Role of Brain-Type Natriuretic Peptide and Cardiac Troponins as Predictors of Outcome in Multiple Myeloma

BACKGROUND: High circulating levels of cardiac troponins, T and I (cTnT and cTnI) and brain-type natriuretic peptide (BNP) are associated with shorter overall survival and increased transplant-related mortality (TRM) in patients with amyloidosis undergoing high-dose chemotherapy and autologous stem cell transplantation (auto SCT). Their role as prognostic markers in myeloma is not clearly defined. We evaluated the utility of BNP, cTnT and cTnI as prognostic markers in patients undergoing auto SCT for myeloma.

METHODS: We retrospectively analyzed patients who received high-dose chemotherapy followed by auto SCT at MD Anderson Cancer Center between January 1 and December 31, 2006. Pre auto SCT levels of BNP, cTnT and cTnI were available in all patients. The upper limit of BNP was 100 ng/L, cTnT 0.01 ng/ml and cTnI 0.03 ng/ml.

RESULTS: A total of 105 patients (68 male and 37 female) with a median age of 57 (31–73) received auto SCT during the study period. Seventy-seven patients received high-dose melphalan 200 mg/m² as preparative regimen, while 28 patients received a combination of melphalan 140 mg/m² + busulfan 130 mg/m² × 4 days. Median follow up of surviving patients was 21 months (1–30). Twenty-four (23%) patients had a high BNP level (>100 ng/L) prior to transplantation, 7 patients had a high cTnT level (>0.01ng/ml) and 12 patients had a high cTnI level (>0.03 ng/ml). In 101 evaluable patients, responses (complete 22 + partial 53) were seen in 75 (74%) patients. Overall survival (OS) and progression-free survival (PFS) at 24 months was 86 and 58%, respectively. There was no significant difference in 24-month OS in the high BNP group (p=0.7). Eight patients died of non-relapse causes, with only one death in patients with high BNP (p=0.67). Grade 3–4 cardiac adverse events were reported in 2 patients only, one of whom had elevated BNP (p=0.54). An increase in either BNP, cTnT or cTNI was seen in 30 patients. These patients did not have a significant increase in TRM (p=0.68) or cardiac toxicity, or a decrease in OS.

CONCLUSION: High pretransplant levels of BNP, cTnT or cTnI levels, either individually or together, did not adversely impact cardiac events, TRM or OS.