Trombose de Prótese Mecânica - by Fábio Soares

Há exatos alguns minutos atrás estávamos discutindo um caso na UTI. Tratava-se de uma paciente feminina, 56 anos, com passado de trova valvar mitral há 18 anos (3 trocas prévias por por disfunção), evoluindo há 30 dias com dispnéia aos esforços. Quando do início dos sintomas, realizou ECO transtorácico que evidenciou prótese mecânica normofuncionante (gradiente médio AE/VE 6mmHg e PSAP estimada em 30mmHg). Os sintomas agravaram-se, sendo admitida na UTI há 48h com franca insuficiência respiratória devido a edema agudo de pulmão. Realizou ecocardiograma transtorácico e transesofágico que evidenciou disfunção de prótese, com restrição da mobilidade de um de seus folhetos, com diferença de velocidade na abertura dos discos, determinando gradiente AE/VE máximo 34mmHg e médio 16mmHg, com PSAP estimada em 90mmHg. Não foram visuaizados trombos. A paciente encontra-se em VM, em uso de baixas drogas de vasoativas, com edema agudo de pulmão refratário. O que fazer? Este foi o motivo de muita discussão entre Ecocardiografistas, Cardiologistas clínicos e Cirurgião Cardiovascular.

Pontos a lembrar

- Idade 56 anos

- Fibrilação atrial permanente

- HP grave

- 4 cirurgias prévias para troca de próteses em posição mitral

- Edema agudo de pulmão refratário /IC CF IV

- TP fora da faixa terapêutica

- Ecocardiograma há 30 dias, sem evidências de disfunção de prótese

O que fazer? Trombolítico? Cirurgia Cardíaca?

Conforme a literatura...

The Thrombosed Prosthetic Valve Current Recommendations Based on Evidence From the Literature

Joseph S. Alpert, MD, FACC
 
1. All patients with suspected TPVs should undergo echocardiographic study. If adequate visualization of the

prosthetic valve is not obtained by a transthoracic study, then a transesophageal echocardiographic study should be undertaken (level of evidence I).

2. Patients with right-sided TPVs should be treated with intravenous rtPA (100 mg administered as 10 mg immediate intravenous bolus followed by 90 mg infused over 90 min) or SK (500,000 IU over 20 min followed by 1.5 million IU infused over 10 h). Reduced doses should be employed in children and very small adults (level of evidence IIa).

3. Patients who are critically ill on presentation with TPV (pulmonary edema, hypotension, NYHA class III/IV symptoms) should receive immediate intravenous thrombolytic therapy as outlined earlier following appropriate echocardiographic confirmation of TPV (level of evidence IIa).

a. Serial echocardiographic studies should be performed in these individuals, and repeated infusions of trombolytic therapy should be administered if complete resolution of prosthetic valve thrombus is not achieved (level of evidence IIa).

b. Concomitant intravenous unfractionated heparin should be administered along with thrombolytic therapy to achieve an activated partial thromboplastin time that is 1.5 to 2.0 times control (level of evidence IIb).

c. Cardiac surgical consultation should be sought urgently. Valve replacement should be seriously considered

if repeated infusions of thrombolytic therapy fail to adequately dissolve the thrombus on the prosthetic valve (level of evidence IIa).

4. Patients with TPV who are clinically stable, that is, in NYHA clinical class I or II, may be managed medically with thrombolytic/antithrombotic therapy or surgically with valve replacement depending on physician/patient preference (level of evidence IIa).

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Echocardiographic signs of obstructive prosthetic valve thrombosis

 

• Reduced valve mobility
• Presence of thrombus
• Abnormal transprosthetic flow
• Central prosthetic regurgitation
• Elevated transprosthetic gradients
• Reduced effective prosthetic area

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 THROMBOSIS OF PROSTHETIC HEART VALVES: DIAGNOSIS AND THERAPEUTIC CONSIDERATIONS
Raymond Roudaut, Karim Serri, Stephane Lafitte

Heart 2007;93:137–142. doi: 10.1136/hrt.2005.071183