Temporal trends, disparities, and ARIMA forecasts of mortality among U.S. adults with coexisting hematologic malignancy and heart failure, 1999–2023, with projections to 2033

Background: Hematologic malignancies (HMs) and heart failure (HF) increasingly coexist as populations age, yet population-level mortality patterns in adults with both conditions remain poorly defined. We characterized long-term temporal trends and demographic disparities in HM-HF mortality and forecasted future rates through predictive modeling. Methods: We analyzed U.S. multiple cause-of-death data (1999-2023) for adults aged ≥45 years with both HMs and HF listed on death certificates. Age-adjusted mortality rates (AAMRs) were calculated per 100,000 population. Joinpoint regression was used to identify changes in temporal trends, with analyses stratified by demographics, HM subtype, and geography. Autoregressive integrated moving average (ARIMA) modeling was applied to project mortality trends through 2033. Results: Among 119,147 deaths, the overall AAMR was 3.96 per 100,000 (95% CI, 3.85-4.07). Joinpoint analysis identified four phases: a significant decline from 1999 to 2013 (annual percent change [APC] -1.97%), a plateau from 2013 to 2018, a sharp increase from 2018 to 2021 (APC + 8.35%), and subsequent stabilization from 2021 to 2023. Mortality was 85% higher in males than females (5.47 vs. 2.95 per 100,000). Rates increased markedly with age, with adults aged ≥85 years showing the steepest rise after 2014 (APC + 5.75%). Non-Hispanic Black and non-Hispanic White populations had the highest absolute AAMRs. All HM subtypes demonstrated a similar decline-rebound pattern, with subtype-specific differences in the timing of inflection points. ARIMA projections suggested a gradual decline from 4.78 per 100,000 in 2024 to 3.77 per 100,000 by 2033. Conclusions: HM-HF mortality declined through 2013 but reversed in the late 2010s, with pronounced increases during 2018-2021 followed by recent stabilization. Persistent disparities by sex, age, race/ethnicity, and geography highlight the need for targeted interventions and strengthened cardio-oncology capacity for this high-risk population.