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Biomedical subjects

R M Califf

Publications and source records attributed to R M Califf.

At least 325 records · Page 18Linked to original sources
PubMed1996

Effect of subintimal resection on initial outcome and restenosis for native coronary lesions and saphenous vein graft disease treated by directional coronary atherectomy. A report from the CAVEAT I and II investigators. Coronary Angioplasty Versus Excisional Atherectomy Trial.

OBJECTIVES: This study was designed to determine whether the depth of tissue resection affected either immediate outcome or subsequent restenosis in patients treated by directional coronary atherectomy (DCA) in the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) I and II studies. BACKGROUND: The relation between the depth of tissue resection, immediate outcome and subsequent restenosis in lesions treated with DCA has been controversial. METHODS: In CAVEAT I, 412 patients undergoing DCA had tissue samples available for analysis by the core laboratory, whereas in CAVEAT II, 113 patients had vein graft tissue specimens available. RESULTS: Subintimal deep arterial wall resection was demonstrated in 169 patients (41%) in CAVEAT I and 40 (35%) in CAVEAT II. The depth of tissue resection did not affect initial procedural outcome in either CAVEAT I or CAVEAT II, nor did it affect subsequent restenosis rates at 6 months in native coronary lesions (CAVEAT I, 50.8% for intimal resection vs. 51.2% for subintimal resection). In patients treated with vein graft disease (CAVEAT II), restenosis rates varied; when resection was limited to the intima, a restenosis rate of 40.4% was documented, whereas in patients with subintimal resection, the restenosis rate was 57.1%. This difference was not statistically significant (p = 0.144). CONCLUSIONS: This combined randomized series of DCA for treatment of primary native coronary artery and vein graft stenoses with quantitative coronary angiography and core laboratory pathologic assessment resolves the controversy created by previous experimental and clinical data regarding deep vessel wall resection and immediate and longer outcome. Directional atherectomy with deep arterial wall resection as practiced in these studies is safe and does not jeopardize initial success rates. More important, deep wall resection is not associated with significantly increased restenosis rates.

Atherectomy, Coronary↗
PubMed1996

Performance of an automated real-time ST-segment analysis program to detect coronary occlusion and reperfusion.

Continuously updated ST-segment recovery analysis has been shown to accurately predict infarct-related artery patency. Salient principles were converted into algorithms and incorporated into a portable ST monitor for optimal application. This study tested the automated program's ability to detect occlusion and reperfusion during balloon angioplasty. ST-segment recordings during 78 balloon occlusions in 31 patients were analyzed. The program requires at least one electrocardiogram with ST elevation of 200 microV or greater in the recording, caused by the current occlusion or by a previous occlusion, before it will yield a patency prediction. All 35 inflations causing peak ST elevation of 200 microV or more were indeed detected. All five inflations causing less than 200 microV ST elevation preceded by an inflation causing 200 microV or higher ST elevation were also detected. Occlusion was detected a median of 40 seconds after inflation, and reperfusion a median of 17 seconds after deflation. Peak ST elevation greater than 200 microV occurred in 19 of 26 left anterior descending artery inflations (73%), 1 of 22 left circumflex artery LCX inflations (5%), and 15 of 30 right coronary artery inflations (50%). Five different leads identified peak ST elevation through 12-lead surveillance. In this model of coronary occlusion during angioplasty balloon inflation, the automated patency assessment program appears to detect coronary angioplasty balloon occlusion and reperfusion within seconds in all occlusions causing a peak ST elevation of 200 microV or greater. Testing this automated patency assessment program as a noninvasive triage tool in myocardial infarction patients seems warranted.

Adult↗
PubMed1996

Long-term survival benefits of coronary artery bypass grafting and percutaneous transluminal angioplasty in patients with coronary artery disease.

The purpose of this study was to evaluate long-term survival benefits of bypass surgery and angioplasty versus medical therapy in 9263 patients at Duke University Medical Center between 1984 and 1990 with coronary artery disease confirmed by cardiac catheterization to involve one, two, or three vessels. Clinical data were prospectively entered into an established cardiovascular database, and annual follow-up was 97% complete for a mean interval of 5.3 years and a maximal interval of 10 years. Outcomes were analyzed with the Coronary Artery Surgery Study "method A" to define patient groups treated by medicine (n = 2449), angioplasty (n = 2924), or bypass surgery (n = 3890). Differences among treatment groups in baseline characteristics were adjusted by Cox proportional hazard models. The anatomic severity of coronary artery stenosis best defined survival benefit from bypass surgery and angioplasty versus medical treatment. One or both interventional treatments provided better long-term survival than did medical treatment for all levels of disease severity. All patients with single-vessel disease, except those with at least 95% proximal left anterior descending stenosis, benefited from angioplasty versus bypass. All patients with three-vessel disease and those two-vessel patients with > or = 95% proximal left anterior descending stenosis benefited from bypass surgery versus angioplasty. All other patients with two-vessel disease and those with > or = 95% proximal left anterior descending stenosis only had similar survival with either interventional treatment. The absolute survival benefit was greatest for patients with severe three-vessel disease treated with bypass surgery.

Angioplasty, Balloon, Coronary↗
PubMed1996

Increased risk of non-Q wave myocardial infarction after directional atherectomy is platelet dependent: evidence from the EPIC trial. Evaluation of c7E3 for the Prevention of Ischemic Complications.

OBJECTIVES: We sought to determine the effects of platelet glycoprotein IIb/IIIa receptor blockade on adverse outcomes, especially non-Q wave myocardial infarction, in patients undergoing directional atherectomy in the Evaluation of c7E3 for the Prevention of Ischemic Complications (EPIC) trial. BACKGROUND: Randomized trials comparing directional atherectomy with percutaneous transluminal coronary angioplasty (PTCA) have demonstrated modest benefits favoring atherectomy but at a cost of increased acute ischemic complications, notably non-Q wave myocardial infarction. The mechanism for this excess risk is unknown. METHODS: Of 2,038 high risk patients undergoing coronary intervention in the EPIC trial, directional atherectomy was performed in 197 (10%). Patients randomly received the chimeric glycoprotein IIb/IIIa antibody 7E3 (c7E3), as a bolus or a bolus and 12-h infusion or placebo. Study end points included death, myocardial infarction, repeat intervention or bypass surgery. RESULTS: Patients undergoing directional atherectomy had a lower baseline risk for acute complications but had a higher incidence of any myocardial infarction (10.7% vs. 6.3%, p = 0.021) and non-Q wave myocardial infarction (9.6% vs. 4.9%, p = 0.006). Bolus and infusion of c7E3 reduced non-Q wave myocardial infarctions by 71% after atherectomy (15.4% for placebo vs. 4.5% for bolus and infusion, p = 0.046). Non-Q wave myocardial infarction rates after PTCA were not affected by c7E3, although Q wave myocardial infarctions were reduced from 2.6% to 0.8% (p = 0.017). CONCLUSIONS: The EPIC trial confirmed the increased risk of non-Q wave myocardial infarction with directional atherectomy use compared with PTCA. A bolus and 12-h infusion of the glycoprotein IIb/IIIa receptor inhibitor c7E3 abolished this excess risk. Directional atherectomy-related non-Q wave myocardial infarction appears to be platelet aggregation dependent.

Abciximab↗
PubMed1996

Angiographic findings and outcome in diabetic patients treated with thrombolytic therapy for acute myocardial infarction: the GUSTO-I experience.

OBJECTIVES: This study sought to determine whether diabetes mellitus, in the setting of thrombolysis for acute myocardial infarction, affects 1) early infarct-related artery patency and reocclusion rates; and 2) global and regional ventricular function indexes. We also sought to assess whether angiographic or baseline clinical variables, or both, can account for the known excess mortality after myocardial infarction in the diabetic population. BACKGROUND: Mortality after acute myocardial infarction in patients with diabetes is approximately twice that of nondiabetic patients. It is uncertain whether this difference in mortality is due to a lower rate of successful thrombolysis, increased reocclusion after successful thrombolysis, greater ventricular injury or a more adverse angiographic or clinical profile in diabetic patients. METHODS: Patency rates and global and regional left ventricular function were determined in patients enrolled in the GUSTO-I Angiographic Trial. Thirty-day mortality differences between those with and without diabetes were compared. RESULTS: The diabetic cohort had a significantly higher proportion of female and elderly patients, and they were more often hypertensive, came to the hospital later and had more congestive heart failure and a higher number of previous myocardial infarctions and bypass surgery procedures. Ninety-minute patency (Thrombolysis in Myocardial Infarction [TIMI] flow grade 3) rates in patients with and without diabetes were 40.3% and 37.6%, respectively (p = 0.7). Reocclusion rates were 9.2% vs. 5.3% (p = 0.17). Ejection fraction at 90 min after thrombolysis was similar in diabetic and nondiabetic patients ([mean +/- SEM] 6.10 +/- 1.6% vs. 60.1 +/- 0.7%, p = 0.7), as was regional ventricular function (number of abnormal chords: 19.1 +/- 2.0 vs. 17.5 +/- 0.8, p = 0.3; SD/chord: -2.3 +/- 0.2 vs. -2.4 +/- 0.1, p = 0.6). Diabetic patients had less compensatory hyperkinesia in the noninfarct zone (SD/ chord: 1.3 +/- 0.2 vs. 1.7 +/- 0.1, p < or = 0.01). No significant difference in ventricular function was noted at 5- to 7-day follow-up. The 30-day mortality rate was 11.3% in diabetic versus 5.9% in nondiabetic patients (p < or = 0.0001). After adjustment for clinical and angiographic variables, diabetes remained an independent determinant of 30-day mortality (p = 0.02). CONCLUSIONS: Early (90-min) infarct-related artery patency as well as regional and global ventricular function do not differ between patients with and without diabetes after thrombolytic therapy, except for reduced compensatory hyperkinesia in the noninfarct zone among patients with diabetes. Diabetes remained an independent determinant of 30-day mortality after correction for clinical and angiographic variables.

Aged↗
PubMed1996

The rationale for thrombolytic therapy.

Substantial progress has been made toward understanding the pathophysiological processes that lead to acute myocardial infarction. Research has shown that the mechanism of infarction is the rupture of an atherosclerotic plaque with a subsequent thrombogenic response from exposed subendothelial tissue, leading to additional or complete obstruction of the vessel. Myocardial cell death then proceeds in a wavefront fashion from the subendocardium to the epicardium. Time to myocardial reperfusion and the extent of collateral flow are the primary determinants of final infarct area. This knowledge led to the development of therapeutic strategies to achieve early and sustained reperfusion of the infarct-related vessel, the presumption being that this would result in increased myocardial salvage and better residual left ventricular function in addition to reductions in infarct expansion and electrical instability. The results of several large thrombolytic trials have supported this model, showing that patients who receive thrombolytic therapy derive a constant relative survival benefit when compared with control patients. The largest comparative thrombolytic trial to date has shown that therapies that result in early, more complete reperfusion are indeed associated with lower mortality; however, these therapies may be associated with higher rate of complications such as intracranial haemorrhage and reocclusion. Future evaluations must include assessment of the benefits relative to the risks of newer, more potent thrombolytic regimens.

Clinical Trials as Topic↗
PubMed1996

Participation of nurses in decision making for seriously ill adults.

The purpose of this study is to describe the involvement of nurses in the decision-making process of seriously ill hospitalized adults. Nurses (696) completed interviews with 1,427 patients. Patient, surrogate, and physician interviews were also completed. Patients and surrogates perceive the nurse as more influential in decision making than does the nurse or physician. Many nurses reported having no (31%) or little (36%) knowledge of their patients' preferences, and 53% of the nurses did not advocate for their patients' preferences. Only 50% of the nurses reported educating their patients about the treatment plan chosen or discussing treatment options with their patients, and few (17%) discuss prognosis. This study indicates nurses are not actively involved in the decision-making process of their patients, especially older or more experienced nurses and those working in intensive care units.

Adult↗
PubMed1995

Abrupt closure: the CAVEAT I experience. Coronary Angioplasty Versus Excisional Atherectomy Trial.

OBJECTIVES: This study sought to assess the incidence and consequences of abrupt closure in a series of patients undergoing directional coronary atherectomy versus percutaneous coronary angioplasty. BACKGROUND: Abrupt closure with coronary angioplasty has been associated with adverse outcome. The results from the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) I, a randomized trial of coronary angioplasty versus directional coronary atherectomy, were analyzed. METHOD: This multicenter trial enrolled 1,012 patients from 1991 to 1992. All records from patients with abrupt closure, which was coded as a discrete complication, were reviewed. RESULTS: Abrupt closure occurred in 60 patients (5.9%) and was associated with a significantly longer hospital stay (median 8 vs. 3 days). Severe proximal target vessel tortuosity was more common in patients with abrupt closure (20.3% vs. 11.6%, p = 0.046), as was preexistent coronary artery thrombus (30.5% vs. 18.3%, p = 0.02). Abrupt closure was associated with a marked increase in subsequent complications (myocardial infarction 46.7% vs. 2.1%, emergency bypass surgery 38.3% vs. 0.32%, death 33% vs. 0%) and occurred more frequently in the directional coronary atherectomy group (8.0% vs. 3.8%, p = 0.005). In the coronary angioplasty group, the occlusion usually occurred at the target lesion (91%), presumably related to the effects of barotrauma. In the directional coronary atherectomy group, the site of the occlusion was the target lesion in only 58% (p = 0.045). The remaining occlusions related to problems with the technique (guide catheter or nose cone trauma), reflecting the fact that directional coronary atherectomy is a more complex procedure. CONCLUSIONS: Abrupt closure remains the principal determinant of adverse outcome after percutaneous procedures for the treatment of coronary artery disease. Although abrupt closure is more common with directional atherectomy than angioplasty, the sequelae are similar.

Aged↗
PubMed1995

Frequency, significance, and cost of recurrent ischemia after thrombolytic therapy for acute myocardial infarction. TAMI Study Group.

Early postinfarction angina implies an unfavorable prognosis. Most published information on this outcome represents data collected in the prethrombolytic era, in which definitions and populations differed considerably. Our purpose was to evaluate the incidence and importance of recurrent ischemia after administration of thrombolytic therapy. We studied patients enrolled in the Thrombolysis and Angioplasty in Myocardial Infarction studies. Patients were enrolled into 5 studies with similar entry criteria; 552 patients were treated with tissue plasminogen activator (t-PA), 293 were treated with urokinase, and 385 received both thrombolytic agents. Recurrent ischemia was defined as symptoms in association with electrocardiographic changes; reinfarction was defined as a reelevation of creatine kinase myocardial band isoenzyme in an appropriate clinical setting. Both recurrent ischemia and reinfarction occurred in 42 patients (3.4%), recurrent ischemia alone occurred in 226 (18%), whereas neither occurred in 964 (78%). Although baseline characteristics were similar among the 3 groups, in-hospital cardiac events (total 73 deaths, 253 heart failure episodes) were not: in-hospital mortality in patients with reinfarction was 21%; with recurrent ischemia, 11%; and with neither event, 4% (p < 0.0001). The in-hospital heart failure rate of patients with reinfarction was 50%; with recurrent ischemia alone, 31%; and with neither event, 17% (p < 0.0001). As expected, median in-hospital costs were highest in patients with reinfarction ($26,802), intermediate for those with recurrent ischemia alone ($18,422), and lowest in patients with neither event ($15,623). Recurrent myocardial ischemia after thrombolytic therapy is a frequent, important, and expensive adverse clinical outcome, making it a critical target for therapeutic intervention.

Aged↗
PubMed1995

Regional variation across the United States in the management of acute myocardial infarction. GUSTO-1 Investigators. Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries.

BACKGROUND: Differences in the management of acute myocardial infarction have been reported among countries, but few studies have investigated this issue in regions of the United States. METHODS: We compared the management of acute myocardial infarction among census regions across the United States, using data from the first Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries trial (GUSTO-1) comprising 21,772 patients, and from the American Hospital Association. RESULTS: We found substantial regional variation in the management of acute myocardial infarction in the United States. Beta-blockers (prescribed for a range of 55 to 81 percent of patients in the various regions), nitrates (prescribed for 61 to 77 percent), and angiotensin-converting-enzyme inhibitors (prescribed for 18 to 23 percent) were used most often in New England, whereas calcium-channel blockers (31 to 42 percent) and lidocaine (14 to 43 percent) were used least often there. Similarly, the proportion of patients undergoing various cardiac procedures differed among regions (range for angiography, 52 to 81 percent of patients; angioplasty, 22 to 35 percent; and coronary-artery bypass surgery, 9 to 17 percent) and was lowest in New England. The regional use of cardiac procedures was closely related to their availability, except in New England. After the analysis was adjusted for clinical and hospital variables, patients in New England were found to be less likely to undergo angiography than patients in the other regions (odds ratio, 0.37; 95 percent confidence interval, 0.32 to 0.42). There was no apparent relation between the use of cardiac procedures and rates of recurrent infarction or death at 30 days or 1 year. CONCLUSIONS: There is substantial regional variation in the use of cardiac medications and procedures to manage acute myocardial infarction in the United States. The use and availability of cardiac procedures are closely related. The management of acute myocardial infarction in New England is atypical in that the relatively limited availability of cardiac procedures does not account for their relatively low use in that region.

Angioplasty↗
PubMed1995

Predictors and sequelae of distal embolization during saphenous vein graft intervention from the CAVEAT-II trial. Coronary Angioplasty Versus Excisional Atherectomy Trial.

BACKGROUND: The purpose of this study was to identify the predictors and sequelae of distal embolization from a multicenter, randomized trial of saphenous vein graft intervention. The CAVEAT-II trial demonstrated that saphenous vein graft directional coronary atherectomy (DCA) was associated with greater angiographic success and less need for repeat intervention compared with percutaneous transluminal coronary angioplasty (PTCA) but at the cost of more acute complications--notably distal embolization. METHODS AND RESULTS: In CAVEAT-II, 305 patients were randomly assigned to DCA (149 patients) or PTCA (156 patients) for lesions with > 60% diameter stenosis in vein grafts > or = 3 mm in diameter. Distal embolization occurred in 20 patients (13.4%) assigned to DCA and 8 patients (5.1%) assigned to PTCA (P = .011). Independent predictors of distal embolization were use of DCA (71% in distal embolization patients versus 47% in patients without distal embolization, P = .011) and presence of thrombus (39% in distal embolization patients versus 14% in patients without distal embolization, P < .00). In-hospital adverse events were more frequent after distal embolization; 71% versus 20%, odds ratio plus (95% confidence intervals) 9.87 (4.65, 20.94). At 12-month follow-up, adverse event rates were also higher in patients with distal embolization (odds ratio, 3.05 [1.95, 4.76]). CONCLUSIONS: In this first prospective multicenter trial of saphenous vein graft intervention, distal embolization was more common after DCA than PTCA and in lesions containing thrombus. It also was associated with worse in-hospital and 12-month outcomes. The risk and sequelae of distal embolization should be considered when choosing a treatment strategy for vein graft disease.

Aged↗
PubMed1995

Job strain and the prevalence and outcome of coronary artery disease.

BACKGROUND: It has been hypothesized that jobs that have both high psychological demands and low decision latitude ("job strain") can lead to coronary disease. The objective of this study was to test whether job strain was correlated with the presence of coronary disease at angiography or with long-term outcome in patients with angiographic coronary disease. METHODS AND RESULTS: Employed patients under the age of 65 years undergoing diagnostic coronary angiography completed a self-administered questionnaire about their job duties and work environment. Job strain was measured by the method of Karasek. Patients were separated into three groups, based on extent of coronary disease: significant disease (> or = 75% stenosis), insignificant disease (> 0% but < 75% stenosis), and normal coronary arteries. Statistical analyses were performed using logistic regression and the Cox proportional hazards model. The 1489 patients enrolled had a median age of 52 years; 76% were male and 88% were white. By design, all patients were employed, 60% in white-collar jobs and only 16% in jobs requiring heavy labor. Traditional cardiac risk factors were most prevalent in the 922 patients with significant coronary artery disease, at intermediate levels in the 204 patients with insignificant disease, and least prevalent in the 363 patients with normal coronary arteries (all P < .01). Job strain was actually more common in patients with normal coronary arteries (35%) than in patients with insignificant (26%) or significant disease (25%, P < .002). In a multivariate analysis, job strain was not significantly correlated with the presence of coronary disease. Job strain was not correlated with angina frequency at the time of angiography. Job strain was not a predictor of cardiac events (cardiac death or nonfatal myocardial infarction) during follow-up. CONCLUSIONS: Job strain was not correlated with the prevalence or severity of coronary artery disease in a cohort of patients undergoing coronary angiography. The outcome of patients with angiographically defined coronary disease was not affected by the level of job strain as measured by the method of Karasek.

Adult↗
PubMed1995

Cost effectiveness of thrombolytic therapy with tissue plasminogen activator as compared with streptokinase for acute myocardial infarction.

BACKGROUND: Patients with acute myocardial infarction who were treated with accelerated tissue plasminogen activator (t-PA) (given over a period of 1 1/2 hours rather than the conventional 3 hours, and with two thirds of the dose given in the first 30 minutes) had a 30-day mortality that was 15 percent lower than that of patients treated with streptokinase in the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO) study. This was equivalent to an absolute decrease of 1 percent in 30-day mortality. We sought to assess whether the use of t-PA, as compared with streptokinase, is cost effective. METHODS: Our primary, or base-case, analysis of cost effectiveness used data from the GUSTO study and life expectancy projected on the basis of the records of survivors of myocardial infarction in the Duke Cardiovascular Disease Database. In the primary analysis, we assumed that there were no additional treatment costs due to the use of t-PA after the first year and that the comparative survival benefit of t-PA was still evident one year after enrollment. RESULTS: One year after enrollment, patients who received t-PA had both higher costs ($2,845) and a higher survival rate (an increase of 1.1 percent, or 11 per 1000 patients treated) than streptokinase-treated patients. On the basis of the projected life expectancy of each treatment group, the incremental cost-effectiveness ratio--with both future costs and benefits discounted at 5 percent per year--was $32,678 per year of life saved. The use of t-PA was least cost effective in younger patients and most cost effective in older patients. At all ages, the use of t-PA in patients with anterior infarctions yielded more favorable cost-effectiveness values. In our secondary analyses, the cost-effectiveness values were most sensitive to a lowering of the projected long-term survival benefits of t-PA and to moderate or greater increases in the projected medical costs for patients in the t-PA group after the first year. In contrast, our results were not sensitive to even very unfavorable assumptions about the additional costs associated with the higher rate of disabling stroke that was noted in patients treated with t-PA in the GUSTO study. CONCLUSIONS: The cost effectiveness of treatment with accelerated t-PA rather than streptokinase compares favorably with that of other therapies whose added medical benefit for dollars spent is judged by society to be worthwhile.

Adult↗
PubMed1995

Distinguishing between early and late responders to symptoms of acute myocardial infarction.

The present study identified factors that distinguish early responders (i.e., requested medical assistance < 60 minutes after the onset of acute myocardial infarction [AMI] symptoms) from late responders (i.e., request made > or = 60 minutes after symptom onset). A questionnaire developed to assess demographic characteristics, contextual factors, antecedents to symptom onset, and behavioral, affective, and cognitive responses was administered in the hospital to 501 patients with documented AMI. Patients who believed that their symptoms were cardiac in nature were more likely to be early responders, whereas patients who attributed their symptoms to indigestion, muscle pain, fatigue, or another cause responded later (p < 0.0009). Early responders believed their symptoms to be more serious (p < 0.0001), felt more comfortable seeking medical assistance (p < 0.0001), were more anxious or upset when they first noticed symptoms (p = 0.0118), and perceived that they had less control of their symptoms (p < 0.0001) than late responders. A stepwise multiple regression analysis further suggested that unmarried patients responded significantly later than married patients, and patients who first experienced their symptoms at work responded significantly later than those who first experienced their symptoms outside of the home but not at work. These results suggest that situational and psychological variables are important determinants of lengthy decision delays in responding to symptoms of AMI.

Affect↗