Abrupt closure: the CAVEAT I experience. Coronary Angioplasty Versus Excisional Atherectomy Trial.

OBJECTIVES: This study sought to assess the incidence and consequences of abrupt closure in a series of patients undergoing directional coronary atherectomy versus percutaneous coronary angioplasty. BACKGROUND: Abrupt closure with coronary angioplasty has been associated with adverse outcome. The results from the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) I, a randomized trial of coronary angioplasty versus directional coronary atherectomy, were analyzed. METHOD: This multicenter trial enrolled 1,012 patients from 1991 to 1992. All records from patients with abrupt closure, which was coded as a discrete complication, were reviewed. RESULTS: Abrupt closure occurred in 60 patients (5.9%) and was associated with a significantly longer hospital stay (median 8 vs. 3 days). Severe proximal target vessel tortuosity was more common in patients with abrupt closure (20.3% vs. 11.6%, p = 0.046), as was preexistent coronary artery thrombus (30.5% vs. 18.3%, p = 0.02). Abrupt closure was associated with a marked increase in subsequent complications (myocardial infarction 46.7% vs. 2.1%, emergency bypass surgery 38.3% vs. 0.32%, death 33% vs. 0%) and occurred more frequently in the directional coronary atherectomy group (8.0% vs. 3.8%, p = 0.005). In the coronary angioplasty group, the occlusion usually occurred at the target lesion (91%), presumably related to the effects of barotrauma. In the directional coronary atherectomy group, the site of the occlusion was the target lesion in only 58% (p = 0.045). The remaining occlusions related to problems with the technique (guide catheter or nose cone trauma), reflecting the fact that directional coronary atherectomy is a more complex procedure. CONCLUSIONS: Abrupt closure remains the principal determinant of adverse outcome after percutaneous procedures for the treatment of coronary artery disease. Although abrupt closure is more common with directional atherectomy than angioplasty, the sequelae are similar.

Directional atherectomy versus balloon angioplasty for coronary ostial and nonostial left anterior descending coronary artery lesions: results from a randomized multicenter trial. The CAVEAT-I investigators. Coronary Angioplasty Versus Excisional Atherectomy Trial.

OBJECTIVES: We hypothesized that atherectomy would be superior to balloon angioplasty for ostial and nonostial left anterior descending coronary artery lesions. BACKGROUND: Balloon angioplasty of ostial coronary artery lesions has been associated with a lower procedural success rate and a higher rate of complications and of restenosis than angioplasty of nonostial stenoses. Directional coronary atherectomy has been proposed as an alternative therapy for ostial lesions. METHODS: In the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I), 1,012 patients were randomized to undergo either procedure; 563 patients had proximal left anterior descending coronary artery lesions, of which 74 were ostial. We compared balloon angioplasty with directional atherectomy for early and 6-month results for ostial as well as nonostial proximal left anterior descending coronary artery lesions. RESULTS: Directional atherectomy led to an initially higher gain in minimal lumen diameter for ostial lesions (1.13 vs. 0.56 mm, respectively, p < 0.001) but a higher rate of adjudicated non-Q wave myocardial infarction (24% vs. 13%, respectively, p < 0.001) than balloon angioplasty and no improvement in restenosis rates (48% vs. 46%, respectively). In the nonostial proximal left anterior descending coronary artery lesions, angiographic restenosis was reduced (51% vs. 66%, p = 0.012), but this was also associated with a higher rate of periprocedural myocardial infarction (8% vs. 2%, p = 0.008 by site and 24% vs. 8%, p < 0.001 by adjudication) and no difference in the need for subsequent coronary artery bypass surgery (7.3% vs. 8.4%, respectively) or repeat percutaneous coronary intervention (24% vs. 26%, respectively). CONCLUSIONS: For ostial left anterior descending coronary artery stenoses, both procedures yielded similar rates of initial success and restenosis, but atherectomy was associated with more non-Q wave myocardial infarction. In this trial the predominant angiographic benefit (increased early gain and less angiographic restenosis) of atherectomy for the left anterior descending coronary artery was in proximal nonostial lesions. However, the tradeoffs for this angiographic advantage were more in-hospital myocardial infarctions and no decrease in clinical restenosis.

The relationship of anticoagulation level and complications after successful percutaneous transluminal coronary angioplasty.

The degree of anticoagulation and its effect on the frequency of abrupt coronary artery closure, coronary ischemia, bleeding complications requiring transfusion, and death were examined in 336 patients after elective percutaneous transluminal coronary angioplasty (PTCA). All patients received a bolus of 10,000 U of heparin at the beginning of the procedure followed by a continuous infusion of 2000 U/hr. At the conclusion of the procedure the infusion was reduced to 1000 U/hr and continued for 18 to 24 hours at which time the heparin infusion was suspended to allow removal of arterial and venous access sheaths. Partial thromboplastin time (PTT) was examined while patients continued to receive the heparin infusion. There was a variable degree of PTT prolongation in response to a standard dose of heparin with a range of 34 seconds to "greater than 150 seconds." Patients were divided into two groups according to the degree of heparin-induced PTT prolongation: group A included 271 patients with PTT greater than or equal to 3 times the control value, and group B comprised 65 patients with PTT less than 3 times the control value. Ischemic complications were analyzed on day 1 after PTCA and at hospital discharge. Bleeding complications and mortality were examined only at hospital discharge. There was a significant reduction in the incidence of abrupt coronary artery closure in group A on day 1 (1.5% vs 10.7%, p less than 0.001) and at hospital discharge (2.6% vs 10.7%, p less than 0.003).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of angiotensin converting enzyme inhibition on the incidence of restenosis after percutaneous transluminal coronary angioplasty.

To determine whether angiotensin converting enzyme (ACE) inhibition may reduce the incidence of restenosis after percutaneous transluminal coronary angioplasty (PTCA), we retrospectively identified 322 consecutive patients who underwent a successful procedure from June 1988 to December 1989. No patients developed chest pain, ST segment elevation, positive cardiac enzymes, or other evidence of abrupt vessel closure following the PTCA. All patients received intravenous heparin after PTCA and aspirin was begun on the day prior to PTCA. Patients were separated into two groups: those at hospital discharge incidentally treated for hypertension or heart failure with ACE inhibitors (n = 36), and those treated with a drug regimen which did not include ACE inhibitors (n = 286). The two groups were similar with respect to age (61 +/- 13.5 vs. 60 +/- 12.5, p = NS) and other demographic characteristics. Restenosis, defined as the presentation to a physician with symptoms of angina within 6 months of the PTCA and the finding on repeat catheterization of a significant restenosis at the site of the PTCA, occurred in 30% of the patients who were discharged on a drug regimen which did not include ACE inhibitors vs. 3% (p less than .05) in those treated with an ACE inhibitor. Thus, it appears that the use of ACE inhibitors may significantly reduce the incidence of restenosis after successful PTCA.

Pathophysiology and medical management of angina pectoris.

Myocardial oxygen demand is a function of the product of heart rate and blood pressure. Agents such as nitroglycerin not only produce coronary vasodilatation, which increases oxygen supply, but also reduce myocardial oxygen demand secondary to a reduction in both preload and afterload. Beta-adrenergic blockers are useful in angina because they reduce myocardial work and, hence, oxygen demand. A heart rate in the 50s does not preclude an increase in the dosage of propranolol when necessary.

Spectrum of coronary arterial spasm. Clinical, angiographic and myocardial metabolic experience in 29 cases.

A relationship of coronary arterial spasm to variant angina pectoris, subendocardial ischemia, major ventricular arrhythmias and myocardial infarction has been demonstrated. In 29 patients, spasm was angiographically observed in normal-appearing coronary arteries (7 patients) as well as superimposed on various degrees of coronary atherosclerotic obstruction (22 patients). All patients experienced an atypical anginal syndrome;16 patients also experienced typical exertional angina. Coronary spasm appeared to be a major contributory factor in eight occurrences of myocardial infarction and in 11 incidents of ventricular tachycardia, ventricular fibrillation and heart block. Coronary spasm in the 29 cases was distributed in the following fashion: left main trunk, 6 cases; right main trunk, 12 cases; proximal left anterior descending artery, 13 cases; proximal circumflex artery, 1 case; distal left anterior descending artery, 1 case; and distal circumflex artery, 2 cases. In 5 cases coronary spasm was noted at multiple sites.

Correlation of abnormal Q waves, coronary pathology, and ventricular contractility.

Four hundred and ninety-two patients with coronary artery disease underwent analysis of their electrocardiograms, coronary arteriograms, and ventriculograms. Significant Q-waves were correlated with critical coronary occlusions (greater than or equal 75 per cent obstruction) and ventricular contractility. It was found that Q-waves correlate equally well with ventriculographic abnormalities and critical coronary occlusions. The Q-wave correlation varied from 77 to 87 per cent, depending on the area of myocardium under consideration, except for true posterior myocardial infarction, which correlated 55 per cent with ventriculographic abnormalities and 55 per cent with critical coronary occlusions. Significant Q-waves in Leads II, III, and aVF are better indicators of ventriculographic abnormality than in Leads III and aVF alone, whereas Q-waves in the latter two leads are more definitive than in Lead III alone. Patients who have critical coronary occlusions and normal electrocardiograms have normal ventriculograms in 71 to 78 per cent of the cases, again depending on the area of the myocardium under consideration. Thus, the normal electrocardiogram correlates better with the ventriculogram than with coronary pathology. The abnormal electrocardiogram correlates equally well with both.

Comparative hemodynamic effects of placebo and oral isosorbide dinitrate in patients with significant coronary artery disease.

Comparative hemodynamic effects of placebo and 10 mg of oral isosorbide dinitrate were studied in patients with significant coronary artery disease (larger than or equal to 75 per cent lumen narrowing) proved angiographically. Isosorbide dinitrate or placebo was given to eight and 10 patients, respectively, in a double-blind fashion. Cardiac performance at rest and during supine leg exercise was evaluated before and 60 minutes after drug administration. In the resting state, isosorbide dinitrate compared to placebo significantly reduced the left ventricualr (systolic and diastolic), mean pulmonary artery and mean aortic pressures, cardiac index, stroke index, left ventricular work index, stroke work index, and mean systolic ejection rate. Isosorbide dinitrate also significantly reduced left ventricular (systolic and diastolic and mean pulmonary artery pressures during exercise. This study indicates that 10 mg of isosorbide dinitrate has a significant influence on ischemic left ventricular dysfunction 60 minutes after its oral administration.

Interpreting cardiac catheterization data. Part 2.

Data obtained by cardiac catheterization, properly interpreted, are an extremely useful supplement to information obtained from the medical history, physical examination, electrocardiography, chest x-ray examination, and other noninvasive diagnostic techniques. Elevations of pressure in the cardiac chambers and great vessels and corresponding patterns of pressure curves are discerned in the presence of various pathologic conditions affecting the heart. Blood samples are taken during cardiac catheterization for measurement of cardiac output and to detect intracardiac shunting. Attempts have been made to estimate the magnitude of shunts from abnormal dye-dilution curves. Exercise stress is often used during cardiac catheterization to evaluate overall cardiovascular performance. Angiocardiography gives a permanent graphic record of structural abnormalities. Myocardial lactate metabolism provides a means of evaluating the adequacy of coronary blood flow.

Ventricular patterns in acute myocardial infarction.

Ventricular dysfunction attendant with acute myocardial infarction results in considerable morbidity and mortality. Acute changes in morphology and physiology underly ventricular dysfunction. The ventricular morphologic changes of AMI differ from those of chronic coronary heart disease only in their temporal characteristics. The pathophysiologic changes are the result of the interaction of several variables. These include infarct size, compliance of both the infarcted and normal myocardium, contractility, heart size, filling pressure, and afterload. Through an understanding of the role played by each of these variables, a better comprehension of events following AMI may be obtained and a more rational basis utilized for selection of therapy.