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Biomedical subjects

J J Jonker

Publications and source records attributed to J J Jonker.

29 records · Page 2Linked to original sources

Home-diagnosis of deep venous thrombosis with impedance plethysmography.

In order to assess the value of I.P.G. for the diagnosis of D.V.T. in general practice, an I.P.G. was carried out by a skilled technician in 255 consecutive patients with suspected D.V.T. at home. Ascending venography was carried out in 185 of these patients. In addition, blood for assay of AT III, platelet count, fibrinogen, a2-antiplasmin, ethanol gelation test and spontaneous platelet aggregation was collected at the time the I.P.G. was performed. In 61 patients (33%) venography showed the presence of D.V.T., and was negative in the remaining 124 patients. I.P.G. was positive in 51 of the 61 patients with D.V.T., a sensitivity of 84%. I.P.G. was normal in 115 of the 124 patients with a negative venogram, a specificity of 93%. The sensitivity of the I.P.G. for proximal vein thrombosis was 92% and for calf vein thrombosis 68%. Mean a2-antiplasmin concentration was significant (p less than 0.05) lower (101 +/- 15%, mean +/- SD) in patients with D.V.T. compared with patients with a normal venogram (107 +/- 11%, mean +/- SD). No differences between the two groups were observed in the other coagulation parameters assayed, and none was of diagnostic value, either alone or in combination with I.P.G. This study shows that I.P.G. is of potential value for the home diagnosis of D.V.T., in particular proximal vein thrombosis. This is potentially clinically useful, because these thrombi are thought to carry a high risk for pulmonary embolism.

Anticoagulants↗

The incidence of deep venous thrombosis in patients with an acute myocardial infarction treated with acenocoumarol or indobufen.

In a randomized double blind clinical trial, we compared indobufen, an antiplatelet drug, with acenocoumarol for the prevention of deep venous thrombosis (D.V.T.) in patients with acute myocardial infarction. Therapy was started on admission and continued for 10 days. All patients were screened daily with impedance plethysmography (I.P.G.) and 125I-fibrinogen leg scanning. Diagnosis of D.V.T. was made when either one or both tests became positive. 74 patients were randomized to treatment with indobufen (200 mg b.i.d.) and 76 patients to acenocoumarol (controlled by thrombotest). The incidence of venous thrombosis in patients with indobufen was 11% and in those treated with acenocoumarol 9%. Major bleeding was observed in 2 patients treated with acenocoumarol. In the indobufen group, no bleeding complications or other serious side-effects were observed. The majority of patients developed thrombosis after the first week of admission. For patients with and without thrombosis, there was no significant difference between the two treatment groups concerning the age, the coronary prognostic index, the maximum C.P.K. value, mobility, incidence of congestive heart failure and the site or extent of the infarct. In this study no clinical or laboratory (fibrinogen, platelet count and anti-thrombin III) parameter, either alone or in combination, was of predictive value for the development of D.V.T. It can be concluded that indobufen appears to be as good as acenocoumarol for the prevention of D.V.T. in patients with acute myocardial infarction. Because it is safe and easy to administer, indobufen seems to be preferable. Prophylaxis is required for at least 10 days.

Acenocoumarol↗

A double blind cross-over comparison of bunitrolol and placebo in the treatment of angina pectoris.

In 20 patients with stable angina pectoris, o-[3-(tert.-butylamino)-2-hydroxypropoxy]-benzonitrile (bunitrolol) was compared with placebo in a double blind cross-over trial, with monthly treatment periods. There was no difference in the subjective condition of the patient. The bunitrolol treated patients showed a significantly better work capacity (P less than 0.05) and pressure-rate product (P less than 0.01) in the exercise tests. No significant difference could be found in the ST-segment changes. The bunitrolol patients showed a significant reduction in heart rate at rest (P less than 0.01); a significant difference in blood pressure was not found. Bunitrolol is an effective beta-adrenergic blocker, without side-effects in this trial.

Adult↗

Costs and effects of long-term oral anticoagulant treatment after myocardial infarction.

OBJECTIVE: To investigate the costs and effects of long-term oral anticoagulant treatment after myocardial infarction. DESIGN: Cost-effectiveness analysis, based on a randomized, double-blind, placebo-controlled trial. SETTING: Sixty Dutch hospitals. PATIENTS: A total of 3404 hospital survivors of acute myocardial infarction randomized within a median period of 4 days after discharge to either oral anticoagulant treatment or placebo. The mean follow-up was 37 months. INTERVENTION: Oral anticoagulant treatment aimed at a target international normalized ratio of 2.8 to 4.8. MAIN OUTCOME MEASUREMENTS: Costs of hospital stay during readmissions, costs related to major cardiologic interventions, and costs of oral anticoagulant treatment. RESULTS: The costs of oral anticoagulant treatment were estimated at 394 Dutch guilders (Dfl) per patient-year (Dfl 1 = US $0.58). Placebo patients stayed 18,830 days in the hospital compared with 15,083 days for anticoagulation patients. Average costs per patient of medical care during follow-up were estimated at Dfl 10,784 for placebo patients and Dfl 9878 for anticoagulation patients. CONCLUSIONS: Costs of long-term anticoagulant treatment are outweighed by the costs of prevented clinical events.

Administration, Oral↗

Laboratory and therapeutic control in the Thrombosis Centre Rotterdam using chromogenic prothrombin time tests.

Growing interest is observed in chromogenic substrate assays, because of their better precision, performance and possibilities for automation. Applied to a Cobas Bio centrifugal analyzer, we compared Nycotest-Chrom (N-test) and Thromboquant-PT (Tbq) with Thrombotest (TT). Precision tests were performed with samples from 4 plasma pools: normal (45 sec), low (100 sec), middle (150 sec) and high (200 sec) segments of the therapeutic range of TT. N-test had the best precision profile in both intraassay and interassay determinations compared with Tbq. Both chromogenic substrate assays were better than TT in this respect. By orthogonal regression a provisional therapeutic range was calculated from 312 determinations and later adjusted in a confirmation experiment with natural logarithm regression in 946 determinations. Compared with a TT range of 105-180 sec, the therapeutic ranges were 71-120 sec for N-test and 63-103 sec for Tbq. In a clinical therapeutic control phase, 110 patients were randomized in equal proportions to two groups A and B. Every 2 weeks for a period of 16 weeks, blood samples were tested for N-test, Tbq and TT. In group A, dose adjustment was based on N-test, and in group B on Tbq. The monitoring physician was blinded for Tbq and TT in group A and for N-test and TT in group B. No differences were found between the groups for mean TT, N-test, Tbq or mean dosage, nor differences were found in complication rate. A definite therapeutic range was complied using sensitivity/specificity curves together with their 95% confidence limits. Given TT 105-180 sec, the therapeutic range of N-test is from 80 (95% confidence limits: 77-82) to 110 (95% confidence limits: 108-115) sec, and of Tbq from 68 (95% confidence limits: 66-71) to 95 (95% confidence limits: 91-98) sec. It was concluded that the two chromogenic substrate assays performed equally safe in the monitoring of patients on oral anticoagulant therapy, despite differences in diagnostic correspondence with the reference TT.

Administration, Oral↗