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Biomedical subjects

H A Taylor

Publications and source records attributed to H A Taylor.

At least 19 recordsLinked to original sources
PubMed1995

Comparison of surgical and medical group survival in patients with left main coronary artery disease. Long-term CASS experience.

BACKGROUND: Observational and randomized studies designed to compare surgical and medical therapies in patients with left main coronary artery disease (LMCD) have shown that coronary artery bypass graft (CABG) surgery prolongs life in most patients with LMCD. The present report of 1484 patients with LMCD in the Coronary Artery Surgery Study (CASS) Registry extends the originally published 5-year surgical and medical group survival analysis to more than 16 years of follow-up and permits analysis of LMCD patient subgroups. METHODS AND RESULTS: The CASS Registry contains 1484 patients with > or = 50% left main coronary artery stenosis initially treated with either surgical or nonsurgical therapy. The 15-year cumulative survival estimates were 37% for the 1153 patients in the surgical group compared with 27% for the 331 patients in the medical group. Median survival in the surgical group was 13.3 years (12.8 to 13.8 years, 95% confidence limits) compared with only 6.6 years (5.4 to 7.9 years) in the medical group (difference, 6.7 years; P < .0001). Median survival was also significantly longer in the surgical group stratified by age, sex, anginal class, left ventricular (LV) function, coronary anatomy, and the extent of LMCD. However, CABG surgery did not significantly prolong median survival in patient subgroups with (1) left main coronary stenosis of 50% to 59%; (2) normal LV systolic function; (3) normal or mildly abnormal LV systolic function and a right coronary artery stenosis > or = 70%; and (4) a nonstenotic (< or = 70%) right coronary artery. The 15-year cumulative survival for patients with normal LV systolic function in the surgical and medical groups was 42% and 51%, respectively. Median survival was 14.7 years in the surgical group and > 15 years in the medical group (P = NS). In patients with normal LV systolic function and a right coronary artery stenosis > or = 70%, the 15-year cumulative survival rates were also similar in the surgical and medical groups (40% and 48%, respectively). Median survival was 14.3 years in the surgical group and 14.2 years in the medical group (P = NS). The 15-year cumulative survival estimates for all subgroups were affected by convergence of the surgical and medical survival group curves owing to a disproportionate increase in the late surgical group mortality. Overall, 25% of patients in the medical group ultimately underwent CABG surgery. If all medical group patients had survived long enough, about 47% would be estimated to have had surgery by 15 years. CONCLUSIONS: This report, which extends follow-up of more than 16 years in CASS Registry patients with LMCD, shows that CABG surgery prolongs life in most clinical and angiographic subgroups. However, median survival was not prolonged by CABG surgery in patients with normal LV systolic function, even if a significant right coronary artery stenosis (> or = 70%) also was present. These results extend our understanding of the natural history of LMCD and permit a more accurate estimate of long-term surgical and medical group survival.

Cohort Studies↗
PubMed1995

Comparison of surgical and medical group survival in patients with left main equivalent coronary artery disease. Long-term CASS experience.

BACKGROUND: Combined severe proximal left anterior descending and proximal left circumflex coronary artery disease, or left main equivalent (LMEQ) disease, defines a prognostic high-risk angiographic subset of patients with chronic ischemic heart disease. While numerous observational and randomized clinical trials showed prolonged survival in surgically compared with medically treated patients with left main coronary artery disease, relatively few observational studies compared surgical and medical therapies in patients with LMEQ disease. The present report of 912 patients with LMEQ disease in the Coronary Artery Surgery Study (CASS) Registry extends the originally published 5-year surgical and medical group survival analysis to more than 16 years of follow-up and permits analysis of LMEQ patient subgroups. METHODS AND RESULTS: The CASS Registry contains 912 patients with LMEQ disease, defined as combined stenoses of > or = 70% in the proximal left anterior descending coronary artery before the first septal perforator and proximal circumflex coronary artery before the first obtuse marginal branch, initially treated with either surgical or nonsurgical therapy. The 15-year cumulative survival estimates were 44% for the 630 patients in the surgical group and 31% for the 282 patients in the medical group. Median survival in the surgical group was 13.1 years (12.7 to 14.1 years, 95% confidence limits) compared with only 6.2 years (4.8 to 7.9 years) in the medical group (difference, 6.9 years; P < .0001). Median survival was also significantly longer in the surgical group stratified by age, sex, anginal class, left ventricular (LV) function, and coronary anatomy. However, coronary artery bypass graft (CABG) surgery did not significantly prolong median survival in patient subgroups with (1) normal LV systolic function, even if a significant right coronary artery stenosis (> or = 70%) also was present, and (2) mildly abnormal (LV score, 6 to 10) LV systolic function. The 15-year cumulative survival in patients with normal LV systolic function in the surgical and medical groups was 63% and 54%, respectively. Median survival was > 15 years in both the surgical and medical groups (P = NS). In patients with normal LV systolic function and right coronary artery stenosis > or = 70%, the 15-year cumulative survival was also similar in the surgical and medical groups (63% and 53%, respectively). Median survival was > 15 years in both the surgical and medical groups (P = NS). The 15-year cumulative survival estimates in all subgroups were affected by convergence of the surgical and medical group survival curves caused by a disproportionate increase in late surgical group mortality. Overall, 26% of patients in the medical group ultimately underwent CABG surgery. If all medical group patients had survived long enough, about 65% would be estimated to have had surgery by 15 years. When the CASS Registry patients with LMEQ disease who participated in the randomized trial or who were randomizable were analyzed, CABG surgery did not prolong the 15-year cumulative survival estimates compared with nonsurgical therapy for randomized (71% versus 67%, respectively) and for randomizable patients (62% versus 92%, respectively) with an LV ejection fraction > or = 50%. CONCLUSIONS: This report, which extends follow-up of more than 16 years in CASS Registry patients with LMEQ disease, shows that CABG surgery prolongs life in most clinical and angiographic subgroups. However, median survival was not prolonged by CABG surgery in patients with normal LV systolic function, even if a significant right coronary artery stenosis (> or = 70%) also was present or in patients with an LV ejection fraction > or = 50% who participated in the CASS randomized trial or who were randomizable.

Coronary Angiography↗
PubMed1995

Race and sex differences in rates of invasive cardiac procedures in US hospitals. Data from the National Hospital Discharge Survey.

BACKGROUND: Lower rates of invasive cardiac procedures have been reported for blacks and women than for white men. However, few studies have adjusted for differences in the type of hospital of admission, insurance status, and disease severity. SETTING, DESIGN, AND PARTICIPANTS: Data from the National Hospital Discharge Survey were used to investigate race and sex differences in rates of cardiac catheterization, percutaneous transluminal coronary angioplasty, and coronary artery bypass surgery among 10,348 persons hospitalized for acute myocardial infarction. RESULTS: White men consistently had the highest procedure rates, followed by white women, black men, and black women. After matching for the hospital of admission and adjusting for age, in-hospital mortality, health insurance, and hospital transfer rates (with white men as the referent), the odds ratios for cardiac catheterization were 0.67 (95% confidence interval [CI], 0.51 to 0.87) for black men, 0.72 (95% CI, 0.63 to 0.83) for white women, and 0.50 (95% CI, 0.37 to 0.68) for black women. Similar race-sex differences were noted for percutaneous transluminal coronary angioplasty and coronary artery bypass surgery. CONCLUSIONS: Race and sex differentials in the rates of invasive cardiac procedures remained despite matching for the hospital of admission and controlling for other factors that influence procedure rates, suggesting that the race and sex of the patient influence the use of these procedures.

Adult↗
PubMed1995

Expression of PAI-1, t-PA and u-PA in cultured human umbilical vein endothelial cells derived from racial groups.

To determine whether inherent fibrinolytic differences may exist in racial groups (black americans, BA vs. white americans, WA), 55 different individual racially-derived human umbilical vein endothelial cell (HUVEC) cultures (35 BA and 20 WA) were analyzed in terms of their fibrinolytic protein (t-PA, u-PA and PAI-1) antigen and mRNA levels. Values (mean +/- SD) for measured fibrinolytic component levels include: cell-associated t-PA antigen (ELISA), 1.14 +/- 0.82 ng/ml/8.6 x 10(5) cells/24 hr in BA and 0.70 +/- 0.85 ng/ml in WA (p = 0.0624); secreted t-PA antigen, 18.65 +/- 17.06 ng/ml in BA and 10.37 +/- 6.38 ng/ml in WA (p = 0.0422); t-PA/cyclophilin mRNA ratios (Northern blot analysis), 1.90 +/- 1.34 in BA and 1.32 +/- 0.70 in WA (p = 0.0776); cell-associated PAI-1 antigen, 71.10 +/- 30.16 ng/ml/8.6 x 10(5) cells/24 hr in BA and 108.85 +/- 56.89 ng/ml in WA (p = 0.0022); secreted PAI-1 antigen, 1,582.13 +/- 612.67 ng/ml in BA and 1,992.17 +/- 711.50 ng/ml in WA (p = 0.0285); 2.4 kb PAI-1/cyclophilin mRNA ratios, 0.59 +/- 0.39 in BA and 0.79 +/- 0.31 in WA (p = 0.1085); 3.4 kb PAI-1/cyclophilin mRNA ratios, 0.70 +/- 0.47 in BA and 0.77 +/- 0.54 in WA (p = 0.6322). These combined data suggest that cultured HUVECs from BA express significantly higher levels of t-PA, lower levels of PAI-1 and approximately 1.72-fold lower molar ratio of PAI-1/t-PA antigen (183.99 +/- 168.81 vs. 315.92 +/- 164.99) (p < 0.05) than cultured HUVECs from WA, presumably reflecting an apparent inherent increased fibrinolytic potential in cultured HUVEC derived from BA.

Black People↗
PubMed1993

Race and prognosis after myocardial infarction. Results of the thrombolysis in myocardial infarction (TIMI) phase II trial.

BACKGROUND: To better understand the role of race/ethnicity in survival after acute myocardial infarction, we compared clinical and laboratory data, response to thrombolytic therapy, and clinical outcome in 2885 patients participating in the Thrombolysis in Myocardial Infarction Phase II (TIMI II) Trial among three groups of patients (2564 whites, 174 blacks, and 147 Hispanics). METHODS AND RESULTS: Differences were found in baseline characteristics among the three groups including (1) age (mean age for whites, 57.2 years; blacks, 54.8 years; Hispanics, 52.8 years; P < .001), (2) sex (percentage of women for whites, 17.6; blacks, 28.7; Hispanics, 14.3; P < .001), and (3) risk factor prevalence: current smoking (percent for whites, 49.4; blacks, 62.1; Hispanics, 55.1; P < .003), history of hypertension (percent for whites, 36.6; blacks, 55.7; Hispanics, 39.5; P < .001), and diabetes mellitus (percent for whites, 11.9; blacks, 22.4; Hispanics, 19.7; P < .001). Changes in hemostatic factors 5 hours after infusion of recombinant tissue plasminogen activator (rt-PA) revealed a more profound fall in fibrinogen levels in black patients compared with the response seen in Hispanic or white patients (mean change in fibrinogen +/- SD, mg/dL: 151.3 +/- 107.4, 112.2 +/- 97.0, 109.4 +/- 98.6; P < .001, respectively) without more frequent infarct-related artery patency or hemorrhagic complications. Mortality was similar in the white, black, and Hispanic patients through the first year after adjustment for baseline variables. CONCLUSIONS: TIMI II data yield evidence that (1) corroborates published reports of a high prevalence of classic cardiovascular risk factors among minority patients with acute myocardial infarction, (2) there is a greater decrease in fibrinogen levels 5 hours after the start of rt-PA infusion among black patients than in white and Hispanic patients without evidence of more frequent infarct-related artery patency or hemorrhagic complications, and (3) thrombolytic therapy with appropriate supplemental measures is associated with comparable 1-year mortality in white, black, and Hispanic patients.

Black or African American↗
PubMed1992

Descriptions and depictions of environments.

Subjects studied maps with the expectation that they would draw or describe them from memory. In fact, subjects did both. Order of drawing or describing landmarks revealed the mental organization of environments. Organization was quite similar across maps and descriptions of the same environments, revealing hierarchical structures based on spatial and functional features of the environments and on conventions for sequencing the landmarks.

Adult↗
PubMed1990

The conjunction fallacy?

Tversky and Kahneman (1983) showed that when subjects are asked to rate the likelihood of several alternatives, including single and joint events, they often make a "conjunction fallacy." That is, they rate the conjunction of two events as being more likely than one of the constituent events. This, they claim, is a fallacy, since the conjunction of two events can never be more probable than either of the component events. In addition, they found that prior training in probability theory does not decrease the likelihood of making this fallacy. We argue that in some contexts, an alternative that contains the conjunction of two events can be more probable than an alternative that contains only one of the conjunction's constituent events. We carried out four experiments in which we manipulated this context. The frequency of making a conjunction fallacy was affected by the manipulation of context. Furthermore, when the context was clearly specified, prior training in statistics influenced the ratings.

Decision Making↗
PubMed1989

Clinical, pathological, and biochemical studies on an infantile case of sulfatide/GM1 activator protein deficiency.

A 28-month-old black male died with severe complications of mental and motor deterioration, seizures, and aspiration. Autopsy demonstrated moderate liver enlargement, normal spleen and kidneys, small testes, and a grossly normal brain. Further examination showed irregular macrogyrae with evidence of a storage or sclerotic process. Thin layer chromatography of the lipids in formalin-fixed tissue demonstrated elevated levels of ceramide trihexoside and possibly sulfatides in liver and a decrease in the ratio of galactosylceramide to sulfatide in brain. Examination of the gangliosides in formalin-fixed brain indicated a slight increase in the percentage of GM1 ganglioside and a clear elevation in GM2 and GM3 gangliosides. Cultured skin fibroblasts had a normal activity for a large number of lysosomal enzymes including arylsulfatase A and galactocerebrosidase. When the cells were loaded with [14C]sulfatide only about 12% of the sulfatide was metabolized after 3 days. Extracts of the cells were subjected to SDS-PAGE and immunoblotting with antisphingolipid activator protein-1 (SAP-1) rabbit antiserum, and no cross-reacting material was detected confirming the diagnosis of metachromatic leukodystrophy caused by SAP-1 deficiency. This patient was clinically more severe than the other patients described previously with this deficiency. Further studies are underway to define the nature of the mutation in this patient.

Autopsy↗
PubMed1989

Asymptomatic left main coronary artery disease in the Coronary Artery Surgery Study (CASS) registry.

Left main coronary artery disease (i.e., greater than or equal to 50% stenosis) was found in 1,477 of 20,137 patients in the Coronary Artery Surgery Study (CAS) registry. Of these patients, 53 (3.6%) were asymptomatic. Asymptomatic and symptomatic patients were similar in regard to 1) severity of left main coronary artery stenosis (67% vs. 70%), 2) extent of proximal coronary artery disease (no differences in number of or severity of proximal stenoses), 3) left ventricular end-diastolic pressure (13 mm Hg vs. 14 mm Hg), 4) left ventricular wall motion score 9.1 vs. 8.7), and 5) number of coronary artery segments with greater than 70% stenosis (4.4 vs. 4.8). Among the asymptomatic patients, 47% received medical and 49% received surgical treatment. In the symptomatic group, 20% received medical and 78% received surgical therapy. The survival rate 5 years after surgery for treatment of left main coronary artery stenosis was 84% for the symptomatic patients and 88% for the asymptomatic patients (p = NS). Medical management of left main coronary artery disease produced a 5-year survival rate of 57% for asymptomatic patients and 58% for symptomatic patients. Within the asymptomatic subgroup, 88% of those surgically treated survived 5 years, whereas only 57% of those medically treated survived 5 years (p = 0.02). Thus, for CASS patients with left main coronary artery disease, the percentage of those that were asymptomatic is low (3.6%); asymptomatic and symptomatic patients with left main coronary artery disease had no significant difference in severity of left main coronary artery stenosis, extent of overall coronary artery disease, or left ventricular function.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Angiography↗
PubMed1983

Sialic acid storage disease with sialuria: clinical and biochemical features in the severe infantile type.

Two unrelated infants with a new disorder characterized biochemically by elevated levels of free sialic acid in urine, serum, and cell lysates have exhibited severe mental and physical impairments since the early weeks of life. Three other biochemically diagnosed cases and two possible cases from the earlier literature are reviewed to delineate this condition. Clinical features including sparse, white hair, coarse facies, hepatosplenomegaly, profound inactivity, diarrhea, and anemia permit early diagnosis of this neurovisceral storage disease. Osseous stippling may be present and clear vacuoles may be demonstrated in lymphocytes and cultured fibroblasts. The course is one of relentless deterioration with death in early childhood. Specific diagnosis depends on demonstration of elevated free sialic acid in urine and cell lysates.

Adult↗
PubMed1982

Safety and effectiveness of probucol as a cholesterol lowering agent.

Monitored clinical studies conducted in 1133 patients, involving 3928 patient years of experience with probucol, have shown that it is an effective cholesterol lowering agent and is well tolerated during long term administration (some patients treated for as long as nine years). The incidence of morbidity and mortality in patients treated with probucol is in the expected range. Although a possibly protective action is suggestive against certain endpoints, the lack of long term parallel placebo groups does not allow for a statistical contrast of the results. Therefore, it is preferable to limit conclusions to observing that no excess of cardiac deaths, sudden deaths or cardiac morbidity occurred in probucol treated men with or without ischemic heart disease compared with men not receiving probucol.

Adult↗