FIT Case of the Month, October 2019: Christopher Tanayan, MD

Syncope and Stroke-like Symptoms in a Young Male with Non-Bacterial Thrombotic Endocarditis

Author: Christopher Tanayan MD, Additional authors^*

Introduction:

Strokes are rare in young healthy adults.
Non-Bacterial Thrombotic Endocarditis (NBTE) is also rare.
We present the case of a young athlete with a stroke secondary to an unexplained non-infectious mitral valve endocarditis.

Case Presentation:

20 year-old African American man, college basketball player
No known medical or surgical history
CC: Syncopal episode lasting minutes preceded by dizziness
Transient bilateral vision loss for 15-20 minutes
Multiple falls at home due to transient loss of sensation in his legs 2 months ago
ROS: (+) light-headedness (-) fevers, night sweats, chest pain, palpitations, SOB
No significant family history; Non-smoker, no substance use
PE: Generally unremarkable. No focal deficits.
Labs: Normal CMP, CBC, coagulation panel

Case Management:

EKG [Fig 1] was negative for ischemia or arrhythmia.
Trans-esophageal echo [Fig 2,3] showed a mobile mass on the mitral valve. EF was 66% with normal LV function.
Brain MRI [Fig 4,5] showed multiple foci of restricted diffusion in bilateral cerebellar hemispheres and the left occipital lobe.
Emergent debridement and resection of a 0.75 cm mass [Fig 6] from the anterior leaflet and repair of mitral valve with pericardial patch was performed.
The mass was sent for pathology evaluation [Fig 7] and cultures. Infectious and rheumatologic work-up was negative.
On a 3-month follow up transthoracic echo, a new mass was seen on the posterior leaflet of the mitral valve [Fig 8]. The mass resolved after 4 days of anticoagulation.
He was discharged on indefinite anticoagulation. Extensive outpatient work-up is still inconclusive.
Lupus, anti-phospholipid antibody syndrome, rheumatoid arthritis, malignancy and other pro-thrombotic conditions have been ruled out.

Discussion:

A cardiac mass must be identified as a tumor or a thrombus for proper management as outlined above [Fig 9].

Initial evaluation: echocardiography +/- cardiac CT or MRI
Goal: confirm presence, location, nature of mass
Tumor was the initial impression of the mass in this case.
Pathology findings, recurrence and subsequent resolution with anticoagulation proved that this was a thrombus.

Tumor

- Myxomas, papillary fibroelastomas and lipomas are the most common benign primary tumors. Secondary tumors are mostly metastatic and rare.
- Symptomatology depend more on the tumor’s location in the heart than on its histopathology.
- Treatment: Regardless of pathology, surgery is recommended if patients are symptomatic (i.e. had embolic events or tumor-related complications).

Thrombus

- Culture-negative infectious endocarditis must be ruled out with special stains, PCR, other techniques.
- Non-bacterial thrombotic endocarditis (NBTE, aka marantic, Libman-Sacks, or verrucous endocarditis) is mostly seen in the aortic or mitral valve. It is most commonly associated with advanced malignancy and systemic lupus erythematosus.
- Treatment: anticoagulation to prevent further embolization and addressing the underlying cause.

Conclusion

This case of NBTE illustrates that this rare entity can occur in the absence of predisposing factors such as rheumatologic disease or pro-thrombotic states.

Though rare, idiopathic cardiac thrombi must be considered in the differential diagnoses of stroke in a young healthy adult.