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T Killip

Publications and source records attributed to T Killip.

At least 37 records · Page 2Linked to original sources
PubMed1985

The coronary artery surgery study (CASS)--a randomized trial and a registry.

In 1973 the National Heart Lung and Blood Institute organized the Coronary Artery Surgery Study (CASS) including a patient registry and a randomized trial designed to compare medical and surgical therapy in patients with coronary artery disease. This study is discussed in detail and compared with two further large randomized trials of coronary artery bypass surgery, the US Veterans Administration Trial (VA) and the European Cooperative Surgical Study (ECSS). Although there are many differences between these three studies, their similarities warrant some conclusions on the improvement of survival in certain high risk patients, protection against myocardial infarction, the deterioration of graft patency, and the postponement of surgery in low risk patients.

Adrenergic beta-Antagonists↗
PubMed1985

Coronary artery surgery study (CASS): a randomized trial of coronary bypass surgery. Eight years follow-up and survival in patients with reduced ejection fraction.

Survival data after 8 years of follow-up for all patients and after 7 years for certain subgroups are reported from CASS, a randomized trial of surgical or medical treatment assignment in patients with coronary artery disease who have less than severe angina or are asymptomatic after myocardial infarction. After 8 years, survival curves are not significantly different between medical and surgical groups; 87% of patients assigned to surgical and 84% of those assigned to medical treatment are alive. A significant advantage favoring surgical assignment was observed in patients with three-vessel disease and reduced ejection fractions (less than 0.5. but greater than 0.35); after 7 years of follow-up, 88% of the patients in the surgical group and 65% of those in the medical group are alive (p = .009). Survival curves for patients with normal resting ejection fractions are identical after 7 years. We conclude that the CASS trial reveals a significant advantage favoring surgical therapy in patients with three-vessel disease and impaired ventricular function who are randomly assigned to treatment.

Adult↗
PubMed1983

Use of survival analysis to determine the clinical significance of new Q waves after coronary bypass surgery.

There are few data on the long-term effects of new Q waves on survival and morbidity after coronary bypass graft surgery (CABG). We followed 1340 patients who underwent CABG in 1978 at 10 hospitals participating in the Coronary Artery Surgery Study (CASS). The incidence of perioperative Q-wave infarction was 4.76% (range 0.0-10.3% by hospital). The rate of infarction was higher in patients who had an increased left ventricular end-diastolic pressure or cardiomegaly on the preoperative chest radiograph. Patients who received more grafts or who had longer cardiopulmonary bypass time were also at higher risk of infarction. In a stepwise discriminant analysis of 44 clinical, angiographic and surgical variables, cardiopulmonary bypass time, topical cardiac hypothermia and cardiomegaly entered the stepwise selection of variables. Long-term survival was adversely affected by the appearance of new postoperative Q waves. The hospital mortality was 9.7% in the 62 patients who had new postoperative Q waves and 1.0% in the 1278 patients who did not (p less than 0.001); the 3-year cumulative survival rates were 85% and 95%, respectively (p less than 0.001). In patients who survived to hospital discharge, the presence of new postoperative Q waves did not adversely affect 3-year survival (94% and 96%, respectively). The survival rates were worse in patients who had a history of infarction or who had impaired left ventricular function preoperatively. The number of readmissions to hospital after CABG among the patients who had a transmural perioperative infarction was similar to to that among patients who did not. We conclude that the appearance of new Q waves after CABG adversely affects survival. The major impact on mortality occurs before hospital discharge. Patients who are destined to have a perioperative infarct cannot be predicted from commonly measured preoperative and angiographic variables.

Adult↗
PubMed1983

Coronary arteriography and coronary artery bypass surgery: morbidity and mortality in patients ages 65 years or older. A report from the Coronary Artery Surgery Study.

Of 2144 patients age 65 years or older entered into the registry of the Coronary Artery Surgery Study (CASS) who had coronary arteriography, 1086 underwent isolated coronary artery bypass grafting. Complications of angiography included death in four patients and nonfatal myocardial infarction in 17. Eight patients suffered neurologic complications, which were transient in five. The perioperative mortality was 5.2% (57 of 1086), which is significantly greater than the perioperative mortality of 1.9% (151 of 7827) in patients younger than 65 years entered in CASS (p less than 0.001). There was a trend toward an increased mortality rate with age; it was 4.6% (37 of 803) in patients age 65-69 years, 6.6% (16 of 241) in those 70-74 years and 9.5% (four of 42) in those 75 years or older. The duration of hospital stay after operation was significantly longer for the patients 65 years or older than for the patients younger than 65 (13.3 vs 11.4 days; p less than 0.001). Stepwise linear discriminant analysis identified five variables predictive of perioperative mortality: presence of 70% or more stenosis of the left main coronary artery and a left-dominant circulation, left ventricular end-diastolic pressure, a history of current cigarette smoking, pulmonary rales on auscultation, and presence of one or more associated medical diseases. A second linear discriminant analysis, incorporating 7658 CASS patients who underwent isolated coronary artery bypass surgery irrespective of age, examined whether age 65 years or older was an independent predictor of perioperative mortality. The variables selected, in order of significance, were congestive cardiac failure score, left main coronary artery stenosis and a left-dominant circulation, age 65 years or older, left ventricular wall motion score, sex and history of unstable angina pectoris. In patients 65 years or older, the mortality from coronary arteriography is low, whereas mortality from coronary artery bypass surgery is greater than that in CASS patients younger than 65 years.

Aged↗
PubMed1983

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.

Angiography↗
PubMed1982

Survival of medically treated patients in the coronary artery surgery study (CASS) registry.

The objective of this study was to evaluate the impact on survival of the anatomic extent of obstructive coronary artery disease and of two measures of left ventricular (LV) performance. This study is based on 20,088 patients without previous coronary artery bypass graft surgery who were enrolled in the registry of the National Heart, Lung, and Blood Institute Coronary Artery Surgery Study from 1975 to 1979. The cumulative 4-year survival of medically managed patients was analyzed to determine the survival of specific subsets of patients with obstructive coronary disease. The vital status of 99.8% of the patients was known. The 4-year survival of medically treated patients with no significant obstructive disease was 97%, in contrast to 92%, 84% and 68% in patients with one-, two- and three-vessel disease, respectively. The presence of left main coronary artery disease decreased survival significantly. The 4-year survival decreased from 70% to 60% in patients with three-vessel disease when significant obstruction of the left main coronary artery was also present. Patients with significant coronary artery disease who had an ejection fraction of 50--100%, 35--49%, and 0--34% had a 4-year survival of 92%, 83% and 58%, respectively. The systolic contraction pattern was assessed in five selected segments and given a score of 1--6, with a score of 1 for normal function, increasing to 6 if an aneurysm was present. In a patient with normal LV contraction in all five segments of the LV ventricular angiogram, the LV score would equal 5. Patients with an LV score of 5--11, 12--16 and 17--30 had 4-year survivals of 90%, 71% and 53%, respectively. Patients with good LV function (a score of 5--11) had a 4-year survival of 94%, 91% and 79% for one-, two- and three-vessel disease, respectively. Patients with poor left ventricular function (score of 17--30) had a 4-year survival rate of 67%, 61% and 42% in one-, two- and three-vessel disease, respectively. Thus, LV function is a more important predictor of survival than the number of diseased vessels.

Coronary Artery Bypass↗
PubMed1982

The clinical spectrum of coronary artery disease and its surgical and medical management, 1974-1979. The Coronary Artery Surgery study.

Data from the National Heart, Lung, and Blood Institute's Coronary Artery Surgery Study (CASS) are used to describe the types of persons who undergo coronary angiography for possible coronary artery bypass surgery, the reasons patients receive coronary bypass surgery, and operative mortality results, as well as changing trends in the therapy assigned. The review is designed to provide background material for those assessing coronary artery bypass technology.

Adrenergic beta-Antagonists↗
PubMed1981

Effect of coronary bypass surgery on survival patterns in subsets of patients with left main coronary artery disease. Report of the Collaborative Study in Coronary Artery Surgery (CASS).

The 3 year cumulative survival rate of 1,492 patients with left main coronary artery disease (50 percent or greater stenosis of luminal diameter) enrolled in the Collaborative Study in Coronary Artery Surgery (CASS) was 91 percent for the surgical group and 69 percent for patients treated medically (p less than 0.0001). Mortality was significantly greater in patients with impaired left ventricular function. The difference between medical and surgical therapy was significant for patients who had normal, moderately abnormal and severely impaired left ventricular function and for patients with stenosis of the left main coronary artery of 50 to 59, 60 to 69, 70 to 79 and 80 percent or greater. Aortocoronary bypass surgery did not significantly improve survival in patient subgroups who had (1) a nonstenotic dominant right or balanced coronary circulation, (2) a stenotic dominant right coronary artery and normal left ventricular function, and (3) left main coronary stenosis of 50 to 59 percent and normal or mildly abnormal left ventricular function. The Cox proportional hazards model was used to select baseline variables that were independent predictors of long-time mortality. The model selected left ventricular score, age, congestive heart failure score, hypertension, percent left main coronary arterial stenosis and coronary arterial dominance as the baseline variables most predictive of long-term survival. A clinical and angiographic prognostic risk index developed from these six baseline variables showed significantly improved survival for the surgical cohort in each of four risk categories. In the best and worst risk category, the 3 year survival rate was 97 and 82 percent, respectively, for the surgical group and 85 and 34 percent, respectively, for the medical group (p less than or equal to 0.0002). The data from this observational study show that coronary bypass surgery prolongs life in most patients with left main coronary artery disease, particularly those who have severe narrowing of the left main coronary artery or impaired left ventricular function. The results permit a better understanding of the natural history of left main coronary artery disease and permit a more accurate estimate of long-term survival for individual patients through the use of a clinical-angiographic risk index.

Cardiac Catheterization↗
PubMed1981

Angiographic prevalence of high-risk coronary artery disease in patient subsets (CASS).

The prevalence of coronary artery stenoses greater than or equal to 70% or left main stenosis greater than or equal to 50% was evaluated in 20,391 patients who underwent angiography in the Coronary Artery Surgery Study from 1975-1979. After the patients with unstable angina or myocardial infarction were excluded, the disease prevalence in the 8157 patients with definite angina, probable angina, and nonspecific chest pain was 93%, 66% and 14% in men and 72%, 36% and 6% in women (p less than 0.001). The age and sex of the patients and character of chest pain were important determinants of disease prevalence and severity. Left main or three-vessel coronary disease occurred in more than 50% of middle-aged men and older women with definite angina and in more than 50% of men who had probable angina and were older than 60 years of age. In contrast, left main coronary disease occurred in less than 2% of 1282 men and less than 1% of 1397 women with nonspecific chest pain regardless of age. In this latter patient subset, less than 5% of men and less than 1% of women in each decade under 60 years had left main or three-vessel coronary artery disease. Thus, high-risk coronary disease is common in middle-aged patients with definite angina and older patients with probable angina, but is rare in patients with nonspecific chest pain. Indications and guidelines for diagnostic noninvasive tests and coronary angiography could be based on these results.

Adult↗
PubMed1980

Operative risk factors in patients with left main coronary-artery disease.

To identify the factors associated with operative mortality, we evaluated clinical, angiographic, and surgical variables in 1172 patients with left main coronary-artery stenoses of at least 50 per cent, who underwent coronary-bypass procedures in the Collaborative Study in Coronary Artery Surgery (CASS). The operative mortality was 4.2 per cent overall and was less than 3 per cent in seven of the 15 participating hospitals. Historical variables associated with an increase in operative mortality were age, female sex, and duration and severity of angina. Other variables associated most closely with poor survival were urgency of operation, left coronary-artery dominance, severity of left main coronary-artery stenosis, and impairment of left ventricular contraction. The results of this multicenter study show that aortocoronary bypass surgery in patients with left main coronary-artery disease can be performed with a low mortality and that patients at high risk can often be identified before surgery.

Age Factors↗
PubMed1980

Risk factors and angiographic coronary artery disease: a report from the coronary artery surgery study (CASS).

The findings for 14 risk variables were correlated with the results of coronary arteriography in 8807 patients registered in the interinstitutional Coronary Artery Surgery Study (CASS). Discriminant-function analysis revealed that age, sex, cigarette smoking and the level of blood cholesterol best distinguished between the groups with (6688 patients) and without (2119 patients) coronary artery disease. A family history of coronary artery disease and the presence of hypertension or diabetes were of addition, but less, discriminating value. The relative risk for coronary artery disease in patients with the combination of cigarette smoking and an elevated cholesterol level was high (> 4) in females age 55 years or younger and in males age 35 years or younger. Few females age 45 years or younger (seven of 97) had coronary artery disease when both of these risk factors were absent. In spite of these correlations, only limited gains accrued from the use of discriminant-function analysis in correctly allocating patients into disease and nondisease groups. This indicates that, while certain factors are significantly correlated with coronary arteriographic findings, their value for predicting the presence of coronary artery disease is limited.

Adult↗
PubMed1980

Unstable angina - an overview.

Unstable angina pectoris is an intermediate syndrome between classic exercise-induced angina pectoris and acute myocardial infarction characterized by the appearance of new ischemic pain, the development of more intense pain, often at rest, or intermittent ischemic attacks complicating the early recovery phase of established acute myocardial infarction. The major risk of unstable angina pectoris is acute myocardial infarction which may occur in about 25% of the patients during the three months following onset of symptoms. Physiologically, ECG changes and hemodynamic alterations generally precede the onset of pain. In unstable angina, the accompanying hemodynamic change and increased oxygen demand in the already-ischemic heart represents positive feedback creating further instability. The hemodynamic alterations may be the result of an abnormal response to stress or to inappropriately high chemoceptor discharge. While coronary spasm may play a definite role in the pathogenesis of unstable angina, other factors such as hemorrhage into the wall of an atherosclerotic plaque, peripheral embolization in the coronary tree from a proximal soft cholesterol "abscess", changes in platelet adherence and aggregability or altered vascular responsiveness must be taken into consideration. Treatment is directed toward inducing coronary and peripheral vasodilatation and reducing cardiac work with medications such as nitrates, calcium antagonists and, with reservations, beta-adrenergic blockers. In patients unresponsive to medical therapy, treatment with the aortic counter-pulsating balloon has been recommended. Surgery should be performed on an elective and not an emergency basis. The full clinical and pathologic significance of unstable angina pectoris is still being uncovered. Problems for the future lie in further exploration of the mechanism, treatment and prevention of the entity.

Angina Pectoris↗
PubMed1979

Complications of coronary arteriography from the Collaborative Study of Coronary Artery Surgery (CASS).

Data were collected prospectively on 7553 consecutive patients undergoing coronary arteriography. The studies were performed at 13 clinics of the Collaborative Study of Coronary Artery Surgery (CASS) using brachial and femoral techniques. There were eight deaths 0--24 hours and seven deaths 24--48 hours after arteriography (2/1000). There were 15 non-fatal myocardial infarctions (MIs) 0--24 hours and four MIs 24--48 hours after arteriography (2.5/1000). Of 657 cases with left main stenosis greater than or equal to 50%, five died and three had MI. Left main disease increased risk of death by 6.8 times (p less than 0.001). Other factors increasing risk were unstable angina, congestive heart failure, multiple premature ventricular contractions, and hypertension. Of the 1187 patients studied from the brachial artery, six died (0.51%) and five had MIs (0.42%). In 6328 patients studied from the femoral artery, nine died (0.14%) and 14 had MIs (0.22%). The brachial artery technique increased the risk of death 3.6 times compared with the femoral approach (p less than 0.05). This result did not apply when analysis was restricted to laboratories with 80% or more brachial procedures. Risk was not altered by heparin. Thus, a prospective, multicenter analysis of complications reveals low risk of coronary arteriography but significant difference between two techniques.

Adult↗