Israel Medical Association Journal

Pulmonary embolism (PE) is very common in cancer patients and is a marker of increased mortality in these patients. Treatment is associated with increased rates of recurrent thrombosis and bleeding and has undergone significant change in the last years with the increasing use of direct oral anticoagulants. Diagnosis of PE and risk stratification is possible with minor changes to existing risk scores. Thrombolytic therapy should be considered in appropriate patients.

Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare, distinct pulmonary vascular disease, which is caused by chronic obstruction of major pulmonary arteries. CTEPH can be cured by pulmonary endarterectomy (PEA). PEA for CTEPH is a challenging procedure, and patient selection and the perioperative management are complex, requiring significant experience.

Objectives: To describe the establishment of a national CTEPH–PEA center in Israel and present results of surgery.

Methods: In this study, we reviewed the outcomes of PEA in a national referral, multi-disciplinary center for CTEPH–PEA. The center was established by collaborating with a high-volume center in Europe. A multidisciplinary team from our hospital (pulmonary hypertension specialist, cardiac surgeon, cardiac anesthesiologist and cardiac surgery intensivist was trained under the guidance of an experienced team from the European center.

Results: A total of 38 PEA procedures were performed between 2008 and 2018. We included 28 cases in this analysis for which long-term follow-up data were available. There were two hospital deaths (7%). At follow-up, median New York Heart Association (NYHA) class improved from III to I (P < 0.0001), median systolic pulmonary pressure decreased from 64 mmHg to 26 mmHg (P < 0.0001), and significant improvements were seen in right ventricular function and exercise capacity.

Conclusions: A national center for performance of a rare and complex surgical procedure can be successfully established by collaboration with a high-volume center and by training a dedicated multidisciplinary team.

Background: Oral anticoagulation with warfarin can lead to life-threatening events as a result of either over-anticoagulation or undertreatment. One of the main contributors to an undesirable warfarin effect is the need to adjust its daily dose for a specific patient. The dose is adjusted empirically based on the experience of the clinician, a method that is often imprecise. There is currently no other well-accepted method for predicting the maintenance dose of warfarin.

Objective: To describe the application of an artificial neural network to the problem of warfarin maintenance dose prediction.

Methods: We designed a neural network that predicts the maintenance dose of warfarin. Data on 148 patients attending a large anticoagulant clinic were collected by file review. Using correlational analysis of the patients' data we selected the best input variables. The network was trained by using the back-propagation algorithm on a subset of our data and the results were validated against the rest of the data. We used a multivariate linear regression to create a comparable model.

Results: The neural network generated reasonable predictions of the maintenance dose (r = 0.823). The results of the linear regression model were similar (r = 0.800).

Conclusion: Neural networks can be applied successfully for warfarin maintenance dose prediction. The results are promising, but further investigation is needed.