The purpose of this study is to better define and understand potential cardiac toxicities of proteasome inhibitors and to understand optimal management strategies to treat and prevent cardiovascular events.

Cancer treatments, using proteasome inhibitors, have the potential in induce cardiac toxicities including heart failure (HF), hypertension, arrhythmias and ischemic heart disease. While the presence of cardiac events may be a class effect of proteasome inhibitors (PI), the effect may be more profound with the irreversible inhibition of carfilzomib compared with reversible inhibition with bortezomib. Data available from currently published clinical trials may be inadequate to fully understand the incidence and severity of cardiac injury in patients treated with proteasome inhibitors because the trials were not designed to fully assess cardiac events. The purpose of this study is to better define and understand potential cardiac toxicity and begin to understand optimal management strategies.

Inclusion Criteria:

• Relapsed multiple myeloma at any time-point in treatment course and planning to start a proteasome inhibitor-based therapy as part of standard care
• Received at least one prior line of therapy for multiple myeloma (induction therapy followed by stem cell transplant and consolidation/maintenance therapy will be considered as one line of therapy)
• Males and females ≥ 18 years of age
• Able to provide written informed consent in accordance with federal, local, and institutional guidelines

Exclusion Criteria:

• POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes)
• Known or suspected AL amyloidosis, secondary amyloidosis or cardiac amyloidosis
• Plasma cell leukemia (> 2.0 × 109/L circulating plasma cells by standard differential)
• Waldenström Macroglobulinemia
• Myelodysplastic syndrome
• History of MI within the last 3 months
• Symptomatic unstable cardiac arrhythmia requiring treatment in the past 3 months
• Class 3 or 4 New York Heart Association Heart Failure in the past 3 months
• Any other clinically significant medical disease or condition that, in the investigator's opinion, may interfere with protocol adherence or a subject's ability to give informed consent

Multiple Myeloma patients being treated with bortezomib or carfilzomib, per oncology physician decision.

There are no plans to share individual participant data.