The Veterans Affairs Cooperative Study of Coronary Artery Bypass Surgery for Stable Angina: a continuing debate after 22 years.
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Angina Pectoris↗
Biomedical subjects
K Detre
Publications and source records attributed to K Detre.
Twenty-two-year follow-up in the VA Cooperative Study of Coronary Artery Bypass Surgery for Stable Angina.
We evaluated the 22-year results of initial coronary artery bypass surgery with saphenous vein grafts compared with initial medical therapy on survival, incidence of myocardial infarction, reoperation, and symptomatic status in 686 patients (average age 51) with stable angina in the Veterans Affairs Cooperative Study of Coronary Artery Bypass Surgery. Between 1972 and 1974, 354 patients were assigned to medical treatment and 332 to surgical revascularization. In the surgical cohort, 312 patients underwent operation (operative mortality 5.8%) and 25% subsequently underwent repeat operation (operative mortality 10.3%). In the medical cohort, 160 patients crossed over to surgery (operative mortality 4.4%) and 21% of these patients had reoperation (operative mortality 9.1%). Neither crossover nor reoperation was predictable by angiographic or clinical risk factors measured at baseline. The overall 22-year cumulative survival rates were 25% and 20% in the medical and surgical cohorts (p = 0.24). Corresponding rates in low-risk patients who had 1 or 2 vessels diseased, or 3 vessels diseased with normal left ventricular function were 31% and 24% (p = 0.024). Although significant at 10 years, there was also no long-term survival benefit for high-risk patients assigned to bypass surgery. The probabilities of remaining free of myocardial infarction and of being alive without infarction were significantly higher with initial medical therapy, 57% versus 41% (p = 0.02) and 18% versus 11% (p = 0.0031), respectively. This trial provides strong evidence that initial bypass surgery did not improve survival for low-risk patients, and that it did not reduce the overall risk of myocardial infarction. Although there was an early survival benefit with surgery in high-risk patients (up to a decade), long-term survival rates became comparable in both treatment groups. In total, there were twice as many bypass procedures performed in the group assigned to surgery without any long-term survival or symptomatic benefit.
Angina Pectoris↗
Predictors of patient and graft survival following liver transplantation for hepatitis C.
End-stage liver disease secondary to hepatitis C virus (HCV) infection is the leading indication for liver transplantation in the United States. Recurrence of HCV infection is nearly universal. We studied the patients enrolled in the National Institute of Diabetes and Digestive and Kidney Diseases Liver Transplantation Database to determine whether pretransplantation patient or donor variables could identify a subset of HCV-infected recipients with poor patient survival. Between April 15, 1990, and June 30, 1994, 166 HCV-infected and 509 HCV-negative patients underwent liver transplantation at the participating institutions. Median follow-up was 5.0 years for HCV-infected and 5.2 years for HCV-negative recipients. Pretransplantation donor and recipient characteristics, and patient and graft survival, were prospectively collected and compared. Cumulative patient survival for HCV-infected recipients was similar to that of recipients transplanted for chronic non-B-C hepatitis, or alcoholic and metabolic liver disease, better than that of patients transplanted for malignancy or hepatitis B (P = .02 and P = .003, respectively), and significantly worse than that of patients transplanted for cholestatic liver disease (P = .001). Recipients who had a pretransplantation HCV-RNA titer of > or = 1 x 10(6) vEq/mL had a cumulative 5-year survival of 57% versus 84% for those with HCV-RNA titers of < 1 x 10(6) vEq/mL (P = .0001). Patient and graft survival did not vary with recipient gender, HCV genotype, or induction immunosuppression regimen among the HCV-infected recipients. While long-term patient and graft survival following liver transplantation for end-stage liver disease secondary to HCV are generally comparable with that of most other indications, higher pretransplantation HCV-RNA titers are strongly associated with poor survival among HCV-infected recipients.
Adult↗
Identification of variables needed to risk adjust outcomes of coronary interventions: evidence-based guidelines for efficient data collection.
OBJECTIVES: Our objectives were to identify and define a minimum set of variables for interventional cardiology that carried the most statistical weight for predicting adverse outcomes. Though "gaming" cannot be completely avoided, variables were to be as objective as possible and reproducible and had to be predictive of outcome in current databases. BACKGROUND: Outcomes of percutaneous coronary interventions depend on patient risk characteristics and disease severity and acuity. Comparing results of interventions has been difficult because definitions of similar variables differ in databases, and variables are not uniformly tracked. Identifying the best predictor variables and standardizing their definitions are a first step in developing a universal stratification instrument. METHODS: A list of empirically derived variables was first tested in eight cardiac databases (158,273 cases). Three end points (in-hospital death, in-hospital coronary artery bypass graft surgery, Q wave myocardial infarction) were chosen for analysis. Univariate and multivariate regression models were used to quantify the predictive value of the variable in each database. The variables were then defined by consensus by a panel of experts. RESULTS: In all databases patient demographics were similar, but disease severity varied greatly. The most powerful predictors of adverse outcome were measures of hemodynamic instability, disease severity, demographics and comorbid conditions in both univariate and multivariate analyses. CONCLUSIONS: Our analysis identified 29 variables that have the strongest statistical association with adverse outcomes after coronary interventions. These variables were also objectively defined. Incorporation of these variables into every cardiac dataset will provide uniform standards for data collected. Comparisons of outcomes among physicians, institutions and databases will therefore be more meaningful.
Adult↗
Adverse lipid and coronary heart disease risk profiles in young women with polycystic ovary syndrome: results of a case-control study.
Polycystic ovary syndrome (PCOS), a disorder of hyperandrogenism and chronic anovulation affects 5%-10% of all women. Women with PCOS often have elevated cardiovascular risk factors. A total of 244 PCOS cases were identified through the Division of Reproductive Endocrinology at Magee-Womens Hospital and were age-matched to 244 neighborhood controls. The average age of cases and controls was 35.3 +/- 7.4 and 36.7 +/- 7.7. Women with PCOS compared to controls had substantially higher LDL-C and total cholesterol levels at each age group under 45 years after adjustment for body mass index, hormone use, and insulin levels. In the over 40-year age group, little difference was noted between cases and controls. Among cases and controls (<40), PCOS predicted LDL-C, total cholesterol and triglycerides, but did not have a significant effect on lipid levels in older cases and controls after controlling for the other variables. The primarily pre- to perimenopausal PCOS cases > or =40 years of age have similar LDL-C and total cholesterol levels as their age-matched controls, probably reflecting the LDL-C increase with age among controls.
Adult↗
Myocardial infarction and cardiac mortality in the Bypass Angioplasty Revascularization Investigation (BARI) randomized trial.
BACKGROUND: Cardiac mortality and myocardial infarction (MI) rates are used to evaluate the efficacy of coronary artery bypass grafting (CABG) and percutaneous transluminal coronary angioplasty (PTCA). We compared 5-year cardiac mortality and MI rates in 1829 patients with multivessel disease randomized to CABG or PTCA. METHODS AND RESULTS: The 5-year cardiac mortality rate was 8.0% in patients assigned to PTCA compared with 4.9% in those assigned to CABG (relative risk [RR] of 1.55 with a 95% confidence interval [CI] of 1.07 to 2.23; P=.022). In a subgroup of 1476 nondiabetic patients, there were no significant differences between treatment groups in cardiac mortality either overall (4.6% versus 4.2%; RR= 1.04, 95% CI, 0.65 to 1.66; P=.908) or in subgroups based on symptoms, left ventricular function, number of diseased vessels, or stenotic proximal left anterior descending artery. The two treatment groups had similar event rates for the combined end point of cardiac death or MI. The RR for cardiac mortality in 264 patients who sustained an MI compared with those who did not was 5.9 (P<.001). MIs were more common after CABG during index hospitalization (P=.004), but in the PTCA group, they were more common after discharge (P<.001). CONCLUSIONS: The Bypass Angioplasty Revascularization Investigation (BARI) trial indicates 5-year cardiac mortality in patients with multivessel disease was significantly greater after initial treatment with PTCA than with CABG. The difference was manifest in diabetic patients on drug therapy. There were no significant differences overall for the composite end point of cardiac mortality or MI between treatment groups or for cardiac mortality in nondiabetic patients regardless of symptoms, left ventricular function, number of diseased vessels, or stenotic proximal left anterior descending artery.
Angioplasty, Balloon, Coronary↗
Value of visual versus central quantitative measurements of angiographic success after percutaneous transluminal coronary angioplasty. NHLBI PTCA Registry Investigators.
This study examined the optimal angiographic definition for long-term success after angioplasty and compared visual and quantitative angiographic measurements in assessing outcome. The National Heart, Lung, and Blood Institutes--Percutaneous Transluminal Coronary Angioplasty Registry prospectively followed 1,768 patients from 15 clinical centers. Symptom-free survival, defined as survival without angina, myocardial infarction, bypass surgery, or death, occurred in 59% of patients. In a subset of 393 patients, quantitative coronary angiography (QCA), done at a core angiographic laboratory, was compared with visual site readings. Although there was considerably more variability for visual readings, a site reading of a change in percent stenosis of >20% correlated highly with symptom-free survival (64.6% for patients who had all lesions successfully dilated, 48% for patients with partial success, and only 21% for patients without angiographic success; p < 0.001). Similar findings were seen for other angiographic definitions, but a change of > 20% was most discriminatory. In contrast, QCA readings had little or no predictive value. This study confirms that visual assessment of the immediate change in percent stenosis is predictive of a successful 1-year outcome. A change of greater than 20% is most discriminatory and should still be used to define angiographic success. QCA does not appear to be superior to visual assessment in predicting 1-year outcome.
Angioplasty, Balloon, Coronary↗
Better functional status in American than Canadian patients with heart disease: an effect of medical care?
OBJECTIVES: This study compared functional status in Americans and Canadians with and without prior symptoms of heart disease to separate the effects of medical care from nonmedical factors. BACKGROUND: Coronary angiography and revascularization are used more often in the United States than in Canada, yet rates of mortality and myocardial infarction are similar in the two countries. Recent data suggest that functional status after myocardial infarction is better among Americans than Canadians, but it is uncertain whether this difference is due to medical care or nonmedical factors. METHODS: Quality of life was measured in patients enrolled in seven American and one Canadian site in the Bypass Angioplasty Revascularization Investigation. Prior symptoms of heart disease were defined as angina, myocardial infarction or congestive heart failure before the episode of illness leading to randomization. Functional status was measured with the Duke Activity Status Index and overall emotional and social health using Medical Outcome Study measures on the basis of patient status before the index episode of acute ischemic heart disease. RESULTS: Quality of life was generally better in the 934 Americans than in the 278 Canadians, with overall health rated as excellent or very good in 30% of Americans versus 20% of Canadians (p = 0.0001), higher median Duke Activity Status Index scores (16 vs. 13.5, p = 0.03) but equivalent emotional health (76 vs. 76, p = 0.74) and social health scores (100 vs. 80, p = 0.07). Among the 350 patients without prior symptoms of heart disease, Americans and Canadians had similar overall health, Duke Activity Status Index and emotional and social health scores. However, of the 860 patients with previous symptoms of heart disease, Americans had higher overall health (p = 0.0001) and Duke Activity Status Index scores (p = 0.0008) but similar emotional and social health scores. The results were essentially unchanged after statistical adjustment for potential confounding factors. CONCLUSIONS: The functional status of patients without prior symptoms of heart disease is similar in Americans and Canadians. However, among patients with previous symptomatic heart disease, functional status is higher in Americans than in Canadians. This difference may be due to different patterns of medical management of heart disease in the two countries.
Aged↗
Has improvement in PTCA intervention affected long-term prognosis? The NHLBI PTCA Registry experience.
BACKGROUND: The NHLBI Percutaneous Transluminal Coronary Angioplasty (PTCA) Registry followed 1345 consecutive patients with first PTCA between 1977 and 1981 (registry 1) and 2136 consecutive patients with PTCA between 1985 and 1986 (registry 2). Changes in patient selection and in immediate and 1-year outcome are presented. This report extends to 5 years the comparison of the effects of early and more recent management with PTCA. METHODS AND RESULTS: Sixteen participating centers entered consecutive patients who had angioplasty for the first time between 1977 and 1981 and between 1985 and 1986. Patients with recent myocardial infarction (MI) were excluded. Vessel disease was defined according to the Coronary Artery Surgery Study. Successful dilatation required > or = 20% reduction in luminal narrowing and < 50% lumen diameter stenosis after intervention. Routine annual follow-up was conducted by telephone interview. The product-limit method was used to estimate freedom from untoward events, Cox regression analysis to model relative risk and adjusted relative risk of events between the two registries, and logistic regression when the exact time of outcome (such as recurrence of symptoms) was not known. Long-term event rates were computed by vessel disease for all patients and for the cohort of patients with initially successful PTCA. After adjustment for extent of disease, diabetes, prior bypass surgery (CABG), hypertension, age, and sex, the 5-year risk of death was similar in the two registry cohorts. However, rates of MI, CABG, and a combined outcome measure of death, MI, and/or CABG were significantly lower in the registry 2 cohort both for all patients and for patients who were initially treated successfully. Use of repeated PTCA was higher, and freedom from symptoms without adverse events was significantly better in the latter cohort. CONCLUSIONS: Compared with registry 1, the management of the registry 2 cohort resulted in lower 5-year morbid event rates and reduced CABG operations. Mortality rates remained similar. When symptomatic status was considered in combination with events, a significantly better outcome was seen overall and in the initially successful cohort. In registry 2, repeated PTCA was used with much greater frequency early after the initial procedure.
Angioplasty, Balloon, Coronary↗
Catheterization and mortality in elderly patients with acute myocardial infarction.
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Cardiac Catheterization↗
Coronary heart disease risk factors in women with polycystic ovary syndrome.
The goal of the study was to compare cardiovascular heart disease risk factors in women with polycystic ovary syndrome (PCOS) and matched control subjects. Women with PCOS have risk factors, including anovulation, hyperandrogenism, and insulin resistance, that suggest a male coronary heart disease risk-factor profile. A total of 206 women with PCOS were recruited by using records from a large reproductive endocrinology practice. A clinical diagnosis of PCOS was made if there was a history of chronic anovulation in association with either clinical evidence of androgen excess (hirsutism) or if total testosterone level was > 2 nm/L or the luteinizing hormone/follicle-stimulating hormone ratio was greater than 2. The overall response rate for cases was 76%. A control population was obtained by using a combination of area voters' registration tapes and directories of households. A control subject was matched to each case subject by age +/- 5 years, race, and neighborhood. The response rate for recruitment of the first or second eligible control subject was 83.6%. The average age at initial interview was 35.9 +/- 7.4 years for case and 37.2 +/- 7.8 years for control subjects. Women with PCOS had significantly increased cardiovascular disease risk factors compared with control women. These included increases in body mass index, insulin, and triglyceride levels (P < .001), decreased total HDL and HDL2 levels (P < .01), and increased total cholesterol and fasting LDL levels, waist/hip ratio, and systolic blood pressure (P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Reliability and predictive value of the National Institute of Diabetes and Digestive and Kidney Diseases Liver Transplantation Database nomenclature and grading system for cellular rejection of liver allografts.
Pathologists participating in the National Institute of Diabetes and Digestive and Kidney Diseases Liver Transplant Database (LTD) created a histopathological grading system for acute liver allograft rejection, and tested it first for inter- and intra-rater reliability among a group of five pathologists experienced in liver and transplantation pathology. Specimens from post-transplantation biopsies from 48 patients with rejection, hepatitis, or other diagnosis(es) were reviewed. There was moderate to good (kappa = 0.40 to 0.55) inter-rater and good (kappa = 0.55 to 0.58) intrarater agreement for the diagnosis and exact grading of mild, moderate, or severe acute rejection, which improved when a short clinical history was provided. Thus, the scheme was reproducible, and few of the disagreements among the pathologists would have affected treatment decisions. Secondly, the ability of the grading system to predict an unfavorable short- or long-term outcome from the initial histopathological diagnosis of cellular rejection was tested on groups of 168 and 133 patients, respectively, from the three LTD clinical centers, who were followed up for at least 6 months after the first onset of rejection. This analysis showed that a higher histopathological grade of acute rejection on first biopsy diagnosis was significantly associated (P < or = .006) with both an unfavorable short-term outcome, defined by failure of the episode to resolve within 21 days or the need for aggressive immunosuppressive treatment, and a long-term outcome defined by death or retransplantation from rejection within 6 months of onset. Lastly, an analysis was performed to determine whether subjective rejection grading by the pathologist or certain "objective" histopathological features identified by logistic regression modeling were more accurate in predicting an unfavorable outcome.(ABSTRACT TRUNCATED AT 250 WORDS)
Databases, Factual↗
Outcome of percutaneous transluminal coronary angioplasty in subsets of unstable angina pectoris. A report of the 1985-1986 National Heart, Lung, and Blood Institute Percutaneous Transluminal Coronary Angioplasty Registry.
OBJECTIVES: The purpose of this study was to characterize the outcome of coronary angioplasty according to the various presentations of unstable angina pectoris. BACKGROUND: Although unstable angina is a mosaic of clinical manifestations, a comprehensive analysis of short- and long-term outcome of coronary angioplasty in subsets of unstable angina is not available. METHODS: Data from 15 clinical centers for the 857 patients with unstable angina in the 1985-1986 National Heart, Lung, and Blood Institute percutaneous transluminal coronary angioplasty registry were analyzed. Five-year follow-up was available in > 96.5%. Patients were first classified as those with (679 [79%]) or without (178 [21%]) rest angina. Patients were also allocated to five mutually exclusive categories of decreasing unstable angina severity: postinfarction angina, acute coronary insufficiency, plain rest angina, accelerating angina and new onset angina. RESULTS: The group with rest angina had more older patients (p < 0.01) and women (p < 0.001), and a greater proportion had a previous myocardial infarction (p < 0.001) and a left ventricular ejection fraction < or = 50% (p < 0.01) than did the group without rest angina. Angiographic characteristics were nearly the same, whereas procedural characteristics and outcome were the same for both categories. At 5-year follow-up, there was a higher crude mortality rate in patients with than without rest angina (p < 0.05). Resolution into five subsets yielded additional information. Women were more represented only in the acute coronary insufficiency and plain rest angina subsets (p < 0.001). Patients with angina after myocardial infarction had the second shortest history of angina (p < 0.001), the highest percent of smokers (p < 0.01) and, with those with acute coronary insufficiency, the highest incidence of congestive heart failure (p < 0.05) and an ejection fraction < or = 50% (p < 0.001). They had the highest percent of totally occluded arteries, coronary thrombus and collateral blood flow received but also the lowest rate of severe stenoses (p < 0.001 for all). Patients with new onset angina had the highest prevalence of single-vessel disease (p < 0.05), critical and complex stenoses (p < 0.001) and no coronary angioplasty-related deaths. The crude 5-year mortality rate was higher for both postinfarction and acute insufficiency groups (p < 0.05) than for the other subsets. After adjustments for risk factors, no significant differences in adverse event rates remained among the different unstable angina subgroups. CONCLUSIONS: Analysis of the diverse clinical presentations of unstable angina supports underlying pathogenetic differences. Coronary angioplasty is safe and effective in all subsets of unstable angina. Long-term survival is good in general but is related to the baseline status of left ventricular function.
Angina, Unstable↗
A randomized comparison of coronary-stent placement and balloon angioplasty in the treatment of coronary artery disease. Stent Restenosis Study Investigators.
BACKGROUND: Coronary-stent placement is a new technique in which a balloon-expandable, stainless-steel, slotted tube is implanted at the site of a coronary stenosis. The purpose of this study was to compare the effects of stent placement and standard balloon angioplasty on angiographically detected restenosis and clinical outcomes. METHODS: We randomly assigned 410 patients with symptomatic coronary disease to elective placement of a Palmaz-Schatz stent or to standard balloon angioplasty. Coronary angiography was performed at base line, immediately after the procedure, and six months later. RESULTS: The patients who underwent stenting had a higher rate of procedural success than those who underwent standard balloon angioplasty (96.1 percent vs. 89.6 percent, P = 0.011), a larger immediate increase in the diameter of the lumen (1.72 +/- 0.46 vs. 1.23 +/- 0.48 mm, P < 0.001), and a larger luminal diameter immediately after the procedure (2.49 +/- 0.43 vs. 1.99 +/- 0.47 mm, P < 0.001). At six months, the patients with stented lesions continued to have a larger luminal diameter (1.74 +/- 0.60 vs. 1.56 +/- 0.65 mm, P = 0.007) and a lower rate of restenosis (31.6 percent vs. 42.1 percent, P = 0.046) than those treated with balloon angioplasty. There were no coronary events (death; myocardial infarction; coronary-artery bypass surgery; vessel closure, including stent thrombosis; or repeated angioplasty) in 80.5 percent of the patients in the stent group and 76.2 percent of those in the angioplasty group (P = 0.16). Revascularization of the original target lesion because of recurrent myocardial ischemia was performed less frequently in the stent group than in the angioplasty group (10.2 percent vs. 15.4 percent, P = 0.06). CONCLUSIONS: In selected patients, placement of an intracoronary stent, as compared with balloon angioplasty, results in an improved rate of procedural success, a lower rate of angiographically detected restenosis, a similar rate of clinical events after six months, and a less frequent need for revascularization of the original coronary lesion.
Angioplasty, Balloon, Coronary↗
Percutaneous transluminal coronary angioplasty in African-American patients (the National Heart, Lung, and Blood Institute 1985-1986 Percutaneous Transluminal Coronary Angioplasty Registry).
Although black patients have a higher prevalence of risk factors for coronary artery disease, the outcome of coronary angioplasty in black patients is not known. The purpose of this study was to determine if any racial differences existed in the clinical characteristics and outcome of patients enrolled in the 1985-1986 National Heart, Lung, and Blood Institute (NHLBI) Percutaneous Transluminal Coronary Angioplasty (PTCA) Registry. The clinical characteristics, in-hospital event rates, and 5-year follow-up results of all patients enrolled in the 1985-1986 NHLBI PTCA Registry were examined with respect to race. Of the patients enrolled in the registry, 1,939 (90.8%) were white and 76 (3.6%) were black. Among black patients there were more women (50% vs 24%, p < 0.001), and more patients who had hypertension (73% vs 45%, p < 0.001) and diabetes (23% vs 13%, p < 0.05). Black patients were more likely to have multivessel disease (72% vs 48%, p < 0.001). Clinical success rates were similar (76.3% for blacks and 79.3% for whites), but because black patients had more vessels with significant disease, complete revascularization was achieved in 26% of black patients compared with 44% of white patients (p < 0.001). After the PTCA procedure there was no significant difference in major complications (death, myocardial infarction, or emergent coronary artery bypass grafting) between the 2 groups. Five-year follow-up data revealed that there was no significant difference in mortality, myocardial infarction, coronary artery bypass grafting, or repeat PTCA.(ABSTRACT TRUNCATED AT 250 WORDS)
Black or African American↗
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↗
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↗
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↗