Search

Background and Aim of the Study: Transesophageal echocardiography (TEE) has been used to document the incidence of non-obstructive thrombosis (NOT) after mechanical prosthetic mitral valve replacement (MVR). The postoperative occurrence and unpredictable evolution of NOT complicate its management. The study aim was to examine the safety and efficacy of prolonged, combined administration of heparin and vitamin K antagonists (VKA) recommended for this indication., Methods: All patients who underwent mechanical prosthetic MVR between July 1999 and December 2004 at the authors' institution were systematically studied with TEE immediately after surgery. Patients who presented with > or = 5 mm NOT were treated with combined heparin and VKA until TEE-confirmed resolution of the thrombus., Results: Among 256 patients who underwent 263 MVRs (seven reinterventions), 47 (17.9%) presenting with > or = 5 mm NOT received combined heparin and VKA for between 7 and 115 days (median 17 days). No thromboembolic or hemorrhagic events or deaths were observed during this period of observation. Four patients were treated with danaparoid and VKA because of thrombocytopenia induced by heparin before the diagnosis of NOT. Over a mean follow up of 39 months, one patient died from cancer and another from the sequelae of a stroke. In total, there were five NOT recurrences, three of which were complicated by embolic events without sequelae within eight months, and one by a recurrent stroke. In addition, three patients without demonstrable NOT recurrence suffered transient ischemic attacks., Conclusion: Among this small sample of patients, combined heparin and VKA was well tolerated and effective, and could prevent reoperation or thrombolysis. These observations may warrant further study in a larger patient population.

Background: Low-molecular-weight heparin appears to be at least as effective and safe as standard, unfractionated heparin for the treatment of deep-vein thrombosis, but only limited data are available on the use of low-molecular-weight heparin to treat acute symptomatic pulmonary embolism. Methods: We randomly assigned 612 patients with symptomatic pulmonary embolism who did not require thrombolytic therapy or embolectomy to either subcutaneous low-molecular-weight heparin (tinzaparin) given once daily in a fixed dose or adjusted-dose, intravenous unfractionated heparin. Oral anticoagulant therapy was begun between the first and the third day and was given for at least three months. We compared the treatments at day 8 and day 90 with respect to a combined end point of recurrent thromboembolism, major bleeding, and death. Results: In the first eight days of treatment, 9 of 308 patients assigned to receive unfractionated heparin (2.9 percent) reached at least one of the end points, as compared with 9 of 304 patients assigned to low-molecular-weight heparin (3.0 percent; absolute difference, 0.1 percentage point; 95 percent confidence interval, -2.7 to 2.6). By day 90, 22 patients assigned to unfractionated heparin (7.1 percent) and 18 patients assigned to low-molecular-weight heparin (5.9 percent) had reached at least one end point (P = 0.54; absolute difference, 1.2 percentage points; 95 percent confidence interval, -2.7 to 5.1). The risk of major bleeding was similar in the two treatment groups throughout the study. Conclusions: Under the conditions of this study, initial subcutaneous therapy with the low-molecular-weight heparin tinzaparin appeared to be as effective and safe as intravenous unfractionated heparin in patients with acute pulmonary embolism. (N Engl J Med 1997;337:663-9.) [ABSTRACT FROM AUTHOR]