American Journal of Therapeutics 23, e252–e255 (2016)

Prosthetic Valve Thrombosis: Diagnosis and Management Jalaj Garg, MD,1* Chandrasekar Palaniswamy, MD,1 Sowmya Pinnamaneni, MD,1 Judy Sarungbam, MD,2 and Diwakar Jain, MD1

St. Jude mechanical prosthesis is the most commonly used prosthetic device with least valvular complications with excellent hemodynamics. However, prosthetic valve thrombosis is one of the serious complications, with rates between 0.03% and 0.13% per patient-year depending on the type of anticoagulation used and compliance to the therapy. Transthoracic echocardiography (TTE) is the initial screening tool (class I) that would provide clues for the assessment of valvular hemodynamics. Fluoroscopy is an alternate imaging modality for the assessment of mechanical leaflet motion, especially in patients when prosthetic valves are difficult to image on TTE or transesophageal echocardiography. A complete fluoroscopic evaluation of a prosthetic valve includes assessment of valvular motion and structural integrity. Opening and closing angles can be measured fluoroscopically to determine whether a specific valve is functioning properly. We discuss a case of a 91year-old man with thrombosis of bileaflet mechanical mitral prosthesis that was demonstrated on real-time fluoroscopy (not evident on TTE). An algorithmic approach to diagnosis and management of prosthetic heart valve thrombosis is outlined. Keywords: prosthetic valve thrombosis, mitral valve thrombosis, fluoroscopy

CASE PRESENTATION We report a case of a 91-year-old man with a history of hypertension, atrial fibrillation, chronic kidney disease, coronary artery disease with a history of coronary artery bypass graft, and mitral valve replacement surgery with a St. Jude bileaflet mechanical prosthesis 20 years ago presented to emergency department with dyspnea on minimal exertion (NYHA class III). Physical examination was significant for bibasilar crackles and muffled

1

Department of Medicine, Division of Cardiology, Westchester Medical Center, New York Medical College, Valhalla, NY; and 2 Department of Pathology, Westchester Medical College, New York Medical College, Valhalla, NY. The authors have no conflicts of interest to declare. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions this article on the journal’s Web site (www.americantherapeutics.com). *Address for correspondence: Department of Medicine, Division of Cardiology, Westchester Medical Center, New York Medical College, Valhalla, NY 10595. E-mail: [email protected]

leaflets clicks in the apical area. His complete blood count, renal, and hepatic function tests were within normal limits. His international normalized ratio was subtherapeutic 1.17 with partial thromboplastin time of 26.3. Transthoracic echocardiogram demonstrated mildly reduced systolic function (45%–50%), paradoxical motion of interventricular septum with severely increased gradient across the mitral prosthesis (mean diastolic gradient 17 mm Hg) without any demonstrable restrictive motion of the valvular leaflets, and any obvious detectable mass over the prosthetic valve. However, the images were suboptimal due to reverberation artifact from the mechanical prosthesis. With a high clinical suspicion of valve thrombosis, the patient subsequently underwent fluoroscopic evaluation of the valve, which demonstrated a complete immobility of one of the leaflets and reduced excursion of the other (Figure 1) (see Video, Supplemental Digital Content 1, http://links.lww.com/AJT/A20). Intraoperative transesophageal echocardiogram confirmed reduced leaflet mobility with turbulent flow demonstrated across the mitral valve (see Video, Supplemental Digital Content 2, http://links.lww.com/AJT/A21). A redo-mitral valve replacement was performed with a bioprosthetic valve

1075–2765 Copyright © 2014 Wolters Kluwer Health, Inc. All rights reserved.

www.americantherapeutics.com

Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.

Prosthetic Valve Thrombosis

e253

FIGURE 1. Fluoroscopy: right anterior oblique view demonstrating complete immobility of one of the prosthetic mitral valve leaflet and reduced excursion of the other.

(# 21 Epic porcine valve) (Figures 2 and 3 demonstrate gross and histopathology of the thrombosed valve).

DISCUSSION St. Jude mechanical prosthesis is the most commonly used prosthetic device with least valvular complications with excellent long-term hemodynamics.1 However, prosthetic valve thrombosis (PVT) is one of the serious complications, with rates between 0.03% and 0.13% per patient-year depending on the type of anticoagulation used and compliance to the therapy.2

DIAGNOSIS Currently available tools for the diagnosis of PVT include fluoroscopy, transthoracic echocardiography

(TTE), and transesophageal echocardiography (TEE). In equivocal cases, computed tomography (CT) may be helpful in differentiating thrombosis from pannus. In the future, 3-dimensional echocardiography, CT, and magnetic resonance imaging may have a role in diagnosis of PVT as well as differentiating this from pannus. However, these are considered only a research tool at this point. The guidelines from American College of Cardiology on management of patients with valvular heart disease include specific recommendations for evaluation and management of PVT.3 An algorithmic approach to diagnosis and management of PVT is outlined in Figure 4. TTE is the initial screening tool (class I) that would provide clues for the assessment of valvular hemodynamics (immobility of leaflet, high valve gradients), but its utility is limited by its dependence on optimal windows and artifact from metallic valves. In patients with a high clinical suspicion, TEE should

FIGURE 2. Gross pictures of the specimen. The St. Jude bileaflet tilting disc prosthesis with external sewing diameter measuring 3.8 cm and 0.6 cm in thickness, with multiple tan pink soft tissue fragments measuring 1.8 3 1.2 3 0.2 cm loosely attached on the metallic leaflets. www.americantherapeutics.com

American Journal of Therapeutics (2016) 23(1)

Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.

Garg et al

e254

FIGURE 3. Microscopic images of the specimen, low power 320 (A), intermediate power 3200 (B), and high power 3400 (C). Hematoxylin and eosin sections of the largest mass demonstrate predominance of fibrin with entrapped degenerated leucocytes, platelets, and red blood cells, consistent with a thrombus.

be performed as it allows direct visualization of the mechanical valve (class I).3 TEE has the advantage of providing size of the thrombus and assessment of valvular hemodynamics. Fluoroscopy and CT are alternate imaging modalities for the assessment of mechanical leaflet motion, especially in patients when prosthetic valves are difficult to image on TTE or TEE (class IIa). A complete fluoroscopic evaluation of a prosthetic valve includes assessment of valvular motion and structural integrity. Opening and closing angles can be measured fluoroscopically to determine whether a specific valve is functioning properly. The ideal angulation for fluoroscopic assessment of a prosthetic valve places the annulus of the prosthesis perpendicular to the imaging plane. The best angle for evaluating a prosthetic mitral valve

is right anterior oblique view. The best angle for evaluating a prosthetic aortic valve is left anterior oblique view.

TREATMENT There are 2 forms of therapy for PVT—thrombolytic therapy and surgical replacement of the thrombosed prosthesis. There are no data available from randomized controlled trials on approach to management of prosthetic heart valve thrombosis. The guidelines are based on limited data from observational studies. Most of these small studies do not provide reasons for the choice of thrombolysis or of surgery as initial therapy.

FIGURE 4. An algorithmic approach to diagnosis and management of PVT. American Journal of Therapeutics (2016) 23(1)

www.americantherapeutics.com

Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.

Prosthetic Valve Thrombosis

Fibrinolysis Fibrinolysis can be attempted as the first-line therapy in right-sided valve thrombosis (class IIa recommendation). Surgery can be reserved for those in whom thrombolysis is ineffective. In a systematic review of 43 patients who had received thrombolysis for thrombosed tricuspid valve (42 had a mechanical valve and 1 had a bioprosthesis), complete success was achieved in 38 (88%) patients, partial success in 1 patient, and was ineffective in 4 patients.4 These 4 patients subsequently underwent surgical tricuspid valve replacement. In patients with left-sided valve thrombosis and recent onset of symptoms (less than 14 days), NYHA class I/II and smaller thrombus (,0.8 cm2) fibrinolysis can be attempted if initial intravenous heparin therapy fails to resolve thrombosis (class IIa). Mitral valve is affected in two-thirds to three-fourths of the cases. A smaller amount of thrombus at the hinges of a mechanical valve can result in thrombosis of the mechanical valve with resultant symptoms. This forms the basis for use of thrombolytic agents in patients with left-sided PVT with a lower thrombus burden. However, thrombolysis in patients who are very symptomatic (NYHA class III/IV) may delay the timing of surgical intervention and lead to a higher mortality. The suggested waiting time for performing surgery after thrombolysis is 24 hours after discontinuation of the fibrinolytic infusion (or 2 hours after neutralization of streptokinase with aprotinin). In a pooled analysis of 17 studies that presented the clinical outcomes of 756 patients who received thrombolysis for 810 episodes of left-sided PVT, 35% were in NYHA functional classes I/II and 65% in NYHA class III/IV.4 Complete success was achieved in 81% of patients with NYHA class I/II and 74% of patients with NYHA class III/IV. The incidence of embolic complications was 14% and recurrent thrombosis occurred in 13% of patients. Patients with successful thrombolysis had a 30-day mortality of 8%, whereas patients with ineffective or partial success had a mortality of at least 12%. Thrombolysis is also the preferred option for patients with very severe comorbid conditions that would be associated with a very high operative mortality. Surgery Available evidence favors surgical intervention for left-sided valve thrombosis, especially if patient is highly symptomatic (NYHA class III/IV). European Society of Cardiology advocates surgery in all critically ill patients unless patient is unstable for the

www.americantherapeutics.com

e255

procedure or if surgery is unavailable or patient cannot be transferred to tertiary care center.5 American College of Cardiology guidelines recommend emergent surgery in all patients with thrombosed leftsided prosthetic heart valve with NYHA class III/IV symptoms (class I recommendation). Also, emergent surgery is a reasonable alternative in patients with left-sided PVT with a higher thrombus burden (.0.8 cm2) (class IIa recommendation).3 In a systematic review of 662 patients with PVT from 13 studies who were treated surgically, 91% had surgery as the initial therapy, whereas 9% had surgery after failed thrombolysis. Of these patients, 81% were in NYHA class III/IV and 9% in NYHA class I/II. Complete success was achieved in all. The incidence of embolic complications was 6% and recurrent thrombosis occurred in 6% of patients. The mortality with surgery was 15%, which may be partly due to the sicker population of patients who underwent surgery. Our patient underwent successful bioprosthetic mitral valve replacement in view of suspected PVT that was demonstrated on real-time fluoroscopy (which was not evident on TTE). In conclusion, realtime fluoroscopy plays a vital role in the diagnosis of PVT in the cases when there is high clinical suspicion and noninvasive modalities yield inconsistent results.

REFERENCES 1. Aoyagi S, Oryoji A, Nishi Y, et al. Long-term results of valve replacement with the St. Jude Medical valve. J Thorac Cardiovasc Surg. 1994;108:1021–1029. 2. Hammermeister K, Sethi GK, Henderson WG, et al. Outcomes 15 years after valve replacement with a mechanical versus a bioprosthetic valve: final report of the veterans affairs randomized trial. J Am Coll Cardiol. 2000;36: 1152–1158. 3. Nishimura RA, Otto CM, Bonow RO, et al. 2014 AHA/ACC Guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association task force on practice guidelines. J Am Coll Cardiol. 2014. pii: S0735– S1097(14)01279-0. Epub ahead of Print. 4. Huang G, Schaff HV, Sundt TM, et al. Treatment of obstructive thrombosed prosthetic heart valve. J Am Coll Cardiol. 2013;62:1731–1736. 5. Joint Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology (ESC), European Association for Cardio-Thoracic Surgery (EACTS), Vahanian A, Alfieri O, et al. Guidelines on the management of valvular heart disease (version 2012). Eur Heart J. 2012;33:2451–2496.

American Journal of Therapeutics (2016) 23(1)

Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.

Prosthetic Valve Thrombosis: Diagnosis and Management.

St. Jude mechanical prosthesis is the most commonly used prosthetic device with least valvular complications with excellent hemodynamics. However, pro...
288KB Sizes 0 Downloads 5 Views