Keith G. Buchan

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OBJECTIVE To assess the performance of the Medtronic Hall valve (Medtronic, Inc, Minneapolis, Minn) in one institution over a 20-year period. METHODS Since 1979, Medtronic Hall valves have been used in 1766 procedures (736 aortic, 796 mitral, and 234 double). Patients were followed up prospectively at 6- to 12-month intervals for a total of 12,688(More)
BACKGROUND Cardiac surgery may be associated with significant perioperative and postoperative morbidity and mortality. Underlying pathology, surgical technique, and postoperative complications may all influence outcome. These factors may be reflected as a rise in postoperative troponin levels. Interpretation of troponin levels in this setting may therefore(More)
BACKGROUND An elevated preoperative white blood cell count has been associated with a worse outcome after coronary artery bypass grafting (CABG). Leukocyte subtypes, and particularly the neutrophil-lymphocyte (N/L) ratio, may however, convey superior prognostic information. We hypothesized that the N/L ratio would predict the outcome of patients undergoing(More)
The neutrophil/lymphocyte (N/L) ratio integrates information on the inflammatory milieu and physiologic stress. It is an emerging marker of prognosis in patients with cardiovascular disease. We investigated the relation between the N/L ratio and postoperative atrial fibrillation (AF) in patients undergoing coronary artery bypass grafting. In a prospective(More)
BACKGROUND Severe renal dysfunction is associated with a worse outcome after coronary artery bypass graft surgery (CABG). Less is known about the effects of milder degrees of renal impairment, and previous studies have relied on levels of serum creatinine, an insensitive indicator of renal function. Recent studies have suggested that estimated glomerular(More)
OBJECTIVE We sought to assess the effect of anticoagulation control on long-term survival after valve replacement with the Medtronic Hall valve (Medtronic, Inc, Minneapolis, Minn). METHODS Prospective follow-up data, including 82,297 international normalized ratios, were collected for 1476 patients undergoing single valve replacement with the Medtronic(More)
BACKGROUND Atrial fibrillation (AF) is a common complication after coronary artery bypass grafting (CABG). We prospectively compared the ability of echocardiographic parameters and the cardiac neurohormones, brain natriuretic peptide (BNP), and N-terminal pro-brain natriuretic peptide (NT-proBNP) to predict AF in this setting. METHODS We recruited 275(More)
The aim of the investigation was to vary certain geometrical features of the mitral valve in vitro, in order to understand their role in valve function. Geometrical changes to mitral valve components are known to affect valve function, but complete understanding of how geometrical changes influence valve function is far from complete. Test apparatus has(More)
BACKGROUND AND AIM OF THE STUDY The study aim was to understand the role of different mitral valve chordae tendineae, and how damage to them affects valve competence. METHODS A test apparatus was used to apply pressure to porcine mitral heart valves that were intact and have had selected chords severed. Anterior leaflet strut and marginal chords were(More)
OBJECTIVE To determine the effects of socio-economic status (SES) on the outcome of coronary artery bypass grafting (CABG). DESIGN Prospective cohort study. SETTING Regional cardiac surgical unit. PATIENTS 1994 consecutive patients undergoing non-emergency CABG. MEASURES SES was determined from the patient's postcode using Carstairs tables. The(More)