Predictors of cardioprotective medication use after a breast cancer diagnosis.

281 Background: Cancer survivors face a high risk of cardiovascular events, and proper use of cardioprotective medication can reduce cardiotoxicity. This study examines factors influencing medication use and adherence after breast cancer diagnosis. Methods: This retrospective cohort study analyzed cardioprotective medication use in Kaiser Permanente Southern California breast cancer patients (2007–2022). Prescription medication use of cardiotonics, antihypertensives, and antihyperlipidemics were captured one year before and after cancer diagnosis. Logistic regression predicted medication initiation and discontinuation post-diagnosis, adjusting for demographics and clinical factors. Linear regression assessed changes in adherence using proportion of days covered (PDC). Results: Among 36,489 included patients, 56.6% had a prescription fill before cancer diagnosis, while 43.4% had no prior cardioprotective medication use. Initiation was more likely with older age, Black race, and diabetes history. Conversely, distant-stage breast cancer increased the likelihood of stopping medication nearly fivefold and led to a 9% decline in adherence post-diagnosis (Table). Conclusions: Breast cancer patients who were older, black, and had comorbidities were more likely to begin cardioprotective medication and less likely to stop medication after their cancer diagnosis. Patients with advanced cancer were more likely to discontinue medication. Factors predicting medication use after breast cancer diagnosis. Begin Medication^(N=15,835) Stop Medication#(N=20,654) Change in Medication Adherence@(N=19,969) OR (95% Confidence Limits) OR (95% Confidence Limits) % Change (95% Confidence Limits) Age (70+/<40) 3.48 (2.61-4.63) 0.12 (0.08-0.18) 2.32 (-1.52-6.17) Race (black/white) 1.63 (1.39-1.90) 0.79 (0.66-0.95) 0.92 (0.16-1.69) Stage (regional/localized) 1.01 (0.89-1.14) 1.47 (1.25-1.73) -0.68 (-1.40-0.04) Stage (distant/localized) 1.75 (1.41-2.17) 4.80 (3.81-6.04) -9.17 (-10.66--7.68) Diabetes 3.09 (2.53-3.78) 0.52 (0.45-0.61) 1.08 (0.50-1.66) Cardiovascular Disease (CVD) History 1.46 (1.18-1.80) 0.95 (0.81-1.12) -0.39 (-1.05-0.27) ^Use of cardioprotective medication within a year after cancer diagnosis in individuals with no prior use in the preceding year. #Discontinuation of cardioprotective medication within a year after cancer diagnosis in individuals who had used them in the preceding year. @Percentage change in adherence calculation was limited to patients with cardioprotective medication use before and after cancer diagnosis. *Covariates: age (<40, 40-50, 50-60, 60-70, 70+, female, race (Asian, black, white, other), Hispanic, ever smoker, Medicaid or Medicare insurance, SEER stage (in situ, localized, regional, unknown/unstaged), CVD history, chemotherapy, diabetes, and year of diagnosis.