weight and hematologic variables including nadir fibrinogen levels and fibrin degradation products also relate to an increased risk. Coronary angioplasty performed alone without thrombolysis is not associated with an excess risk of bleeding and appears to have complications similar to those reported for angioplasty in patients undergoing elective procedures. Systemic anticoagulation has a low (less than 2%) incidence of bleeding, and serious bleeding is rare. These risks must be considered in the decision to institute a treatment strategy in patients with acute myocardial infarction.

Effect of high dose angiotensin-converting enzyme inhibition on restenosis: final results of the MARCATOR Study, a multicenter, double-blind, placebo-controlled trial of cilazapril. The Multicenter American Research Trial With Cilazapril After Angioplasty to Prevent Transluminal Coronary Obstruction and Restenosis (MARCATOR) Study Group.

OBJECTIVES: We conducted a randomized, double-blind, placebo-controlled trial to assess the effect of low and high dose angiotensin-converting enzyme inhibition with cilazapril on angiographic restenosis prevention after percutaneous transluminal coronary angioplasty. BACKGROUND: Angiotensin-converting enzyme inhibitors possess antiproliferative effects in animal models of vascular injury. However, a recent clinical trial using low dose cilazapril, a long-acting angiotensin-converting enzyme inhibitor, failed to prevent restenosis. METHODS: Patients received either cilazapril (1 or 2.5 mg in the evening after successful coronary angioplasty, then 1, 5 or 10 mg twice daily for 6 months) or matched placebo. All patients received aspirin for 6 months. Coronary angiograms before and after angioplasty and at 6-month follow-up were quantitatively analyzed. In addition, the clinical, procedural and angiographic factors associated with restenosis were determined with the use of stepwise logistic analysis. RESULTS: A total of 1,436 patients with a successful coronary angioplasty were recruited. As assessed by an intention-to-treat analysis, the mean difference in minimal coronary lumen diameter (mean +/- 1 SD) between the postangioplasty and follow-up angiogram at 6 months (primary end point) was -0.35 +/- 0.51 for the placebo group and -0.37 +/- 0.52, -0.45 +/- 0.52 and -0.412 +/- 0.53, respectively, for the 1-, 5- and 10-mg twice daily cilazapril groups (p = NS). Clinical events during follow-up did not differ among the four study groups. Multivariate analysis revealed only six variables as independent predictors of the loss of minimal lumen diameter: duration of angina < 6 months, history of myocardial infarction, minimal lumen diameter before and after angioplasty as well as a proximal lesion location and reference diameters. Traditional risk factors for atherosclerosis did not relate to restenosis. CONCLUSIONS: Long-term angiotensin-converting enzyme inhibition with cilazapril in high as well as low dosages does not prevent restenosis and does not favorably influence the overall clinical and angiographic outcome after coronary angioplasty. Few factors are predictive of restenosis.

Restenosis after percutaneous transluminal coronary angioplasty: have we been aiming at the wrong target?

Restenosis after percutaneous coronary balloon angioplasty remains a significant problem. Despite success with a variety of agents in animal models, no agent has proved clearly successful in reducing restenosis in humans. There are many potential reasons for this, but one possibility is that because of our incomplete understanding of the restenotic process, therapy has been directed at the wrong target. Arterial remodeling (changes in total vessel area or changes in area circumscribed by the internal elastic lamina) is well described in de novo atherosclerosis, and there is increasing evidence that this process occurs after angioplasty. Thus, restenosis can be thought of not merely as neointimal formation in response to balloon injury, but as arterial remodeling in response to balloon injury and neointimal formation. Arterial remodeling may consist of actual constriction of the artery, as has been described in some animal models and in preliminary fashion in humans, or of compensatory enlargement as has been described in de novo atherosclerosis and in the hypercholesterolemic rabbit iliac artery model. Arterial constriction can result in restenosis with minimal neointimal formation. Compensatory enlargement accommodates significant amounts of neointimal formation, with preservation of lumen area despite an increase in neointimal area adequate to cause restenosis in a noncompensated artery. This expanded paradigm of arterial remodeling and intimal formation may in part account for the lack of success in clinical trials to date, and therapy directed at arterial remodeling as well as intimal formation may be required to reduce restenosis after coronary interventions.

Experimental angioplasty: circumferential distribution of laser thermal energy with a laser probe.

A new laser probe that converts argon laser energy to heat in a metallic cap on a fiberoptic fiber was compared with a bare argon laser fiberoptic catheter system for the dissolution of atherosclerotic obstructions under fluoroscopic guidance in 24 atherosclerotic rabbits. Twelve animals were randomly assigned to receive treatment with either a bare fiberoptic system or a laser probe coupled to an argon laser. Both fibers had similar outer (0.9 mm) and core (400 mu) diameters. Pulses of 1 watt for 1 second's duration were delivered from the tip of the fiberoptic system, while pulses of 6 watts for 2 seconds' duration were delivered to the laser probe. The results of angiography indicated that widening of luminal stenosis was seen in only 2 of 12 animals treated with the fiberoptic system compared with 8 of 12 animals treated with the laser probe. Perforation of the vessel wall occurred more frequently with the fiberoptic fiber (9 of 12 animals) as compared with the laser probe (1 of 12 animals). Histologic examination of direct laser radiation with the fiberoptic fiber revealed a small localized laser defect along one side of the vessel wall associated with charring, a gradient of thermal injury and considerable thrombus formation. In contrast, those vessels treated with the laser probe showed histologic evidence of thermal injury distributed evenly around the entire luminal circumference. This was associated with minimal charring, a gradient of thermal injury and thinner, flatter thrombus formation. Carbonization of the metallic tip and adherence of atherosclerotic debris with secondary vessel tearing were potential adverse effects of the laser probe.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous coronary laser thermal angioplasty.

Percutaneous coronary laser thermal angioplasty was successfully performed before conventional balloon angioplasty in a 55 year old white man with a 90% left anterior descending artery stenotic lesion and angina at rest (Canadian Heart Association class IV). The lesion was reduced to 50% residual stenosis using a 1.7 mm laser-heated metallic capped fiber and two pulses of 8 W of argon laser energy, each delivered for 5 seconds. With subsequent balloon angioplasty, the lesion was further decreased to 10% residual stenosis. The entire procedure was well tolerated without chest pain or burning, vessel perforation or spasm, thrombus formation or embolization of debris. The patient was free of pain at 1 month follow-up. This case demonstrates the feasibility of safely performing percutaneous coronary laser thermal angioplasty. Additional studies are indicated to determine the clinical role and potential benefits of coronary laser thermal angioplasty in relation to the established procedures of bypass surgery and conventional balloon angioplasty.

Abnormal endothelium-dependent coronary vasomotion in hypertensive patients.

Coronary vasomotion is abnormal in hypertensive patients, as evidenced by reduced coronary vasodilator reserve, but endothelium-dependent coronary vasomotion in hypertensive patients has not been studied. To assess the integrity of endothelium-dependent vasodilation, the response of coronary arteries to acetylcholine (an endothelium-dependent vasodilator) and nitroglycerin (an endothelium-independent vasodilator) was studied in 14 patients undergoing cardiac catheterization. Eight patients with essential hypertension were compared with six normotensive patients. None had obstructive disease detectable by coronary arteriography. Coronary artery diameter was measured with digital-subtracted arteriography and coronary blood flow velocity with a Doppler flow velocity catheter. At baseline, coronary artery diameter was similar in the hypertensive and the normotensive control patients (2.4 +/- 0.3 vs. 2.8 +/- 0.7 mm). During intracoronary acetylcholine infusion (30 micrograms/min), coronary artery diameter decreased to 1.3 +/- 0.7 mm in the hypertensive patients (p less than 0.005), but was unchanged (2.7 +/- 0.8 mm) in the normotensive patients. With intracoronary nitroglycerin (200 micrograms), coronary artery diameter increased significantly in both groups. Calculated coronary blood flow decreased during acetylcholine infusion by 59 +/- 31% in the hypertensive patients but increased by 3 +/- 3% in the normotensive group (p less than 0.005). There was a significant negative correlation between the percent change in estimated coronary blood flow during acetylcholine infusion and mean arterial pressure measured at baseline (r = 0.67, p less than 0.02). Therefore, these hypertensive patients exhibited marked coronary vasoconstriction in response to intracoronary acetylcholine but normal vasodilation in response to nitroglycerin, suggesting abnormal endothelium-dependent vasodilation.(ABSTRACT TRUNCATED AT 250 WORDS)

Microwave balloon angioplasty effectively seals arterial dissections in an atherosclerotic rabbit model.

OBJECTIVES: The purpose of this study was to determine the effectiveness of microwave balloon angioplasty in sealing arterial dissections and to characterize the histologic features associated with this intervention. BACKGROUND: Coronary dissection accompanying balloon dilation is frequently associated with abrupt closure and acute ischemic complications. Effective management of this complication remains an active area of investigation. Because thermal energy is effective in welding separated atherosclerotic plaques, a microwave-based catheter system that provides controlled local heating was utilized in vessels with angioplasty-induced dissections. METHODS: Iliac artery dissections were induced in ahypercholesterolemic rabbit model. Vessels were randomly assigned to treatment with standard balloon angioplasty (control vessels) or microwave balloon angioplasty using an average temperature of 80 degrees C. The response of the artery was assessed angiographically and histologically. RESULTS: Angiographic success, defined as a reduction of dissection length by > 50% or the resolution of lumen haziness, was achieved in 63% of microwave-treated vessels and in 16% of control vessels (p < 0.005). Dissection length (mean +/- SD) was reduced 8.0 +/- 4.8 mm in microwave-treated vessels compared with 0.1 +/- 7.9 mm in vessels receiving standard balloon inflations (p < 0.005). Cellular necrosis was more commonly observed in microwave-treated vessels than in control vessels (73% vs. 17%, p < 0.05), but less intraluminal thrombus was seen in vessels exposed to microwave energy (p < 0.05). CONCLUSIONS: Microwave balloon angioplasty is more effective than routine balloon inflations in sealing arterial dissections in this model and appears to be less thrombogenic in these markedly disrupted vessels.

Low molecular weight heparin (enoxaparin) reduces restenosis after iliac angioplasty in the hypercholesterolemic rabbit.

Smooth muscle cell proliferation is central to the process of restenosis. Attempts to inhibit the events leading to this proliferation have met with little success. In addition to its known antithrombotic effects, heparin also has inhibitory effects on smooth muscle cell proliferation. These effects appear to be unrelated to its anticoagulant properties and are retained in low molecular weight heparin derivatives. Although the use of heparin for as long as 18 to 24 h after coronary angioplasty in humans has not prevented restenosis, longer treatment periods have not been assessed. This study examines the effect of treatment with a low molecular weight heparin (enoxaparin) in a hypercholesterolemic rabbit iliac artery model. Control rabbits had a mean iliac artery diameter of 0.70 +/- 0.06 mm, which increased to 1.73 +/- 0.09 mm after balloon angioplasty. At follow-up angiography 4 weeks later, the mean vessel diameter was 0.56 +/- 0.12 mm. Animals treated with low dose enoxaparin (1 mg/kg per day) for 4 weeks and high dose enoxaparin (10 mg/kg per day) for either 2 or 4 weeks had similar mean luminal diameters before and immediately after angioplasty. At follow-up angiography, the mean luminal diameter was 0.82 +/- 0.17 mm for low dose enoxaparin, 1.04 +/- 0.20 mm for 2 week high dose enoxaparin (p = 0.03 versus control) and 1.19 +/- 0.09 mm for 4 week high dose enoxaparin (p = 0.001 versus control). When defined as loss of 50% of the initial gain achieved with angioplasty, restenosis was found in all control vessels.(ABSTRACT TRUNCATED AT 250 WORDS)

Contribution of vasopressin to vasoconstriction in patients with congestive heart failure: comparison with the renin-angiotensin system and the sympathetic nervous system.

Ten patients with advanced congestive heart failure were treated with an arginine vasopressin V1 antagonist during hemodynamic monitoring to determine the contribution of vasopressin to vasoconstriction in this disorder. The vasopressin antagonist caused a decrease in systemic vascular resistance in the three patients whose plasma vasopressin was greater than 4.0 pg/ml (average for the group was 2.4 +/- 0.6). Plasma vasopressin concentration correlated with the percent decrease of systemic vascular resistance (r = 0.70, p less than 0.025), serum sodium (r = 0.72, p less than 0.02) and serum creatinine (r = 0.85, p less than 0.005). To compare the relative roles of vasopressin, the renin-angiotensin system and the sympathetic nervous system, these patients also received captopril and phentolamine. Captopril decreased systemic vascular resistance by 20% (p less than 0.05), mostly in patients with high plasma renin activity. Levels of plasma renin activity ranged between 1 and 46 ng/ml per h (average 14.7 +/- 5.7) and correlated with serum sodium (r = 0.77, p less than 0.025), serum creatinine (r = 0.73, p less than 0.025) and right atrial pressure (r = 0.67, p less than 0.05). Phentolamine decreased systemic vascular resistance in all patients (average 34%, p less than 0.01), but the decrease did not correlate with the pretreatment norepinephrine concentration. Norepinephrine levels were elevated in all patients (694 +/- 110 pg/ml) and correlated with baseline stroke volume index (r = 0.75, p less than 0.025) and plasma renin activity (r = 0.67, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Task Force 4: The relationship between cardiovascular specialists and generalists.

1. An imbalance between generalists and cardiovascular subspecialists exists that will require decades to correct. We question the validity of the 50:50 generalist/specialist ratio in view of current practice patterns for cardiology. 2. There has been a large increase in the number of cardiovascular specialists in the past 30 years that will continue if training programs remain at their current size. 3. Cardiovascular specialists provide a substantial amount of inpatient care, care to older patients and care to those with cardiovascular symptoms, although generalists actually provide the majority of office-based cardiovascular care. 4. A significant portion of cardiovascular specialist care can be classified as comprehensive care to patients with and without cardiovascular disease. 5. Most generalists and cardiovascular specialists do not perceive a need for additional cardiovascular specialists. 6. Many providers perform cardiovascular procedures at levels below the recommended threshold for maintenance of clinical competence. 7. Managed care may result in a reduced demand for cardiovascular specialists. 8. If cardiovascular specialists provide general care, it may not be assumed that previous training prepares them for generalist practice. 9. The appropriate boundaries of cardiovascular care between generalists and cardiovascular specialists are indistinct. They are defined somewhat by the training programs from which the generalists graduate. 10. Many generalists have deficiencies in basic skills in clinical cardiology. 11. Desirable interactions between generalists and cardiovascular specialists involve referral of patients in both directions to the provider who can give care to a given patient, at a given time, with the best outcome and lowest cost.(ABSTRACT TRUNCATED AT 250 WORDS)

Outcome of percutaneous transluminal coronary angioplasty in subsets of unstable angina pectoris. A report of the 1985-1986 National Heart, Lung, and Blood Institute Percutaneous Transluminal Coronary Angioplasty Registry.

OBJECTIVES: The purpose of this study was to characterize the outcome of coronary angioplasty according to the various presentations of unstable angina pectoris. BACKGROUND: Although unstable angina is a mosaic of clinical manifestations, a comprehensive analysis of short- and long-term outcome of coronary angioplasty in subsets of unstable angina is not available. METHODS: Data from 15 clinical centers for the 857 patients with unstable angina in the 1985-1986 National Heart, Lung, and Blood Institute percutaneous transluminal coronary angioplasty registry were analyzed. Five-year follow-up was available in > 96.5%. Patients were first classified as those with (679 [79%]) or without (178 [21%]) rest angina. Patients were also allocated to five mutually exclusive categories of decreasing unstable angina severity: postinfarction angina, acute coronary insufficiency, plain rest angina, accelerating angina and new onset angina. RESULTS: The group with rest angina had more older patients (p < 0.01) and women (p < 0.001), and a greater proportion had a previous myocardial infarction (p < 0.001) and a left ventricular ejection fraction < or = 50% (p < 0.01) than did the group without rest angina. Angiographic characteristics were nearly the same, whereas procedural characteristics and outcome were the same for both categories. At 5-year follow-up, there was a higher crude mortality rate in patients with than without rest angina (p < 0.05). Resolution into five subsets yielded additional information. Women were more represented only in the acute coronary insufficiency and plain rest angina subsets (p < 0.001). Patients with angina after myocardial infarction had the second shortest history of angina (p < 0.001), the highest percent of smokers (p < 0.01) and, with those with acute coronary insufficiency, the highest incidence of congestive heart failure (p < 0.05) and an ejection fraction < or = 50% (p < 0.001). They had the highest percent of totally occluded arteries, coronary thrombus and collateral blood flow received but also the lowest rate of severe stenoses (p < 0.001 for all). Patients with new onset angina had the highest prevalence of single-vessel disease (p < 0.05), critical and complex stenoses (p < 0.001) and no coronary angioplasty-related deaths. The crude 5-year mortality rate was higher for both postinfarction and acute insufficiency groups (p < 0.05) than for the other subsets. After adjustments for risk factors, no significant differences in adverse event rates remained among the different unstable angina subgroups. CONCLUSIONS: Analysis of the diverse clinical presentations of unstable angina supports underlying pathogenetic differences. Coronary angioplasty is safe and effective in all subsets of unstable angina. Long-term survival is good in general but is related to the baseline status of left ventricular function.

Antecedent angina: a predictor of residual stenosis after thrombolytic therapy.

Patients with a significant residual stenosis after thrombolytic therapy are believed by many to be at increased risk for repeat ischemic events and may be candidates for prompt angiography and revascularization. To test the hypothesis that patients with antecedent angina (Canadian classes I to IV, greater than or equal to 24 h before myocardial infarction) are more likely to have a significant residual stenosis (greater than or equal to 60% diameter reduction) than are those without antecedent angina, the coronary angiograms of 82 consecutive patients undergoing routine angiography after thrombolytic therapy were reviewed. Compared with the patients without antecedent angina, the group with antecedent angina had an increased mean stenosis (74% versus 58%) and more multivessel disease (44% versus 5%). The sensitivity and specificity of a clinical history of antecedent angina predicting the presence of a significant residual stenosis were 75% and 96%, respectively; the positive predictive accuracy was 98%. These data suggest that antecedent angina can be used to identify a high risk subgroup whose condition may warrant routine coronary angiography.

Incidence and prognostic implications of heart block complicating inferior myocardial infarction treated with thrombolytic therapy: results from TIMI II.

OBJECTIVES: The aim of this study was to determine the incidence and significance of second- or third-degree heart block among patients with inferior myocardial infarction treated with thrombolytic therapy. BACKGROUND: Data from the prethrombolytic era suggest that heart block occurs in approximately 20% of patients with acute inferior myocardial infarction and is associated with a marked increase in mortality. Little is known about the incidence and prognostic implications of heart block among patients receiving thrombolytic therapy. METHODS: We studied 1,786 patients with acute inferior myocardial infarction enrolled in the Thrombolysis in Myocardial Infarction (TIMI) II Trial who received recombinant tissue-type plasminogen activator (rt-PA) within 4 h of the onset of symptoms. RESULTS: Heart block occurred in 214 patients (12%); 113 (6.3%) had heart block on presentation and 101 (5.7%) developed heart block in the 24 h after treatment with rt-PA. Patients with heart block at entry were slightly older and a greater proportion had cardiogenic shock. The 21-day mortality rate among patients with heart block at entry was 7.1% (8 of 113), compared with 2.7% (45 of 1,673) among patients without heart block at study entry (relative risk 2.6, p = 0.007). However, heart block was not independently associated with 21-day mortality after adjustment for other variables, including shock. Mortality and other adverse cardiac events in the following year were similar among patients with and without heart block. Among patients without heart block at study entry, coronary angiography among patients randomly assigned to coronary catheterization 18 to 48 h after admission revealed that the infarct-related artery was occluded in 28.2% (11 of 39) of patients who developed heart block versus 15.5% (112 of 723) of patients without heart block (p = 0.04). The 21-day mortality rate was increased among patients in whom heart block developed after thrombolytic therapy (9.9% [10 of 101] versus 2.2% [35 of 1,572] of patients without heart block, relative risk 4.5, p less than 0.001). Analysis of the increased mortality among patients who developed heart block suggests that mortality was due to severe cardiac dysfunction; no patient was considered to have died as a result of the heart block or its treatment. CONCLUSIONS: Heart block is common among patients with inferior infarction given thrombolytic therapy and is associated with increased mortality. These clinical and anatomic data provide insight into the mechanism of heart block and increased mortality among such patients.

Acute and long-term effects of enalapril on the cardiovascular response to exercise and exercise tolerance in patients with congestive heart failure.

Enalapril is a recently developed angiotensin-converting enzyme inhibitor that improves cardiac function at rest in patients with congestive heart failure. This study investigated the acute effects of enalapril on the cardiovascular response to exercise, and then evaluated the long-term effects of enalapril on exercise capacity and functional status during a 12 week placebo-controlled trial in patients with heart failure. Ten patients underwent hemodynamic monitoring while at rest and during incremental bicycle exercise before and after 5 to 10 mg of enalapril orally. At rest, enalapril decreased mean blood pressure 13% (p less than 0.01) and systemic vascular resistance 20% (p less than 0.05) and increased stroke volume index 21% (p less than 0.01). During maximal exercise, enalapril decreased systemic vascular resistance and increased both cardiac and stroke volume indexes. Enalapril acutely increased exercise duration (p less than 0.05) and maximal oxygen consumption (p less than 0.001). These 10 patients and an additional 13 patients were then randomized to either placebo or enalapril treatment and followed up for 12 weeks. Of the 11 patients assigned to active treatment, 73% considered themselves improved compared with 25% of the patients assigned to placebo treatment (p less than 0.02). During long-term treatment, exercise capacity increased in patients receiving enalapril (p less than 0.001) but was unchanged in patients receiving placebo (intergroup difference, p less than 0.05). During long-term treatment, no adverse effects of enalapril occurred. Thus, enalapril improves cardiac function at rest and during exercise. Compared with placebo, maintenance therapy with enalapril results in symptomatic improvement and increased exercise capacity.

Invasive versus conservative strategy after thrombolytic therapy for acute myocardial infarction in patients with antecedent angina. A report from Thrombolysis in Myocardial Infarction Phase II (TIMI II).

OBJECTIVES: This study was designed to assess the possibility that a subgroup of patients at high risk for recurrent ischemia and reinfarction after thrombolytic therapy might benefit from early intervention. BACKGROUND: The Thrombolysis in Myocardial Infarction Phase II (TIMI II) study recently concluded that an obligatory invasive strategy after thrombolytic therapy offered no advantage over a more conservative strategy. METHODS: Data from the 3,534 patients enrolled in the TIMI II trial were analyzed to determine whether a history of antecedent angina before myocardial infarction identifies patients at high risk for subsequent ischemia and whether these patients might benefit from an invasive strategy. RESULTS: Within the TIMI II population, antecedent angina identified patients at increased risk for recurrent chest pain in the hospital (32.3% vs. 22.1%, p < 0.001) and recurrent infarction during the 1st year of follow-up (11.2% vs. 7.9%, p = 0.001) compared with that of patients without antecedent angina. Among patients assigned to the invasive strategy, coronary arteriography revealed that those with antecedent angina had a more severe residual stenosis of the infarct-related artery after thrombolytic therapy (77.1 +/- 0.7% vs. 73.0 +/- 0.9%, p < 0.001) and more multivessel disease (37.9% vs. 26.4%, p < 0.001). The clinical outcome of the patients with antecedent angina assigned randomly to either the invasive or the conservative strategy were compared. The invasive strategy patients had a slightly lesser incidence of recurrent chest pain in the hospital (29.9% vs. 34.8%, p = 0.13) and more negative (normal) findings on exercise tolerance tests (24.7 vs. 18.9%, p = 0.003), but there was no difference between the treatment strategies in the end point variable of recurrent myocardial infarction or death. CONCLUSIONS: These data demonstrate that antecedent angina identifies patients at increased risk for recurrent ischemic events after thrombolytic therapy. However, similar to the results for the overall population, the invasive strategy does not alter the risk of reinfarction or death compared with the conservative approach.

Five-year angiographic follow-up of factors associated with progression of coronary artery disease in the Coronary Artery Surgery Study (CASS). CASS Participating Investigators and Staff.

OBJECTIVES: The Coronary Artery Surgery Study (CASS) required participants to undergo follow-up angiography at 5 years to identify clinical and angiographic features associated with progression of coronary artery disease. BACKGROUND: The CASS randomized 780 patients at 11 participating clinical centers between an initial strategy of medical therapy versus bypass surgery. Five clinical sites accomplished follow-up angiography in > 50% of their randomized subjects within a 42- to 66-month period after the entry arteriogram (n = 314). METHODS: Qualified clinical site angiographers, using side by side film review, evaluated an average of 13 segments/patient on both arteriograms for initial stenosis severity, morphologic features, lesion location and occurrence of disease progression or occlusion. Progression was defined as further definite narrowing by > or = 15% and occlusion as lesion progression to > or = 98%. Lesions were subcategorized as to whether they were univariate and had or had not been treated with bypass surgery. Multivariate logistic regression analyses were performed. RESULTS: For nonbypassed segments, right coronary artery and left anterior descending artery proximal and midlocations were associated with disease progression. For stenosis-containing segments, the initial severity, a non-left anterior descending artery location and increased treadmill duration predicted progression. Segment occlusion was associated with initial lesion severity, right coronary artery location and subsequent interval myocardial infarction. There were few predictors of progression or occlusion in bypassed arteries, other than initial lesion severity. CONCLUSIONS: Univariate and multivariate associations with lesion progression and occlusion included diabetes, lesion location, elevated cholesterol level, interval infarction and lesion morphology. These angiographic results, collected in a prospective trial, are consistent with known risk factors.

Restenosis, reocclusion and adverse cardiovascular events after successful balloon angioplasty of occluded versus nonoccluded coronary arteries. Results from the Multicenter American Research Trial With Cilazapril After Angioplasty to Prevent Transluminal Coronary Obstruction and Restenosis (MARCATOR).

OBJECTIVES: This study sought to compare the frequency of restenosis, reocclusion and adverse cardiovascular events after angioplasty of occluded versus nonoccluded coronary arteries. BACKGROUND: Angioplasty of chronically occluded coronary arteries is believed to be associated with a higher frequency of restenosis and reocclusion than angioplasty of subtotal stenoses. Whether this leads to adverse cardiovascular events is unknown. METHODS: The Multicenter American Research Trial With Cilazapril After Angioplasty to Prevent Restenosis (MARCATOR) was a placebo-controlled trial with angiographic follow-up to determine the effect of the angiotensin-converting enzyme inhibitor cilazapril on the frequency of restenosis. In this trial, restenosis was defined as 1) angiographic reduction of minimal lumen diameter > or = 0.72 mm between angioplasty and the follow-up visit; and 2) > 50% diameter stenosis on the follow-up angiogram. We identified 139 patients with successful angioplasty of a coronary occlusion (Group 1) and compared the frequency of restenosis, reocclusion and adverse cardiovascular events with that in 1,295 patients with successful angioplasty of a subtotal stenosis (Group 2). RESULTS: Restenosis occurred in 36 patients with occluded arteries (29%) versus 264 with nonoccluded arteries (23%, p = 0.177) by definition 1 and in 62 patients with occluded arteries (49%) versus 478 with nonoccluded arteries (42%, p = 0.119) by definition 2. Occlusion was present in 24 Group 1 patients (19%) compared with 74 Group 2 patients (7%) (p < 0.001). During the 6 month follow-up period, two Group 1 patients (1.4%) and six Group 2 patients (0.5%) died; no Group 1 patients and 10 Group 2 patients (0.8%) developed severe congestive heart failure; nonfatal myocardial infarction occurred in 4 Group 1 patients (2.9%) and 31 Group 2 patients (2.4%); repeat coronary angioplasty or bypass surgery was performed in 29 Group 1 patients (21%) and 232 Group 2 patients (18%); and angina was present in 18 Group 1 and 163 Group 2 patients (13% for both). Eighty-six Group 1 patients (62%) and 853 Group 2 patients (66%) remained free of these adverse events during the 6-month follow-up period (p = 0.513). CONCLUSIONS: The frequency of restenosis was slightly but not significantly greater after successful angioplasty of an occluded artery than after angioplasty of a subtotal stenosis. Although reocclusion was more frequent, occurring in 19% of patients, the net clinical benefit of angioplasty in such patients was similar to that in patients with subtotal stenoses over the 6-month follow-up period.

Comparison of complications during percutaneous transluminal coronary angioplasty from 1977 to 1981 and from 1985 to 1986: the National Heart, Lung, and Blood Institute Percutaneous Transluminal Coronary Angioplasty Registry.

Because the effects of changing technology in percutaneous transluminal coronary angioplasty, increased operator experience and use of the procedure in patients with extensive disease are unknown in regard to complication patterns, the initial 1977-1981 cohort and the recent 1985-1986 cohort of the National Heart, Lung, and Blood Institute Percutaneous Transluminal Coronary Angioplasty Registry were analyzed with respect to complications. Compared with the initial cohort of 1,155 patients, the 1,801 new cohort patients were older and had an increased prevalence of multivessel coronary artery disease, depressed left ventricular function and prior infarction. Overall complication rates in the recent cohort were either unchanged or decreased from the rates in the initial cohort despite a higher risk patient population. The most significant decreases were in the incidence of coronary spasm (p less than 0.001) and the need for emergency coronary bypass surgery (p less than 0.01). Overall in-hospital mortality was low but was dependent on the extent of vessel disease--0.2% for single vessel disease, 0.9% for double vessel disease and 2.2% for triple vessel disease (p less than 0.001 for linear trend). Acute coronary complications of branch occlusion, dissection or abrupt closure were associated with increased rates of death, nonfatal infarction or need for emergency surgery. Factors showing a multivariate association with increased mortality included a history of congestive heart failure (p less than 0.001), age greater than or equal to 65 years (p less than 0.01), triple vessel or left main coronary artery disease (p less than 0.05), female gender (p less than 0.05) and new onset angina.(ABSTRACT TRUNCATED AT 250 WORDS)

Survival following coronary angioplasty versus coronary artery bypass surgery in anatomic subsets in which coronary artery bypass surgery improves survival compared with medical therapy. Results from the Bypass Angioplasty Revascularization Investigation (BARI).

OBJECTIVES: We sought to compare survival after coronary artery bypass graft (CABG) and percutaneous transluminal coronary angioplasty (PTCA) in high-risk anatomic subsets. BACKGROUND: Compared with medical therapy, CABG decreases mortality in patients with three-vessel disease and two-vessel disease involving the proximal left anterior descending artery (LAD), particularly if left ventricular (LV) dysfunction is present. How survival after PTCA and CABG compares in these high-risk anatomic subsets is unknown. METHODS: In the Bypass Angioplasty Revascularization Investigation (BARI), 1,829 patients with multivessel disease were randomized to an initial strategy of PTCA or CABG between 1988 and 1991. Stents and IIb/IIIa inhibitors were not utilized. Since patients in BARI with diabetes mellitus had greater survival with CABG, separate analyses of patients without diabetes were performed. RESULTS: Seven-year survival among patients with three-vessel disease undergoing PTCA and CABG (n = 754) was 79% versus 84% (p = 0.06), respectively, and 85% versus 87% (p = 0.36) when only non-diabetics (n = 592) were analyzed. In patients with three-vessel disease and reduced LV function (ejection fraction <50%), seven-year survival was 70% versus 74% (p = 0.6) in all PTCA and CABG patients (n = 176), and 82% versus 73% (p = 0.29) among non-diabetic patients (n = 124). Seven-year survival was 87% versus 84% (p = 0.9) in all PTCA and CABG patients (including diabetics) with two-vessel disease involving the proximal LAD (n = 352), and 78% versus 71% (p = 0.7) in patients with two-vessel disease involving the proximal LAD with reduced LV function (n = 72). CONCLUSION: In high-risk anatomic subsets in which survival is prolonged by CABG versus medical therapy, revascularization by PTCA and CABG yielded equivalent survival over seven years.

Relation between estrogen replacement therapy and restenosis after percutaneous coronary interventions.

OBJECTIVES: We attempted to determine the relation between estrogen replacement therapy and the rate of restenosis after coronary angioplasty and atherectomy. BACKGROUND: Although estrogen replacement therapy in women has been associated with a reduction in cardiovascular events and improvement in endothelial function, no study has examined whether estrogen reduces restenosis rates after percutaneous coronary interventions. METHODS: A total of 204 women enrolled in the Coronary Angioplasty Versus Excisional Atherectomy Trial with angiographic follow-up were contacted, and their menopausal and estrogen replacement status was determined. Late loss in minimal lumen diameter, late loss index, minimal lumen diameter, rate of restenosis > 50% and actual percent of stenosis were compared in estrogen users and nonusers by quantitative coronary angiography at 6-month follow-up. RESULTS: Late loss in minimal lumen diameter was significantly less in women using estrogen than in nonusers (-0.13 vs. -0.46 mm, p = 0.01). A regression analysis of the determinants of late loss in minimal lumen diameter revealed that estrogen use was the single most important predictor of subsequent late loss (F = 13.38, p = 0.0006). Formal testing revealed a highly significant interaction between the use of estrogen and intervention (angioplasty or atherectomy). Women undergoing atherectomy who received estrogen had a significantly lower late loss index (0.06 vs. -0.63, p = 0.002), less late loss (0.06 vs. -0.61 mm, p = 0.0006), larger minimal lumen diameter (p = 0.044) and lower restenosis rates (p = 0.038 for > 50% stenosis) than those not using estrogen. In contrast, estrogen had minimal effects on restenosis end points after angioplasty. CONCLUSIONS: This study demonstrates the potential for estrogen replacement therapy to reduce angiographic measures of restenosis in postmenopausal women after coronary intervention, particularly in those undergoing atherectomy.