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Interact CardioVasc Thorac Surg 2008;7:1167-1169. doi:10.1510/icvts.2007.172155 © 2008 European Association of Cardio-Thoracic Surgery
Freedom from complications related to dual ball-and-cage mechanical valve prostheses despite thirty years without anticoagulationDepartment of Medicine, Lehigh Valley Hospital and Health Network, Allentown, PA 18103, USA Received 21 November 2007; received in revised form 2 June 2008; accepted 2 June 2008
Corresponding author. Department of Internal Medicine/Division of Cardiology, Lehigh Valley Hospital and Medical Center, Allentown, PA 18103, USA. Tel.: +1 (610) 770-2200; fax: +1 (610) 776-6645.
We report a case of a 57-year-old patient with a history of a Starr-Edwards mitral valve prosthesis and DeBakey-Surgitool aortic valve prosthesis implanted 30 years ago who presented with symptoms consistent with class IV heart failure. The patient had been on no anticoagulation for approximately 30 years secondary to recurrent epistaxis occurring two years after starting warfarin therapy postoperatively. Throughout the patient's lifetime he experienced no thromboembolic complications from the lack of anticoagulation, despite developing concomitant atrial fibrillation approximately ten years prior to admission. In place of warfarin the patient had substituted large doses of aspirin. A workup revealed normal function of the mechanical valves for this extensive period.
Key Words: Prosthetic valve; Debakey Surgitool; Starr-Edwards; Warfarin
In January 2007, a 53-year-old Hispanic male was transferred to our hospital after several weeks of progressive dyspnea, lower extremity edema, and orthopnea. On admission, the patient was tachycardic but with otherwise stable vital signs. He was noted to have an irregularly irregular cardiac rhythm, with a soft systolic ejection murmur at the left sternal border and prominent crisp artificial valve sounds. There was evidence of elevated jugular venous pulsations. On respiratory exam, the patient had bibasilar crackles, and his lower extremities revealed 2+ pitting edema. Admission labs were notable for a platelet count of 164,000 (normal 150–400,000/ml), a partial thromboplastin time of 32.5 s (normal range 21.6–35.6 s), a prothrombin time of 16.3 s (normal range 11.7–13.8 s), and an international normalized ratio (INR) of 1.3. The patient had a history of bacterial endocarditis requiring dual valve replacements in 1973, consisting of a Starr-Edwards mechanical prosthesis in the mitral position and a DeBakey-Surgitool mechanical prosthesis in the aortic position. The patient reported that he was initially maintained on warfarin therapy postoperatively but independently stopped this medication approximately two years after his surgery due to recurrent epistaxis. In place of warfarin he self-maintained high dose aspirin therapy for the greater part of the past 30 years, taking anywhere from four- to twelve- 325 mg tablets daily. Throughout this time period the patient experienced no thrombotic complications, and despite the high aspirin dose he never experienced bleeding complications. Approximately 10 years ago, he developed atrial fibrillation, but despite this he remained free from thromboembolic events. While never formally tested, the patient had no clinical evidence of an inherited clotting disorder to account for his surprising freedom from thrombotic events. His mildly elevated prothrombin time on admission was felt to be due to chronic alcohol abuse and poor nutritional status, as prior measurements had been within the normal range. A chest radiograph (Fig. 1) depicted an enlarged cardiac shadow and appropriate anatomic position of the two prosthetic valves. Subsequent examination of the patient with transesophageal echocardiography revealed a dilated, severely hypocontractile left ventricle with an estimated ejection fraction of 10–15% and global hypokinesis. Both mechanical valves appeared to be well-seated and with normal excursion of the caged balls, and there was no evidence of vegetation or thrombus.
Despite the patient's long-term thromboembolism-free course and alcohol abuse history, it was felt that anticoagulation was warranted given his high-risk features of dual mechanical valves, atrial fibrillation, and congestive heart failure. Therefore, he was started on intravenous heparin therapy with initiation of warfarin anticoagulation. Several days after the initiation of warfarin the patient developed a retrocecal hematoma associated with a Meckel's diverticulum (Fig. 2). The patient underwent surgical evacuation of the hematoma and appendectomy without complication. He was cautiously re-anticoagulated and was discharged on wafarin for a goal INR 2.5–3.5 and was maintained on appropriate therapy for congestive heart failure. In the course of his hospitalization, the patient had placement of a prophylactic ICD based on current criteria for primary prophylaxis of ventricular sudden cardiac death (EF  35% for three months duration and class III congestive heart failure).
The DeBakey-Surgitool mechanical heart valve prosthesis was designed by DeBakey and Cromie and was first implanted in 1967. The valve consists of a closed ball-in-cage suspended from a prosthetic ring with three titanium struts, and differed from the older Starr-Edwards valve in that it lacked the cloth covered cage and used a ball made of pyrolitic carbon [1]. Both the DeBakey-Surgitool and Starr-Edwards valves had relatively high thromboembolic rates and problems related to strut fracture and were ultimately withdrawn from the market, the DeBakey-Surgitool in 1978 [2]. The case described above is a demonstration of exemplary prosthetic valve durability and freedom from prosthetic valve complications despite the lack of anticoagulation. There have been several published case reports of similar experiences of the longevity of both the DeBakey-Surgitool and Starr Edwards valve prostheses [3–7]. Only one of these cases describes a patient with a Starr-Edwards aortic prosthesis that was managed long-term without anticoagulant therapy and remained event-free [7]. To the best of our knowledge, this is the first report of long-term durability and freedom from complications related to dual ball-and-cage valves without the use of warfarin. Current recommendations for anticoagulant therapy for mechanical valve replacement include dose-adjusted warfarin for a goal INR of 2.5–3.5 with recommendation of the addition of aspirin for mitral valve prostheses with high-risk features (such as atrial fibrillation), even in the absence of an additional prosthetic valve in the aortic position [8]. First generation valves such as the above-mentioned valves have a particularly high frequency of thromboemboli in comparison with modern valves. The frequency of thromboemboli in a patient with a ball and caged disk valve is estimated to be 2.5% per year, highlighting the incredible record of freedom from thromboembolic complications in our patient. Aspirin therapy is considered to be acceptable thromboprophylaxis therapy for patients with bioprosthetic valves and without high-risk thrombotic features such as atrial fibrillation or prior thromboembolic event [8]. Early case series in children using aspirin therapy alone for thromboprophylaxis of mechanical prosthetic valves in the aortic position generated brief enthusiasm for this strategy [9]. However, several subsequent studies were not favorable and noted a higher than expected incidence of valve thrombosis [10], and, as a result, aspirin or other antiplatelet therapy alone is clearly not supported by current guidelines [8].
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Abstract
1. Case report
