Acute weight gain and diastolic dysfunction as a potent risk complex for post stem cell transplant atrial fibrillation.

The management of atrial fibrillation (AF) following stem cell transplant (SCTX) is often challenging because of the universal presence of profound bone marrow suppression. The incidence of and risk factors for AF/flutter following SCTX are not well known. A total of 395 multiple myeloma (MM) patients consecutively underwent SCTX between 2002 and 2005 at the Mayo Clinic, and 383 of whom, mean age 57 +/- 9 years, had no history of evidence of AF/flutter constituted the study population. During 1,002 person-years of follow up, 39 (10%) patients developed first AF/flutter (incidence of 39 per 1,000 person years), and 28 of these (72%) occurred within 21 days of SCTX. In multivariable-adjusted analyses, weight gain of > or = 7% in the 1st week post-SCTX (HR 3.68; P = 0.0120) and presence of diastolic dysfunction at MM diagnosis (HR 2.294; P = 0.0082) were independent predictors of AF/flutter. The risk of AF/flutter post-SCTX increased by about ninefold when both factors were present. Compared to age and sex-matched MM patients without SCTX, the risk of AF/flutter differed significantly only over the 1st year after MM diagnosis, during which SCTX was performed for the majority. Beyond the 1st year, there was no significant difference in risk of AF/flutter between the two groups. The data suggested that SCTX was associated with significantly increased risk of first AF/flutter, which typically occurred within the first 21 days of the transplant. Weight gain of > or = 7% was strongly predictive of first AF/flutter, and the risk was augmented by the presence of diastolic dysfunction at baseline.