While studies have explored risks among patients with multiple myeloma, recent research is the first to compare cardiovascular mortality risk in multiple myeloma to that of the general population.
Patients with multiple myeloma (MM) are often older and prone to comorbidities, including cardiovascular diseases (CVDs), and a recent study published in Therapeutic Advances in Hematology suggests that patients with MM may be at a higher cardiovascular disease mortality (CVM) risk than the general population.
MM survival rates have increased in recent decades thanks to novel treatments and an improved understanding of disease pathophysiology. But, despite the known correlations between MM and CVDs, there is a lack of studies evaluating CVM in MM patients compared with the general population. Instead, the most current research on CVM related to MM is solely based on patients with MM.
In the current study, Surveillance, Epidemiology, and End Results (SEER) program data were used to assess the risk and trends of CVM in MM patients versus the general population. Potential cardiotoxic effects of therapies and lifestyle risk factors were also explored. A total of 88,328 patients with MM between 1975 and 2016 were included in the study, and CVM risk was assessed using standardized mortality ratios (SMRs).
Patients were classified under 4 categories for cause of death — death due to primary disease, death from cardiovascular causes, death from other cancers, and death from other non-cancers — with a primary end point of CVM. Rather than mortality records associated with incident cancer cases, incidence-based mortality (IBM) cases from 1985 to 2016 were included in this study to avoid underrating IBM rates during the first several years of the study period. The average survival for patients with MM was 10 years by 2014, which is why this time frame was chosen.
SEER data do not include treatment information for individual patients, so study authors stratified the overall cohort into 5 eras of diagnosis based on changes in treatment methods over the years: 1975 to 1995, 1996 to 2000, 2001 to 2005, 2006 to 2011, and 2012 to 2016.
In the overall MM group, CVM incidence decreased at a rate of -1.2% each year over the study period. When stratified by age, patients diagnosed between 65 and 74 years of age saw an annual percentage change (APC) of -1.2% over the study period. Those older than 75 years saw an APC of -1.9%, and younger patients did not see a significant APC for CVM incidence. Non-cardiovascular mortality incidence rates decreased across age groups.
The rate of CVM among patients with MM was 123.95 per 10,000 person-years, and the SMR was 1.84 times that of the general US population. Patients diagnosed with MM at a younger age showed higher SMR of CVM, and there was a gradual drop in SMR of CVM when patients were diagnosed at later ages.
Patients with MM saw the highest SMR for CVM (2.62) in the first year after diagnosis, with a decline over the follow-up period. There were no significant changes in SMR of CVM between the time frames noted for different therapy eras.
Within the group of patients with MM, risk factors for CVM included male sex, Black race, older age, and earlier diagnosis. Patients with MM who were diagnosed between 2012 and 2016 saw a 53.4% decrease in CVM compared with patients diagnosed between 1975 and 1995.
Using SEER data comes with limitations, such as a lack of patient-level information on comorbidities that may affect CVM risk. There is also no record of venous thromboembolism, an important component of CVM, in SEER data. Even so, the findings showed that the SMR of CVM in patients with MM is significantly higher than that of the general population and varies based on patient age, sex, race, the time after diagnosis, and the point in time at which a patient was diagnosed in this dataset.
“This research has the potential to improve the advancement of cardio-oncological risk stratification in MM patients and help clinicians make informed decisions about which patient groups have a higher risk and who would benefit more from precautions,” the authors concluded.
Yin X, Fan F, Zhang B, Hu Y, Sun C. Cardiovascular-specific mortality among multiple myeloma patients: a population-based study. Ther Adv Hematol. Published online March 31, 2022. doi:10.1177/20406207221086755