Caring for patients with prosthetic heart valves.

Abstract

Patients with prosthetic heart valves require regular examinations and echocardiograms, antithrombotic therapy, and appropriate antibiotic prophylaxis against endocarditis. Physicians must also be on the alert for several uncommon but potentially devastating complications: valve structural failure, thrombosis, embolism, endocarditis, paravalvular leak, and hemolytic anemia. s KEY POINTS Doppler echocardiography should be performed regularly to monitor left ventricular function and valve structure and to screen for stenosis or regurgitation. Auscultation can identify many valvular problems. Antithrombotic therapy is begun shortly after implantation. Goals are different for different valve types. Patients with prosthetic valves require antibiotic prophylaxis against endocarditis before dental treatment and other procedures. If thrombosis is detected, the first goal is to optimize the anticoagulation therapy. Surgery or thrombolysis may be required for larger thromboses.

Anticoagulation in Pregnancy with Mechanical Heart Valves: 10-Year Experience

“…6 Women with mechanical valves are at a high risk of thromboembolism. 5,7 Warfarin use in pregnancy is associated with a low risk of maternal thromboembolic complications but a high rate of fetal loss. 5 It has been suggested that warfarin should be avoided in the fi rst trimester of pregnancy as it is teratogenic and causes coumadin embryopathy (0%-3.4%).…”

Valvular Heart Disease in Clinical Practice

“…Cryopreserved mitral homografts have been proposed recently [27] as a better option. Although this operation has significant theoretical advantages including better longevity, lack of need for anti-coagulants in patients with sinus rhythm and achieving a low forward gradient, this remains an innovative procedure with a mortality of 25-50% of failing valves within 3 years of implantation [28]. Finally, The use of a pulmonary autograft in a Dacron tube for mitral valve replacement has been proposed but the general experience is limited [29].…”

“…Rarely, if transthoracic and, when needed, transesophageal echocardiography or cinefluoroscopy studies are not informative in a patient with exertional symptoms, exercise stress echocardiography may be needed to assess the valve prosthesis function at higher cardiac output [28]. A disproportionate (>100%) rise of transvalvular gradient suggests prosthesis dysfunction [29][30][31][32][33][34][35][36].…”

“…Although this technique is the mainstay in assessing aortic valve instantaneous pressure drop it has its known limitations, particularly when compared with catheter measured transvalvar pressures. Continuous wave pressure drop values are often higher than the peak to peak (left ventricular-aortic) pressure obtained by the pull-back technique possibly because of the aortic site of the latter being often the velocity recovery area in the ascending aorta, thus underestimating the difference[27,28]. Also, tip catheter placement in the hypertrophied ventricles commonly seen in this condition underestimates the real pressure drop across the valve.…”

Maternal, fetal outcome, and anticoagulant management in pregnant women with prosthetic heart valves

“…Pregnant women with mechanical valves are at a high risk of thromboembolism. Warfarin use during pregnancy is related with a low risk thromboembolic complications but a high risk of fetal complication such as embryopathy or haemorrhagic complication for fetus [9,10]. Antithrombotic therapy with unfractioned heparin (UFH) or low molecular weight heparin (LMWH) significantly decreased of fetal complication, but up to a third of pregnant women with mechanical valves have thromboembolic complications [10] The American College of Cardiology and European Society of Cardiology have recommended strategies for anticoagulation during pregnancy in patients with PHV [11,12].…”