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C Maynard

Publications and source records attributed to C Maynard.

At least 127 records · Page 7Linked to original sources
PubMed1985

The western Washington randomized trial of intracoronary streptokinase in acute myocardial infarction. A 12-month follow-up report.

After cardiac catheterization and coronary arteriography, 134 patients who had had an acute myocardial infarction were randomly assigned to treatment with intracoronary streptokinase (4000 U per minute, begun approximately 4 1/2 hours after the onset of symptoms, for a total of 286,000 +/- 77,800 U over 72 +/- 24 minutes); 116 control patients received standard care after they returned to the coronary care unit, immediately after angiography. Preliminary results of this trial have been published in the Journal (1983; 309:1477-81). During the first 30 days, 5 deaths occurred in the streptokinase group and 13 occurred in the control group (3.7 vs 11.2 per cent, P = 0.02); during the first year, the corresponding figures were 11 and 17 deaths (8.2 vs. 14.7 per cent, P = 0.10). However, when a minor imbalance in the ejection fraction and infarct location between the two groups was adjusted by logistic regression, the difference in one-year mortality became significant (P = 0.03). In the streptokinase group, 2 of the 80 patients in whom perfusion was reestablished (2.5 per cent) had died by one year, whereas 3 of the 13 with partial reperfusion (23.1 per cent) and 6 of the 41 with no reperfusion (14.6 per cent) had died (P = 0.008). Mortality among patients with partial reperfusion was not significantly different from that among those without reperfusion (P greater than 0.90). No base-line clinical, angiographic, or hemodynamic variable was predictive of successful reperfusion, according to univariate and multivariate analyses. We conclude that intracoronary streptokinase reduces one-year mortality among patients with acute myocardial infarction, but this improvement occurs only among those in whom thrombolysis results in coronary artery reperfusion.

Coronary Angiography↗
PubMed1985

Acute myocardial infarction treated with intracoronary streptokinase: a report of the Society for Cardiac Angiography.

The Society for Cardiac Angiography maintains a registry of intracoronary streptokinase therapy (IC-SK) in patients with acute myocardial infarction. Between July 1981 and August 1984, 1,029 patients were entered into the registry. The baseline and clinical characteristics of patients were determined, the early results of therapy were evaluated, and baseline characteristics of those in whom reperfusion was achieved were compared with those in whom it was not. Multivariate discriminant analysis was used to identify the predictors of reperfusion and hospital mortality. The overall rate of reperfusion was 71.2%. Reperfusion was positively associated with hypotension, absence of cardiogenic shock and early treatment. The hospital mortality rate for all patients was 8.2% and was higher for women and the elderly. The hospital mortality was significantly lower among patients in whom reperfusion was achieved compared with those in whom it was not (5.5% vs 14.7%, p less than 0.0001) and for several high-risk subgroups. Thus, coronary artery reperfusion induced by IC-SK significantly reduces hospital mortality in high-risk patients with acute myocardial infarction. High-risk patients in whom reperfusion fails with IC-SK therapy should be considered for early coronary angioplasty or coronary artery bypass surgery.

Age Factors↗
PubMed1985

Surgical survival in the Coronary Artery Surgery Study (CASS) registry.

The overall surgical survival data in the Coronary Artery Surgery Study (CASS) registry have not been published to date, pending the report of the randomized medical-surgical comparison (CASS randomized trial). Non-randomized surgical survival data from the CASS registry are given in this article. The overall medical survival data from the registry were reported previously as a natural history study. There were 8,991 patients in the registry portion of CASS who had primary isolated coronary artery bypass grafting and 8,971 with follow-up of more than 30 days. The 5-year survival for all 8,971 patients was 90%, and the operative mortality was 2.37%. Patients with left main coronary artery disease had an operative mortality of 3.84% and a 5-year survival of 85%, while patients with lesions in other vessels had an operative mortality of 2.12% and a 5-year survival of 91%. Among patients without left main coronary disease, the 5-year survival was 93% in those with single-vessel and 92% in those with double-vessel disease (operative mortality was 1.50% and 1.92%, respectively) and 88% in patients with triple-vessel disease (operative mortality was 2.62%; p = 0.009). When results for patients with left main coronary artery obstruction were compared with those for triple-vessel disease, the 5-year survival figures were 85% and 88%, respectively (p = 0.02) and the operative mortality, 3.84% and 2.62%, respectively (p = 0.03). Patients with normal or nearly normal left ventricular (LV) function (i.e., LV segmental wall motion scores ranging from 5 through 11) had a 5-year survival of 92% and an operative mortality of 1.97%. Patients with moderate impairment (LV score range, 12 through 16) had a 5-year survival of 80% and an operative mortality of 4.21%. In those with poor ventricular function (LV score of 17 or greater), the 5-year survival was 65% and the operative mortality was 6.21%. The difference in survival among the three groups was significant (p less than 0.0001). Of 29 variables used in a stepwise Cox regression analysis, LV wall motion score, congestive heart failure score, age, number of operable vessels, smoking history, LV end-diastolic pressure, and percent of left main coronary artery stenosis were found to have a significant effect on long-term survival (excluding 30-day mortality), and these variables plus surgical priority and height influenced surgical mortality. When height was used in the Cox proportional hazards model, female sex was no longer a significant variable.

Adult↗
PubMed1985

Late effects of intracoronary streptokinase on regional wall motion, ventricular aneurysm and left ventricular thrombus in myocardial infarction: results from the Western Washington Randomized Trial.

To determine whether intracoronary streptokinase improves late regional wall motion or reduces left ventricular aneurysm or thrombus formation in patients with acute myocardial infarction, two-dimensional echocardiography was performed at 8 +/- 3 weeks after infarction in 83 patients randomized to streptokinase (n = 45) or standard therapy (n = 38) in the Western Washington Intracoronary Streptokinase Trial. Among the patients treated with streptokinase, the average time to treatment was 4.7 +/- 2.5 hours after the onset of chest pain, and 67% had successful reperfusion. Regional wall motion was assessed in nine left ventricular segments on a scale of 1 to 4 (normal, hypokinetic, akinetic and dyskinetic). Left ventricular thrombus formation was interpreted as positive, equivocal or negative. All patients received anticoagulant therapy in the hospital and 52 received such therapy after hospital discharge. The mean (+/- SD) global (1.5 +/- 0.4 in both groups) and regional wall motion scores in the streptokinase-treated and control groups were not significantly different. The prevalence of aneurysm was 16% in both groups. Left ventricular thrombus was identified in only five patients (positive identification in four, and equivocal in one), all in the streptokinase-treated group (p = NS). There were also no differences between streptokinase and control treatment in any of the echocardiographic variables in subgroups of patients with anterior infarction, inferior infarction, no prior infarction or reperfusion with streptokinase. It is concluded that intracoronary streptokinase given relatively late in the course of acute myocardial infarction does not result in improved global or regional wall motion or a reduction in left ventricular thrombus or aneurysm formation in survivors studied 2 months after myocardial infarction.

Aged↗
PubMed1985

Coronary anatomy and left ventricular function in the first 12 hours of acute myocardial infarction: the Western Washington Randomized Intracoronary Streptokinase Trial.

The relationships among clinical variables, coronary anatomy, and left ventricular function during the early hours of acute myocardial infarction (AMI) were evaluated from data acquired in the Western Washington Intracoronary Streptokinase Trial. All patients had symptoms and electrocardiographic changes typical of AMI. All data were obtained before treatment with streptokinase. Mean time to catheterization was 4.1 hr after onset of symptoms. Coronary angiograms (n = 245) were analyzed for location of infarct-related occlusion and collateral flow to the infarct bed. Left ventricular ejection fraction and regional left ventricular function were quantitated in 227. Sixty-two percent of occlusions were in the most proximal segment of the involved coronary artery. Collateral circulation was seen in 42% overall, in 31% with left anterior descending artery (LAD) occlusion, and in 52% with right coronary artery (RCA) occlusion (p less than .005). Left ventricular ejection fraction was lowest and regional function was most abnormal in the group with proximal LAD occlusion. Hyperkinesis was present in 32%; in those with hyperkinesis, hyperkinetic segment length was longest in those with RCA or circumflex occlusion. Multivariate analysis identified proximal LAD occlusion as the factor most closely associated with left ventricular ejection fraction and with measures of left ventricular regional hypofunction. We conclude that (1) AMI is usually caused by occlusion or subtotal occlusion in the most proximal portion of the involved coronary artery, (2) collateral circulation is more frequent with RCA than with LAD occlusion, and (3) location of the infarct-related occlusion is the most important determinant of global and regional left ventricular function in the early hours of AMI.

Aged↗
PubMed1983

Results of coronary artery surgery in patients with poor left ventricular function (CASS).

We identified 420 medically treated and 231 surgically treated patients (coronary graft plus myocardial surgery in 30%) who had severe left ventricular dysfunction manifest by an ejection fraction below 0.36 and markedly abnormal wall motion. Compared with medically treated patients, those treated surgically had more severe angina (56.7% vs 29.0% class III or IV; p less than .001), less heart failure as predominant symptom (11.1% vs 18.8%; p less than .003), more severe coronary disease (66.7% vs 50.2% three-vessel disease; p less than .001), a greater concentration of left main coronary artery lesions greater than 70% (12.6% vs 3.8%: p less than .001), and a greater estimated extent of jeopardized myocardium (p less than .001). Multivariate regression analysis of survival, which adjusts for the above covariates, showed that surgical treatment prolonged survival (p less than .05), although it ranked below severity of heart failure symptoms, age, ejection fraction, and left main stenosis greater than 70% in determining prognosis. Surgical benefit was most apparent for patients with ejection fractions below 0.26 who had a 43% 5 year survival with medical treatment vs 63% with surgery. Surgically treated patients experienced substantial symptomatic benefit compared with medically treated patients if their presenting symptoms were predominantly angina; however, there was no relief of symptoms caused primarily by heart failure. We conclude that patients with predominantly ischemic pain symptoms, despite poor left ventricular function, benefit from surgery; however, operative mortality in this high-risk subset must equal or better the 6.9% obtained in this study.

Actuarial Analysis↗
PubMed1982

Interobserver variability in interpreting contrast left ventriculograms (CASS).

Randomly selected left ventricular cineangiograms performed by 14 medical centers (clinical sites) participating in a large multicenter study of medical and surgical treatment of coronary artery disease (CASS) were systematically recalled and reread by one of four designated quality control centers. The end diastolic volume (EDV), end systolic volume (ESV), and ejection fraction (EF) calculated by the quality control center were compared with those calculated by the clinical site, and correlation coefficients of 0.71, 0.84, and 0.79, respectively, were obtained. Regional left ventricular (LV) wall motion abnormalities were assessed by dividing the LV wall as viewed in the right anterior oblique (RAO) and left anterior oblique (LAO) views into five segments each and grading the motion of each segment according to six categories of increasing abnormalities from normal to aneurysm. When discrepancies based on "nearest neighbor" differences in naming adjacent segments were eliminated and only marked differences of more than one degree of severity of wall motion abnormality were considered, interobserver differences were 7% and 10% for RAO and LAO segments, respectively. Agreement was less frequent in designating a segment "aneurysmal." When each LV segment was assigned a numerical score based on increasing severity of wall motion abnormality and a total LV score for each ventriculogram computed, the quality control and clinical site readings were in good agreement with a correlation coefficient of 0.83.

Cardiac Volume↗
PubMed1982

Reproducibility of coronary arteriographic reading in the coronary artery surgery study (CASS).

Eight hundred seventy arteriograms from the Coronary Artery Surgery Study (CASS) were independently read by readers at two different clinics to evaluate the reproducibility of the interpretation of coronary arteriograms. Among proximal segments, the interpretation of lesions of the left main coronary artery were the least reproducible, P less than .02. When one angiographer reads a stenosis of 50% or more in the left main coronary artery, it is estimated that a second reader will report no lesion 18.6% of the time. In 94.7% of the films, the number of significantly (greater than or equal to 70% stenosis) diseased vessels was the same for both readers (72.1%) or differed by one vessel (22.6%). The reproducibility of interpretation of films of good or acceptable quality or completeness was better than the reproducibility of readings of arteriograms judged to be of poor quality or incomplete studies. The mean absolute difference between readings of the percent stenosis decreased over the time of the patient enrollment, 1975 to 1978. This may have resulted from major collaborative efforts made during the course of the study to improve the quality of angiography and to standardize the reading of the cine films.

Angiography↗
PubMed1982

Association of sex, physical size, and operative mortality after coronary artery bypass in the Coronary Artery Surgery Study (CASS).

The Collaborative Study in Coronary Artery Surgery (CASS) is a large multi-institutional study of the medical and surgical treatment of coronary artery disease. Fifteen cooperative institutions have carried out isolated coronary artery bypass grafting (CABG) on 6,258 men and 1,153 women during the period August, 1975, through May, 1980. The operative mortality in men was 1.9%, while the operative mortality for women undergoing CABG in the same institutions during the same time period was 4.5%. In an effort to explain this result, we used multivariate analysis to identify factors associated with increased mortality in women after CABG. The hypothesis that smaller physical size might be contributing to increased mortality was considered. Basic clinical and angiographic variables, size variables, including the average diameter of the grafted vessels, and gender were examined separately for patients who underwent elective and urgent and emergency procedures. Using multivariate information theory, we found that the most information regarding survival after operation is contained in basic clinical and angiographic variables. The physical size of the patient, including coronary artery diameter, helps predict operative mortality even after adjusting for differences in risk predicted by the basic variables and gender. However, the patient's sex is not statistically significantly related to the risk of surgical death given the information available from clinical and angiographic variables and from knowledge of patient size. One possible explanation of the excess risk for coronary artery operations in women is the smaller stature and the smaller diameter of the coronary arteries in this group of patients.

Adult↗
PubMed1982

[Variability in the interpretation of coronary angiograms by different specialists based on data from the cooperative Coronary Artery Surgery Study].

Randomly selected cine arteriographic films of 30 diseased patients were read twice by each of three experienced observers. The intrareader variability was less than one-half of the interreader variability in reading the stenosis of segments of the coronary anatomy - a statistically significant difference (p less than 0.001). When extent of disease was evaluated by the number of diseased vessels, interreader variability was larger than intrareader variability (p less than 0.01). One reader read considerably less disease than the other two readers. The films were rated as to quality of the arteriographic films and the completeness of the study. In each case there was a greater interreader than intrareader variability (p less than 0.01). The films were rated good, acceptable, or poor. One of the three interpreters consistently gave worse ratings than the other two readers. It was particularly noteworthy that a larger amount of interreader variability was observed in both the left main coronary artery and the proximal left anterior descending artery.

Canada↗
PubMed1982

Determinants of coronary surgery in a consecutive patient series from geographically dispersed medical centers. The coronary artery surgery study.

The Coronary Artery Surgery Study registry enrolled 24,959 patients from 1974 through 1979. Of these patients, 12,556 had anginal chest pain symptoms and significant angiographic coronary disease (greater than or equal to 70% lesion in a major vessel or greater than or equal to 50% in the left main coronary artery) and were considered coronary bypass surgery candidates. Stepwise linear discriminant-function analysis of clinical and angiographic determinants of therapeutic assignment revealed that myocardial jeopardy (a composite score of the relationship of proximal lesions to retained wall motion in anterior and inferior segments) was the most important determinant. Site-to-site variability, another important predictor of therapeutic assignment, was assessed after adjusting for differing patient populations and was found to be significant (p less than 0.001). Other significant predictors were angina severity, the number of operable vessels, change in activity level, unstable angina and the presence of a left main lesion. Temporal changes (between 1974 and 1979) in the use of beta-blocking drugs and in therapeutic assignment of patients with left main lesions and one-vessel disease suggested altered decision-making in response to the reporting of major coronary surgery trials. We conclude that the dominant factors in therapeutic assignment for patients with completed arteriographic evaluations reflect considerations of jeopardized myocardium and continuing diversity of opinion about the importance of therapeutic and prophylactic indications for coronary surgery.

Actuarial Analysis↗
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↗
PubMed1980

Multivariate discriminant analysis of the clinical and angiographic predictors of operative mortality from the Collaborative Study in Coronary Artery Surgery (CASS).

The Collaborative Study in Coronary Artery Surgery (CASS) is a large multi-institutional study of the medical and surgical treatment of coronary artery disease (CAD). Fifteen cooperating institutes have carried out isolated coronary artery bypass grafting (CABG) on 6,176 patients from August, 1975, through December, 1978. The operative mortality (OM) was 2.3%. In an effort to better understand the clinical and angiographic characteristics predictive of OM, we have done a multivariate discriminant analysis of variables associated with OM. Numerous clinical and angiographic variables were selected from the CASS data file and evaluated in a univariate manner for their relationship to OM. Twenty of these variables were then selected for multivariate discriminant analysis. Clinical variables of most predictive value were age, female sex, increased heart size, and congestive heart failure (CHF). Angiographic variables of importance included left ventricular wall motion abnormalities, and left main coronary disease (LMCD). The priority of operation (elective, urgent, or emergent) was also associated with OM. Six variables that contained the most predictive information were selected by discriminant analysis for a group of 6,176 patients who had isolated bypass operations. In descending order of importance they were age, left main coronary artery stenosis greater than or equal to 90%, female sex, left ventricular wall motion score, left ventricular end-diastolic pressure (LVEDP), and râles. Five other groups or subgroups of patients were also analyzed in a similar manner. There is a strong association of OM with advanced age, female sex, and variables associated with left ventricular dysfunction. The risk of OM for an individual patient may be estimated with the use of these clinical and angiographic characteristics.

Adult↗
PubMedDate not supplied

Serial prognostic capabilities of electrocardiographic indices of infarcted and hibernating myocardium in predicting short- and long-term outcome following coronary artery bypass surgery.

The present study was performed to test the hypothesis that patients with a large amount of ischemic (hibernating) myocardium are most likely to develop a perioperative myocardial infarction undergoing coronary artery bypass grafting (CABG). Furthermore, we evaluated the Selvester QRS scoring system as a postoperative prognostic tool. A relationship between a high amount of hibernating myocardium determined by ventriculographic and electrocardiographic investigations and an increased risk of perioperative myocardial infarction was found. The Selvester QRS scoring system used in diagnosing and prognosing after acute myocardial infarction was proven valid in predicting prognosis after CABG as well.

Adult↗
PubMedDate not supplied

Institutional differences in therapeutic decision making in the Coronary Artery Surgery Study (CASS).

This article examines institutional differences in therapeutic decision making in the Coronary Artery Surgery Study (CASS). The initial decision to use medical therapy or coronary artery bypass surgery for coronary artery disease is studied. Data from the CASS registry and a survey of CASS principal investigators were used to examine the effects of institutional characteristics, individual physician characteristics, and decision making responsibility on the recommended therapy, the actual therapy, and the ratio of the observed to expected number of surgeries. The results indicated that the experience and involvement of the surgeon in the decision making process were related to actual and recommended rates of surgery. The percentage of urgent transfers from other hospitals and the percentage of surgical referrals to outside hospitals were related to the ratio of the observed to expected numbers of surgery, an adjusted rate of surgery. A major conclusion of this study is that despite the effects of certain institutional constructs, scientific criteria in the form of clinical and angiographic data are the most important determinants of whether a patient receives coronary artery bypass surgery.

Adult↗
PubMedDate not supplied

The exclusion of women from clinical trials of thrombolytic therapy: implications for developing the thrombolytic predictive instrument database.

The thrombolytic predictive instrument (TPI) was developed to identify those patients most likely to benefit from thrombolytic therapy for acute myocardial infarction as well as to facilitate the earliest possible administration of this treatment. The TPI consists of predictive models derived from clinical data obtained from both clinical trials and data registries. These models are subject to potential bias due to combinations of primary data from different sources. The purpose of this investigation was to assess the influence of gender in developing the TPI database. In this database, there were 1,096 (22%) women and 3,826 (78%) men; only 38% of the women were enrolled in clinical trials, whereas 46% of the men were (p < 0.0001). Within clinical trials, there were few significant eligibility differences between women and men, as the vast majority of patients met eligibility standards for entry in these trials. However, within clinical registries, the women were older (p < 0.0001) and more often had elevated blood pressure on admission (p = 0.002). Multivariate logistic regression indicated that after adjustment for significant predictors of trial inclusion, women were 25% less likely to be included in clinical trials (odds ratio = 0.76, 95% confidence interval = 0.60, 0.96). In order to counter bias introduced by the exclusion of women from clinical trials, the TPI database included patients from non-trial settings. Carefully including patients from clinical registries or non-trial settings may be an important strategy in constructing generally applicable predictive instruments.

Aged↗
PubMedDate not supplied

Institutional volumes and coronary angioplasty outcomes before and after the introduction of stenting.

CONTEXT: An increasing number of patients undergoing percutaneous transluminal coronary angioplasty (PTCA) are receiving coronary stents. OBJECTIVES: To assess whether the introduction of coronary stenting has changed hospital mortality or same-admission coronary artery bypass grafting (CABG) and whether the hospital's procedure volume affects these outcomes. DESIGN: Observational study using hospital claims. SETTING: Nonfederal hospitals that performed PTCA in California in 1993 and 1996. PATIENTS: 35,350 patients who underwent PTCA in 1993 (before the introduction of stenting) and 43,040 patients who had PTCA in 1996 (43% of whom received stents). MEASUREMENTS: Hospital stenting volumes for 1996 were divided into terciles; total PTCA procedures per year were categorized as low (< or = 200), medium (201 to 400), or high (> 400). Outcome variables included hospital death and coronary artery bypass grafting (CABG) performed during the same admission. Patients with a principal diagnosis of acute myocardial infarction (AMI) were analyzed separately from those without such a diagnosis. RESULTS: From 1993 to 1996, the characteristics of patients undergoing PTCA did not change substantially. The use of same-admission CABG decreased by 13% (from 6.0% to 5.2%; P = 0.008) in the AMI group and by 30% (from 3.7% to 2.6%; P < 0.001) in the no-AMI group. Hospital mortality did not change significantly in either group. Procedure volume was not related to hospital mortality. However, rates of same-admission CABG were significantly lower at hospitals with high annual stenting volumes than at low-volume centers (1.3% vs. 2.3% among patients in the no-AMI group; P < 0.001). CONCLUSIONS: Hospital mortality rates after PTCA have not changed considerably since the introduction and diffusion of coronary stenting. However, rates of same-admission CABG have decreased in recent years and are lowest at hospitals with high procedure volumes.

Aged↗