Adherence to cardiac rehabilitation after acute coronary syndrome and its impact on patient outcome

Background

Secondary prevention after acute coronary syndrome (ACS) mirrors a key position in the reduction of morbidity and mortality in this highly vulnerable patient population. Especially cardiac rehabilitation proved to be one of the most beneficial therapeutic approaches for the reduction of re-events and overall modification of cardiovascular risk factors. However, profound epidemiological measures on adherence to a recommended cardiac rehabilitation after ACS remain scare, but seem of major importance in terms of preventing fatal cardiac adverse events. Therefore, we aimed to investigate adherence to cardiac rehabilitation after ACS and its impact on patient outcome from an Austrian nationwide perspective.

Methods

Within this population-based national observation all patients presenting with ACS between 04/2011 and 8/2015 in Austria were enrolled. Patient characteristics and co-morbidities were assessed via the Austrian national health insurance system and elucidated according to ICD10 definitions. Adherence to recommended cardiac rehabilitation was investigated according to health insurance documentation. Patients were followed prospectively until the primary study endpoint (= mortality) was reached. Cox Regression hazard analysis was used to investigate the impact of non-adherence to cardiac rehabilitation on patient outcome and was adjusted for a comprehensive subset of confounders within the multivariate model.

Results

During the observation period a total of 16.518 patients (median age: 64 years [54–74]; male: 68.4% [n=11.306]) met the inclusion criteria. Of alarming importance 86.6% (n=14.305) of all patients presenting with ACS did not perform any cardiac rehabilitation as recommended by current guidelines. During patient follow-up until 01/2018 a total of 1774 (10.7%) individuals died. Adherence to recommended cardiac rehabilitation had a strong an independent inverse association with mortality with an adjusted hazard ratio of 0.73 (95% CI: 0.54–0.98; p=0.036) (see Figure 1).

Conclusion

The present nationwide investigation highlighted an overall low adherence to recommended cardiac rehabilitation after ACS. Since cardiac rehabilitation after ACS was associated with a 27% risk reduction for fatal cardiovascular events during the observation period, awareness in terms of cardiac rehabilitation and associated intensified risk factor modification should be promoted, in order to prevent fatal atherothrombotic events.

Figure 1. Cumulative mortality

Funding Acknowledgement

Type of funding source: None

Adherence to high-intensity statin therapy after acute coronary syndrome and its impact on patient outcome

Background

Secondary prevention after acute coronary syndrome (ACS) mirrors a key position in the reduction of morbidity and mortality in this highly vulnerable patient population. Especially lipid lowering therapy – via high-intensity statins (atorvastatin and rosuvastatin) – proved to be one of the most beneficial therapeutic approaches for the reduction of re-events and stent thrombosis. However, profound epidemiological measures on adherence to statin intake after ACS remain scare, but seem of major importance in terms of preventing fatal cardiac adverse events. Therefore, we aimed to investigate adherence to high-intensity statin therapy after ACS and its impact on patient outcome from an Austrian nationwide perspective.

Methods

Within this population-based national observation all patients presenting with ACS between 04/2011 and 8/2015 in Austria were enrolled. Patient characteristics and co-morbidities were assessed via the Austrian national health insurance system and elucidated according to ICD10 definitions. Adherence to high-intensity statins was investigated according to handing in prescriptions for rosuvastatin and atorvastatin at local pharmacies. Patients were followed prospectively until the primary study endpoint (=mortality) was reached. Cox Regression hazard analysis was used to investigate the impact of non-adherence to high-intensity statin therapy on patient outcome and was adjusted for a comprehensive subset of confounders within the multivariate model.

Results

During the observation period a total of 23.240 patients (median age: 65 years [55–75]; male: 67.7% [n=15.728]) met the inclusion criteria. Individuals that died during the index event (n=366; 1.6%), presented with a re-ACS (n=569; 2.4%) or were lost during follow-up (n=158; 0.6%) were not included within the final analysis. Of alarming importance 66.4% (n=15.422) of all patients presenting with ACS did not take high-intensity statins as recommended by current guidelines. The highest rate of drug interruption/end of therapy was observed within the first month after the index event with more than 50% of all cases. During patient follow-up until 01/2018 a total of 3522 (15.2%) individuals died. Non-adherence to high-intensity statins had a strong an independent association with mortality with an adjusted hazard ratio of 1.16 (95% CI: 1.06–1.25; p<0.001) (see Figure 1).

Conclusion

The present nationwide investigation highlighted an overall low adherence to high-intensity statins after ACS, with the highest interruption/end of therapy rate within the first month after the index event. Since the intake of high-intensity statins after ACS was associated with a 14% risk reduction for fatal cardiovascular events during the observation period, awareness in terms of drug-adherence and intensified patient follow-up should be promoted, in order to prevent fatal atherothrombotic events.

Figure 1. Cumulative mortality

Funding Acknowledgement

Type of funding source: None

Adherence to dual anti-platelet therapy after acute coronary syndrome and its impact on patient outcome

Background

Secondary prevention after acute coronary syndrome (ACS) mirrors a key position in the reduction of morbidity and mortality in this highly vulnerable patient population. Especially dual anti-platelet therapy (DAPT) – including aspirin plus a P2Y12 inhibitor – proved to be one of the most beneficial therapeutic approaches for the reduction of re-events and stent thrombosis. However, profound epidemiological measures on adherence to DAPT intake after ACS remain scare, but seem of major importance in terms of preventing fatal cardiac adverse events. Therefore, we aimed to investigate adherence to DAPT after ACS and its impact on patient outcome from an Austrian nationwide perspective.

Methods

Within this population-based national observation all patients presenting with ACS between 04/2011 and 8/2015 in Austria were enrolled. Patient characteristics and co-morbidities were assessed via the Austrian national health insurance system and elucidated according to ICD10 definitions. Adherence to DAPT was investigated according to handing in prescriptions for aspirin and P2Y12 inhibitors at local pharmacies. Patients were followed prospectively until the primary study endpoint (=mortality) was reached. Cox Regression hazard analysis was used to investigate the impact of non-adherence to DAPT on patient outcome and was adjusted for a comprehensive subset of confounders within the multivariate model.

Results

During the observation period a total of 22.331 patients (median age: 65 years [55–75]; male: 69.7% [n=15.176]) met the inclusion criteria. Patients presenting with the indication for oral anticoagulation (n=2165; 9.7%), individuals that died during the index event (n=151; 0.7%), patients that presented with a re-ACS (n=396; 1.7%) or those who were lost during follow-up (n=96; 0.4%) were not included within the final analysis. Of alarming importance 70.7% (n=15.792) of all patients presenting with ACS did not take DAPT as recommended by current guidelines. The highest rate of drug interruption/end of therapy was observed within the first month after the index event with almost 50% of all cases. During patient follow-up until 14 months after the index event 513 individuals died. Non-adherence to DAPT proved a strong an independent association with mortality with an adjusted hazard ratio of 1.25 (95% CI: 1.09–1.41; p<0.001). (see Figure 1)

Conclusion

The present nationwide investigation highlighted an overall low adherence to DAPT after ACS, with the highest interruption/end of therapy rate within the first month after the index event. Since the intake of DAPT after ACS was associated with a 20% risk reduction for fatal cardiovascular events during the observation period, awareness in terms of drug-adherence and intensified patient follow-up should be promoted, in order to prevent fatal atherothrombotic events.

Figure 1. Cumulative Mortality

Funding Acknowledgement

Type of funding source: None

ArchiMed: A Medical Information and Retrieval System

ArchiMed is a highly flexible medical data storage and retrieval system which adds sophisticated clinical research support to a standard hospital information system (HIS).

Currently, the HIS of Vienna General Hospital-University Hospital (2000 beds) stores the clinical data of over 2 million patients. While this system supports patient care (e.g., ADT, clinical chemistry, diagnosis, procedures), it has no features to facilitate research, such as the management of clinical studies.

ArchiMed is designed to support clinical research. It includes an independent database, which mirrors virtually all the information held in the HIS while also allowing new data to be collected independently and to be added to the database. Flexible retrieval and analysis of data contained in the database are then possible. Thus, existing patient data can be smoothly incorporated into a study together with data collected specifically for research purposes. The system has already been successfully installed in the departments of surgery and soon in other departments as well.

Retrieval-Oriented Design of Clinical Research Forms

Computerized clinical forms are subject to a wide variety of different requirements. They have to allow detailed documentation and must be user-friendly. State-of-the-art applications for design permit clinicians themselves to create their own forms as needed, with the various variables presented in different ways depending on their intended use. Often, however, only aspects of clinical documentation are considered, with no thought being given to subsequent data retrieval. This article presents guidelines for the retrieval-oriented design of clinical forms. It discusses where anticipatory measures for structuring forms are easier to accomplish than complex data linkage at the time of retrieval and analysis.

Clinical Data Retrieval: 25 Years of Temporal Query Management at the University of Vienna Medical School

Objectives: Today, many clinical information systems include analysis components which allow clinicians to apply a selection of predefined statistical functions that satisfy typical cases. They are mostly to inflexible to handle complex, non-standard problems, however. The focus of this paper, therefore, is to present an approach that enables clinicians to autonomously create ad hoc queries including temporal relations in an interactive environment.

Methods: We developed the query language AMAS, which was specifically customized for users from the medical domain to flexibly retrieve and interpret temporal, clinical data. AMAS provides for a significant temporal expressiveness in data retrieval using timestamped clinical databases and relies on an operator-operand concept for the specification of a query.

Results: Within the last 25 years, four different clinical retrieval systems have been implemented at the Department of Medical Computer Sciences, based on the AMAS query language. Currently, these systems allow access to the medical records of more than 2 million patients. Physicians of 46 different departments at the University of Vienna and Graz Medical Schools have made extensive use of these systems in the course of clinical research and patient care, executing more than 10.000 queries per year.

Conclusions: We discuss a list of 20 issues that represent the most essential lessons we have learned in the development of the four systems mentioned above. Amongst others, our experiences indicate that the operator-operand concept allows an intuitive specification of complex, temporal queries. Further, customization to different user classes, based on their statistical background, is essential.

The Strategic Approach of Managing Healthcare Data Exchange in Austria

Objectives: The exchange of electronic medical data between healthcare providers constitutes an integral part of modern medicine, and its importance is growing. Efficient application on a national level requires a uniform approach to the management of healthcare data exchange, avoiding isolated solutions that are expensive and also incompatible.

Methods: In this communication we explain the basic concepts of establishing a nationwide framework to guide healthcare data exchange in Austria. To achieve this goal, a three-step approach was adopted: (i) creating general guidelines to direct electronic medical data exchange; (ii) defining detailed standards for electronic messages; (iii) organizing pilot projects to implement these standards, and further improving the general guidelines based on the results of the pilot projects.

Results: We present the MAGDA-LENA framework which guides healthcare data exchange in Austria, and compare it with the US framework HIPAA. We describe several communication scenarios for which concrete message standards were developed in recent years, based on the MAGDA-LENA framework. We further discuss the implementation of these standards in four pilot projects.

Conclusions: The strategic approach of managing healthcare data exchange presented in this paper is expected to have a substantial impact on medical informatics in Austria over the next few years.

Austria’s Path Toward Nationwide Electronic Health Records

Objectives: This article discusses current planning activities in Austria after legislation has been passed to introduce the electronic health record (EHR).

Methods: After describing similar activities in several other countries, the authors explore the current situation of healthcare telematics and imminent steps toward the implementation of a lifelong EHR.

Results: Substantial efforts have been made to coordinate healthcare telematics in Austria since the mid-1990s. One result of these efforts was the definition of a framework for electronic data exchange. A number of standardization projects were also implemented. Major steps have been taken as part of an ongoing healthcare reform to promote the use of healthcare telematics. One important example is a national initiative whose objective is to implement the EHR. This initiative is extensively discussed along with other national activities related to healthcare telematics.

Conclusion: This EHR initiative has prepared the ground for extensive planning that is currently under way to implement a lifelong EHR in Austria on a national level. Introducing the EHR will have a strong impact on Austrian healthcare and should be performed in concert with international activities. The authors offer a number of practical recommendations for the implementation of an EHR on a national level.

The amino acid response to a mixed meal in patients with type 2 diabetes: effect of sitagliptin treatment

AIMS

Amino acid (AA) metabolism is altered in type 2 diabetes (T2D), and fasting levels of α-hydroxybutyrate (α-HB), a biomarker for insulin resistance, have been suggested to track AA metabolism. We investigated the changes in AA and α-HB induced by a mixed-meal tolerance test (MTT) and the effects of sitagliptin treatment.

METHODS

Forty-seven T2D patients [56 ± 7 years, body mass index (BMI) 29.9 ± 4.2 kg/m(2) ] were randomized to sitagliptin (100 mg/day, 6 weeks) or placebo. Seven age- and BMI-matched non-diabetic subjects served as control (CT).

RESULTS

During a 5-h MTT, branched-chain AA (BCAA) peaked earlier in T2D than CT [75(25) vs. 62(3) mmol/l · h over 2 h, median(interquartile range), p = 0.05], and rose higher [5-h increment: 31(23) vs. 19(24) mmol/l · h, p = 0.05]. Fasting α-HB was higher [7.5(2.7) vs. 5.9(1.3) µg/ml, p = 0.04 T2D vs. CT], and its meal-induced increments were larger [24(99) vs. -41(86) µg/ml · h, p = 0.006]. Plasma non-esterified fatty acids (NEFA) declined during MTT, but their increments were greater in patients (53 ± 16 vs. 35 ± 10 mEq/l · h, p = 0.005). Compared to placebo, both BCAA [-6.4(21.1) vs. 0.0(48.0) mmol/l · h, p = 0.01] and α-HB increments [-114(250) vs. 114(428) µg/ml · h, p = 0.002] decreased with sitagliptin, and meal-induced NEFA suppression was improved. Changes in BCAA and α-HB were reciprocally related to changes in insulin sensitivity (ρ = -0.37 and -0.43, p ≤ 0.01).

CONCLUSIONS

T2D is associated with a hyperaminoacidaemic response to MTT, which circulating α-HB levels track. Sitagliptin-induced glycaemic improvement was associated with reductions in BCAA and α-HB excursions and better NEFA suppression, in parallel with improved insulin sensitivity, confirming that α-HB is a readout of metabolic overload.

Estimation of severe drug-drug interaction warnings by medical specialist groups for Austrian nationwide eMedication

OBJECTIVE

The objective of this study is to estimate the amount of severe drug-drug interaction warnings per medical specialist group triggered by prescribed drugs of a patient before and after the introduction of a nationwide eMedication system in Austria planned for 2015.

METHODS

The estimations of interaction warnings are based on patients' prescriptions of a single health care professional per patient, as well as all patients' prescriptions from all visited health care professionals. We used a research database of the Main Association of Austrian Social Security Organizations that contains health claims data of the years 2006 and 2007.

RESULTS

The study cohort consists of about 1 million patients, with 26.4 million prescribed drugs from about 3,400 different health care professionals. The estimation of interaction warnings show a heterogeneous pattern of severe drug-drug-interaction warnings across medical specialist groups.

CONCLUSION

During an eMedication implementation it must be taken into consideration that different medical specialist groups require customized support.

JADE: a tool for medical researchers to explore adverse drug events using health claims data

OBJECTIVE

The objective of our project was to create a tool for physicians to explore health claims data with regard to adverse drug reactions. The Java Adverse Drug Event (JADE) tool should enable the analysis of prescribed drugs in connection with diagnoses from hospital stays.

METHODS

We calculated the number of days drugs were taken by using the defined daily doses and estimated possible interactions between dispensed drugs using the Austria Codex, a database including drug-drug interactions. The JADE tool was implemented using Java, R and a PostgreSQL database.

RESULTS

Beside an overview of the study cohort which includes selection of gender and age groups, selected statistical methods like association rule learning, logistic regression model and the number needed to harm have been implemented.

CONCLUSION

The JADE tool can support physicians during their planning of clinical trials by showing the occurrences of adverse drug events with population based information.

Crucial factors for the acceptance of a computerized national medication list: insights into findings from the evaluation of the Austrian e-Medikation pilot

OBJECTIVE

The objective of this paper is to present crucial factors among registered doctors and pharmacists for acceptance of the Austrian 'e-Medikation' system which is aimed at providing, on a national level, complete and recent information on all the medication that were prescribed or dispensed to a patient.

METHODS

As the accompanying formative evaluation study of the pilot project showed different overall acceptance rates among participating physicians and pharmacists, a decision tree analysis of 30 standardized survey items was performed to identify crucial acceptance factors.

RESULTS

For the physicians' group, only two items (fear of improper data use and satisfaction with software support) were crucial for overall e-Medikation acceptance. The analysis of the pharmacists' data resulted in five crucial factors primarily focusing on functional aspects and the perceived benefits of e-Medikation.

CONCLUSION

The results indicate that the acceptance among physicians and pharmacists depends on quite different factors. This must be taken into account during the planned rollout of e-Medikation or of comparable products.

Utilizing IHE-based Electronic Health Record systems for secondary use

OBJECTIVES

Due to the increasing adoption of Electronic Health Records (EHRs) for primary use, the number of electronic documents stored in such systems will soar in the near future. In order to benefit from this development in secondary fields such as medical research, it is important to define requirements for the secondary use of EHR data. Furthermore, analyses of the extent to which an IHE (Integrating the Healthcare Enterprise)-based architecture would fulfill these requirements could provide further information on upcoming obstacles for the secondary use of EHRs.

METHODS

A catalog of eight core requirements for secondary use of EHR data was deduced from the published literature, the risk analysis of the IHE profile MPQ (Multi-Patient Queries) and the analysis of relevant questions. The IHE-based architecture for cross-domain, patient-centered document sharing was extended to a cross-patient architecture.

RESULTS

We propose an IHE-based architecture for cross-patient and cross-domain secondary use of EHR data. Evaluation of this architecture concerning the eight core requirements revealed positive fulfillment of six and the partial fulfillment of two requirements.

CONCLUSIONS

Although not regarded as a primary goal in modern electronic healthcare, the re-use of existing electronic medical documents in EHRs for research and other fields of secondary application holds enormous potential for the future. Further research in this respect is necessary.

The strategic approach of managing healthcare data exchange in Austria

OBJECTIVES

The exchange of electronic medical data between healthcare providers constitutes an integral part of modern medicine, and its importance is growing. Efficient application on a national level requires a uniform approach to the management of healthcare data exchange, avoiding isolated solutions that are expensive and also incompatible.

METHODS

In this communication we explain the basic concepts of establishing a nationwide framework to guide healthcare data exchange in Austria. To achieve this goal, a three-step approach was adopted: (i) creating general guidelines to direct electronic medical data exchange; (ii) defining detailed standards for electronic messages; (iii) organizing pilot projects to implement these standards, and further improving the general guidelines based on the results of the pilot projects.

RESULTS

We present the MAGDA-LENA framework which guides healthcare data exchange in Austria, and compare it with the US framework HIPAA. We describe several communication scenarios for which concrete message standards were developed in recent years, based on the MAGDA-LENA framework. We further discuss the implementation of these standards in four pilot projects.

CONCLUSIONS

The strategic approach of managing healthcare data exchange presented in this paper is expected to have a substantial impact on medical informatics in Austria over the next few years.

Clinical data retrieval: 25 years of temporal query management at the University of Vienna Medical School

OBJECTIVES

Today, many clinical information systems include analysis components which allow clinicians to apply a selection of predefined statistical functions that satisfy typical cases. They are mostly to inflexible to handle complex, non-standard problems, however. The focus of this paper, therefore, is to present an approach that enables clinicians to autonomously create ad hoc queries including temporal relations in an interactive environment.

METHODS

We developed the query language AMAS, which was specifically customized for users from the medical domain to flexibly retrieve and interpret temporal, clinical data. AMAS provides for a significant temporal expressiveness in data retrieval using time-stamped clinical databases and relies on an operator-operand concept for the specification of a query.

RESULTS

Within the last 25 years, four different clinical retrieval systems have been implemented at the Department of Medical Computer Sciences, based on the AMAS query language. Currently, these systems allow access to the medical records of more than 2 million patients. Physicians of 46 different departments at the University of Vienna and Graz Medical Schools have made extensive use of these systems in the course of clinical research and patient care, executing more than 10,000 queries per year.

CONCLUSIONS

We discuss a list of 20 issues that represent the most essential lessons we have learned in the development of the four systems mentioned above. Amongst others, our experiences indicate that the operator-operand concept allows on intuitive specification of complex, temporal queries. Further, customization to different user classes, based on their statistical background, is essential.

Moving time window aggregates over patient histories

Moving window concepts are used in temporal query languages for aggregate functions over the dimension 'time'. In the medical domain, aggregation of patient data over time windows builds a powerful mechanism within clinical database queries to satisfy a class of typical medical question formulations. Contrary to other fields, like the business domain for example, there is the additional need to synchronize time windows with the individual course of diseases rather than with the calendar system only. In this paper, we present several variants of shifting time windows over patient histories and suggest a set of essential options for a moving window clause. The proposed parameters for window creation as well as suitable default settings are discussed in the context of retrieving data from medical records.

Extracting a statistical data matrix from electronic patient records

This paper describes the processing and transformation of medical data from a clinical database to a statistical data matrix. Precise extraction and linking tools must be available for the desired data to be processed for statistical purposes. We show that flexible mechanisms are required for the different types of users, such as physicians and statisticians. In our retrieval tools we use logical queries based on operands and operators. The paper describes the method and appliance of the operators with which the desired matrix is created through a process of selection and linking. Examples with a Kaplan-Meier function and time-dependent covariables demonstrate how our model is useful for different user groups.

Retrieval-oriented design of clinical research forms

Computerized clinical forms are subject to a wide variety of different requirements. They have to allow detailed documentation and must be user-friendly. State-of-the-art applications for design permit clinicians themselves to create their own forms as needed, with the various variables presented in different ways depending on their intended use. Often, however, only aspects of clinical documentation are considered, with no thought being given to subsequent data retrieval. This article presents guidelines for the retrieval-oriented design of clinical forms. It discusses where anticipatory measures for structuring forms are easier to accomplish than complex data linkage at the time of retrieval and analysis.

Incorporating family and social structures into clinical documentation and retrieval

Referencing familial and social relationships between patients supplies valuable information for the retrieval and interpretation of clinical data. We present a technique for the incorporation of patient relations into data retrieval that takes into account the specific properties of routinely collected clinical data. In most clinical databases, family relations are documented in a fragmentary manner at best. Furthermore, clinical retrieval systems do not support inter-patient queries in most cases. Our model is designed to formulate direct relations between patients and to identify patients as members of either temporary or persistent communities. In this way, the model supplies information on both genetic and social relations.

Unambiguous identification of hospital patients: case study at the university departments of the General Hospital, Vienna

This article considers the problem of identifying patients in one or more heterogeneous personal databases. The unambiguous identification of patients is an essential prerequisite for an efficient patient care system. We discuss the problems involved in this task and suggest how they can be dealt with. The solution of automatic consolidation of patient records sequires programming, organisational and work psychology measures. Following a survey of conventional identification methods, the method developed at the Department of Medical Computer Sciences, which is based on the current clinical situation at the General Hospital in Vienna (AKH--Allgemeines KrankenHaus), is described in detail. The basic principle is to identify patients unambiguously by means of an ID (IZAHL) derived directly from the personal data. Thereby a deterministic technique without probability weighting is used-all compared information must correspond completely. The article closes with a critical survey of experience gathered to date.

A retrieval system for the selection and statistical analysis of clinical data

Within the last years computer-aided clinical documentation has provided researchers and administrators with very large volumes of data for research. User-friendly retrieval tools are needed when processing these clinical databases. Clinical researchers require applications by means of which steps in selection and analysis can be performed in an iterative process. During the deduction of statistical parameters from routinely collected data a number of problems occur that do not appear in the analysis of data gathered within clinical studies. Unlike clinical studies, routine data have complex structures and must first be formatted and above all temporally synchronized. In this paper we will describe the medical retrieval system ArchiMed developed at the Vienna General Hospital. A main objective in the design of this system was to support a joint evaluation of data from clinical studies and routinely collected data. The retrieval system comprises the main functions: Selection of Patients; Selection and Joining of Variables; and Statistical Analysis.

ArchiMed: a medical information and retrieval system

ArchiMed is a highly flexible medical data storage and retrieval system which adds sophisticated clinical research support to a standard hospital information system (HIS). Currently, the HIS of Vienna General Hospital-University Hospital (2000 beds) stores the clinical data of over 2 million patients. While this system supports patient care (e.g., ADT, clinical chemistry, diagnosis, procedures), it has no features to facilitate research, such as the management of clinical studies. ArchiMed is designed to support clinical research. It includes an independent database, which mirrors virtually all the information held in the HIS while also allowing new data to be collected independently and to be added to the database. Flexible retrieval and analysis of data contained in the database are then possible. Thus, existing patient data can be smoothly incorporated into a study together with data collected specifically for research purposes. The system has already been successfully installed in the departments of surgery and soon in other departments as well.

Thrombolytic therapy of axillary-subclavian venous thrombosis

Patients with axillary-subclavian vein thrombosis often have a poor outcome when treated with intravenous heparin sodium and oral warfarin sodium. Four patients were therefore treated with thrombolytic therapy. Good initial and excellent long-term results were achieved. In follow-up that has ranged up to four years, these patients do not have the common complaints of edema, fatigue, cramping, or weakness seen after traditional anticoagulation. Patients have returned to their previous occupations and have normal arm function. Noninvasive Doppler vascular laboratory studies suggest continued patency of axillary veins. Thrombolytic therapy should be considered in the treatment of spontaneous axillary-subclavian vein thrombosis.

[Tracheal stenosis (author's transl)]

13 cases of stenosis of the trachea are reported and its causes are reviewed. The main causal factors are malignant and benign growths, but chronic granulating tracheitis consequent on prolonged artificial ventilation also plays a role. The extent of the stenosis necessitated partial resection of the trachea in 9 patients. Problems attendant on the operation are reviewed with special reference to after-treatment. In cases of inoperable cancer with tracheal narrowing endoscopic removal of tumour tissue may be life-prolonging measure.