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Biomedical subjects

R M Califf

Publications and source records attributed to R M Califf.

At least 505 records · Page 28Linked to original sources
PubMed1988

Coronary arterial thrombolysis with combined infusion of recombinant tissue-type plasminogen activator and urokinase in patients with acute myocardial infarction.

To determine whether tissue-type plasminogen activator (t-PA) and urokinase (UK) act synergistically to achieve coronary thrombolysis, incremental doses of both drugs were infused intravenously over 60 min. In 146 consecutive patients treated 3.0 +/- 1.0 hr from symptom onset, coronary angiography was performed 90 min after the start of the infusion and at 7 days. The groups of patients treated by different dose regimen were as follows: group I, 14 patients treated with t-PA 25 mg and UK 0.5 million U; group II, 20 patients given t-PA 25 mg and UK 1.0 million U; group III, 24 patients given t-PA 1.0 mg/kg and UK 0.5 million U; group IV, 33 patients treated with t-PA 1.0 mg/kg and UK 1.0 million U; and group V, 55 patients given t-PA 1.0 mg/kg and UK 2.0 million U. In groups I and II, patency of the infarct-related vessel at 90 min was only 36% and 42%, respectively. With 1 mg/kg t-PA and increasing doses of UK (groups III to V), patency ranged from 72% to 75% (overall 73%). Repeat catheterization at 7 days demonstrated reocclusion in groups III to V in 10 of 110 (9%). The patency and reocclusion rates in groups III to V were not significantly different from those in our previous study of 386 patients treated with t-PA alone (150 mg over 6 to 8 hr). In that study the patency rate of the infarct-related vessel at 90 min was 75% (p = .66) and reocclusion occurred in 15% (p = .11).(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon↗
PubMed1988

Failure of simple clinical measurements to predict perfusion status after intravenous thrombolysis.

To determine whether coronary patency could be detected early during thrombolytic therapy, commonly used markers of perfusion were recorded in 386 patients with acute myocardial infarction treated with tissue plasminogen activator. Infarct artery angiography 90 minutes after initiation of therapy was used to determine perfusion status. Of patients with complete resolution of ST segment elevation before the angiogram, 96% (95% confidence interval, 79% to 100%) showed perfusion on the angiogram, and among those with partial improvement, 84% (95% confidence interval, 76% to 90%) showed perfusion, but these findings occurred in only 6% and 38% of patients respectively. When complete resolution of chest pain occurred before the angiogram, 84% of patients (95% confidence interval, 75% to 90%) showed perfusion, but this finding occurred in only 29% of patients. Although arrhythmias occurred frequently in the first 90 minutes of therapy, none were associated with a higher patency rate. No other factors predicted coronary patency. A logistic regression model showed 25% of patients with 90% or greater probability of patency, but 56% of patients with no ST segment or symptom resolution had patent arteries.

Angina Pectoris↗
PubMed1988

Current prognosis of ischemic mitral regurgitation. Implications for future management.

Ischemic mitral regurgitation is a serious and increasingly common clinical disorder, but at present, little is known of the associated prognostic implications, especially in specific therapeutic subgroups. Over a 6.5-year period beginning January 1, 1981, postinfarction mitral regurgitation was demonstrated ventriculographically in 2,343 (19%) of 11,748 patients having significant coronary artery disease defined at cardiac catheterization. Moderate or severe regurgitation was observed in 381 (3%), and among these patients, four treatment groups were defined: Group I (medical, n = 165), Group II (reperfusion, n = 63), Group III (coronary artery bypass only, n = 94), and Group IV (valve replacement or repair in addition to coronary bypass, n = 59). Multivariable regression analysis of survival data in the overall population and in specific treatment groups was performed with the Cox proportional hazards model. Defined and undefined selection biases precluded formal quantitative survival comparisons among some treatment groups; however, unadjusted and adjusted survival analysis for each group revealed several interesting concepts. First, increasing severity of mitral regurgitation had a progressively negative impact on survival prognosis regardless of treatment. Congestive heart failure, the number of associated disorders, acute presentation requiring cardiac care unit admission, diminished ejection fraction, increasing coronary obstruction, and advanced age all worsened prognosis (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Heart attack.

Explore the source record for details and available documents.

Humans↗
PubMed1988

Surgical survival benefits for coronary disease patients with left ventricular dysfunction.

Controversy still exists about the proper selection of patients with coronary artery disease and left ventricular dysfunction for coronary bypass surgery. To examine this issue, we studied 710 patients with significant coronary artery disease and left ventricular dysfunction (ejection fraction less than or equal to 40%). Of 301 patients treated surgically, 232 had bypass grafts; 17, left ventricular surgery; and 52, both procedures. At 3 years after treatment, unadjusted survival was 84% for surgical patients and 64% for medical patients. At baseline, medical patients had more left ventricular dysfunction than surgical patients, but surgical patients had more coronary artery disease and angina than medical patients. In Cox survival models, two invasive factors (ejection fraction and extent of coronary artery disease) and three noninvasive indexes (assessment of myocardial infarction, angina, and conduction disturbances) were the five best predictors of survival (p less than 0.001). After adjustment for these factors between the two treatment groups, overall surgical survival at 3 years after treatment was 86%, and medical survival was 68%. Long-term surgical survival benefits appeared greatest in patients with the most severe left ventricular dysfunction, most extensive coronary artery disease, and most severe anginal symptoms. We conclude that surgery provides significant survival benefits for coronary disease patients with left ventricular dysfunction; in general, the sicker the patient, the greater the benefit.

Angina Pectoris↗
PubMed1988

Changing efficacy of coronary revascularization. Implications for patient selection.

To evaluate the potential impact of patient selection for coronary artery bypass graft surgery on long-term survival, the outcomes of 5,809 consecutive patients with symptomatic coronary disease documented by angiography at Duke University Medical Center were examined. Over the entire study period (1969-1984), surgical therapy was associated with improved survival compared with medical therapy whether or not adjustment was made for imbalances in baseline prognostic factors. When patients were categorized according to coronary anatomy and left ventricular function, patients with multivessel disease and poor left ventricular function had a greater long-term survival benefit with surgery than did patients with less coronary artery disease and better left ventricular function. When 5-year survival rates were examined as a function of operative risk, a direct relation was found between estimated operative risk and the medical-surgical survival difference. For patients with an operative risk of 1%, the expected 5-year mortality with surgical therapy was 3% versus 8% with medical therapy (an absolute survival difference at 5 years of 5%). In comparison, for patients with an operative risk of 5%, the expected 5-year mortality with surgery was 10% versus 23% with medical therapy (an absolute survival difference at 5 years of 13%). Over 50% of patients with significant coronary artery disease undergoing cardiac catheterization have an estimated operative mortality risk under 2.5%. These patients would be expected to have a small survival advantage treated surgically. As operative mortality rates are subjected to increasing public scrutiny, selection of low-risk patients will reduce the overall benefit of the operation to the population.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Artery Bypass↗
PubMed1988

A clinical comparison of mitral valve repair versus valve replacement in ischemic mitral regurgitation.

Severe mitral regurgitation caused by acute myocardial infarction has been a particularly difficult management problem with disappointing clinical results. Over a 75-month period, ending March 31, 1987, 611 patients underwent mitral valve operations at Duke University Medical Center. Within this group, 55 patients had clearly defined ischemic mitral regurgitation, and 37 of these required emergency operations. Thirty-one of the 55 patients had isolated posterior papillary muscle dysfunction, nine had papillary muscle rupture, and 15 had severe ventricular dysfunction and generalized annular dilatation. Thirty-two patients were treated with primary mitral valve replacement, and 23 had mitral valve repair. In 18, repair was accomplished by a transventricular approach, combining the techniques of commissural annuloplasty, papillary muscle shortening or reimplantation, and infarct exclusion. Transventricular mitral valve repair proved to be safe, expeditious, and effective in restoring valve competence. Although the repair and replacement groups were similar with respect to all relevant baseline characteristics, improved operative survival was observed after valve repair, as compared to replacement, both for the overall group (p = 0.03) and for acute papillary muscle dysfunction (p = 0.05). These data suggest that a policy of predominant mitral valve repair, when appropriately applied in patients with ischemic mitral regurgitation, offers the potential for improving therapeutic results.

Cardiopulmonary Bypass↗
PubMed1987

Outcome in suspected acute myocardial infarction with normal or minimally abnormal admission electrocardiographic findings.

Seven hundred seventy-five consecutive patients with symptoms suggestive of acute myocardial infarction (AMI) who were admitted to the cardiac care unit from the emergency room were studied; 107 had normal electrocardiographic findings and 73 had only minimal nonspecific changes. AMI subsequently evolved in 11 patients (10%) with normal electrocardiographic findings and in 6 (8%) with minimal changes, compared with 245 (41%) with frankly abnormal emergency room findings. Only 1 (1%; 95% confidence limits 0.02 to 5%) and 4 (6%; 95% confidence limits 2 to 15%) of those with normal and nonspecific initial electrocardiographic findings, respectively, had a complication for which they potentially benefited from intensive care unit intervention, although many patients received prophylactic therapy. Thus, the initial emergency room electrocardiogram can effectively separate patients into high- and low-risk groups for AMI and serious complications. Admission to a monitored intermediate care ward may be an acceptable practice in patients with chest pain and a normal or minimally changed initial electrocardiogram.

Age Factors↗
PubMed1987

A randomized trial of immediate versus delayed elective angioplasty after intravenous tissue plasminogen activator in acute myocardial infarction.

We compared the efficacy of immediate coronary angioplasty after acute myocardial infarction with that of elective angioplasty at 7 to 10 days in patients treated initially with intravenous tissue plasminogen activator. The plasminogen activator (150 mg) was administered 2.95 +/- 1.1 hours after the onset of symptoms, to 386 patients with acute myocardial infarction. Ninety minutes later, patency of the coronary artery serving the area of the infarct was demonstrated by coronary angiography in 288 patients (75 percent). Bleeding problems were frequently encountered, as evidenced by an average drop in hematocrit of 11.7 +/- 6.5 points from base line to nadir and by a need for transfusion not related to bypass surgery in 70 patients (18 percent). After successful thrombolysis, 197 patients with a patent but severely stenotic vessel suitable for angioplasty were randomly assigned to immediate angioplasty (n = 99) or, if indicated 7 to 10 days after infarction, to deferred (elective) angioplasty (n = 98). The incidence of reocclusion was similar in the two groups: 11 percent in the group assigned to immediate angioplasty and 13 percent in the group assigned to elective angioplasty. Neither group had a significant improvement in global left ventricular function, and regional wall motion in the infarct zone improved to a similar extent in the two groups. In the elective-angioplasty group, the rate of crossover to emergency angioplasty for recurrent ischemia was 16 percent (whereas 5 percent of the immediate-angioplasty group required emergency repeated angioplasty; P = 0.01). In 14 percent of the patients in the elective group, the stenosis was substantially reduced by the time of the seven-day follow-up angiography, obviating the need for angioplasty. We conclude that in patients with initially successful thrombolysis and suitable coronary-artery anatomy, immediate angioplasty offers no clear advantage over delayed elective angioplasty.

Angioplasty, Balloon↗
PubMed1987

Prognostic effect of bundle branch block related to coronary artery bypass grafting.

The incidence and prognostic effect of the development of new perioperative ventricular conduction abnormalities were examined in all patients undergoing coronary artery bypass surgery at Duke University Medical Center between 1976 and 1981. Of the 913 patients included, transient (resolved before discharge) ventricular conduction abnormalities developed in 156 (17%) and persistent (until discharge) changes developed in 126 (14%). Complete right bundle branch block (BBB) was the most frequent type of new ventricular conduction abnormality, followed by left anterior hemiblock and incomplete right BBB (found in 60%, 26%, and 9%, respectively, of all patients with transient changes and 29%, 33% and 26% of all patients with persistent changes). Development of new ventricular conduction abnormalities was most strongly related to date of operation (p less than 0.0001, univariate chi 2 = 122), increasing from 2% transient and 7% persistent in 1976 to 36% transient and 22% persistent in 1981. The incidence was also higher in older patients. Preoperative ejection fraction and number of diseased vessels were related to development of perioperative ventricular conduction abnormalities but were not independently related after adjustment for other baseline characteristics. Contrary to findings in other studies, development of new perioperative ventricular conduction abnormalities, including isolated new left BBB, did not worsen the survival rate in patients followed up to 3 years after surgery.

Adult↗
PubMed1987

Identification of the optimal electrocardiographic leads for detecting acute epicardial injury in acute myocardial infarction.

Current coronary care electrocardiographic (ECG) monitoring techniques are aimed at detection of cardiac arrhythmias rather than myocardial ischemia. However, in patients with acute myocardial infarction (AMI) who undergo reperfusion therapy, monitoring ST-segment deviation could provide an early noninvasive indicator of coronary artery reocclusion. In this study, the admission 12-lead ECGs of patients with initial AMI were used to propose optimal lead locations for ST-segment monitoring. The study population was selected from consecutive Duke University Medical Center admissions during 1965 to 1981 who met the following inclusion criteria: chest pain for no more than 8 hours, initial AMI documented by ECG and 3 of 4 enzyme criteria, greater than or equal to 0.1 mV (1 mV = 10 mm) of ST elevation in at least 1 of the standard 12 leads (not aVR) on admission ECG, and no ECG evidence of conduction disturbances, ventricular hypertrophy or tachycardia. ST-segment deviation was quantified; AMI location was assigned based on the lead with maximal deviation. Of the 80 patients who had an inferior AMI, lead III was both the most frequent location for ST elevation (94%) and the most common site with maximal ST deviation. Lead V2 had the highest incidence of ST-segment depression (60%). In the 68 patients who had an anterior AMI, lead V2 had the highest frequency of ST elevation (99%). Leads V2 and V3 were the most common sites of maximal elevation. Thus, for monitoring ST deviation, leads III and V2 may be superior to leads II and V1, which are commonly used in arrhythmia monitoring.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1987

Medical approaches to prevention of restenosis after coronary angioplasty.

Although initial success rates for coronary angioplasty have improved, the rate of restenosis within 6 months of the procedure has persisted at 30 to 40%. The relation of restenosis to initial success, recurrence of symptoms and risk factors suggests that high grade or total lesions, long lesions, lesions in the proximal left anterior descending artery or in saphenous grafts, and the absence of intimal dissection after angioplasty are associated with an increased risk of restenosis. Unstable angina, male sex and diabetes are clinical factors associated with a greater risk of restenosis. Pathologic specimens suggest that plaque splitting and disruption are found acutely after angioplasty, but that restenosis occurs as an excessive reparative, proliferative response of smooth muscle cells leading to recurrent luminal narrowing. A prospective analysis of therapeutic interventions to prevent restenosis, such as administering antiplatelet and lipid-lowering agents, intensive diabetic therapy and administration of calcium antagonists, is proposed. Problems with timing of studies, design and sample size are considered. Current recommendations for anti-restenosis therapy include antiplatelet therapy before and after angioplasty, administration of heparin in some patients and intensive risk factor intervention for the 6 months after the procedure.

Angioplasty, Balloon↗
PubMed1987

Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) trial.

The Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) trial was a randomized, multicenter study performed to determine whether immediate or elective (7 day) coronary angioplasty was preferable once infarct vessel recanalization had been confirmed. In addition, a major focus of the effort was to collect detailed information about the clinical course and outcome of all 386 patients entered into the trial, whether randomized or not. This article reports the major end points of acute and follow-up mortality, the incidence and timing of recurrent ischemic events and acute and convalescent infarct-vessel patency. The optimal timing of coronary angioplasty and intravenous tissue plasminogen activator (rt-PA) administration is discussed. The subsets of patients who: 1) were unsuccessfully treated with rt-PA; 2) had a minimal residual (less than 50%) lesion after rt-PA; or 3) underwent emergency coronary bypass surgery are presented. A current practical approach to acute intervention is extrapolated from the TAMI results.

Angioplasty, Balloon↗
PubMed1987

Localizing coronary artery obstructions with the exercise treadmill test.

To determine if patterns of ST depression or elevation during exercise testing provide reliable information about the location of an underlying coronary lesion, we studied 452 consecutive patients with one-vessel disease who underwent treadmill testing. Exercise ST changes were classified as elevation or depression and by lead groups involved. The ST depression occurred most commonly in leads V5 or V6 regardless of which coronary artery was involved. In contrast, anterior ST elevation indicated left anterior descending coronary disease in 93% of cases, and inferior ST elevation indicated a lesion in or proximal to the posterior descending artery in 86% of cases. Furthermore, anterior ST elevation in leads without diagnostic Q waves usually indicated a high-grade, often proximal, left anterior descending stenosis, whereas anterior ST elevation in leads with Q waves usually indicated a totally occluded left anterior descending coronary artery. Thus, ST elevation during exercise testing, although uncommon, is a reliable guide to the underlying coronary lesion, whereas ST depression is not.

Constriction, Pathologic↗
PubMed1987

Exercise treadmill score for predicting prognosis in coronary artery disease.

To determine the prognostic value of the treadmill exercise test, we evaluated 2842 consecutive patients with chest pain who had both treadmill testing cardiac catheterization. The population was randomly divided into two equal-sized groups and the Cox regression model was used in one to form a treadmill score that was then validated in the other group. The final treadmill score was calculated as follows: exercise time--(5 X ST deviation)--(4 X treadmill angina index). Using this treadmill score, 13% of the patients were found to be at high risk; 53%, at moderate risk; and 34%, at low risk. The treadmill score added independent prognostic information to that provided by clinical data, coronary anatomy, and left ventricular ejection fraction: patients with three-vessel disease with a score of -11 or less had a 5-year survival rate of 67%, and those with a score of +7 or more had a 5-year survival rate of 93%. The treadmill score was useful for stratifying prognosis in patients with suspected coronary artery disease who were referred to us for catheterization, and may provide a useful adjunct to clinical decision making in the larger population of patients being evaluated for chest pain.

Adult↗
PubMed1987

The changing survival benefits of coronary revascularization over time.

Previous comparisons of medical and surgical therapy for coronary artery disease were performed in the 1970s and may need to be updated to reflect current treatment efficacy. The purpose of this investigation was to determine the impact on long-term patient survival of changes over time in medical and surgical therapy. Among 5125 patients referred for catheterization between 1969 and 1984, 2261 underwent surgery, and 2864 received medical therapy. Survival in both medically and surgically treated patients improved over time. The improvement in medical patients was due to less sick patients being treated (a decreasing baseline risk), while that observed in surgical patients was due to refinements in care. The rate of improvement in survival over time was much greater in surgical patients, and the difference as compared with medical therapy was highly significant (treatment interaction with time p less than .0001). Estimates of 5 year survival adjusted for baseline risk factors for a patient in 1977 with one-, two-, or three-vessel disease and an ejection fraction of 0.40 were 0.88, 0.80, and 0.64 in medically treated, and 0.88, 0.87, and 0.80 in surgically treated patients. Corresponding projected estimates for 1984 were unchanged for medical patients but improved for surgical patients (0.93, 0.92, and 0.90). Thus, the projected survival benefits of surgery in 1984 appear more significant for all categories of coronary artery disease because of a differential improvement in surgical therapy. These data are relevant to therapeutic decision making for current patients and emphasize the importance of continued analysis of this topic as treatment efficacies change over time.

Coronary Artery Bypass↗
PubMed1986

Prognostic implications of angiographically normal and insignificantly narrowed coronary arteries.

The clinical presentation and prognosis of 1,977 consecutive patients with normal coronary arteries or "insignificant" coronary artery disease (CAD) (no major epicardial artery with 75% or more luminal diameter narrowing) were examined. Compared with patients with significant CAD, these patients had a lower frequency of traditional cardiac risk factors and abnormalities on the rest and exercise electrocardiogram. Cardiac survival was 99% at 5 years of follow-up and 98% at 10 years for patients with normal or insignificantly narrowed coronary arteries. Patients with normal coronary arteries differed from those with insignificant CAD in their myocardial infarction free survival rate: 99% at 5 years and 98% at 10 years for patients with normal coronary arteries, compared with 97% at 5 years and 90% at 10 years for patients with insignificant CAD. A strong relation occurred between the amount of insignificant CAD and follow-up cardiac events (chi 2 = 21.5, p less than 0.0001). Cardiac risk factors were statistically related to the risk of follow-up cardiovascular events when considered alone (chi 2 = 4.93, p = 0.026), but this relation lost significance after adjusting for the effect of coronary anatomy. Patients in both groups continued to have cardiac symptoms that resulted in frequent hospitalizations, medication use and job disability. Almost 50% in any given year of follow-up could not perform activities of high metabolic equivalent requirement and 70% had continuing symptoms of chest discomfort. Although these patients are at low risk of death, many remain functionally impaired for years.

Coronary Angiography↗