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Biomedical subjects

K S Bay

Publications and source records attributed to K S Bay.

24 records · Page 2Linked to original sources
PubMedDate not supplied

Changes in acute myocardial infarction risk and patterns of practice for patients older and younger than 70 years, 1987-90.

OBJECTIVE: To evaluate temporal changes in risk and patterns of hospital practice for acute myocardial infarction (AMI). DESIGN/PATIENTS: Retrospective analysis of age-related medical therapy and outcome of 342 consecutive patients (132 at least 70 years old and 210 younger than 70) with AMI between July 1, 1989, and June 30, 1990, and comparison with data from two previous analyses of AMI practice in 1987 (n = 207) and 1988-89 (n = 402). SETTING: Tertiary care medical centre. INTERVENTIONS: No direct interventions; results of the two previous AMI practice pattern analyses, however, were propagated during the practice time of the most recent analysis. RESULTS: In 1989-90, hospital mortality was higher (19%) among patients at least 70 years old compared with patients younger than 70 (8%) (P less than 0.01). Therapies proven by repeated clinical trials to be effective in reducing AMI risk were all used less frequently in patients aged at least 70 years: thrombolysis (20 versus 43%); beta-blockers (41 versus 62%); acetylsalicylic acid (71 versus 87%); and nitrates (86 versus 97%). Qualitatively, these age-specific patterns of AMI mortality and therapy were similar to previous studies. Quantitatively, however, comparing 1987 with 1989-90 demonstrated parallel and marked increases in the use of all proven medications in both age groups, ranging from 42 to 230% (P less than 0.01). There was also a significant overall decrease in mortality from the 1987 patient cohort (20%) to the 1989-90 cohort (13%) (P less than 0.05). The decrease in mortality was entirely due to decreased mortality within the group 70 years or older; 35% in 1987 versus 19% in 1989-90 (P less than 0.05). Mortality in the AMI patients younger than 70 years old remained unchanged from 1987 to 1989-90. CONCLUSIONS: Pattern of practice analyses were associated with, and may have contributed to, improved patient care and outcomes in AMI. Increased use of effective AMI medical therapy had a greater benefit in elderly higher risk AMI patients than lower risk younger patients. Persisting age-specific differences in AMI therapy may respond to more direct quality improvement measures, such as critical path management.

Adrenergic beta-Antagonists↗
PubMedDate not supplied

Mortality risk factors associated with mitral valve replacement: a survival analysis of 10 year follow-up data.

The primary purpose of this study was to evaluate the long term performance of several prosthetic cardiac valves and the influence on outcome of different surgeons by following 328 patients for up to 10 years after mitral valve replacement surgery in a tertiary care centre. This type of follow-up study is faced with severe methodological difficulties, as mortality and complications after surgery can be influenced not only by preoperative clinical status but also by the competence of the operating surgeons, the type of prosthesis used, and system-related variables such as the overall quality of nursing care. The primary statistical models used were life-table analysis, logistic regression and Cox's proportional hazard regression, employing prosthesis type, surgeon and other patient- or system-specific variable as covariates. The relative performance of valve prostheses and surgeons were assessed for short and long term survival. Biologic and Omniscience valves outperformed others for short and long term survival, while Lillehei-Kaster valves performed well for short term but not long term survival. The results also suggest that the performance levels of surgeons do vary, and the choice of surgeon could be a significant risk factor in a given medical centre.

Adult↗
PubMedDate not supplied

The changing clinical profile of coronary artery bypass graft patients, 1970-89.

OBJECTIVE: To review the changing clinical profile of isolated coronary artery bypass graft (CABG) surgery patients at the University of Alberta Hospitals during the past two decades. DESIGN: Data were obtained retrospectively by review of patients' hospital charts and cardiologists' charts. The three patient cohorts consisted of the first 411 consecutive patients who underwent isolated CABG surgery between 1970 and 1974, 302 consecutive patients who had CABG surgery in 1984 and 346 consecutive patients who had the operation in 1989. RESULTS: Patients who underwent CABG surgery in 1984 and 1989 were older than patients undergoing the same operation in the 1970s. Emergency and/or urgent operations and the number of patients with prior myocardial infarct were increased significantly in 1984 and 1989. The incidence of patients with multiple vessel disease and left main stem stenosis increased significantly over the two decades. The number of bypass grafts per patient and the use of internal mammary grafts have increased since 1970. The endarterectomy procedure was performed less frequently in 1984 and 1989. The use of radial artery grafts has been discontinued. Perioperative mortality remained stable throughout the study period despite an increasing incidence of high risk patients. The major cause of death was pump failure. The incidence of peripostoperative myocardial infarct was higher in the 1970s. A multivariate analysis of the 1984 and 1989 cohorts was performed to identify temporal trends in risk factors. Emergency surgery, preoperative heart failure, age (older than 65 years), prior CABG surgery and preoperative renal failure are significant predictors of operative motility. CONCLUSIONS: The clinical profile of patients for isolated CABG surgery has changed over the years. The mortality rate has been stable over two decades despite the advancement of medical and surgical practices, representing a balance of increasingly high risk patients presenting for CABG surgery.

Adult↗