AbstractBackground:Cardiac comorbidities, particularly coronary artery disease (CAD), are linked to worse outcomes in multiple myeloma (MM) patients. This study aims to compare in-hospital complications associated with autologous stem cell transplant (ASCT) between MM patients with and without CAD in the U.S.Methods:Data from the Nationwide Inpatient Sample (2016-2021) for MM patients undergoing ASCT were analyzed using ICD-10 codes. Baseline characteristics were compared using χ2 tests for categorical variables and logistic regression for continuous variables. Propensity score matching was employed to mitigate confounding factors. All covariate imbalances were alleviated. The impact of CAD on primary and secondary outcomes, such as major adverse cardiovascular events (MACEs), in-hospital complications, and length of hospital stay, was assessed using logistic regression analysis. Adjustments for illness severity, baseline mortality risk at admission, and comorbidity burden were made using All Patient Refined Diagnosis Related Groups metrics and the Charlson Comorbidity Index.Results:We analyzed 12,775 patients with MM who underwent ASCT between 2016 and 2021. Approximately 1,165 (9.1%) patients had CAD. Patients with CAD were significantly older (Median age [IQR]: 67 [63-72 years] vs. 62 [56-68 years]; P<0.001). Compared with individuals without CAD, MM hospitalizations with CAD included more men (78.1% vs. 55.8%; P < 0.001), hospitalizations with greater comorbidity burden (CCI ≥ 3: 995 [85.4%] vs 8,465 [72.9%]; P<0.001), and higher prevalence of hyperlipidemia (550 [47.2%] vs. 2,195 [18.9%], Old MI (260 [22.3%] vs. 65 [0.6%]; P<0.001), previous PCI (360 [30.9%] vs. 5 [0.04]; P<0.001) or CABG (135 [11.6%] vs. 1 [0.01]), congestive heart failure (255 [21.9%] vs. 700 [6%]; P<0.001), chronic kidney disease (270 [23.2%] vs. 1,650 [14.2%]; P=0.001), and hypertension (500 [42.9%] vs. 4,165 [35.9%]; P=0.038). CAD was significantly correlated with greater odds of cardiac arrhythmias (154 [13.2%] vs. 635 [5.5%]; P=0.026), MACEs (111 [9.5%] vs. 332 [2.9%]; P<0.001), acute heart failure (38 [3.3%] vs. 207 [1.8%]; P=0.043), acute myocardial infarction (58 [5%] vs. 105[1.1%]; P=0.032), and need for urgent coronary revascularization (13 [1.1%] vs. 8 [0.07%]; P<0.05). MM hospitalizations with CAD were more likely to be in the top decile of length of hospital stay (366 [31.5%] vs. 3,320 [28.6%]; P=0.002). CAD did not significantly impact mortality (80 [6.9%] vs. 710 [6.1%]; P=0.687), incidence of graft vs. host disease (5 [0.4%] vs. 85 [0.7%]; P=0.485).Conclusion:CAD complicates nearly 1 in 10 patients undergoing ASCT for MM and is associated with increased odds of cardiac arrhythmias, MACEs, and prolonged hospital stays. CAD did not significantly impact in-hospital mortality, graft-versus-host disease, or hospital costs.Citation Format:Krishna Kishore Anne, Ani Gvajaia, Maria Fernanda Albuja Altamirano, Michael Imeh, Fidelis Uwumiro, kai He. In-hospital outcomes of autologous stem cell transplantation in patients with multiple myeloma with and without coronary artery disease in the United States [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 5966.