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W Rutishauser

Publications and source records attributed to W Rutishauser.

At least 19 recordsLinked to original sources
PubMed2000

[Economic evaluation of different treatment strategies in patients with stable angina pectoris or asymptomatic myocardial ischemia on basis of results from the Asymptomatic-Cardiac-Ischemia Pilot study (ACIP)].

BACKGROUND: In patients with stable angina pectoris or silent myocardial ischemia, who had signs of ischemia in ECG during exercise, the Asymptomatic Cardiac Ischemia Pilot (ACIP) study compared 2 types of medication strategies (ischemia-guided and angina-guided) and a strategy of primary revascularization by PTCA or CABG. ACIP substantiated, after 2 years of observation, a clear advantage of the revascularization strategy compared to both drug strategies in terms of clinical effectiveness. This advantage is even more distinct in patients with very severe angiographic results. PATIENTS AND METHODS: This is a retrospective, incremental cost-effectiveness analysis from the perspective of the German third party payer (statutory sick funds) on the basis of the ACIP study. RESULTS: The direct costs of the revascularization strategy after 2 years are about 2 to 3 times higher than those of the drug therapies. The incremental cost-effectiveness of the ischemia-guided strategy versus an angina-guided strategy is DM 2,600 per life-year saved. Furthermore, the cost-effectiveness of a revascularization strategy versus an angina guided therapy is DM 15,100 per life-year saved. CONCLUSION: A primary revascularization strategy is cost-effective in patients with stable coronary artery disease with proven myocardial ischemia and positive angiographic signs.

Aged↗
PubMed2000

Effect of sexual activity on cycle ergometer stress test parameters, on plasmatic testosterone levels and on concentration capacity. A study in high-level male athletes performed in the laboratory.

BACKGROUND: The purpose of this study was to investigate the effect of sexual activity on cycle ergometer stress test parameters, on plasmatic testosterone levels and on concentration capacity in high-level male athletes. METHODS: Experimental design. Analysis of two days of testing accomplished in a laboratory setting, comparing a day with to a day without sexual activity (control day). Participants. Fifteen high-level male athletes, consisting of 8 team players, 5 endurance athletes and 2 weight-lifters, participated in the study. Measures. Each subject completed the following on each test day: two maximal graded stress tests on a cycle ergometer and a one-hour exercise stress test coupled to an arithmetic mental concentration test. Blood samples of testosterone were obtained and cardiac activity of each athlete was monitored with a 24-hour ECG tape recording over the two test days. RESULTS: Significantly higher differences were achieved for post-effort heart rate (HR) values at 5 minutes (p<0.01) and at 10 minutes (p<0.01) during the recovery phase of the morning stress test 2 hours after sexual activity. These differences disappeared during the recovery phase of the afternoon stress test performed approximately 10 hours after sexual intercourse took place. CONCLUSIONS: Our findings show that sexual activity had no detrimental influence on the maximal workload achieved and on the athletes' mental concentration. However, the higher posteffort HR values after the maximal stress test on the morning of sexual intercourse suggest that the recovery capacity of an athlete could be affected if he had sexual intercourse approximately 2 hours before a competition event.

Adult↗
PubMed1999

The Denolin Lecture 1998. Towards measurement of coronary blood flow in patients and its alteration by interventions.

AIM: Several methods of measuring coronary blood flow in intact conscious man are reviewed, on the basis of personal contributions or the experiences of our teams. METHODS AND RESULTS: It is important to distinguish between global, regional and transmural blood flow measurements. The advantages and limitations of the following methods are discussed: diffusible inert and radioactive tracers, dye dilution, roentgendensitometry, magnetic resonance imaging and contrast echocardiography. In interventional cardiology it is most important to be able to measure flow through single coronary vessels. Information on coronary artery Doppler velocity during vasodilation and at rest is less useful than the concept of fractional flow reserve. This is based on pressure measurements under maximal vasodilation to ascertain the presence of borderline flow-limiting lesions. This information is necessary in order to decide whether to proceed with angioplasty or not. CONCLUSIONS: The historical design of percutaneous coronary angioplasty and beta-irradiation of coronary restenosis, established under the author's guidance, are put into perspective. The author pays tribute to many excellent colleagues who worked with him at the Zurich and Geneva University Hospitals.

Angioplasty, Balloon, Coronary↗
PubMed1997

Feasibility of intracoronary beta-irradiation to reduce restenosis after balloon angioplasty. A clinical pilot study.

BACKGROUND: With the aim of decreasing the incidence of restenosis after coronary balloon angioplasty, we developed a technique of intracoronary beta-irradiation using an endoluminally centered pure metallic 90Y source. The purpose of the present study was to evaluate the clinical feasibility and safety profile of this approach with a dose of 18 Gy delivered to the inner arterial surface. METHODS AND RESULTS: Between June 21 and November 15, 1995, fifteen patients (6 women and 9 men; mean age, 71 +/- 5 years) underwent intracoronary beta-irradiation immediately after a conventional percutaneous transluminal coronary angioplasty (PTCA) procedure. The PTCA/irradiation procedure was technically feasible in all attempted cases, and the delivery of the 18 Gy dose was accomplished without complications. In 4 patients, the intervention was completed through intra-arterial stent implantation because of dissection induced by the initial PTCA. During the follow-up period of 178 +/- 17 days (range, 150 to 225 days), no complication occurred that could be attributed to radiation therapy. No aneurysm or angiographically detectable thrombus was observed in any of the irradiated arterial segments. The clinical event rate (4 of 15 patients underwent further target lesion revascularization) and the angiographic follow-up (6 of 15 patients had a > 50%-diameter stenosis at the previously treated site) did not suggest a marked impact on the expected restenosis rate. CONCLUSIONS: This early experience demonstrates that our approach is feasible, and no side effects attributable to radiation were noted during a 6-month period of follow-up. Whether higher doses of beta-irradiation will favorably affect post-PTCA restenosis in patients must await further evaluation.

Aged↗
PubMed1997

Long-term prognostic significance of ventricular late potentials after a first acute myocardial infarction.

Ventricular late potentials (VLP) have been shown to be independent predictors of arrhythmic events after myocardial infarction. However, many studies have had one or more limitations: limited follow-up period, small study group, possible selection bias, inadequate statistical analysis, or inclusion of patients with previous infarction. The purpose of this study was to assess the long-term prognostic value of VLP in a large group of unselected patients after a first acute myocardial infarction. Time-domain signal averaging was performed in 458 patients (380 male, 78 female, mean age 59 +/- 11 years) a mean of 10 days (range 7 to 13 days) after a first acute myocardial infarction. The overall prevalence of VLP was 20% (90 of 458 patients). By univariate analysis a left ventricular ejection fraction <40% (p = 0.002) and the presence of an occluded infarct-related artery (p = 0.006) were the only statistically significant predictors for the development of VLP. During a median follow-up of 70 months, 21 (5%) patients died suddenly, and 11 (2%) patients had documented sustained ventricular tachycardia. The presence of VLP (p < 0.0001), older age (p = 0.02), and an occluded infarct-related artery (p = 0.045) were the only variables significantly associated with the occurrence of serious arrhythmic events during follow-up. The probability of having no arrhythmic events was 99% at 1 year and 96% at 5 years in the absence of VLP and 87% at 1 year and 80% at 5 years in the presence of VLP (4.6-fold increase in arrhythmic risk; 95% confidence interval: 2.3 to 9.1). VLPs are powerful predictors of serious arrhythmic events in patients after a first acute myocardial infarction, and their prognostic value, although waning with time, persists for at least 7 years. This study also provides further evidence that an open infarct-related artery may reduce the arrhythmic risk after myocardial infarction.

Action Potentials↗
PubMed1997

A new technique for improved densitometric quantification of coronary artery stenoses in angiographic images.

In vitro studies have demonstrated that densitometric quantification of coronary artery stenoses is superior to geometric methods to assess non-circular lumens. However, in patients, several authors have reported significant discrepancies between area reduction percentages obtained densitometrically from two different imaging projections. Some of the factors causing the discrepancies can be reduced by simple precautions taken during image acquisition. Some others may be compensated for during analysis. Nevertheless, two factors remain problematic. The first is the inadequate spatial orientation of the vessel axes at the stenotic and reference cross sections with respect to the x-rays. The second is the difficulty in identifying the same vessel cross section in both planes at the time of analysis. We have designed a new densitometric technique that eliminates the error contributions of these two factors. The technique requires simultaneously acquired biplane coronary angiograms and biplane images of a translucent cube bearing steel markers acquired in exactly the same biplane geometry. Using the two projection matrices calculated from the images of the cube, the centerlines and the edges of the coronary arteries can be reconstructed in space from the biplane angiograms. The angles between the vessel axes and the x-ray beams can be determined and the densitometric cross sections can be corrected accordingly. Moreover, the 3D reconstruction allows the identification of the same cross section in the two planes for the determination of the area reduction percentages. Validation measurements were performed on a Perspex phantom and in patients, before and after angioplasty. In both types of measurement, the interplane discrepancies could be roughly halved. The densitometric technique presented can be incorporated into routine angiography and could become a strong alternative to the geometric approach that is presently dominating this field.

Coronary Angiography↗
PubMed1997

Long-term (10 years) prognostic value of a normal thallium-201 myocardial exercise scintigraphy in patients with coronary artery disease documented by angiography.

In order to assess the prognostic significance of normal exercise thallium-210 myocardial scintigraphy in patients with documented coronary artery disease, we studied the incidence of cardiac death and non-fatal myocardial infarction in 69 symptomatic patients without prior Q wave myocardial infarction, who demonstrated one or more significant coronary lesions (stenosis > or = 70%) on an angiogram performed within 3 months of scintigraphy (Group 1). These patients were compared to a second group of 136 patients with an abnormal exercise scintigram, defined by the presence of reversible defect(s) and angiographically proven coronary artery disease (Group 2), and to a third group of 102 patients with normal exercise scintigraphy without significant coronary lesions (stenosis < or = 30%) or with normal coronary angiography (Group 3). In contrast to coronary lesions observed in Group 2, patients in Group 1 presented more frequently with single-vessel disease (83% vs 35%, P < 0.0001) and with more distal lesions (55% vs 23%, P < 0.0001). Over a mean follow-up period of 8.6 years, one fatal and eight non-fatal cases of myocardial infarction were observed in Group 1. The majority of patients in Group 1 were treated medically: only 24 (35%) underwent myocardial revascularization, usually by coronary angioplasty. There was no significant difference in the incidence of combined major cardiac events (cardiac death, non-fatal myocardial infarction) in patients with normal exercise scintigraphy, with or without documented coronary artery disease (Groups 1 and 3), while the incidence was higher in Group 2. However, while the mortality remained very low in Group 1, the incidence of non-fatal myocardial infarction was not different from that of Group 2, where most patients underwent revascularization procedures. In conclusion, patients with coronary artery disease and a normal exercise thallium-201 myocardial scintigram usually have mild coronary lesions (single-vessel disease, distal location) and good long-term prognosis, with a low incidence of cardiac death.

Adult↗
PubMed1997

C-reactive protein as a marker for acute coronary syndromes.

BACKGROUND: For several years, acute coronary syndromes have been perceived as causing the most hospital admissions, and even hospital mortality. The syndrome of unstable angina frequently progresses to acute myocardial infarction but its pathogenesis is poorly understood, and prognosis determination is still problematic. We tested the hypothesis that measurement of the C-reactive protein in patients admitted for chest pain could be a marker for acute coronary syndromes. METHODS AND RESULTS: We studied 110 patients admitted with suspected ischaemic heart disease, but without elevated serum creatine-kinase levels at the time of hospital admission. Patients were subsequently divided into two groups based on their final diagnosis: group 1 comprised patients with unstable angina; group 2 patients with acute myocardial infarction. We measured the C-reactive protein at the time of hospital admission. The concentration of C-reactive protein was elevated in 59% of the patients with a final diagnosis of acute myocardial infarction, and in 5% of the patients with a final diagnosis of unstable angina, (P < 0.001). CONCLUSION: This study indicates that C-reactive protein levels measured at the time of admission in patients with suspected ischaemic heart disease could be a marker for acute coronary syndromes, and helpful in identifying patients at high risk for acute myocardial infarction. Measurement of C-reactive protein may have practical clinical significance in the management of patients hospitalized for suspected acute coronary syndromes.

Acute Disease↗
PubMed1997

A new densitometric approach to the assessment of mean coronary flow.

RATIONALE AND OBJECTIVES: The authors present an angiographic method to measure absolute coronary blood flow in patients. METHODS: The left or right coronary tree is three-dimensional (3D)-reconstructed from biplane coronary angiograms. This allows the determination of the intravascular volumes needed for flow measurement. The 3D distance traveled by the contrast medium during one cardiac cycle is determined by appropriately thresholding the "concentration-distance", curves computed on two pairs of images taken one cardiac cycle apart. RESULTS: The angiographic flow measurements were compared with nearly simultaneous flow determinations obtained with an intracoronary ultrasonic Doppler flow velocity measuring device. The mean relative difference between the Doppler and the 3D measurements was 11% and the two sets of flow values correlated well (r = 0.81). CONCLUSIONS: A method for the determination of mean coronary flow is presented. The procedure is simple and can be incorporated easily into clinical routine.

Blood Flow Velocity↗
PubMed1997

[Dynamic three-dimensional cardiac reconstruction by transesophageal echocardiography. A clinical experience apropos of 100 cases].

Three-Dimensional (3D) echocardiography was performed during routine transesophageal examinations in 100 patients to identify the most promising applications. The approach used was based on the integration of multiple two-dimensional images recorded with a multiplane probe to achieve 3D reconstruction. A series of 90 cardiac cycles was recorded from a fixed position during computer-controlled rotation of the transducer. The images were digitized, then reorganized according to their spatial and temporal location. The cardiac structures were then represented dynamically in three dimensions. In 100 patients referred for transesophageal echocardiography, the 3D reconstruction provided good quality images, under new angles, such as the view of the atrial aspect of the mitral valve as seen from the roof of the left atrium. This method was particularly well suited to assess mitral valve prolapse or stenosis. The spatial extent, direction and number of jets of mitral regurgitation were easily appreciated throughout systole, as were the regurgitant jets of mechanical prosthetic valves. However, the sensitivity of the 3D method was not as good as 2D echocardiography for detecting bacterial vegetations in cases of infective endocarditis. On the other hand, the determination of the precise localization of infectious, degenerative and tumoral lesions and their size were facilitated by 3D reconstruction. The authors conclude that 3D echocardiography is applicable in routine practice and the complementary information provided in certain cardiac diseases should help management of these patients.

Adult↗
PubMed1997

[What is the value of palpation and auscultation?].

In the diagnosis of heart disease--as in other domains of medicine--an integral approach to the patient complaints is essential. Careful observation and evaluation of his personality during medical history taking as well as an optimal clinical examination by palpation and auscultation of the heart, great vessels and lungs may lead to a semiquantitative diagnosis specially in valvular and congenital heart disease. The results of select imaging techniques may therefore be anticipated in these conditions by skilled clinical judgment alone. The palpatory and auscultatory findings are easily explained by the underlying hemodynamics. This article summarizes the most relevant clinical diagnostic clues in valvular and some congenital heart diseases.

Diagnosis, Differential↗
PubMed1997

Feasibility and safety of beta irradiation in human coronary arteries.

We have developed a technique of endoluminally centred endovascular beta irradiation aimed at preventing restenosis after PTCA. The source consists of a pure metallic 90-Yttrium coil that can be positioned within the lumen at the target site by the use of a centering device and an afterloading console. Experimental evaluation of this approach showed that a dose of 18 Gy delivered at the inner arterial surface was highly effective in preventing fibrointimal hyperplasia in rabbit carotid and iliac arteries. A pilot clinical evaluation in the coronary arteries of 15 patients using the same dose demonstrated excellent feasibility and no unexpected side-effects. A dose-finding evaluation in the clinical setting is now planned.

Angioplasty, Balloon, Coronary↗
PubMed1996

A novel system for intracoronary beta-irradiation: description and dosimetric results.

PURPOSE: A dosimetric evaluation of a new device dedicated to intravascular irradiation, associating a beta source and a centering device, was carried out before initiation of a clinical pilot study. METHODS AND MATERIALS: A 29-mm-long 90Y coil, coated with titanium and fixed to the end of a thrust wire, was introduced into the inner lumen of purpose-built centering balloons of different diameters (2.5, 3, 3.5, and 4 mm). Dose homogeneity was evaluated by studying both axial and circumferential dose variations, based on readings from thermoluminescent dosimeters (TLDs) placed on the balloon surface. Axial homogeneity was determined by comparing the readout values of dosimeters located on peripheral balloon segments with those located on segments adjacent to the midpoint of the source. The centering ability of the device was studied by comparing measurements on opposing surfaces of the balloon. The dose attenuation by water and contrast medium was evaluated and compared with that in air. The balloon contamination was studied using a contamination counter. The total 90Y coil activity was measured by liquid scintillation to relate activity to surface dose. RESULTS: Activity-surface dose correlation showed that for a linear coil activity of 1 mCi/mm, the mean dose rate at the surface of a 2.5-mm balloon filled with contrast medium was 8.29 Gy/min. The doses at the surface of larger balloons (3, 3.5, and 4 mm) filled with contrast were 78%, 59%, and 47%, respectively, of the dose measured at the surface of the 2.5-mm balloon. The coefficient of variation (CV) in surface dose for 2.5-, 3-, 3.5-, and 4-mm centering devices filled with contrast medium were 9%, 8%, 9%, and 12%, respectively. There was no statistically significant difference between readouts from central and peripheral balloon segments or among rows of dosimeters facing each other. For a 2.5-mm balloon, compared with air the dose attenuation by water and contrast medium was similar (0.70 and 0.69, respectively), but a significant difference was seen between the readouts of water- and contrast-filled balloons when the diameter was larger than 3 mm (p < 0.001). No contamination was found in the balloon shaft after source retrieval. CONCLUSION: The dosimetric tests showed very good surface dose homogeneity, demonstrating satisfactory centering of the source within the centering balloons. The achievable dose rates will permit intravascular irradiation within a short time interval. The absence of residual balloon contamination after source retrieval meets the requirements for a sealed source used in a clinical setting.

Brachytherapy↗
PubMed1996

The impact of vessel orientation in space on densitometric measurements of cross sectional areas of coronary arteries.

Under ideal conditions, densitometric measurement of a coronary arterial cross section in biplane angiographic images should result in nearly equal cross sectional areas for both planes. However, quite appreciable discrepancies have been found by some authors in patients. In this study, the role of inadequate spatial orientation of the vessel axes relatively to the x-rays was assessed by use of a 3D technique applied to 60 stenoses (45 pre PTCA and 15 post PTCA) in simultaneously acquired digital biplane coronary angiograms of 27 CAD patients. The 3D technique yields two radius values per projection directly in mm at any arterial cross section of interest. This was used to determine the areas Ar(in mm2) of the reference cross sections. As with catheter calibration, these cross sections were thus assumed to be more or less circular, but out-of-plane effects and errors due to a catheter diameter determination in pixels were avoided. The areas of the stenotic sections were then determined densitometrically (in mm2) from the two projections (1 and 2) according to As1 = ArDs1/Dr1, resp. As2 = ArDs2/Dr2, where Dr1, Dr2, Ds1 and Ds2 are the conventional densitometric areas of the reference and stenotic cross sections measured in planes 1 and 2. As expected, the areas As1 and As2 correlated only moderately: As2 = 0.92 As1 + 0.7 mm2, r = 0.82, n = 60, SEE = 1.4 mm2. The 3D method also yielded the two spatial angles between the local vessel axis and the X-rays of both planes. These two angles were then used to correct each densitometric area for inadequate orientation. With the corrected densitometric areas As1c and As2c, the correlation improved to: As2c = 1.05 As1c + 0.03 mm2, r = 0.93, n = 60, SEE = 0.8 mm2. Inadequate orientation of the cross sections in space thus appears to be an important factor of inaccuracy in densitometric measurements of stenotic cross sections in patients.

Absorptiometry, Photon↗