Associazione Nazionale Medici Cardiologi Ospedalieri




Collareta Michele Khartoum(Estero) – The Salam Centre for Cardiac Surgery | Vera-Mondazzi Liliana Khartoum(Estero) – The Salam Centre for Cardiac Surgery | Abd Almhmoud Sidiq Monera Khartoum(Estero) – The Salam Centre for Cardiac Surgery

The annual incidence of blocked mechanical valvular prosthesis (BMVP) is 0.3-5.7%. 78% of cases are due to thrombosis and development of pannus is the second more frequent etiology. The risk of thrombosis is higher for mitral prosthesis, during the 1st year after valve replacement, and for poor INR trend. TEE is the gold standard for diagnoses, but it is seldom required if adequate TTE and cine-fluoroscopy are performed. As therapy, redo surgery is recommended in case of NYHA III-IV patients or in presence of big thrombi: if surgery is contraindicated or too high-risk, systemic thrombolysis is a reasonable option. In less compromised patients, upgrading of the anti-thrombotic therapy can be considered.

In our Centre (around 600 valve replacement surgeries/year, mainly high risk patients) we use thrombolysis for BMVP in decompensated patients, choosing between two different protocols: the so called “fast” protocol (alteplase 15 mg iv bolus, then 0.75 mg/kg over 30′ and 0.5 mg/kg over 1h) is provided for NYHA IV patients, while the “slow” protocol (25 mg over 6 h) is the treatment of choice for the NYHA III ones. Many complications, mainly bleeding, are associated to thrombolysis.

A 30 years old lady who underwent MVR in 08/2021, already successfully treated with thrombolysis in 11/2021 due to BMVP, presented in 01/2023 due to NYHA IV heart failure. TTE and cine-fluoroscopy showed BMVP (grad. 29/21 mmHg, area 0.7 cm2). The LV was hypekynetic (EF 81%), and severe pulmonary hypertension (calcSPAP 82 mmHg) was present. Fast thrombolysis was performed, with decrease of gradients (11/6 mmHg) and of pulmonary pressure (45 mmHg), and preserved LV function (EF 55%), without acute complications. On the 2nd day, the patient developed generalized seizures and pulsless VT, with ROSC after DC shock (7′ low-flow time). The neurological recovery was complete, but haemodynamic instability developed; new onset LBBB, and progressive worsening of the LV function (EF 40%, then 25%, medioapical hypokinesia) were documented. The coronary angiography showed a thrombus in the proximal LAD, not occluding the vessel, and TIMI 3 downstream flow. Heparin continuous infusion was provided for 48 h with a 1.8-2.3 aPTT ratio target. The patient was eventually discharged home with normal gradients (12/7 mmHg), EF (67%), ECG and pulmonary pressure.

Coronary embolism is a possible complication of BMVP, and can follow systemic thrombolysis. Close multimodal clinical monitoring is mandatory.