Recurrent thrombosis in patients with antiphospholipid antibodies and arterial thrombosis on antithrombotic therapy.

Management for patients with antiphospholipid syndrome (APS) and arterial thrombosis is controversial. There are no prospective data demonstrating the superiority of high- or moderate-intensity anticoagulation with vitamin K antagonists over antiplatelet agents. Using 2 antiphospholipid antibody databases (single center [New York Presbyterian Hospital] and multicenter [Antiphospholipid Syndrome Alliance for Clinical Trials and International Networking]), we retrospectively collected demographic and clinical data of patients with APS and arterial thrombosis. The primary outcome was recurrent thrombosis rate after initial arterial thrombosis in patients with APS treated with antiplatelet and/or anticoagulant therapy. We identified 139 patients with a median follow-up time of 4.24 years after initial thrombosis. Thirty-seven patients (27.3%) received anticoagulants, 43 (30.9%) antiplatelets, and 58 (41.7%) combined therapy. Sixteen patients (37.2%) in the antiplatelet group, 9 (23.7%) in the anticoagulant group, and 4 (6.9%) in the combined therapy group experienced recurrent thrombosis. We estimate that 20% of patients will experience a recurrence by 3.4, 7.3, and 16.3 years, respectively, depending on assignment to antiplatelet, anticoagulant, or combined therapy. These results suggest that combined therapy decreases the rate of and increases the time to thrombosis recurrence in patients with APS presenting with arterial thrombosis.

Military aviators with mitral valve prolapse: long-term follow-up and aeromedical endpoints.

INTRODUCTION: Mitral valve prolapse (MVP) is a disqualifying condition for USAF aviators. Trained USAF aviators, and in recent years flying training applicants, may be granted waiver for initial or continued flying duties following extensive, periodic evaluation. This study examines the usefulness of the various tests performed in that evaluation process and provides long-term follow-up from 404 USAF flyers with MVP. METHODS: We retrospectively reviewed 2-dimensional echocardiography, Holter monitoring, treadmill exercise, thallium imaging, coronary fluoroscopy, cardiac catheterization, and centrifuge testing results from 404 military aviators evaluated at the Aeromedical Consultation Service between 1 January 1972 and 31 October 1993. Follow-up was achieved through questionnaires (91%) and death certificates, etc. RESULTS: Mean follow-up was 8.6 yr (range 1-21 yr). Age at study entry was 21 to 64 yr (mean = 36 yr). The occurrence rate for suddenly incapacitating events (sudden cardiac death, syncope, pre-syncope, and cerebral ischemic episodes) was 0.32%/yr. CONCLUSIONS: Echocardiographic MVP in military aviators is associated with a low but statistically increased prevalence of "incapacitating" aeromedical events. Univariate predictors of adverse outcome included study entry with an enlarged left ventricle or left atrium, cardiovascular symptoms or findings, or MVP with thickened leaflets. Evaluation of coronary artery disease (CAD) in this population, absent specific indicators of CAD risk, is not indicated.

Hostility, anger, and depression predict increases in C3 over a 10-year period.

We examined the relation of hostility, anger, and depression to 10-year changes in the third (C3), and fourth (C4) complement in 313, apparently healthy male participants enrolled in the Air Force Health Study (AFHS), a 20-year study designed to evaluate the health consequences of dioxin exposure. Hostility, depression, and anger were assessed using subscales from the Minnesota Multiphasic Personality Inventory (MMPI), which was administered in 1985. Given the high intercorrelations among these psychological scales, we used a principal component analysis to generate a composite score representing the linear combination of the hostility, anger, and depression scales. The dependent variables, C3 and C4 levels, were determined from samples collected in 1992, 1997, and 2002. Regression analyses controlling for age, race, alcohol use, body mass index, and cigarette use as well as onset of disease, and use of lipid lowering and blood pressure medications during follow-up revealed a significant timexcomposite score interaction for C3 complement (p<.0003), but not C4. Post-hoc analyses revealed that high composite scores were associated with larger 10-year increases in C3. These observations suggest that men who are hostile and are prone to experience frequent and intense feelings of anger, and depression show activation of the complement system, and specifically increases in C3, that may contribute to the development of coronary heart disease.

Insulin sensitivity following agent orange exposure in Vietnam veterans with high blood levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin.

Our objective was to determine whether insulin sensitivity was related to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in Vietnam veterans exposed to Agent Orange. Air Force veterans of Operation Ranch Hand, the unit responsible for spraying Agent Orange and other herbicides in Vietnam from 1962 to 1971, and comparison veterans who did not spray herbicides were included. We measured insulin sensitivity (S(I)) using a frequently sampled iv glucose tolerance test in a matched study of 29 matched pairs of veterans and a quantitative insulin sensitivity check index (QUICKI) based on fasting glucose and insulin in 71 matched pairs. No group differences were found with regard to the mean values of S(I), QUICKI, TNFalpha, adiponectin, and two measures of insulin secretion. However, S(I) and QUICKI decreased significantly with regard to TCDD (P = 0.01 and 0.02). A corresponding pattern (although not significant) was found for blood levels of TNFalpha and adiponectin. These data suggest that high blood TCDD levels may promote an insulin-resistant state, but the magnitude of this effect appeared to be small, such that an 18-fold increase in blood TCDD due to increased exposure resulted in only a 10% change in S(I) in the 29 matched pairs.

Serum dioxin and psychological functioning in U.S. Air Force veterans of the Vietnam War.

Using the Minnesota Multiphasic Personality Inventory and the Millon Clinical Multiaxial Inventory, we assessed the psychological functioning of U.S. Air Force veterans exposed to Agent Orange and its contaminant, 2,3,7,8-tetrachlodibenzo-p-dioxin (dioxin), during the Vietnam War. Index subjects were veterans of Operation Ranch Hand (N = 1,109). Comparisons (N = 1,493) were U.S. Air Force veterans not involved with spraying herbicides. We found few consistent psychological abnormalities associated with serum dioxin levels. Ranch Hand veterans with higher dioxin levels showed some difficulties in anxiety, somatization, depression, and a denial of psychological factors. However, those with background levels also showed indications of emotional distress, primarily in emotional numbing and lability; a guarded, suspicious, and withdrawn style of relating to others; and unusual thoughts or behaviors.

Positive predictive value of a health history questionnaire.

The U.S. Air Force Academy (USAFA) is one of the nation's military universities, with the mission to educate and motivate cadets to be career Air Force officers. This diverse population arrives at the USAFA with varying immunization records and disease histories. Analyses of costs and benefits regarding immunization strategies rely on accurate data and assumptions used in their calculation. Health history questionnaires are a low-cost way of evaluating immunization and disease history. However, this requires a good estimate of the questionnaire's positive predictive value, which may vary among populations. This study attempts to provide a more accurate estimate of the positive predictive value of health history questionnaires regarding varicella and rubella disease and vaccination strategies for the population of fourth degree (freshman) cadets at the USAFA. We found positive predictive values of 99% for rubella and 86% for varicella. These data emphasize the importance of analyzing the specific population for which a program is intended rather than broadly applying recommendations that were developed in other populations.