A 78-year-old African-American male with a history of paroxysmal atrial fibrillation, syncope, hypertension, and HF with reduced ejection fraction of 30%-40% (diagnosed 2016) presented to the emergency department with increased exercise intolerance, episodic chest pressure, and shortness of breath. Other past medical history included stroke, chronic kidney disease, and small bowel obstruction. Home medications were rivaroxaban, beta blocker, statin, angiotensin-converting enzyme (ACE) inhibitor, and torsemide. The vital signs on arrival were normal. The physical examination was significant for a non-obese male with an irregular heartbeat, elevated jugular venous distention (6 cm above sternal angle), bilateral lower extremity edema, and inspiratory crackles. Cardiac auscultation did not reveal any extra heart sounds. Labs were significant for troponin I (TnI) of 0.27 ng/mL (normal < 0.03 ng/mL) and brain natriuretic peptide (BNP) of 389 pg/mL (normal < 100 pg/mL), both of which were higher than his known baselines (0.14 ng/mL and 300 pg/mL, respectively). Furthermore, chart review revealed a persistently elevated TnI (mean = 0.145 ng/mL) for approximately 10 years (5 years before his CHF diagnosis). All other labs, including kidney and liver function, hematology, and urine drug screen, were normal.
Chest X-ray revealed no acute cardiopulmonary abnormalities. Electrocardiogram (Figure 1) showed normal sinus rhythm with low voltage, but no signs of ischemia. The patient was admitted for management of non-ST elevation myocardial infarction (NSTEMI) and CHF exacerbation.
Transthoracic echocardiography (TTE) (Figure 2) revealed a progressive decline in left ventricular ejection fraction (LVEF) to 25%-35%. It was also significant for worsening diastolic dysfunction with E/A of 3.5 and medial E/E' of 24, despite the patient's adherence to medical management. The initial TTE done 3 years prior to this presentation showed LVEF 50%-55% and mild diastolic dysfunction with E/A 0.78. The repeat TTE done 1.5 years later revealed a decline in LVEF to 30%-40%.
Given the progressive decline in LVEF, a cardiac MRI (magnetic resonance imaging) was performed to rule out apical ventricular thrombi. The MRI revealed diffuse late gadolinium enhancement concerning for amyloidosis. Follow-up nuclear bone imaging (Figure 3) revealed increased cardiac uptake greater than bone, suggestive of grade III CA. Fat pad biopsy and mass spectrometry confirmed TTR amyloidosis. The patient was managed conservatively with diuretics, with significant improvement in symptoms, and was discharged with appropriate follow-up in place. Metoprolol was discontinued on discharge due to concerns of worsening the amyloidosis symptoms.