Introduction: Heart failure is the most common initial manifestation of infiltrative cardiomyopathies, which in many instances can remain underdiagnosed. In patients with oncological history, it can be due to cancer or its treatment complications. The incidence of metastatic disease to the heart is rare at less than <10% (most common with lung, breast, melanoma, and hematological malignancies). We present a rare case of recurrent breast cancer that presented as new-onset heart failure.  

Case description: 81 y/o female with a past medical history of hypertension and breast cancer treated with lumpectomy and radiation without adjuvant chemotherapy in remission since 2004, presented with dyspnea on exertion and orthopnea. Noted to have elevated BNP, bilateral pleural effusions, and ejection fraction (EF) of 30 %, was treated for CHF exacerbation. During outpatient follow-up, a new echocardiogram showed an EF 40-45% with an apical thrombus, which resolved with apixaban. On cardiac catheterization, she was noted to have mild nonobstructive coronary disease. Her EF eventually improved to 55%, however, she continued with symptoms despite diuresis and heart failure treatment. She was readmitted 2 months later and found to be in CHF exacerbation, right pleural effusion, for which she had a thoracentesis and was discharged when stable. Cardiac MRI was done and showed normal EF with diffuse late gadolinium enhancement consistent with infiltrative disease. A Technetium pyrophosphate scan was performed and was negative for amyloidosis. The patient presented recurrent symptoms and pleural effusion a month later. She was referred to the hospital for a myocardial biopsy. The procedure was complicated with right ventricle perforation and pericardial effusion with tamponade and cardiogenic shock that warranted an emergent pericardial window. She was in the ICU until improved. Pleural fluid from prior thoracentesis, and myocardial biopsy revealed malignant cells consistent with breast cancer ER+. She was started on letrozole and would continue further oncologic workup with PET/CT as an outpatient.  

Discussion: Detection of Infiltrative cardiomyopathies has led to improved to better outcomes via disease-specific therapy. Heart failure in oncologic patients can be caused by different mechanisms including radiation, chemotherapy, and cancer metastases. Breast cancer gets to the heart by lymphatic spread most commonly in pericardium; myocardium metastases are rare. Treatment is symptomatic. In our case, the recurrent malignant pleural effusions, nonobstructive CAD, MRI suggestive of infiltrative disease, and negative PYP led to the suspicion of cardiac metastasis. Pathology is the gold standard for the diagnosis of cardiac metastasis. 

Conclusion: Cardiac metastases should be considered in any individual with new cardiac symptoms and known malignancy. The prognosis of patients with breast cancer with cardiac metastases is poor.

References:

1. Spectrum of Restrictive and Infiltrative Cardiomyopathies: Part 1 of a 2-Part Series. J Am Coll Cardiol 2018;71:1130-1148. 
2. Yusuf SW, Negi SI, Lenihan DJ. Infiltrative cardiomyopathy and pericardial disease. Seminars in Oncology. 2013;40(2):199-209. doi:10.1053/j.seminoncol.2013.01.009 Articles links 
3. Goldberg AD, Blankstein R, Padera RF. Tumors Metastatic to the Heart. Circulation. 2013;128(16):1790-1794. doi:10.1161/circulationaha.112.000790