HISTORY, CURRENT ILLNESS AND PHYSICAL EXAMINATION

History
48-year-old woman.
Cardiovascular risk factors: hypertension under medical treatment. Ex-smoker (accumulated 20 packs/year). Overweight (body mass index: 29 kg/m2). Habitual ethanol consumer (20 grams/day).

Cardiological history:
Bicuspid aortic valve diagnosed in childhood due to murmur, with evolution towards severe aortic stenosis.
In 2005 aortic valve replacement (St Jude Regent No19 prosthesis) and 30 mm ascending aorta graft.
Subsequent follow-up in cardiology outpatient clinic with good functional class (NYHA: I-II) and reporting occasional palpitations.
The last echocardiogram in 2016 showed preserved left ventricular ejection fraction (LVEF) and a normofunctioning prosthesis although with slightly elevated gradients (maximum gradient of 47 and mean gradient of 24, estimated aortic valve area [AVA] of 1.5 cm2).

Other history:
Anxiety-depression disorder to mental health follow-up since 2016.
Assessed in neurology in 2015 for visual phenomena, with small lacunar infarcts and microembolism on cranial magnetic resonance imaging (MRI).
Bronchial asthma. Psoriasis.

Surgical interventions:
Gastric bypass (Roux-en-Y) and eventroplasty as a treatment for morbid obesity in 2008.
Cholecystectomy and hysterectomy in 2009.

Home medication:
Acenocoumarol according to guideline, amiodarone 200 mg/24 h, enalapril 20 mg/24 h, diltiazem 60 mg/8 h, furosemide 40 mg/24 h, almotriptan 12.5 mg/24 h, escitalopram 20 mg/24 h, ketazolam 15 mg/24 h, omeprazole 20 mg/24 h, formoterol/budesonide/24 h, 5 mg folic acid/24 h, lorazepam 1 mg/24 h, salbutamol if required.

Present illness
A 48-year-old woman attended the emergency department of our centre due to sudden dyspnoea in the last few hours, accompanied by dizziness, general malaise and palpitations. She reported good adherence to medical treatment, although higher than usual ethanol consumption in recent months and regular control of anticoagulation levels with significant fluctuations.

Physical examination
Vital signs: blood pressure 80/40 mmHg, heart rate 110 bpm, saturation 90%.
General condition: fair, sweating and respiratory work. Cardiac auscultation: rhythmic heart sounds, systolic murmur in aortic focus, no auscultation of prosthetic click. Pulmonary auscultation: scattered crackles and rhonchi. Jugular ingurgitation. Absence of oedema in the lower limbs.

COMPLEMENTARY TESTS
Laboratory tests:
CBC: haemoglobin 14.1 g/dl, leukocytes 6.55 x10E3/μl, platelets 128 x10E3/μl. Biochemistry: Na 138 mmol/l, K 4.5 mmol/l, Cr 0.93 mg/dl, ultrasensitive troponin T 158 ng/l, NTproBNP 13000.
Coagulation: INR 1.10.
Arterial blood gas: pH 7.45, pO2 51 mmHg, pCO2 33 mmHg, HCO3 23.5 mmHg.
Electrocardiogram (ECG): sinus tachycardia at 100 bpm with diffuse repolarisation alterations.
Chest X-ray: normal cardiothoracic index. Middle sternotomy wires and aortic ring. No data of acute pathology.
Angio-CT of pulmonary arteries: no evidence of TEPA. No signs of congestion.
Transthoracic echocardiogram: non-dilated left ventricle with mild hypertrophy and mildly impaired systolic function. High filling pressures. Right ventricle of normal size and function. Slightly dilated left atrium. Mechanical aortic prosthesis with severe double lesion, very high gradients (maximum gradient of 100 and mean of 75 mmHg). Moderate mitral insufficiency. Moderate tricuspid insufficiency allowing estimation of a PSAP of 55.
Fluoroscopy: absence of movement of one of the prosthetic discs.
Transesophageal echocardiogram: image compatible with thrombus on the ventricular side of the most posterior disc and another image on the aortic side of the most anterior disc, indicating very severe aortic stenosis and severe aortic insufficiency in the context of prosthetic thrombosis.

CLINICAL EVOLUTION
On arrival at the emergency department, the patient presented with significant dyspnoea associated with respiratory distress. Initially, given the clinical situation and normal chest X-ray and prior to the arrival of the analytical results, an angio-CT scan of the pulmonary arteries was performed which ruled out pulmonary thromboembolism and showed no evidence of fluid overload.
Urgent cardiology assessment was requested and a transthoracic echocardiogram (described above) was performed, showing a severe double aortic lesion with very high gradients.
Suspicion of acute prosthetic thrombosis led to fluoroscopy, which confirmed the diagnosis. However, for a better aetiological affiliation, a transesophageal echocardiogram was performed which showed images suggestive of thrombus in both discs.
The patient was transferred to the cardiac intensive care unit and remained in a poor haemodynamic condition, hypotensive and tachycardic, with little response to diuretic treatment. Urgent assessment by cardiac surgery was requested, who decided to perform emergency aortic valve replacement.
Intraoperative findings showed blockage of the prosthetic discs due to the presence of organised thrombus in both hinges. Finally, an ATS No 18 mechanical prosthesis was implanted, given the impossibility of implanting a biological prosthesis due to the size of the annulus, without complications.
The postoperative period passed without complications, allowing early discharge to the ward. The control echocardiogram showed a normally functioning mechanical prosthesis (maximum gradient 27.5 and mean gradient 14.6 mmHg) and hospital discharge was therefore decided.

DIAGNOSIS
Acute mechanical aortic prosthetic prosthesis thrombosis. Cardiogenic shock secondary to the same. Implantation of a mechanical aortic prosthesis ATS No18. LVEF preserved at discharge.
