Clonal Hematopoiesis Risk Score and All-Cause and Cardiovascular Mortality in Older Adults

Importance Clonal hematopoiesis (CH) with acquired pathogenic variants in myeloid leukemia driver genes is common in older adults but of unknown prognostic value.Objective To investigate the prevalence of CH and the utility of the CH risk score (CHRS) in estimating all-cause and disease-specific mortality in older adults with CH.Design, Setting, and Participants This population-based prospective cohort study involved community-dwelling older adults (aged 67-90 years) without hematologic malignant neoplasms (HMs) who were participants in the Atherosclerosis Risk in Communities Visit 5 at 4 US centers: Forsyth County, North Carolina; Jackson, Mississippi; Minneapolis, Minnesota; and Washington County, Maryland. Samples were collected from 2011 to 2013, sequencing was performed in 2022, and data analysis was completed in 2023.Exposure The exposure was a diagnosis of CH. CHRS scores (calculated using 8 demographic, complete blood cell count, and molecular factors) were used to categorize individuals with CH into low-risk (CHRS <= 9.5), intermediate-risk (CHRS >9.5 to <12.5), and high-risk (CHRS >= 12.5) groups.Main Outcomes and Measures The primary outcome was all-cause mortality, and secondary outcomes were HM mortality, cardiovascular disease mortality, and death from other causes.Results Among 3871 participants without a history of HM (mean [SD] age, 75.7 [5.2] years; 2264 [58.5%] female individuals; 895 [23.1%] Black individuals; 2976 White individuals [76.9%]), 938 (24.2%) had CH. According to the CHRS, 562 (59.9%) were low risk, 318 (33.9%) were intermediate risk, and 58 (6.2%) were high risk. During a median (IQR) follow-up of 7.13 (5.63-7.78) years, 570 participants without CH (19.4%) and 254 participants with CH (27.1%) died. Mortality by CHRS risk group was 128 deaths (22.8%) for low risk, 93 (29.2%) for intermediate risk, and 33 (56.9%) for high risk. By use of multivariable competing risk regression, subdistribution hazard ratios (sHRs) for all-cause mortality were 1.08 (95% CI, 0.89-1.31; P = .42) for low-risk CH, 1.12 (95% CI, 0.89-1.41; P = .31) for intermediate-risk CH, and 2.52 (95% CI, 1.72-3.70; P < .001) for high-risk CH compared with no CH. Among individuals in the high-risk CH group, the sHR of death from HM (6 deaths [10.3%]) was 25.58 (95% CI, 7.55-86.71; P < .001) and that of cardiovascular death (12 deaths [20.7%]) was 2.91 (95% CI, 1.55-5.47; P < .001).Conclusions and Relevance In this cohort study, the CHRS was associated with all-cause, HM-related, and cardiovascular disease mortality in older adults with CH and may be useful in shared decision-making to guide clinical management and identify appropriate candidates for clinical trials.