Background: Orthostatic hypotension (OH) is a well-recognized phenomenon occurring in multiple myeloma (MM) patients undergoing autologous stem cell transplant (ASCT) that poses a morbidity and mortality threat due to increased risk of falls. Surprisingly, few studies have examined its incidence, risk and protective factors, and prognostic implications. Methods: This was a retrospective, single-center study of 226 consecutive newly diagnosed MM patients who were admitted for first ASCT between June 2012 to April 2014 at Dana Farber Cancer Institute/Brigham and Women’s Hospital, Boston, MA. Patients with AL amyloidosis were excluded. Orthostatic vital signs were checked on Monday, Wednesday and Friday. Median time to onset of OH, progression free survival (PFS), overall survival (OS), and time to discharge were estimated using the Kaplan-Meier method. Univariable and multivariable logistic regression were used to investigate factors associated with the development of OH. Results: Overall, 165/226 (73%) patients were diagnosed with OH during the course of their hospital admission for ASCT. Fifty-one patients were found to have OH on the day of first orthostatic vitals check, making it impossible to distinguish whether OH was pre-existent or developed during the transplant admission. Excluding these 51 patients, 114/175 (65%) patients developed OH during the peri-transplant period, at a median of 7 days post ASCT (range; 6–8). Of these patients, only eleven were found to have moderate to severe dehydration as defined by weight loss ≥ 5% body weight, suggesting OH could not be simply be explained by volume depletion. Multivariable analysis revealed three risk factors (white race, gabapentin, antihypertensives) and two protective factors (antihistamine, proton pump inhibitor) associated with the development of peri-transplant OH that were independent of significant fluid losses. Further, we found that OH did not significantly impact length of hospitalization, progression free and overall survival. Conclusions: New onset OH occurs frequently (65%) during the peri-transplant period in MM patients undergoing ASCT (median time of onset of 7 days post ASCT). White race, use of gabapentin and antihypertensives were identified as risks factors, while use of antihistamines and proton pump inhibitor were identified as protective factors.
Univariable and multivariable comparisons of patients with or without orthostatic hypotension. The table outlines variables associated with increased or decreased risk of developing OH in patients who did not have OH on first check (b); only patients who did not experience significant weight loss before OH and did not have OH on first check (c); only patients who developed OH on D+1 or after.