Prognostic value of angiographic indices of coronary artery disease from the Coronary Artery Surgery Study (CASS).

The Coronary Artery Surgery Study, CASS, enrolled 24,959 patients between August 1975 and June 1979 who were studied angiographically for suspected coronary artery disease. This paper compares the prognostic value for survival without early elective surgery of eight different indices of the extent of coronary artery disease: the number of diseased vessels, two indices using the number of proximal arterial segments diseased, two empirically generated indices from the CASS data, and the published indices of Friesinger, Gensini, and the National Heart and Chest Hospital, London. All had considerable prognostic information. Typically 80% of the prognostic information in one index was also contained in another. Our analysis shows that good prediction from angiographic data results from a combination of left ventricular function and arteriographic extent of disease. Prognosis may reasonably be obtained from three simple indices: the number of vessels diseased, the number of proximal arterial segments diseased, and a left ventricular wall motion score. These three indices account for an estimated 84% of the prognostic information available. 6-yr survival varies between 93 and 16% depending upon the values of these three indices.

Inhibition of the sodium-hydrogen exchanger with cariporide to prevent myocardial infarction in high-risk ischemic situations. Main results of the GUARDIAN trial. Guard during ischemia against necrosis (GUARDIAN) Investigators.

BACKGROUND: The transmembrane sodium/hydrogen exchanger maintains myocardial cell pH integrity during myocardial ischemia but paradoxically may precipitate cell necrosis. The development of cariporide, a potent and specific inhibitor of the exchanger, prompted this investigation of the potential of the drug to prevent myocardial cell necrosis. METHODS AND RESULTS: A total of 11 590 patients with unstable angina or non-ST-elevation myocardial infarction (MI) or undergoing high-risk percutaneous or surgical revascularization were randomized to receive placebo or 1 of 3 doses of cariporide for the period of risk. The trial failed to document benefit of cariporide over placebo on the primary end point of death or MI assessed after 36 days. Doses of 20 and 80 mg every 8 hours had no effect, whereas a dose of 120 mg was associated with a 10% risk reduction (98% CI 5.5% to 23.4%, P=0.12). With this dose, benefit was limited to patients undergoing bypass surgery (risk reduction 25%, 95% CI 3.1% to 41.5%, P=0.03) and was maintained after 6 months. No effect was seen on mortality. The rate of Q-wave MI was reduced by 32% across all entry diagnostic groups (2.6% versus 1.8%, P=0.03), but the rate of non-Q-wave MI was reduced only in patients undergoing surgery (7.1% versus 3.8%, P=0.005). There were no increases in clinically serious adverse events. CONCLUSIONS: No significant benefit of cariporide could be demonstrated across a wide range of clinical situations of risk. The trial documented safety of the drug and suggested that a high degree of inhibition of the exchanger could prevent cell necrosis in settings of ischemia-reperfusion.

Predictors of mortality and mortality from cardiac causes in the bypass angioplasty revascularization investigation (BARI) randomized trial and registry. For the BARI Investigators.

BACKGROUND: The impact of percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG) on long-term mortality rates in the presence of various demographic, clinical, and angiographic factors is uncertain in the population of patients suitable for both procedures. METHODS AND RESULTS: In the Bypass Angioplasty Revascularization Investigation (BARI) randomized trial and registry, 3610 patients who were eligible to receive PTCA and CABG were revascularized between 1989 and 1992. Multivariate Cox models were used to identify factors associated with 5-year mortality and cardiac mortality, with particular attention to factors that interact with treatment. Diabetic patients receiving insulin had higher mortality and cardiac mortality rates with PTCA compared with CABG (relative risk [RR] 1.78 and 2.63, respectively, P<0.001), and patients with ST elevation had higher cardiac mortality rates with CABG than with PTCA (RR 4.08, P<0.001). Factors most strongly associated with high overall mortality rates were insulin-treated diabetes, congestive heart failure, kidney failure, and older age. Black race was also associated with higher mortality rates (RR 1.49, P=0.019). CONCLUSIONS: A set of variables was identified that could be used to help select a revascularization procedure and to evaluate risk of long-term mortality in the population of patients considering revascularization.

The changing role of the exercise electrocardiogram as a diagnostic and prognostic test for chronic ischemic heart disease.

The exercise electrocardiogram has been the subject of intense research over the last 50 years, as both a diagnostic and prognostic method to assess patients with chronic ischemic heart disease. In 1986, the strengths and limitations of the technique to predict coronary and multivessel disease in clinical patient subsets are understood. The diagnostic accuracy of the test is improved by consideration of Bayesian theory, multivariate models and new non-ST segment criteria. Post-test coronary disease risk estimates are best reported in terms of a conditional probability, rather than statements of "positive" or "negative." The value of exercise testing in prognostic risk stratification is considerably enhanced by recent reports of long-term follow-up data in asymptomatic and symptomatic patients. Powerful prognostic information can be obtained when the clinical, electrocardiographic and physiologic data from the exercise test are used to formulate the post-test risk of a cardiac event, even in patients whose coronary anatomy is known. The changing role of the exercise electrocardiogram as a diagnostic and prognostic test is reviewed, with emphasis on the strengths and limitations of the procedure.

A dose-ranging, placebo-controlled, double-blind trial of nisoldipine in effort angina: duration and extent of antianginal effects.

Maximal treadmill exercise testing at 1, 3 and 8 hours was used to assess the onset, duration and antianginal efficacy of the dihydropyridine slow channel calcium-blocking agent, nisoldipine, in an oral dose range of 5, 10 and 20 mg. A double-blind, randomized, placebo-controlled design was used involving 12 patients with stable effort angina. Exercise tolerance was significantly increased 3 hours after each dose, when the maximal beneficial effect occurred. The improvement was observed as early as 1 hour after the 10 and 20 mg dose, and persisted for 8 hours after the 20 mg dose. At 3 hours, the onset of an exercise-induced ST segment depression of 0.1 mV or greater was increased by 62 (p less than 0.05), 75 (p less than 0.01) and 117 seconds (p less than 0.01) with the 5, 10 and 20 mg dose of nisoldipine, respectively, compared with placebo. Similarly, time to onset of angina was significantly increased. The sum of exercise-induced ST segment depression at peak exercise was significantly decreased (p less than 0.05) from 8.7 +/- 2.3 to 6.7 +/- 1.8 and 6.4 +/- 2.0 mm, respectively, after the 10 and 20 mg dose of nisoldipine. The rate-pressure product was significantly greater with nisoldipine than with placebo at the onset of ischemia and at peak exercise (22.8 +/- 1.1 versus 20 +/- 1.4 X 10(3) U for the 20 mg dose; p less than 0.01). Thus, nisoldipine is an effective antianginal agent with a rapid onset of action that improves exercise tolerance, increases angina threshold and persists for at least 8 hours after oral dosing.

Comparison of 15-year survival for men and women after initial medical or surgical treatment for coronary artery disease: a CASS registry study. Coronary Artery Surgery Study.

OBJECTIVES: This study compared the rates of coronary artery bypass graft surgery and 15-year survival for men and women after initial medical or surgical management. BACKGROUND: There has been concern that women with coronary artery disease are managed differently than men and that men and women have a different prognosis. The Coronary Artery Surgery Study (CASS) registry is a large data base of well characterized patients with long-term follow-up. METHODS: Patients underwent cardiac catheterization at 1 of 15 hospitals during 1974 to 1979. Bypass surgery rates were based on 12,452 men and 2,366 women. Survival results were based on 6,018 men and 1,095 women with operable coronary artery disease and initial medical management and 6,922 men and 1,291 women initially managed surgically. RESULTS: At 15 years, bypass surgery rates were 75% for men and 72% for women (p = 0.91). The rates remained similar after adjustment for clinical and angiographic variables. The 15-year survival rate was 50% for men and 49% for women with initial medical treatment (p = 0.53) and 52% for men and 48% for women (p = 0.004) with initial surgical treatment, a difference similar to that for operative mortality (men 2.5%, women 5.3%, p < 0.0001). Survival was improved by bypass surgery in most subgroups, with largest relative risks for high risk patients. Relative risks were similar for men and women. CONCLUSIONS: The rate of bypass surgery did not differ between men and women. There were few differences in the survival of men and women. In general, both men and women with initial surgical treatment survived longer, although benefits were clinically and statistically significant only in those at high risk. The benefit was similar in both men and women.

The Brugada syndrome: clinical, electrophysiologic and genetic aspects.

This review deals with the clinical, basic and genetic aspects of a recently highlighted form of idiopathic ventricular fibrillation known as the Brugada syndrome. Our primary objective in this review is to identify the full scope of the syndrome and attempt to correlate the electrocardiographic manifestations of the Brugada syndrome with cellular and ionic heterogeneity known to exist within the heart under normal and pathophysiologic conditions so as to identify the cellular basis and thus potential diagnostic and therapeutic approaches. The available data suggest that the Brugada syndrome is a primary electrical disease resulting in abnormal electrophysiologic activity in right ventricular epicardium. Recent genetic data linking the Brugada syndrome to an ion channel gene mutation (SCN5A) provides further support for the hypothesis. The electrocardiographic manifestations of the Brugada syndrome show transient normalization in many patients, but can be unmasked using sodium channel blockers such as flecainide, ajmaline or procainamide, thus identifying patients at risk. The available data suggest that loss of the action potential dome in right ventricular epicardium but not endocardium underlies the ST segment elevation seen in the Brugada syndrome and that electrical heterogeneity within right ventricular epicardium leads to the development of closely coupled premature ventricular contractions via a phase 2 reentrant mechanism that then precipitates ventricular tachycardia/ventricular fibrillation (VT/VF). Currently, implantable cardiac defibrillator implantation is the only proven effective therapy in preventing sudden death in patients with the Brugada syndrome and is indicated in symptomatic patients and should be considered in asymptomatic patients in whom VT/VF is inducible at time of electrophysiologic study.

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

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

Coronary angioplasty: a therapeutic option for symptomatic patients with two and three vessel coronary disease.

Coronary angioplasty is a widely applied revascularization procedure for patients with multivessel coronary artery disease. However, follow-up in this patient subgroup is relatively limited. From 1983 to 1986, coronary angioplasty was performed in 349 and 121 patients with, respectively, two- and three-vessel coronary disease with a primary success rate of 83 and 88%. The in-hospital mortality rate was 2.8% (13 of 470 patients). Complete revascularization was achieved in 128 patients. Among the 397 patients with a successful outcome, 373 (94%) were followed up greater than or equal to 1 year; 79% were free of death, nonfatal myocardial infarction or the need for coronary bypass grafting, and 82% of patients had symptomatic improvement by at least one angina functional class. A second coronary angioplasty procedure was required in 13% of patients. After a mean follow-up period of 27 months, an increased incidence of coronary bypass grafting was noted in patients with incomplete versus complete revascularization (16 versus 7%, p less than 0.05). Among the 222 patients who had repeat cardiac catheterization performed an average of 7 months after angioplasty, 103 were symptomatic; 50% of the 222 patients had at least one vessel with greater than or equal to 50% restenosis and 14% of patients had multiple restenoses. In conclusion, coronary angioplasty can be performed with a high initial success rate and marked symptomatic improvement in patients with multivessel coronary disease. However, in this group's experience, the majority of patients selected for coronary angioplasty with multivessel coronary disease will have incomplete revascularization that can be predicted in the majority of patients before the procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Heparin-induced prolongation of partial thromboplastin time after thrombolysis: relation to coronary artery patency. HART Investigators.

Having previously shown in the Heparin Aspirin Reperfusion Trial that the empiric use of early intravenous heparin after recombinant tissue-type plasminogen activator (rt-PA) is an important component in the overall treatment strategy, we examine in this report the specific relation between the degree of prolongation of activated partial thromboplastin time and coronary artery patency. To evaluate the hypothesis that arterial patency after administration of rt-PA for acute myocardial infarction is sustained by effective anticoagulation, activated partial thromboplastin time of heparin recipients was determined 8 and 12 h after the start of thrombolysis. Mean activated partial thromboplastin time was higher among patients with an open infarct-related artery than in those with a closed artery (81 +/- 4 vs. 54 +/- 9 s, p less than 0.02). Only 45% of patients with values less than 45 s at both 8 and 12 h had Thrombolysis in Myocardial Infarction (TIMI) flow grade 2 or 3 in the infarct-related artery at 18 h. In contrast, 88% of patients with activated partial thromboplastin time greater than 45 s and 95% of those with values greater than 60 s had an open infarct-related artery at 18 h (p = 0.003 and 0.0006, respectively). Among patients with an initially patent infarct-related artery who underwent repeat angiography at 7 days, activated partial thromboplastin time was similar in those with a persistently patent artery and those with late reocclusion. Excessive anticoagulation did not appear to increase hemorrhagic risk except that access site-related hemorrhage was more common in patients with activated partial thromboplastin time greater than 100 s at 8 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of carbon monoxide exposure in patients with documented cardiac arrhythmias.

OBJECTIVE: This study was designed to determine whether carbon monoxide has proarrhythmic effects at rest and during upright exercise in patients with myocardial ischemia and moderate baseline ectopic activity. BACKGROUND: Exposure of patients with documented myocardial ischemia to low levels of carboxyhemoglobin (COHb) alters the myocardial response to exercise. Anecdotal reports from patients with myocardial ischemia have noted the development of arrhythmias related to carbon monoxide exposure. Increased frequency of arrhythmias related to carbon monoxide exposure in patients performing supine bicycle exercise has been recently reported. METHODS: Twenty-eight nonsmoking men and five nonsmoking women with documented coronary artery disease and a minimum of 30 ventricular ectopic beats/h over a 20-h period were studied. Subjects were exposed in a randomized double-blind fashion to either room air or sufficient carbon monoxide to elevate their COHb concentration to 3% or 5% in 1 h, followed by a maintenance exposure to carbon monoxide. The subjects then left the laboratory and resumed their normal daily activity to determine changes in ventricular ectopic beats after carbon monoxide exposure. RESULTS: There was no significant change in the frequency of single ventricular ectopic beats at rest from 115 +/- 28 (in room air) to 121 +/- 31 at 3% COHb to 94 +/- 23 at 5% COHb. Exercise itself increased the frequency of ventricular ectopic beats, but there was no additional effect of carbon monoxide exposure on the exercise-induced increase in isolated ectopic beats or complex ectopic waveforms. Analysis of the data based on grouping of the subjects by the severity of disease (ventricular ectopic beat frequency, ejection fraction, presence of exercise-induced ischemia) indicated no proarrhythmic effect of carbon monoxide. CONCLUSIONS: In patients with frequent ventricular ectopic activity (> or = 30 ectopic beats/h), exposure to carbon monoxide producing either 3% or 5% COHb does not increase arrhythmia frequency of single or multiple beats during rest or exercise.

Prognostic importance of silent myocardial ischemia detected by intravenous dipyridamole thallium myocardial imaging in asymptomatic patients with coronary artery disease.

One hundred seven asymptomatic patients who underwent intravenous dipyridamole thallium imaging were evaluated to determine prognostic indicators of subsequent cardiac events over an average follow-up period of 14 +/- 10 months. Univariate analysis of 18 clinical, scintigraphic and angiographic variables revealed that a reversible thallium defect, a combined fixed and reversible thallium defect, number of segmental thallium defects and extent of coronary artery disease were significant predictors of subsequent cardiac events. Of the 13 patients who died or had a nonfatal infarction, 12 had a reversible thallium defect. Stepwise logistic regression analysis selected a reversible thallium defect as the only significant predictor of cardiac events. When death or myocardial infarction was the outcome variable, a combined fixed and reversible thallium defect was the only predictor of outcome. In patients without previous myocardial infarction, the cardiac event rate was significantly greater in those with an abnormal versus normal thallium scan (55% versus 12%, p less than 0.001). Thus, intravenous dipyridamole thallium scintigraphy is a useful noninvasive test to risk stratify asymptomatic patients with coronary artery disease. A reversible thallium defect most likely indicates silent myocardial ischemia in a sizable fraction of patients in this clinical subset and is associated with an unfavorable prognosis.

Long-term survival of African Americans in the Coronary Artery Surgery Study (CASS).

OBJECTIVES: This study sought to determine the long-term (> 15 years) outcome of a clinically well characterized cohort of African Americans with known or suspected coronary artery disease (CAD). BACKGROUND: The mortality rate from CAD is higher in African Americans than in whites. An earlier analysis of data from the Coronary Artery Surgery Study (CASS) registry suggested that African American and white patients treated surgically had equal 5-year survival rates. METHODS: Survival data from the CASS registry were analyzed to determine whether 1) African American race is an independent predictor of mortality; and 2) initial therapy is predictive of mortality among African American patients. RESULTS: Overall, 60% of white and 52% of African American patients survived 16 years (p < 0.00001). Multivariate Cox models confirmed that African American race was independently associated with higher mortality in both the medical group (hazard ratio [HR] 1.34, 95% confidence interval [CI] 1.11 to 1.63) and the surgical group (HR 1.63, 95% CI 1.19 to 2.23). Initial therapy was not predictive of survival among African American patients (p = 0.81). However, smoking status significantly influenced survival: African Americans who did not smoke experienced significantly improved survival (60% vs. 48% for smokers), which equaled survival for white nonsmokers (61%, p = NS). CONCLUSIONS: In contrast to results from shorter term studies, African Americans experienced higher overall mortality rates than whites over the long term, regardless of the type of initial treatment. Survival among nonsmoking African Americans at 16 years equaled survival among nonsmoking whites.

Noninvasive diagnostic test choices for the evaluation of coronary artery disease in women: a multivariate comparison of cardiac fluoroscopy, exercise electrocardiography and exercise thallium myocardial perfusion scintigraphy.

Several diagnostic noninvasive tests to detect coronary and multivessel coronary disease are available for women. However, all are imperfect and it is not yet clear whether one particular test provides substantially more information than others. The aim of this study was to evaluate clinical findings, exercise electrocardiography, exercise thallium myocardial scintigraphy and cardiac fluoroscopy in 92 symptomatic women without previous infarction and determine which tests were most useful in determining the presence of coronary disease and its severity. Univariate analysis revealed two clinical, eight exercise electrocardiographic, seven myocardial scintigraphic and seven fluoroscopic variables predictive of coronary or multivessel disease with 70% or greater stenosis. The multivariate discriminant function analysis selected a reversible thallium defect, coronary calcification and character of chest pain syndrome (p less than 0.05) as the variables most predictive of presence or absence of coronary disease. The ranked order of variables most predictive of multivessel disease were cardiac fluoroscopy score, thallium score and extent of ST segment depression in 14 electrocardiographic leads. Each provided statistically significant information to the model. The estimate of predictive accuracy was 89% for coronary disease and 97% for multivessel coronary disease. The results suggest that cardiac fluoroscopy or thallium scintigraphy provide significantly more diagnostic information than exercise electrocardiography in women over a wide range of clinical patient subsets.

An epidemic of pulmonary hypertension after toxic rapeseed oil ingestion in Spain.

The cardiac profile of 38 patients readmitted to the hospital with the clinical and radiologic findings of pulmonary artery hypertension and right ventricular failure 2 months after ingestion of toxic rapeseed oil was determined with M-mode and two-dimensional echocardiography, pulsed Doppler flow studies and right and left heart catheterization and ventriculography. The echocardiogram and pulsed Doppler recordings revealed right ventricular enlargement in 84% of the patients, indirect evidence of pulmonary artery hypertension in 76% and tricuspid insufficiency in 13%. At cardiac catheterization (n = 11) the mean (+/- standard deviation) pulmonary artery pressure was 40 +/- 9 mm Hg, mean pulmonary systemic vascular resistance ratio was 0.45 +/- 0.12 and mean right ventricular end-diastolic pressure was 13 +/- 4 mm Hg. Pulmonary artery hypertension was sustained after the acute administration of 100% oxygen and persisted in six patients who were restudied within 6 months. Cardiac index and left heart pressures were normal in all but one patient. The contrast ventriculographic studies revealed right ventricular dilation in all patients, tricuspid regurgitation in three patients and a normal left ventricular contraction pattern in all but one patient. The data confirm that symptomatic pulmonary artery hypertension and associated right ventricular dysfunction can complicate toxic rapeseed oil ingestion and that these findings persist for at least 6 months.

Comparison of coronary artery bypass surgery and medical therapy in patients with exercised-induced silent myocardial ischemia: a report from the Coronary Artery Surgery Study (CASS) registry.

To determine whether coronary artery bypass surgery would prolong survival in patients with silent myocardial ischemia during exercise testing, the data on 692 such patients from the Coronary Artery Surgery Study (CASS) registry were analyzed. The patients were followed up for up to 7 years after medical (n = 424) or surgical (n = 268) therapy. Stratification of patients into subsets was based on the results of cardiac catheterization. Surgical benefit was greatest in the patients with three vessel coronary artery disease or abnormal left ventricular function. Among the 75 patients with three vessel coronary disease and left ventricular dysfunction, the 7 year survival rate was 37% for the medical group and 90% for the surgical group (p less than 0.0001). Thus, among patients with silent myocardial ischemia during exercise testing in this nonrandomized study, survival appeared to be enhanced by coronary artery bypass surgery in subsets of patients with severe coronary artery disease and abnormal left ventricular function.

Safety and diagnostic accuracy of dipyridamole-thallium imaging in the elderly.

The noninvasive diagnosis of coronary artery disease in the elderly can occasionally be difficult. Intravenous dipyridamole-thallium imaging is a potentially useful diagnostic test to determine presence and severity of coronary disease; however, the safety of the procedure has not been determined in an older population. The side effect profile and frequency of severe ischemic responses after 0.56 mg/kg of intravenous dipyridamole were compared in 101 patients greater than or equal to 70 years old and 236 patients less than 70 years old. There were no side effects in 64% and 62% of patients greater than or equal to 70 and less than 70 years old, respectively (p = NS). Among the 337 patients tested, there were no complications of myocardial infarction or death. The most common cardiac side effect was chest pain, which occurred in 21 (21%) of the 101 patients aged greater than or equal to 70 years and in 64 (27%) of the 236 patients less than 70 years (p = NS). Aminophylline was required to reverse cardiac or noncardiac side effects in 15 (15%) and 36 (15%) of the patients greater than or equal to 70 and less than 70 years old, respectively (p = NS). A severe ischemic response occurred in 2% and 2.5% of patients greater than or equal to 70 and less than 70 years old, respectively (p = NS). The sensitivity of intravenous dipyridamole-thallium imaging for obstructive coronary artery disease was 86% (25 of 29) and 83% (68 of 82) in older and younger patients, respectively (p = NS); the specificity was 75% (6 of 8) and 70% (16 of 23), respectively (p = NS). Thus, intravenous dipyridamole-thallium imaging is a safe noninvasive method for assessment of older patients with obstructive coronary disease; its side effect profile and diagnostic accuracy are similar to those seen in younger patients. The technique is associated with severe ischemic responses in only a small minority of patients.

Histopathology after Nd-YAG laser percutaneous transluminal angioplasty of peripheral arteries.

Laser recanalization of occluded femoral or popliteal arteries was performed in 12 patients using a continuous wave neodymium yttrium aluminum garnet (Nd-YAG) laser. The histologic findings of the laser-irradiated arterial segments in two of these patients are reported. The specimens were obtained 2 and 4 weeks after the laser procedure. The laser-irradiated vessel in Patient 1 had been partially recanalized with reduction of the atherosclerotic occlusion from 3 to 1 cm. The lased arterial lumen manifested thermal injury to the inner quarter of the arterial wall with vacuolization and a rim of carbonization occupying 10% of the width of the arterial wall, but without thrombus formation. Histologic examination in Patient 2 revealed no fibrin deposits, atherosclerotic debris or thrombi at the intimal arterial edge. At the crater site, thermal injury was apparent with vacuolization of the intimal fibrous tissue. The histologic sections obtained 4 weeks after the procedure revealed new fibrous intimal tissue without endothelialization in some of the heavily calcified tissue sections. Where the plaques were noncalcified, reendothelialization was noted with only minimal damage to the surrounding tissue. No medial or elastic fiber disruption was seen, and no aneurysmal dilation had occurred. Intimal splitting with a cleft between the tunica media and the intima was noted at the site of previous balloon angioplasty. In conclusion, the follow-up histologic findings 2 and 4 weeks after laser angioplasty in two patients using a specially designed catheter delivery system and cooling blood perfusate revealed thermal injury to the inner quarter of the arterial vessel wall and no evidence of thrombus formation.

Should airline pilots be eligible to resume active flight status after coronary bypass surgery?: a CASS registry study.

Medical certification to return to work after coronary bypass surgery in occupations that carry a risk to public safety is controversial, particularly for airline pilots. To address this issue, 10,312 patients from the CASS registry who underwent coronary bypass surgery were studied and 2,326 men with clinical and postoperative characteristics similar to those of the average airline pilot who might apply to renew his license after surgery were selected. The 5 year probability of remaining free of an acute cardiac event, defined as acute coronary insufficiency, myocardial infarction or sudden death, was 0.92 +/- 0.01 (mean +/- SE) for the 1,207 men without previous myocardial infarction and 0.98 +/- 0.01 for the 122 men who never smoked and did not have a history of hypertension. Among the 1,119 men with a previous myocardial infarction, the probability of remaining free of acute cardiac events was 0.91 +/- 0.02 and 0.92 +/- 0.02 when left ventricular contraction score was 5 to 9 and 10 or greater, respectively. In this patient subgroup, mortality rate was similar to that of the age-matched U.S. male population when the left ventricular contraction score was 5 to 9 (4.0% versus 4.3%; p = NS) but significantly worse when the left ventricular contraction score was 10 or greater (7% versus 4.2%; p = 0.05). The data from this CASS registry study are pertinent to the question of operationally unlimited first-class medical certification of carefully selected airline pilots after coronary bypass surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of exercise testing in identifying patients with improved survival after coronary artery bypass surgery.

To determine whether exercise testing can identify patients whose survival might be prolonged by coronary artery bypass surgery, the results of bypass surgery were compared with those of medical therapy alone in 5,303 nonrandomized patients from the Coronary Artery Surgery Study registry who underwent exercise testing. Patients in the two treatment groups differed substantially with regard to important baseline variables. Analysis of 32 variables by Cox's regression model for survival revealed an independent beneficial effect of bypass surgery on survival (p less than 0.00001). Patients were then stratified into subsets according to the results of exercise testing. Surgical benefit was greatest in the 789 patients who exhibited at least 1 mm of ST segment depression and who could exercise only into stage 1 or less. Among the 398 patients with three vessel coronary disease showing these characteristics, 7 year survival was 58% for the medical group and 81% for the surgical group (p less than 0.001). There was no difference in survival between the surgical and medical groups among the 1,545 patients without ischemic ST segment depression who were able to exercise into stage 3 or greater. Thus, in patients who demonstrate ischemia on exercise testing and whose exercise capacity is limited, coronary bypass surgery appears to improve survival in comparison with medical therapy alone.