Eisinger, Amy D.

Abstract Background: Clinical observations within our tertiary care setting suggested that atrial arrhythmia is common following hematopoietic stem-cell transplant (SCT). Yet little is known with regard to the incidence of such arrhythmia and factors contributing to its development. We assessed the frequency of first atrial fibrillation/flutter (AF/flutter) development in multiple myeloma (MM) patients who underwent SCT at the Mayo Clinic over a 4 year period. Method: Using a case-control design, we compared 395 consecutive patients who underwent SCT at the Mayo Clinic during the period 2002–2005 to control subjects who did not have SCT (2:1 matched by age, gender, and date of MM diagnosis) in terms of the baseline risk factors and the frequency of new AF/flutter after MM diagnosis. Patients who had a prior history or evidence of atrial arrhythmia were excluded from analyses. Factors predictive of atrial arrhythmia in the cases were also determined. Results: First AF/Flutter developed in 38 of 395 cases (mean age 58 ± 9 years) and 47 of 790 controls subjects within 5 years of MM diagnosis (P=0.002). The 5-year Kaplan-Meier estimates of the risk of AF/flutter were 17% and 8% for cases and controls, respectively. Amongst the cases who developed new AF/flutter, the onset of the arrhythmia was within 21 days of SCT for the majority (94%). In multivariable analysis, body weight change of ≥3% in the first week post-transplant (HR 2.86; CI 1.13–7.24; P=0.026) and presence of diastolic dysfunction (HR 1.79; CI 0.99–3.23; p=0.054) at MM diagnosis were independent predictors of first AF/flutter in the cases, adjusting for age, sex, and well established clinical risk factors. Conclusion: The risk for new AF/flutter was remarkably high in the early post- SCT period in MM patients. In addition to established risk factors for atrial arrhythmia, a weight change ≥3% during the first 7 days after SCT, and the presence of diastolic dysfunction at baseline, were independent novel risk factors for new AF/flutter. These findings warrant further investigation, as modification of fluid management and diastolic filling may potentially lower the risk of post-SCT atrial arrhythmia.