Search PubMed⌕ Search

Biomedical subjects

R M Califf

Publications and source records attributed to R M Califf.

At least 469 records · Page 26Linked to original sources
PubMed1989

A brief self-administered questionnaire to determine functional capacity (the Duke Activity Status Index).

To develop a brief, self-administered questionnaire that accurately measures functional capacity and assesses aspects of quality of life, 50 subjects undergoing exercise testing with measurement of peak oxygen uptake were studied. All subjects were questioned about their ability to perform a variety of common activities by an interviewer blinded to exercise test findings. A 12-item scale (the Duke Activity Status Index) was then developed that correlated well with peak oxygen uptake (Spearman correlation coefficient 0.80). To test this new index, an independent group of 50 subjects completed a self-administered questionnaire to determine functional capacity and underwent exercise testing with measurement of peak oxygen uptake. The Duke Activity Status Index correlated significantly (p less than 0.0001) with peak oxygen uptake (Spearman correlation coefficient 0.58) in this independent sample. The Duke Activity Status Index is a valid measure of functional capacity that can be obtained by self-administered questionnaire.

Activities of Daily Living↗
PubMed1989

The evolution of medical and surgical therapy for coronary artery disease. A 15-year perspective.

To elucidate the factors associated with improved survival following coronary artery bypass surgery, we studied 5809 patients receiving medical or surgical therapy for coronary artery disease. Three factors were associated with a significant surgical survival benefit: more severe coronary disease, a worse prognosis with medical therapy, and a more recent operative date. Patients with more extensive coronary obstruction had the greatest improvement in survival. Patients with a poor prognosis because of factors such as older age, severe angina, or left ventricular dysfunction had a reduction in risk that was proportionate to their overall risk on medical therapy. Survival with surgery progressively improved over the study period and by 1984 surgery was significantly better than medical therapy for most patient subgroups. Thus, contemporary coronary revascularization is associated with improved longevity in many patients with ischemic heart disease, especially in those with adverse prognostic indicators.

Age Factors↗
PubMed1989

Repeat percutaneous transluminal coronary angioplasty and predictors of recurrent restenosis.

One hundred seventeen consecutive patients undergoing repeat percutaneous transluminal coronary angioplasty (PTCA) were studied to assess procedural success and recurrent restenosis rates. Clinical, anatomic and procedural variables were examined as predictors of recurrent restenosis using stepwise logistic regression analysis. Primary success was achieved in 114 patients (97.5%). One patient (0.8%) died after acute occlusion. No other in-hospital complications were encountered. After a mean follow-up interval of 218 +/- 160 days, 72 of 114 successfully dilated patients (63%) remained angina free. There were no late deaths. Three patients (2.6%) experienced a late myocardial infarction. Follow-up arteriography was performed in 100 patients (88%), of whom 32% had recurrent restenosis (greater than 50% luminal diameter narrowing). On univariate analysis, the presence of 3 clinical variables at repeat PTCA was associated with significantly higher recurrent restenosis rates compared with their absence, that is, unstable angina (48 vs 20%, p = 0.003), diabetes (61 vs 26%, p = 0.003) and hypertension (46 vs 18%, p = 0.003). Patients with recurrent restenosis had a shorter interval between first and second PTCA compared with those who remained patent (136 +/- 116 vs 214 +/- 163 days, p = 0.018). Multivariate analysis confirmed unstable angina, diabetes and hypertension as independent predictors of recurrent restenosis. Repeat PTCA may be performed for restenosis with a high likelihood of success and low incidence of complications. The rate of recurrent restenosis is similar to that reported for initial angioplasty. Patients with unstable angina, diabetes and hypertension appear to be at higher risk for recurrent restenosis.

Aged↗
PubMed1989

Prediction of early recurrent myocardial ischemia and coronary reocclusion after successful thrombolysis: a qualitative and quantitative angiographic study.

To determine the association of qualitative and quantitative measurements of the myocardial infarct-related coronary narrowing with subsequent recurrent ischemia/reocclusion after successful thrombolysis, 47 patients treated with high-dose (150 mg) tissue plasminogen activator over 6 to 8 hours were studied in the setting of acute myocardial infarction. No patient underwent emergent coronary angioplasty. All patients had Thrombolysis in Myocardial Infarction (TIMI) grade 2 flow or higher at the baseline (90-minute) angiogram; 31 patients had a protocol 24-hour catheterization as well. Eighteen patients had recurrent ischemia/reocclusion whereas 29 had an uneventful hospital course. There was no significant difference in baseline clinical characteristics between the 2 groups. Twenty-five (86%) of those with an uneventful course had TIMI grade 3 flow at baseline angiogram compared with 56% of patients with recurrent events. No significant difference in angiographic morphologic characteristics was found between the 2 groups at baseline catheterization. At 24 hours, however, none of the patients who subsequently had recurrent events had a concentric narrowing, while 13 (58%) of them had a complex morphology. In contrast, quantitative parameters of minimal lumen diameter, percent area stenosis and percent diameter stenosis at baseline and 24 hours were not significantly different between those who did and did not have recurrent ischemia/reocclusion. These findings suggest that the degree and quality of coronary flow at baseline catheterization are more important determinants of sustained patency and event-free hospitalization than are quantitative dimensions or coronary morphology. In addition, narrowings that fail to become concentric within the first 24 hours are more likely to be associated with subsequent ischemia or reocclusion during the early periinfarct period.

Aged↗
PubMed1989

Favorable early and long-term prognosis following coronary bypass surgery therapy for myocardial infarction: results of a multicenter trial. TAMI Study Group.

Coronary bypass surgery was performed before hospital discharge on 82 (21%) of 386 consecutive patients enrolled in the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) multicenter trial of intravenous tissue plasminogen activator and coronary angioplasty for acute myocardial infarction. Time from infarct symptom onset to coronary bypass surgery was 7.3 +/- 1.9 hours for 24 patients operated upon on an emergency basis and 9.3 +/- 5.2 days for 58 patients having late in-hospital surgery. There were no operative deaths and five in-hospital deaths in the surgical group, all of which occurred in patients with preoperative cardiogenic shock. Although patients in the surgical group were older (59.7 +/- 10.4 years versus 54.9 +/- 10.2 years; p = 0.03), had more extensive coronary artery disease (42% three-vessel disease versus 11%; p = 0.001), and had a higher incidence of anterior wall myocardial infarction (48% versus 39%; p = 0.02), in-hospital mortality for the surgical group (6%) was similar to that in 301 patients not undergoing surgery (7%) in this trial. For patients discharged from the hospital, mortality at 1 year was 2.5% in the surgical group and 1.8% in patients not having coronary bypass surgery before hospital discharge. At a 1 year follow-up, there were no significant differences in the frequency of cardiac or noncardiac-related hospitalizations or in event-free survival between surgical and nonsurgical groups. The majority of patients in both groups considered themselves to be in excellent or good condition. Coronary bypass surgery can be performed with low morbidity and mortality rates in close temporal association to acute myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon↗
PubMed1989

Early treatment with intravenous metoprolol for suspected acute myocardial infarction: a phase IV United States trial. Phase IV Metoprolol in Myocardial Infarction Study Group.

Recent randomized clinical trials have shown that total mortality and cardiovascular mortality are reduced by the early intravenous administration of beta-blockers to patients suspected of suffering from acute myocardial infarction. These trials were conducted on patients meeting strict entry criteria. In order to assess this therapy when applied to a broader range of myocardial infarction patients, we performed a Phase IV study of metoprolol in acute myocardial infarction. The study was designed to test whether early (less than 8 hours from onset of chest pain) intervention by practicing physicians with open label intravenous metoprolol for cases of suspected acute myocardial infarction achieved mortality results similar to those obtained in large randomized clinical trials. We studied 3824 patients treated by 741 physicians representing a broad spectrum of clinical practice in the United States. Seventy-two percent of the patients entered into the study had confirmed myocardial infarction (39% anterior, 39% inferior, 22% other locations) and 85% of all individuals treated tolerated the full intravenous dose of 15 mg of metoprolol. The 15 day total mortality and cardiovascular mortality rates were 4.9% and 4.5%; 90 day mortality rates were 6.9 and 5.9%. Patients with anterior infarctions had a significantly greater cumulative mortality rate than patients with other types of infarctions. Marked bradycardia (heart rate less than 45 beats per minute) in the first 8 hours post treatment occurred in 4.7% cases and hypotension (systolic blood pressure less than 90 mm Hg) occurred in 9.8% of cases. When compared with the results of the Göteborg and MIAMI trials of metoprolol, it appears that there is no appreciable increase in mortality or morbidity when metoprolol is used in the community practice of acute coronary care.

Adult↗
PubMed1989

Combined tissue-type plasminogen activator and prostacyclin therapy for acute myocardial infarction. Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) 4 Study Group.

Current limitations of recombinant tissue-type plasminogen activator (rt-PA) therapy for acute myocardial infarction include failure to achieve recanalization in 25% of patients, reocclusion and reperfusion injury. Iloprost, a stable analogue of prostacyclin (PGI2), has been demonstrated to facilitate thrombolysis and reduce myocardial stunning in experimental models. To evaluate combined therapy, rt-PA (100 mg 3 h) and Iloprost (2 ng/kg per min for 48 h) were administered to 25 patients and then rt-PA alone (same dose) was given to an additional 25 patients with evolving myocardial infarction. At 90 min after drug administration, infarct-related vessel patency was observed in 11 (44%) of 25 who received rt-PA plus Iloprost compared with 15 (60%) of 25 who received rt-PA alone (p = 0.26). At 1 week, reocclusion had occurred in 3 (14%) of 21 patients who received combined therapy compared with 6 (26%) of 23 patients treated with rt-PA alone (p = 0.46). Ejection fraction increased significantly from baseline to 7 days for rt-PA alone whereas it decreased with combined therapy (rt-PA alone whereas it decreased with combined therapy (rt-PA alone: 47.3 +/- 11.5% at baseline to 50.4 +/- 9.8% at 7 days; rt-PA plus Iloprost: 51.3 +/- 10.1% at baseline to 49.0 +/- 9.4% at 7 days; difference between groups p = 0.05). At 4 h after therapy, fibrinogen decreased 33% for rt-PA plus Iloprost compared with a 52% for rt-PA alone (p = 0.001). Fibrinogen degradation products increased 60% more for rt-PA alone than for rt-PA plus Ilprost. Thus, the combination of rt-PA plus Iloprost at the doses employed did not improve immediate or follow-up coronary artery patency or left ventricular functional recovery compared with that achieved with rt-PA alone.

Cardiovascular Agents↗
PubMed1989

Painless exercise ST deviation on the treadmill: long-term prognosis.

To evaluate the clinical correlates and long-term prognostic significance of silent ischemia during exercise, 1,698 consecutive symptomatic patients with coronary artery disease who had both treadmill testing and cardiac catheterization were studied. These patients were classified into three groups: Group 1 = patients with no exercise ST deviation (n = 856), Group 2 = patients with painless exercise ST deviation (n = 242) and Group 3 = patients with both angina and ST segment deviation during exercise (n = 600). Patients with exercise angina had a history of a longer and more aggressive anginal course (with a greater frequency of angina, with nocturnal episodes and/or progressive symptom pattern) and more severe coronary artery disease (almost two-thirds had three vessel disease). The 5 year survival rate among the patients with painless ST deviation was similar to that of patients without ST deviation (86% and 88%, respectively) and was significantly better than that of patients with both symptoms and ST deviation (5 year survival rate 73% in patients with exercise-limiting angina). Similar trends were obtained in subgroups defined by the amount of coronary artery disease present. In the total study group of 1,698 patients, silent ischemia on the treadmill was not a benign finding (average annual mortality rate 2.8%) but, compared with symptomatic ischemia, did indicate a subgroup of patients with coronary artery disease who had a less aggressive anginal course, less coronary artery disease and a better prognosis. Thus, silent ischemia during exercise testing in patients with symptomatic coronary artery disease represents an intermediate risk response in the spectrum of exercise-induced ischemia.

Adult↗
PubMed1989

Thrombolysis and Angioplasty in Myocardial Infarction (TAMI-1) trial: influence of infarct location on arterial patency, left ventricular function and mortality.

The influence of infarct location on arterial patency, left ventricular function and mortality after 150 mg of intravenous recombinant tissue-type plasminogen activator (rt-PA) and selective coronary angioplasty was studied in 386 patients with acute myocardial infarction. In 329 patients with acute and 1 week angiograms, the 90 min infarct-related artery patency rate after rt-PA in the left anterior descending, the left circumflex and the right coronary artery was 77, 68 and 68%, respectively. Angioplasty, performed in half the patients, resulted in a final acute patency rate of 93%, which was not related to arterial distribution. Repeat catheterization and revascularization were required in 12% of patients before day 7 and were independent of arterial distribution. The reocclusion rate for the right coronary artery (21%) was higher than that for the left anterior descending (12%) or left circumflex (5%) artery (p = 0.01). Acute and 1 week contrast ventriculograms suitable for analysis were available in 266 patients. Whereas serial left ventricular ejection fraction did not improve during the course of this study, serial regional wall motion (centerline chord method) improved in each arterial distribution. The in-hospital mortality rate of 6% was not related to arterial distribution, although death was twice as likely with proximal compared with distal lesions. Ten of 11 patients who died in the group with the left anterior descending artery as the infarct-related artery had a lesion proximal to the first septal perforator branch.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

Current management of mitral valve incompetence associated with coronary artery disease.

At a time when hospital mortality for adult cardiac operations is continuing to fall, the combined mitral valve coronary bypass subset remains at relatively high risk. Efforts to improve results should be directed toward a more general application of mitral reconstruction in this population, tailoring the type of repair to the pathological anatomy of valve dysfunction. Other promising therapeutic measures include the liberal use of reperfusion therapy in the acute papillary muscle dysfunction group, better selection patients for operation, and perhaps operative recommendation to a greater proportion of the more stable patients that previously were treated medically. Finally increasing the general awareness of this problem should hasten the development of improved management strategies.

Coronary Artery Bypass↗
PubMed1989

Prognostic implications and predictors of enhanced regional wall motion of the noninfarct zone after thrombolysis and angioplasty therapy of acute myocardial infarction. The TAMI Study Groups.

Although impairment of left ventricular function in acute myocardial infarction is closely related to extent of necrosis, function in the noninfarct zone also contributes to global performance and thus may be of prognostic importance. We evaluated left ventricular regional wall motion by the centerline chord method in 332 patients treated with intravenous tissue-type plasminogen activator (t-PA) in the multicenter Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) I trial. All patients had acute contrast ventriculograms of suitable quality for analysis, and 266 patients had paired acute and day 7 ventriculograms. Enhanced function of the noninfarct zone was present during acute catheterization (+0.3 SD/chord) and was associated with preservation of the acute ejection fraction (p = 0.0001). Multiple linear regression analysis revealed the most powerful clinical factor associated with enhanced function of the noninfarct zone was the absence of multivessel disease (p = 0.0001). Clinical factors that were related weakly to noninfarct zone function included female gender (p = 0.08) and higher flow in the infarct artery (p = 0.03). Neither the degree of infarct zone dysfunction nor infarct location was associated with hyperkinesis of the noninfarct zone. In hospital, mortality was closely related to function in the noninfarct zone (p = 0.006), ejection fraction (p = 0.025), and the number of diseased vessels (p = 0.009) but was not related to infarct zone function (p = 0.128).(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon↗
PubMed1989

Recurrent ischemia without warning. Analysis of risk factors for in-hospital ischemic events following successful thrombolysis with intravenous tissue plasminogen activator.

Ischemic events after successful thrombolysis have been reported to occur in 18-32% of patients treated for acute myocardial infarction with thrombolytic therapy, and previous studies in which patients received streptokinase suggest that risk of early recurrent ischemia is closely related to the presence of a high-grade residual stenosis. If these events are predictable after intravenous recombinant tissue-plasminogen activator (rt-PA) thrombolytic therapy, then further intervention after its use could be targeted at selected patients. One-hundred ninety-two patients from the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) I and TAMI III trials had successful rt-PA-mediated thrombolysis without immediate coronary angioplasty (PTCA). One-hundred seventy-four of these patients (92%) had prehospital discharge angiography. The mean age was 56 +/- 11 years; 81% were men; the infarct-related artery was the left anterior descending in 76 (39.8%), the left circumflex in 24 (12.6%), and the right coronary artery in 91 (47.6%). Thrombolysis with rt-PA resulted in a residual 73 +/- 13% diameter and 0.95 +/- 0.51 mm stenosis by quantitative coronary arteriography, and Thrombolysis in Myocardial Infarction (TIMI) flow grade 2 in 59.2% and 3 in 40.8% of stenoses as assessed on angiograms obtained 90 minutes after the initiation of rt-PA therapy. Recurrent ischemic events (ischemia requiring emergency percutaneous transluminal coronary angioplasty or urgent bypass surgery, reocclusion of the infarct-related artery, or cardiac death) occurred in 41 patients (21.3%).(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1989

Pharmacodynamics of thrombolysis with recombinant tissue-type plasminogen activator. Correlation with characteristics of and clinical outcomes in patients with acute myocardial infarction. The TAMI Study Group.

Coagulation analysis was performed on blood samples from 386 patients with acute myocardial infarction drawn before, during, and after a continuous intravenous infusion of 150 mg recombinant tissue-type plasminogen activator (rt-PA) (Activase). Plasma rt-PA rose to peak levels of 2.1 +/- 3.1 micrograms/ml (mean +/- SD). Fibrinogen levels measured by coagulation rate and by sulfite precipitation decreased from baseline levels of 3.0 +/- 0.9 and 3.2 +/- 1.0 g/l, respectively, to nadir levels of 1.4 +/- 0.75 and 1.8 +/- 0.92 g/l, respectively, and were associated with peak levels in serum of fibrinogen-degradation products (FDP) of 230 +/- 470 micrograms/ml. Forty percent of patients experienced a nadir functional-fibrinogen level of less than 1.0 g/l, whereas 20% fell below 0.5 g/l. Nadir fibrinogen levels did not correlate with patency of the infarct-related coronary artery at 90 minutes or with risk of coronary vessel reocclusion within 7-10 days. However, the risk of coronary artery reocclusion was inversely related to the baseline functional fibrinogen level (p = 0.0008), with the magnitude of its drop to nadir level (p = 0.0003) as well as to peak levels of FDP (p = 0.038). Quantitative blood loss correlated with all markers for systemic fibrinogenolysis including nadir fibrinogen level (r = -0.20, p = 0.0011), percent decrease of fibrinogen (r = 0.22, p = 0.001), and peak FDP levels (r = 0.14, p = 0.020). Both patients who experienced intracranial hemorrhage presented with high baseline fibrinogen levels and experienced extensive degradation of coagulable fibrinogen. Overall, patients at greatest risk of systemic fibrinogenolysis tended to be relatively older women with lower body weight.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Coagulation↗
PubMed1989

Exercise treadmill testing is a poor predictor of anatomic restenosis after angioplasty for acute myocardial infarction.

This study evaluated whether an exercise treadmill test could predict restenosis in 289 patients 6 months after a successful emergency angioplasty of the infarct-related artery for acute myocardial infarction. After excluding those with interim interventions (64), medical events (36), or medical contraindications to follow-up testing (25), both a treadmill test and a cardiac catheterization were completed in 144 patients, 88% of those eligible for this assessment. Four patients with left bundle branch block or pacemaker rhythm at the time of treadmill testing were also excluded from analysis. Of six follow-up clinical and treadmill variables examined by multivariable logistic regression analysis, only exercise ST deviation was independently correlated with restenosis at follow-up (chi 2 = 5, p = 0.02). The clinical diagnosis of angina at follow-up, although marginally related to restenosis when considered by itself (p = 0.04), did not add significant information once ST deviation was known. The sensitivity of ST deviation of 0.10 mV or greater for detecting restenosis was only 24% (13 of 55 patients), and the specificity was 88% (75 of 85 patients). The sensitivity of exercise-induced ST deviation for detection of restenosis was not affected by extent or severity of wall motion abnormalities at follow-up, by the timing of thrombolytic therapy or of angioplasty, or by the presence of collateral blood flow at the time of acute angiography. A second multivariable analysis evaluating the association of the same variables with number of vessels with significant coronary disease at the 6-month catheterization found an association with both exercise ST deviation (p = 0.003) and exercise duration (p = 0.04). Angina symptoms and exercise treadmill test results in this population had limited value for predicting anatomic restenosis 6 months after emergency angioplasty for acute myocardial infarction.

Angina Pectoris↗