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K Detre

Publications and source records attributed to K Detre.

At least 37 records · Page 2Linked to original sources
PubMed1994

Evaluating new devices. Acute (in-hospital) results from the New Approaches to Coronary Intervention Registry.

BACKGROUND: To be used optimally, new interventional devices (stent, lasers, atherectomy catheters) must be carefully evaluated in terms of optimal patient and lesion selection, technique of use, expected acute success and complications, and long-term results. Sources for that information include single-center and multicenter (single-device) reports, although randomized trials may then be performed to provide a more definitive picture of any clinical benefits. One interim option, however, consists of carefully collected registry data. The purpose of this article is to review data collected in the National Heart, Lung, and Blood Institute-funded New Approaches to Coronary Intervention (NACI) Registry and to compare them with existing reports. METHODS AND RESULTS: NACI is an independent, investigator-driven effort that seeks to collect uniform data on patients undergoing treatment with one of several investigational devices and thereby provide an unbiased report of procedure outcome. Between November 1990 and November 1992, 36 participating centers treated a total of 3201 lesions in 2835 patients, using one of seven study devices: directional atherectomy (1084 lesions), transluminal extraction atherectomy (240 lesions), rotational atherectomy (349 lesions), Palmaz-Schatz stent (674 lesions), Gianturco-Roubin stent (213 lesions), and the Advanced Interventional Systems (474 lesions) or Spectranetics (167 lesions) excimer lasers. Data on each procedure were recorded on a unique modular database that captured the reason for (and interim result after) each device use. Device success (defined here as stenosis improvement by > or = 20% and a residual stenosis < 50% after new device use) was 66.5% overall. Adjunctive angioplasty was used in 75.5% of lesions, either before (25.9%) or after (43.5%) new device use, yielding an overall lesion success (> or = 20% stenosis improvement with a final residual stenosis < 50% after all devices) of 92.2%. Adjunctive angioplasty after new device use produced further enlargement in minimal lumen diameter (from 2.2 to 2.7 mm) and further reduction in residual stenosis (26.4% to 16.1%) compared with the results present after use of the new devices themselves. Major complications consisting of death (1.6%), Q-wave myocardial infarction (1.3%), or emergency bypass surgery (1.7%) occurred in 4.0% of patients (range, 2.6% to 8.7% across devices). Procedural success, defined as lesion success in all new device-treated lesions without a major complication, was achieved in 90.8% of patients, with a median length of hospital stay of 4 days. CONCLUSIONS: NACI illustrates the type of information that can be obtained in a registry format that examines the acute angiographic and clinical results of new devices according to uniform definitions. Although no registry can substitute for formal interdevice trials, registries such as this can supplement earlier single-center and multicenter reports. In doing so, they can help focus subsequent randomized interdevice comparisons on lesion types for which two or more devices have promising acute results. Given the substantial interdevice differences in baseline patient and lesion characteristics found in NACI, simple "head-to-head" comparison of the results of different devices might give misleading impressions and should be avoided unless such comparisons are restricted to carefully matched patient and lesion subgroups.

Angioplasty, Laser↗
PubMed1994

Liver transplantation for fulminant hepatic failure in the United States: October 1987 through December 1991.

BACKGROUND: Early mortality and retransplantation rates following liver transplantation for fulminant hepatic failure (FHF) are high. We investigated possible reasons for these findings. METHODS: Data were obtained from the liver transplantation database of the United Network for Organ Sharing (UNOS) Scientific Registry. Recipient information was limited to waiting time; diagnosis; demographic, laboratory and serologic data; and six UNOS functional status codes. Donor information included demographic characteristics, cause of death, ABO blood type, and serology test results. Comparisons between FHF and non-FHF were carried out for children and adults separately. The influence of an FHF diagnosis on 1-year patient and graft survival was examined using the Cox proportional hazard model. The same model was used to determine independent predictors of outcome following transplantation for FHF. RESULTS: The majority of FHF recipients were on pretransplant life support, had much shorter waiting times, and were less well matched for ABO blood type (especially the children) than their non-FHF counterparts. Although 1-year survival and graft survival were significantly lower, the significance of these differences was eliminated when the initial recipient, donor and matching characteristics between the two groups were controlled in the analysis. For FHF recipients, ABO mismatch and abnormal kidney function were the strongest independent predictors of adverse outcome. CONCLUSIONS: The results of this study provide circumstantial evidence that patients with FHF derive as much benefit from liver transplantation as patients with other diagnoses of comparable severity.

ABO Blood-Group System↗
PubMed1993

Analysis as-randomized and the problem of non-adherence: an example from the Veterans Affairs Randomized Trial of Coronary Artery Bypass Surgery.

In most randomized clinical trials not all patients adhere to the therapy to which they were randomly assigned. Instead, they may receive the therapy assigned to another treatment group, or a therapy different from any prescribed in the protocol. When non-adherence occurs, problems occur with the analysis comparing the treatments under study. Rigorous statistical principles require attributing outcome events to the original random treatment assignment ('intent-to-treat' analysis). Using data from the Veterans Administration Cooperative Study of Coronary Artery Bypass Surgery, we report the intent-to-treat analysis and apply four other methods of analysis for analysing non-adherers: 1. exclude non-adherers from analysis; 2. transfer them to the alternative treatment group at the time of randomization; 3. censor them at the time of treatment change, and 4. transfer them to the alternative treatment group at the time of treatment change. Inherent problems and biases of these four other methods are discussed.

Angina Pectoris↗
PubMed1991

The NACI Registry: an instrument for the evaluation of new approaches to coronary intervention. The NACI Investigators.

The New Approaches to Coronary Intervention (NACI) Registry was developed to collect in-depth data about patients whose coronary artery lesions are being treated with new interventional techniques such as atherectomy, stents, and laser devices. The NACI Registry database distinguishes among several possible "modes" for device use, such as preparatory, planned definitive, and bailout use. Common definitions are used for data collection across all devices, and device-specific forms are used to record procedural details. NACI's unique modular form design facilitates thorough data collection, even for the most complex treatment scenarios. The database structure allows for data analysis at the patient, procedure, lesion, and device levels, as required to perform in-depth analyses of the immediate and long-term success of new devices. Once adequate knowledge of basic device performance has been collected, the Registry structure can also allow expeditious planning and performance of randomized trials comparing a new device to conventional PTCA.

Angioplasty, Balloon, Coronary↗
PubMed1991

Intraobserver and interobserver variation in the histopathological assessment of liver allograft rejection. The Liver Transplantation Database (LTD) Investigators.

A study to determine the reproducibility of histopathological findings and diagnoses of rejection was carried out on a series of 42 liver allograft needle biopsy specimens by five pathologists practicing at four liver transplant centers. Pathologists from each of the four centers read each slide independently on two different occasions and were asked to assess 12 histopathological features and render a diagnosis. For all histological variables, the intrarater agreement was higher than the interrater agreement. Moderate to excellent agreement occurred among the pathologists about all histological variables thought to be important in establishing the diagnosis of acute rejection (i.e., portal tract inflammation, subendothelial inflammation and bile duct damage). Other variables such as lobular disarray, bile duct proliferation and particularly arteritis, however, were only fairly or poorly reproducible. Surprisingly, the diagnosis of acute rejection was more reproducible than the individual histopathological findings that were thought to be the basis for the diagnosis. The agreement for the diagnosis of chronic rejection, however, varied according to observer. We noted that relatively inexperienced observers within this group had some difficulties agreeing with more experienced observers in establishing a diagnosis of chronic rejection. These findings demonstrate that the histopathological diagnosis of acute cellular liver allograft rejection is highly reproducible within a group of experienced pathologists and that this diagnosis can be pooled in a common data base with confidence.

Biopsy, Needle↗
PubMed1991

Ten-year incidence of myocardial infarction and prognosis after infarction. Department of Veterans Affairs Cooperative Study of Coronary Artery Bypass Surgery.

BACKGROUND: The 10-year incidence of myocardial infarction (fatal and nonfatal) and the prognosis after infarction were evaluated in 686 patients with stable angina who were randomly assigned to medical or surgical treatment in the Veterans Administration Cooperative Study of Coronary Artery Bypass Surgery. METHODS AND RESULTS: Myocardial infarction was defined by either new Q wave findings or clinical symptoms compatible with myocardial infarction accompanied by serum enzyme elevations with or without electrocardiographic findings. Treatment comparisons were made according to original treatment assignment; 35% of the medical cohort had bypass surgery during the 10-year follow-up period. The overall cumulative infarction rate was somewhat higher in patients assigned to surgery (36%) than in medical patients (31%) (p = 0.13) due to perioperative infarctions (13%) and an accelerated infarction rate after the fifth year of follow-up (average, 2.4%/yr in the surgical group versus 1.4%/yr in the medical group). The 10-year cumulative incidence of death or myocardial infarction was also higher in surgical (54%) than in medical (49%) patients (p = 0.20). According to the Cox model, the estimated risk of death after infarction was 59% lower in surgical than in medical patients (p less than 0.0001). The reduction in postinfarction mortality with surgery was most striking in the first month after the event: 99% in the first month (p less than 0.0001) and 49% subsequently (p less than 0.0001). The estimated risk of death in the absence of infarction was nearly identical regardless of treatment (p = 0.75). Exclusion of perioperative infarctions did not alter the findings. CONCLUSIONS: Although surgery does not reduce the incidence of myocardial infarction overall, it does reduce the risk of mortality after infarction, particularly in the first 30 days after the event (fatal infarctions).

Angina Pectoris↗
PubMed1991

Intent-to-treat analysis and the problem of crossovers. An example from the Veterans Administration coronary bypass surgery study.

In randomized clinical trials of treatment for ischemic heart disease that compare medical with surgical treatment, many persons initially assigned to medical therapy eventually receive surgical intervention. For example, in the three major trials of bypass grafting for stable angina, crossover rates from medical to surgical therapy were approximately 25% at 5 years. For this reason, the classic intent-to-treat analyses have been criticized for their inability to evaluate the "true" effect of treatment. In this article we emphasize the concept of "initial treatment" as it applies to intent-to-treat analyses and examine four proposed alternative methods of analysis based on adherence with survival data from the Veterans Administration Cooperative Study to illustrate the concepts. The alternative methods include (1) censoring crossovers when treatment changes, (2) transferring crossovers from the original to the new treatment group when treatment changes, (3) excluding all crossovers from analysis, and (4) counting crossovers from the date of randomization in the treatment ultimately received group. We point out the biases attendant on analyses based on adherence and reaffirm the validity of intent-to-treat analysis.

Actuarial Analysis↗
PubMed1989

Reproductive history of women dying of sudden cardiac death: a case-control study.

Reproductive history events may be risk factors for sudden coronary death (SCD) among women. A retrospective case-control study of SCD among women aged 25-64 was conducted in Allegheny County, Pennsylvania. The present analysis focused on a description and analysis involving the childbearing and reproductive history of 67 ever-married female SCD cases and 73 ever-married neighbourhood controls with a mean age of 54.6 and 53.4 years respectively. Information included: age and number of years married, number of children, age at first birth, cardiovascular risk factors, obstetric and gynaecological history. Age and the risk factors, history of hypertension or diabetes, cigarette intake, death of significant other and psychiatric disease, were controlled for in the analysis. More cases than controls experienced their first birth before age 20 (14 of the SCD and 7 controls). However, after adjustment for cigarette smoking status, a strong predictor of sudden cardiac death, the effect of early childbearing did not remain significant for this population. In women less than or equal to 50 years of age, childlessness was not a risk factor for SCD (1 of 16 cases and 2 of 26 controls were childless). However in women greater than 50 years of age, childlessness was a significant predictor of SCD (OR = 6.7 (1.3-32] 12 of 51 cases were childless compared to 2 of 46 controls. After adjustment for aged and other coronary heart disease (CHD) risk factors, the relationship of nulliparity with sudden cardiac death remained in this age group. There was no difference in hysterectomy or miscarriage history or in the total years married between cases and controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

One-year follow-up results of the 1985-1986 National Heart, Lung, and Blood Institute's Percutaneous Transluminal Coronary Angioplasty Registry.

In 1,801 patients in the 1985-1986 Percutaneous Transluminal Coronary Angioplasty Registry, overall 1-year mortality was 3.2%, the 1-year myocardial infarction rate was 7.2%, and the 1-year coronary artery bypass surgery rate was 13.2%. In the 78% of the cohort with all lesions successfully dilated and without major procedural complications (successful patients), the corresponding rates were 1.9%, 2.6%, and 6.4%. Nearly 20% of all deaths, 40% of all infarctions, and 25% of all bypass operations occurred in the small subset of patients (6.8%) who sustained periprocedural occlusion. Event rates were higher in patients with multivessel disease than in those with one-vessel disease. At 1 year, angina-free status was reported by approximately three fourths of all surviving patients, regardless of initial success. However, compared with successful patients, unsuccessful patients underwent intervening bypass surgery (42% vs. 6%) to achieve asymptomatic status more frequently. Comparison of the 1-year event rates in the 1985-1986 registry with those in the 1977-1981 registry indicated reductions in all major untoward events. These reductions became apparent after controlling for the more extensive disease of the 1985-1986 registry patients. In contrast, use of repeat angioplasty has increased by 50%. We conclude that the improved initial results reported in the 1985-1986 registry cohort were maintained at 1-year follow-up.

Angina Pectoris↗
PubMed1988

Percutaneous transluminal coronary angioplasty in 1985-1986 and 1977-1981. The National Heart, Lung, and Blood Institute Registry.

In August 1985, the Percutaneous Transluminal Coronary Angioplasty Registry of the National Heart, Lung, and Blood Institute reopened at its previous sites to document changes in angioplasty strategy and outcome. The new registry entered 1802 consecutive patients who had not had a myocardial infarction in the 10 days before angioplasty. Patient selection, technical outcome, and short-term major complications were compared with those of the 1977 to 1981 registry cohort. The new-registry patients were older and had a significantly higher proportion of multivessel disease (53 vs. 25 percent, P less than 0.001), poor left ventricular function (19 vs. 8 percent, P less than 0.001), previous myocardial infarction (37 vs. 21 percent, P less than 0.001), and previous coronary bypass surgery (13 vs. 9 percent, P less than 0.01). The new-registry cohort also had more complex coronary lesions, and angioplasty attempts in these patients involved more multivessel procedures. Despite these differences, the in-hospital outcome in the new cohort was better. Angiographic success rates according to lesion increased from 67 to 88 percent (P less than 0.001), and overall success rates (measured as a reduction of at least 20 percent in all lesions attempted, without death, myocardial infarction, or coronary bypass surgery) increased from 61 to 78 percent (P less than 0.001). In-hospital mortality for the new cohort was 1 percent, and the nonfatal myocardial infarction rate was 4.3 percent. Both rates are similar to those for the old registry. The long-term efficacy of current angioplasty remains to be determined.

Age Factors↗
PubMed1988

Predictors of electromechanical dissociation during cardiac arrest.

ECG patterns observed during cardiac arrest were analyzed in 261 comatose cardiac arrest survivors. Forty-seven patients (18%) exhibited electromechanical dissociation (EMD) at some point before restoration of stable spontaneous circulation. These patients had a higher mortality (P = .05) and a lower rate of cerebral recovery (P = .01) during the one-year follow-up than study patients who did not exhibit EMD. Patients who developed EMD subsequent to defibrillation had better outcome than patients presenting with EMD. Multivariate analysis revealed that age more than 70 years old (P = .007), pulmonary disease (P less than .001), diabetes (P = .013, in-hospital arrests only), and prearrest hypoxemia (P = .013, outside-hospital arrests only) were independently predictive of the occurrence of EMD. Although the generalizability of these findings is limited, they may offer new clues to the pathophysiology of EMD.

Aged↗
PubMed1988

Scientific evaluation of clinical interventions in resuscitation medicine.

The image of the physician as a therapist, as well as the general perception of the physician's role in society and in the life of patients and their families, has changed dramatically in past decades. In response, many conferences, editorials, and planning activities for medical and premedical curricula have been devoted to the subject of restoring the elements of compassion and personal involvement to the relationship between physician and patient. Nonetheless, the change in the doctor-patient relationship might merely reflect the growing indifference to people as individuals that seems to pervade our society in all service-related areas. Although the loss is particularly objectionable for the sick, some may claim it is compensated by scientifically superior care in present-day medical practice. This paper will reflect briefly on past and present views of medical care and its evaluation. It will conclude that a scientifically sound evaluation of treatment might also offer a solution for restoration of human elements in the delivery of medical care.

Clinical Trials as Topic↗