Mechanical heart valves: an insight into thrombotic complications

The purpose of this retrospective analysis was to improve the follow-up care of patients with mechanical heart valves. Clinical data of 88 patients who had undergone valve replacement surgery in various cardiothoracic centres in the country and followed up in Tata Main Hospital, Jamshedpur, India were analysed. The incidences of thrombotic complications with Starr-Edwards, St. Jude and Medtronic-Hall valves placed in mitral, aortic or both the sites were studied. In the single valve replacement group, St. Jude valve in mitral position had the highest thromboembolic risk of 12.5 per 100 patient-years. In the double valve replacement group, all the three prostheses had high thrombotic risk: St. Jude 22.2, Medtronic-Hall 12.5 and Starr-Edwards 8.6 per 100 patient-years. The high thrombotic incidence with St. Jude and Medtronic Hall in this series was correlated with early post-operative period. Subtherapeutic antiocoagulation was the key factor for thrombotic complications. Some of the commonly used drugs and diet rich in vitamin K interfere with anticoagulation, causing thrombosis in those who were more prone. Education of patients as well as the primary care physician is required to reduce life threatening thromboembolic complications, as more centres are replacing damaged valves with prostheses in patients who return to their hometown for follow-up care.