Incidence Of Hypotension In Patients With Multiple Myeloma During High Dose Chemotherapy and Autologous Stem Cell Rescue
Authors: Sehgal Priya , Biran Noa , Sahni Gagan , Chari Ajai 
Published: October 2019

Abstract

Background
The median age of patients diagnosed with multiple myeloma (MM) is 69. Up to 60-80% of patients in this age group have hypertension (HTN) (Burt VL et al. Hypertension 1999), and are on anti-hypertensive medications. A standard treatment for MM is high dose melphalan (HDM) chemotherapy with autologous stem cell transplant (ASCT), which often results in gastrointestinal complications that can result in hypovolemia.
The combined effect of anti-HTN agents and ASCT-related complications may result in blood pressure (BP) ranges that are precariously low. To date, the incidence of hypotension in the setting of ASCT for MM is unknown. In this case series of 102 patients who received ASCT for MM, we compare the characteristics of those who became hypotensive with those who did not.

Methods
We reviewed the charts of 102 consecutive MM/AL amyloid patients admitted for HDM chemotherapy with ASCT at Mount Sinai Hospital between May 2011 and June 2013. May 2011 was chosen as the date of inclusion because at this time, electronic medical records were implemented, allowing for detailed review of vital signs and other clinical data.
Patients were classified into two groups. Patients included in group 1 demonstrated a drop in BP which was defined as meeting at least 1 of the following criteria:
A) One or more anti-HTN medications were discontinued during ASCT
B) Although normotensive on admission for ASCT, the median systolic or diastolic blood pressure (SBP or DBP) on date of discharge was ≤ 100 or 60 mm Hg respectively
C) A decrease in SBP of ≥ 20 mm Hg was observed between admission and discharge
Patients who did not meet any of the above criteria were classified into group 2. Baseline and peri- SCT characteristics of the two groups were compared using the chi square test.

Results
Of the 102 patients analyzed, 6 had AL amyloid and the remaining 96 had MM. 43 met at least one inclusion criteria for group 1 and the remaining 59 were classified as group 2. Specifically, of the patients in group 1, 18 met inclusion criteria A, 21 met inclusion criteria B, and 23 met inclusion criteria C. Among the patients in group 1 who met 2 criteria: 4 patients met criteria A and B, 4 patients met criteria A and C, and 9 patients met criteria B and C.
Baseline characteristics including median age (64 and 63), gender distribution (55.8% and 47.5% females respectively), and a history of HTN (41.9% vs. 37.3%) were comparable in both groups (p>0.05). The median length of stay was 17 days in both groups.
The incidence of gastrointestinal complications was comparable in both groups including diarrhea 72.1% vs. 62.7%, mucositis 14.0 % vs 8. 5%, and Clostridium difficile infection 9.3% vs. 6.8%. The ensuing weight loss in the 2 groups was also comparable 2.4 kg and 1.9 kg respectively.
The incidence of infectious complications was similarly comparable in the 2 groups with fever 51.1 % vs 61% and bacteremia occurring in 7.0% vs 11.9%. Of the 43 patients in group 1, one patient had shock requiring ICU transfer for vasopressors in the setting of adrenal insufficiency and sepsis/bacteremia.
Interestingly, of the 102 included patients, only 15 were reported to have clinically significant hypotension on the discharge summary. Of these 15 patients, 3 experienced transient hypotension, (i.e. for 1 -2 days,) with rapid normalization of pressure, and therefore, did not meet our inclusion criteria of persistent hypotension.

Conclusions
Although the incidence of hypotension in this series of MM patients undergoing ASCT was 42%, only 15% had documentation of this occurrence in the discharge summary.
Interestingly, there were no statistically significant differences in the risk factors for ASCT associated hypotension in the 2 groups, including gastrointestinal and infectious complications.
Given the unexpectedly high incidence of hypotension during ASCT, consideration should be given to the following: 1) Prior to SCT, anti-HTN medications should not be added (as is sometimes done for perioperative clearance) or titrated up; 2) During ASCT, anti-HTN medications may need to be discontinued; 3) Prior to discharge from ASCT, physical therapy/orthostatic evaluation and risk of falls from new relative hypotension needs to be assessed, especially in the setting of recovering thrombocytopenia.
Although further studies are required, we hypothesize that fatigue, presyncopal events, and falls post SCT could be minimized with increased attention to HTN management peri ASCT.

Disclosures:
Chari: Celgene: Consultancy, Membership on an entity’s Board of Directors or advisory committees; Millenium : Membership on an entity’s Board of Directors or advisory committees; Onyx: Membership on an entity’s Board of Directors or advisory committees.