PubMed Health⌕ Search

Biomedical subjects

K Pieper

Publications and source records attributed to K Pieper.

At least 19 recordsLinked to original sources
PubMed1995

Predictors and sequelae of distal embolization during saphenous vein graft intervention from the CAVEAT-II trial. Coronary Angioplasty Versus Excisional Atherectomy Trial.

BACKGROUND: The purpose of this study was to identify the predictors and sequelae of distal embolization from a multicenter, randomized trial of saphenous vein graft intervention. The CAVEAT-II trial demonstrated that saphenous vein graft directional coronary atherectomy (DCA) was associated with greater angiographic success and less need for repeat intervention compared with percutaneous transluminal coronary angioplasty (PTCA) but at the cost of more acute complications--notably distal embolization. METHODS AND RESULTS: In CAVEAT-II, 305 patients were randomly assigned to DCA (149 patients) or PTCA (156 patients) for lesions with > 60% diameter stenosis in vein grafts > or = 3 mm in diameter. Distal embolization occurred in 20 patients (13.4%) assigned to DCA and 8 patients (5.1%) assigned to PTCA (P = .011). Independent predictors of distal embolization were use of DCA (71% in distal embolization patients versus 47% in patients without distal embolization, P = .011) and presence of thrombus (39% in distal embolization patients versus 14% in patients without distal embolization, P < .00). In-hospital adverse events were more frequent after distal embolization; 71% versus 20%, odds ratio plus (95% confidence intervals) 9.87 (4.65, 20.94). At 12-month follow-up, adverse event rates were also higher in patients with distal embolization (odds ratio, 3.05 [1.95, 4.76]). CONCLUSIONS: In this first prospective multicenter trial of saphenous vein graft intervention, distal embolization was more common after DCA than PTCA and in lesions containing thrombus. It also was associated with worse in-hospital and 12-month outcomes. The risk and sequelae of distal embolization should be considered when choosing a treatment strategy for vein graft disease.

Aged↗
PubMed1995

Directional atherectomy versus balloon angioplasty for coronary ostial and nonostial left anterior descending coronary artery lesions: results from a randomized multicenter trial. The CAVEAT-I investigators. Coronary Angioplasty Versus Excisional Atherectomy Trial.

OBJECTIVES: We hypothesized that atherectomy would be superior to balloon angioplasty for ostial and nonostial left anterior descending coronary artery lesions. BACKGROUND: Balloon angioplasty of ostial coronary artery lesions has been associated with a lower procedural success rate and a higher rate of complications and of restenosis than angioplasty of nonostial stenoses. Directional coronary atherectomy has been proposed as an alternative therapy for ostial lesions. METHODS: In the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I), 1,012 patients were randomized to undergo either procedure; 563 patients had proximal left anterior descending coronary artery lesions, of which 74 were ostial. We compared balloon angioplasty with directional atherectomy for early and 6-month results for ostial as well as nonostial proximal left anterior descending coronary artery lesions. RESULTS: Directional atherectomy led to an initially higher gain in minimal lumen diameter for ostial lesions (1.13 vs. 0.56 mm, respectively, p < 0.001) but a higher rate of adjudicated non-Q wave myocardial infarction (24% vs. 13%, respectively, p < 0.001) than balloon angioplasty and no improvement in restenosis rates (48% vs. 46%, respectively). In the nonostial proximal left anterior descending coronary artery lesions, angiographic restenosis was reduced (51% vs. 66%, p = 0.012), but this was also associated with a higher rate of periprocedural myocardial infarction (8% vs. 2%, p = 0.008 by site and 24% vs. 8%, p < 0.001 by adjudication) and no difference in the need for subsequent coronary artery bypass surgery (7.3% vs. 8.4%, respectively) or repeat percutaneous coronary intervention (24% vs. 26%, respectively). CONCLUSIONS: For ostial left anterior descending coronary artery stenoses, both procedures yielded similar rates of initial success and restenosis, but atherectomy was associated with more non-Q wave myocardial infarction. In this trial the predominant angiographic benefit (increased early gain and less angiographic restenosis) of atherectomy for the left anterior descending coronary artery was in proximal nonostial lesions. However, the tradeoffs for this angiographic advantage were more in-hospital myocardial infarctions and no decrease in clinical restenosis.

Angioplasty, Balloon↗
PubMed1995

Peripheral vascular complications in the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I).

OBJECTIVES: In-hospital peripheral vascular complications of balloon angioplasty were compared with those of directional atherectomy in the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I) to identify patients at risk and evaluate costs and outcomes. BACKGROUND: The incidence, costs and outcomes of peripheral vascular complications after coronary intervention have not been fully characterized as a function of randomly assigned therapy. METHODS: At 35 sites in the United States and Europe, 1,012 patients were randomized. Peripheral vascular complications were defined as the composite of pulse loss, pseudoaneurysm, hematoma > 4 cm in diameter or groin hemorrhage necessitating blood transfusion. Logistic models were derived to 1) predict these complications from baseline and procedural characteristics, 2) test the relevance of randomization assignment, and 3) assess their impact on hospital costs and long-term outcomes. RESULTS: Sixty-seven patients (6.6%) developed peripheral vascular complications, of whom 15 (22.4%) required a blood transfusion, 14 (20.9%) underwent vascular surgery, and 2 (3.0%) died. Both in-hospital deaths occurred in patients with peripheral vascular complications. There was no difference in composite peripheral vascular complication rates among patients randomized to angioplasty or atherectomy. Greater age, female gender, postprocedural heparin and intraaortic balloon counterpulsation were predictive of increased risk. In a representative 60% subset, mean hospital costs increased from $9,583 in patients without to $18,350 in those with peripheral vascular complications (p = 0.0001). The unadjusted mortality rate at 1 year was 7.5% for patients with peripheral vascular complications compared with 1.1% for all others (p = 0.0001). These complications identified patients at greater risk of death, myocardial infarction or repeat revascularization at 30 days and 1 year. The atherectomy group had a trend toward more frequent deaths and myocardial infarction. CONCLUSIONS: Directional atherectomy and balloon angioplasty had similar in-hospital peripheral vascular complication rates. Female gender, greater age, postprocedural heparin and intraaortic balloon counterpulsation were predictive of higher risk. The twofold increase in cost and sevenfold increase in long-term deaths highlight the need to prevent these periprocedural events and monitor patients closely.

Angioplasty, Balloon, Coronary↗
PubMed1992

Recruitment of an inotropic reserve in moderately ischemic myocardium at the expense of metabolic recovery. A model of short-term hibernation.

The regional, functional as well as metabolic consequences of inotropic stimulation on myocardium subjected to prolonged moderate ischemia were investigated. In 35 enflurane-anesthetized swine the left anterior descending coronary artery was cannulated and perfused at constant flow. The vein paralleling the left anterior descending coronary artery was cannulated for measurement of lactate and oxygen content. Transmural biopsies from the anterior myocardium were taken for the measurement of ATP, creatine phosphate, and glycogen. After control measurements, flow was adjusted to reduce regional contractile function (expressed as a work index, determined by sonomicrometry) by approximately 50%. After either 5, 25, 40, or 85 minutes of moderate ischemia, dobutamine was infused for 5 minutes into the ischemic region. In a separate group of five swine also subjected to 85 minutes of ischemia followed by infusion of dobutamine and 2 hours of reperfusion, triphenyltetrazolium chloride staining and light microscopy were used to identify infarcted tissue. Moderate ischemia (regional myocardial blood flow, 0.21 +/- 0.07 ml.min-1.g-1, determined by radiolabeled microspheres) was associated with a reduction of creatine phosphate after 5 minutes (from 9.35 +/- 2.54 to 6.43 +/- 1.06 mumol/g wet wt, p less than 0.05) and a further reduction after 25 minutes (3.18 +/- 0.69 mumol/g wet wt, p less than 0.05). Thereafter, creatine phosphate recovered despite continued ischemia (after 40 minutes, 4.95 +/- 1.37 mumol/g wet wt; after 85 minutes, 5.78 +/- 2.27 mumol/g wet wt). Lactate consumption during control conditions was reversed to production after 5 minutes of ischemia, which moderated during more prolonged ischemia. Without changing regional myocardial blood flow, infusion of dobutamine increased the work index significantly at any time point but also caused worsening of metabolic markers of ischemia. Nevertheless, even after 85 minutes of ischemia followed by the infusion of dobutamine and 2 hours of reperfusion, there was no evidence of necrosis. This experimental model provides a means of characterizing the mechanisms of short-term hibernation.

Animals↗
PubMed1991

[Virucidal efficacy of inorganic per-compounds].

Among 7 inorganic per-compounds tested potassium permanganate as 1% solution showed the greatest virucidal efficacy against poliovirus type I and reached a reduction rate of 4.1 after 30 sec exposure time. Potassium peroxomonosulfate produced a reduction rate of 5.6 after 5 min, whereas perchloric acid and sodium perborate needed 15 min and hydrogen peroxide 60 min to show a reduction of 10(4) of the infectivity level. Potassium peroxodisulfate and sodium perborate yielded a reduction rate of 0.9 and 1.3, respectively. With protein load a slight reduction of antiviral efficacy was observed, whereas with extended standing times only the reduction rate of sodium percarbonate was lowered from greater than or equal to 4.9 to 2.0 after 60 min exposure time.

Antiviral Agents↗
PubMed1991

[A long-term study of amalgam and composite fillings].

549 amalgam and 257 composite fillings, which were made by students, were reexamined. The functional loss of restorations was recorded and present fillings were assessed regarding marginal integrity, anatomy, surface condition and colour as referred to composite fillings. After 2-4 years of wear 90.3% of the amalgam fillings were still present, the percentage for 5-8 years-old amalgams was 88.5% and for 9-11 years-old amalgams 85.3%. Composite fillings were substituted or lost at a rate of 7.1% after 2-4 years, 10.8% after 5-8 years and 10.5% after 9-11 years.

Composite Resins↗
PubMed1991

[A prospective study on the incidence of mercury levels in dental students. 2. Correlation analysis].

The urinary mercury levels of 49 dental students have been examined in a longitudinal study for one year. The correlation of the measured values with the number of amalgam fillings, age, sex, smoking habits, and nutrition was assessed. The urinary mercury levels did not correlate with sex and smoking habits, but there was a correlation with the number of amalgam fillings. The data obtained in our longitudinal study confirm the results of cross sectional studies: amalgam fillings contribute a measurable though small amount to urinary mercury excretion.

Adult↗
PubMed1991

[Amalgam fillings in the deciduous and mixed dentition--a post-treatment evaluation of service life and quality].

295 amalgam fillings in deciduous teeth and 150 amalgam restorations in permanent first molars were examined in 112 child patients. The functional loss of restorations was corded and present fillings were assessed in view of marginal integrity, anatomy and surface condition. For primary molar amalgams the 4-year survival rates "estimate" ist ein Schätzwert--wenn der Autor es so gemeint hat, muss "estimate" stehenbleiben, andernfalls heisst es "iate" (= Quote) were 67% for Class 1 restorations and for 55% Class 2 fillings. After 4 years of placement 78% of the Class 1 restorations in permanent first molars were still intact.

Child↗
PubMed1991

[Preventive measurement in Gottingen kindergartens from 1975-1990].

379 children, age 3 to 6, were examined for caries prevalence in kindergartens in Göttingen. 64% of subjects had healthy natural dentitions, the df-s value was 2.3. In 1990 the mean df-s value for 4-5 year old children was 10% lower than 1985 and 45% lower than 1983. Oral health had improved differently in the various institutions. The mean df-s was between 0.6 and 4.7.

Child↗
PubMed1991

[Pathologic X-ray signs in tuberculosis of ornamental birds and birds of prey].

Tuberculosis is still important as a disease of birds kept as pets and in zoos, and as a zoonosis. In living birds the diagnosis is difficult. In combination with the clinical and laboratory examination, radiology may help to lead to the diagnosis "generalised mycobacterial infection". Eight cases of tuberculosis seen in the clinic of our institute showed the different radiographic signs which may occur in the course of a mycobacterial infection. The specificity of the x-rays in combination with clinical and laboratory results is discussed.

Animals↗
PubMed1990

[Patient with high risk of caries. Definition, epidemiology and clinical aspects].

Epidemiological studies have shown that there is a small group of patients with high caries prevalence. This survey illustrates the clinical picture of caries-active patients on the basis of exemplary cases and defines a number of terms which are important in this context. In addition to this, possible causes of an increased caries risk are discussed.

Adolescent↗
PubMed1990

[Selective intensive prophylaxis in area of group prophylaxis].

An increasing polarisation of caries prevalence in children was found in recent years. A needs-related prevention programme was thus developed which provides for selective intensive treatment of pupils with increased caries risk. A corresponding prevention programme was tested at elementary schools in Göttingen in 1985-1989: whereas in 1985, 31% of the 4th-class pupils had caries-free permanent teeth, this percentage had increased to 45% in 1989. The average DMF-S was 1.9 in 1989 (1985: 3.9).

Child↗
PubMed1990

[Test of an electronic fissure caries detector].

The reliability of an electronic detector for caries in pits and fissures was tested by means of physical measurements, histological sections and clinical evaluation. The device measures the ohmic resistance of the tooth, technical data are given. First we compared measurements and histological sections of teeth due for extraction. The results indicated a high sensitivity of the device for caries, false positive diagnoses did not occur. Based on this, a clinical evaluation on 179 teeth was performed. Under practical conditions the sensitivity of the electronic detector (0.77) was lower than in the first part of the study; conventional diagnosis revealed more carious lesions in dentine (sensitivity: 0.82).

Dental Fissures↗
PubMed1989

Cardiovascular and renal toxicity of a nonionic radiographic contrast agent after cardiac catheterization. A prospective trial.

STUDY OBJECTIVE: To determine the incidence of cardiovascular and renal toxicity of a nonionic contrast agent when used for cardiac catheterization, and to assess the value of electrolytes and urinalysis results as predictors of nephropathy induced by a contrast agent. STUDY DESIGN: Nonrandomized trial using a criterion standard and a cohort analytic study with a 48-hour follow-up. SETTING: Referral-based university hospital. PATIENTS: Convenience sample of patients having diagnostic cardiac catheterization. Renal function and clinical status were evaluated at baseline in 1,144 patients; at 24 hours in 1,077 (94%); and at 48 hours in 663 (57%). INTERVENTIONS: After patients received saline for hydration, coronary angiography and left ventriculography were done with iopamidol (average dose, 203 +/- 56 cc). MEASUREMENTS AND MAIN RESULTS: The definite and possible incidence of major acute cardiovascular complications from nonionic contrast media was 0.2% and 0.7%, respectively. The mean serum creatinine level increased 11.5 mumol/L from baseline at 24 hours (P less than 0.0001) and 16.8 mumol/L from baseline at 48 hours (P less than 0.0001). Results in a randomly selected training sample were studied to determine predictors of a rise in serum creatinine of 44.2 mumol/L or more. The baseline serum creatinine level and age were significant predictors of renal injury, but hypertension, diabetes mellitus, congestive heart failure, vascular disease, the volume of contrast agent injected or baseline values of urinary variables did not predict nephrotoxicity. In an independent validation sample, only the baseline serum creatinine level was confirmed as a predictor of nephrotoxicity, whereas age was not. A model that predicted contrast-induced nephropathy by the serum creatinine level showed an exponential increase in the risk for nephrotoxicity if the baseline level was 106.1 mumol/L or higher. CONCLUSIONS: Patients have a small but significant rise in serum creatinine after cardiac catheterization with a nonionic contrast agent. Baseline renal insufficiency is the only confirmed predictor of nonionic contrast-induced nephrotoxicity.

Aged↗
PubMed1989

Use of an electronic apex locator in the treatment of teeth with incomplete root formation.

An electronic apex locator was used to determine length and control apical bridge formation in the treatment of teeth with incomplete root formation. Measurements were taken in 10 teeth in which apexification therapy had just started and in 11 teeth where the formation of the apical barrier was considered to be complete. In the beginning of the apexification therapy, when the apical foramen was still open, endometric measurements gave incorrect results in all instances. After apical closure had occurred and definite obturation of the root canal seemed possible, the apex locator in all teeth gave correct results and complete agreement was obtained between the radiographs and the electronic tests. Even in teeth in which complete apical closure could not be obtained, the results of electronic measurements were correct. Electronic apex locators may be used as auxilliary devices in controlling apical hard tissue closure in the treatment of teeth with incomplete root formation.

Adolescent↗
PubMed1989

[Caries and gingivitis prevention in handicapped children and youth. Part 3. Five-year results].

In schools for handicapped children in Göttingen 104 mentally and physically handicapped and 150 learning disabled pupils participated in an intensive care preventive program. Their teeth were examined before beginning the prevention, after 6 months, and subsequently at annual intervals. The examinations consisted of caries diagnosis and assessment of periodontal health. Five years after the onset of the prevention program the incidence of caries in the various age groups and institutions was 23% to 64% lower than 1982. Results were best in mentally and physically handicapped children aged 9 to 11 years (mean DMF-S 1987: 2.4 versus 1982: 6.6). In the same period of observation the degree of oral health in mentally and physically handicapped children improved from 43% to 73%, in learning disabled from 32% to 63%. Mean SBI values were reduced by 60%.

Adolescent↗
PubMed1989

[A selective, need-oriented prevention program for primary schoolchildren - results after two years].

427 first grade pupils from primary schools in Göttingen participated in a selective, need-oriented preventive program. Following a clinical examination and an additional saliva test the children were assigned to three risk groups, according to the severity of the initial findings. Each group received preventive care of varying intensity. Two years later the children of risk group 1 ("minor caries risk") showed a mean 0.5 and those of risk group 2 ("medium caries risk") a mean 1.0 new DF surfaces. In the children of the high caries risk group the average caries increment was 1.8 DF surfaces. The degree of sanation of the deciduous teeth could be improved from 10% to 47% within the two years' test period. The saliva tests revealed that the number of cariogenic organisms was markedly reduced in the course of the preventive program.

Child↗