Biomedical subjects

Peter Buser

Publications and source records attributed to Peter Buser.

22 records · Page 2Linked to original sources

PubMed2002

Bedside quantification of atherosclerosis severity for cardiovascular risk stratification: a prospective cohort study.

OBJECTIVES: We sought to assess the ability of a new noninvasive method to quantify atherosclerosis severity and to examine its power to predict cardiovascular events. BACKGROUND: Drug prevention of cardiovascular events is effective but costly, leading to a debate about who should receive this treatment. Patient selection is often based on surrogate markers, but quantification of atherosclerosis severity is desirable. METHODS: Atherosclerosis severity was quantified by determination of specific aortic wall elastance in transthoracic echocardiography, applying the biomechanics of pulse wave propagation. After validating the method in 52 patients by measuring aortic plaque burden in transesophageal echo directly, another 336 patients were prospectively studied by monitoring atherosclerotic events at one year and comparing the results with conventional risk stratification. RESULTS: Specific aortic elastance was well correlated with plaque burden (p < 0.0001) and largely independent of confounding variables. Specific aortic elastance predicted the primary end point of "atherosclerotic death, myocardial infarction or stroke" at one year (p < 0.0002). Event rate at one year in the lowest specific elastance tertile was 1.8% (CI 0.0% to 4.3%), in the middle tertile 5.4% (CI 1.1% to 9.7%) and in the highest tertile 12.7% (CI 6.3% to 19%). Secondary end points supported these findings. Stepwise multivariate analysis identified specific aortic elastance, prior atherosclerotic events and left ventricular ejection fraction as independent risk predictors. Specific elastance was of incremental value to clinically identified variables. CONCLUSIONS: Bedside measurement of specific aortic elastance allows assessment of atherosclerosis severity. It predicts the risk for future atherosclerotic events beyond conventional risk factors, promising better targeting of pharmacologic prevention and improved cost effectiveness.

Adult↗

PubMed2002

Late Aspergillus fumigatus endomyocarditis with brain abscess as a lethal complication after heart transplantation.

We report the case of a 65-year-old male patient who died from lethal Aspergillus fumigatus endomyocarditis and multiple cerebral septic emboli 6 months after cardiac transplantation. This complication developed 4 weeks after diagnosis of bilateral pulmonary aspergillosis, which was immediately treated by surgical removal and intravenous amphotericin B. Preceding colonization with Aspergillus spp was not identified. Primary cytomegalovirus infection (donor+/recipient-) and toxoplasmosis reactivation (donor+/recipient+) occurring at 1 and 2 months post-transplantation were successfully treated.

Aged↗

PubMed2002

Biopsy of right atrial angiosarcoma guided by transesophageal echocardiography.

When an intracardiac mass is detected, a histologic examination is frequently needed before making critical treatment modality decisions. This demands an open-chest procedure, often with cardiopulmonary bypass, with its associated morbidity. We describe a closed-chest approach using echocardiographically guided catheter biopsy.

Biopsy↗

PubMed1998

Long-Term Follow-Up and Dobutamine Stress Echocardiography of 19-mm Prosthetic Heart Valves.

BACKGROUND: In patients with a small aortic root, the use of 19-mm valve prostheses for valve replacement is controversial because of the small orifice area of these valves. METHODS: To assess stress hemodynamics in patients with 19-mm valve prostheses, to find predictors of unfavorable hemodynamics, and to document the long-term follow-up, we examined 30 patients (age, 64 +/- 19 years; 27 women and 3 men; follow-up, 38 +/- 50 months) clinically and with the use of dobutamine stress echocardiography. A history was taken, and a physical examination was performed. At rest and during dobutamine stress, Doppler echocardiography was performed. RESULTS: At rest, transprosthetic gradients were moderately elevated with mean and peak gradients of 15 +/- 7 and 32 +/- 14 mmHg, and effective orifice areas were small (0.91 +/- 0.31 cm(2)). Gradients rose markedly during stress (mean, 37 +/- 14 mmHg; peak, 83 +/- 41 mmHg). Predictors of high transprosthetic gradients were larger body surface area, younger age, and valve type. Mean and peak gradients were lower with St. Jude Medical Hemodynamic Plus valves than with standard St. Jude Medical (P < 0.05) and other valves, and the effective orifice area was highest (1.07 +/- 0.29 cm(2); P < 0.05 versus standard St. Jude Medical) in this valve model. Sixty percent of patients developed significant dynamic subvalvular or intraventricular gradients (84 +/- 41 mmHg) during dobutamine stress. CONCLUSIONS: After aortic valve replacement with 19-mm prostheses in patients with a small aortic root, dobutamine stress leads to high transvalvular gradients, which are dependent on valve model, age, and body surface area. In addition, 60% of patients develop significant dynamic outflow obstructions. These findings and the persistence of some degree of exercise-induced symptoms in 70% of patients suggest that alternative surgical techniques should be considered if the size of the aortic annulus demands a 19-mm valve, especially if the patient seeks physical activity, is young, or is of larger body size.

Journal Article↗