THE SIGNIFICANCE OF HEMATURIA IN THE ANTICOAGULATED PATIENT

Background: There have been many case reports of substantial renal dis ease in association with anticoagulation, yet the intensity of anticoa gulation has changed over the years. In 1986, the American College of Chest Physicians and the Heart, Lung, and Blood Institute recommended a decrease in anticoagulation intensity. In addition, a variety of new methods to investigate hematuria have evolved, including computed tom ography and red blood cell morphologic analysis. Because of these deve lopments, we initiated a prospective study to evaluate the relationshi p between anticoagulation, microscopic hematuria, and major genitourin ary tract disease. Methods: To determine the incidence, prevalence, an d cause of microscopic hematuria, patients receiving longterm anticoag ulation therapy and controls not receiving such therapy were monitored with monthly urinalyses in a 2-year prospective study. Patients who d eveloped hematuria were further studied for genitourinary tract diseas e. The incidence of hematuria was analyzed with regard to relative lev els of anticoagulation. Results: The incidence of hematuria in the ant icoagulated and control groups was 0.05 and 0.08 per 100 patient-month s, respectively. The prevalence of hematuria was 3.2% in the anticoagu lated group and 4.8% in the control group. Genitourinary tract disease was identified in 81% of patients with more than one episode of micro scopic hematuria, and the cause of hematuria did not vary between grou ps. There was no correlation between the level of anticoagulation and the incidence of hematuria. Conclusions: Anticoagulation at currently recommended levels does not predispose patients to hematuria. Identifi able genitourinary tract disease is present in the majority of anticoa gulated patients with microscopic hematuria.