It is expected to include 40 patients with M-protein related cardiac disease. The treatment medication for enrolled patients must comply with the treatment regimen of Daratumumab + Bortezomib + Dexamethasone. All patients were given Dapagliflozin 10mg/day at the beginning of treatment (creatinine clearance rate greater than 20ml/min).

This study is a multicenter, single arm, observational clinical study.It is expected to include 40 patients with M-protein related cardiac disease, who will sign informed consent forms. Collect baseline examination, treatment period (planned 6 cycles), and follow-up period (survival follow-up) data for patients who meet the inclusion and exclusion criteria. The treatment medication for enrolled patients must comply with the treatment regimen of Daratumumab + Bortezomib + Dexamethasone: subcutaneous injection of 1800mg of Daratumumab, d1, 8,15,22 (28 day cycle); (After 2 cycles of improvement in cardiac indicators, it can be adjusted to intravenous injection of daratumumab); Bortezomib 1.3 mg/m2 d1, 8, 15, 22; D1, 8, 15, 22; Dexamethasone 20 mg d1, 2, 8, 9, 15, 16, 22, 23. When NTProBNP is greater than 5400ng/ml, bortezomib 1.0mg/m2; When NTProBNP is greater than 8500ng/ml, bortezomib is 0.7mg/m2. When NTProBNP is greater than 10000ng/ml, bortezomib is temporarily not allowed; NTProBNP greater than 4500ng/ml dexamethasone starts at 10 mg/dose. All patients were given Dapagliflozin 10mg/day at the beginning of treatment (creatinine clearance rate greater than 20ml/min).

Inclusion Criteria:

• M-protein related cardiac disease aged 18 and above (at least one of the following criteria is met): (1) Systemic amyloidosis of the affected heart; (2) Presence of M component and presence of arrhythmia, cardiac enzyme abnormalities, cardiac function abnormalities, and exclusion of other diagnosable cardiac diseases;
• ECOG score 0-2;
• Sign a written informed consent form.

Exclusion Criteria:

• Acute myocardial infarction;
• Severe functional abnormalities in important organs such as lungs, liver, and kidneys (the carbon monoxide diffusion ability caused by chronic respiratory diseases is 50% lower than expected);
• Major surgery, radiation therapy, infections requiring systemic antibiotic treatment, or other serious infections within 14 days after enrollment;
• Individuals with mental illness, comprehension disorders, or other reasons that make it difficult to control themselves;
• Pregnant or lactating women, as well as reproductive age patients who refuse to take appropriate contraceptive measures during this trial. If the patient is male, refuse to use adequate contraceptive methods or donate semen during the study period and within 3 months after receiving the last cycle of drug study;
• Diagnosed or treated another malignant tumor within 2 years prior to enrollment;
• Individuals with allergies to daratumumab, bortezomib, or dexamethasone components or more severe allergic constitutions;
• HIV infected individuals (HIV antibody positive);
• Active infection of hepatitis B and hepatitis C (hepatitis B B virus surface antigen positive and/or hepatitis B core antibody positive, hepatitis B virus DNA more than 1x103 copies/mL; hepatitis C virus RNA more than 1x103 copies/mL);
• Participate in another clinical trial 30 days after the start of the trial and throughout the entire trial period;
• The researcher determined that patients who are not suitable to participate in this study;

Observe patient data from Beijing Chaoyang Hospital affiliated with Capital Medical University, Beijing Chuiyangliu Hospital, and Beijing Boren Hospital.