Association Between Clonal Hematopoiesis and Left Ventricular Reverse Remodeling in Nonischemic Dilated Cardiomyopathy

Abstract

Although clonal hematopoiesis of indeterminate potential (CHIP) is an adverse prognostic factor for atherosclerotic disease, its impact on nonischemic dilated cardiomyopathy (DCM) is elusive. The authors performed whole-exome sequencing and deep target sequencing among 198 patients with DCM and detected germline mutations in cardiomyopathy-related genes and somatic mutations in CHIP driver genes. Twenty-five CHIP driver mutations were detected in 22 patients with DCM. Ninety-two patients had cardiomyopathy-related pathogenic mutations. Multivariable analysis revealed that CHIP was an independent risk factor of left ventricular reverse remodeling, irrespective of known prognostic factors. CHIP exacerbated cardiac systolic dysfunction and fibrosis in a DCM murine model. The identification of germline and somatic mutations in patients with DCM predicts clinical prognosis.

Keywords: clonal hematopoiesis of indeterminate potential; dilated cardiomyopathy; genetics; heart failure; left ventricular reverse remodeling.

Graphical abstract

Figure 1

Summary of Genetic Analysis for Germline and Somatic Mutations (A) TTN was the most commonly mutated cardiomyopathy-related gene. (B) Twenty-five clonal hematopoiesis of indeterminate potential (CHIP) driver mutations were identified in 22 patients (11%). (C) The prevalence of CHIP increases with age. (D) DNMT3A was the most frequent mutated CHIP driver gene.

Figure 2

Prevalence of LVRR (A) Left ventricular reverse remodeling (LVRR) was present in 88 (44%) of the entire cohort and was more frequent in noncarriers than in clonal hematopoiesis of indeterminate potential (CHIP) carriers (47.2% vs 22.7%; P = 0.023). (B) Patients with pathogenic germline mutation had a lower occurrence rate of LVRR than patients without germline mutations (33.7% vs 53.8%; P = 0.005). (C,D) Absolute changes in left ventricular ejection fraction (LVEF) for 175 patients, excluding the 23 individuals (including 3 CHIP carriers) who underwent left ventricular assist device implantation within 1 year. Patients with improvement of LVEF are depicted in red, and others are shown in blue. Although no differences in left ventricular systolic function were observed for 1 year in the CHIP carrier group (24.9% ± 8.1% vs 32.3% ± 14.9%; P = 0.069), the CHIP noncarrier group exhibited a significant improvement in LVEF (24.7% ± 7.9% vs 36.1% ± 14.9%; P < 0.001). The mean absolute change in LVEF between the 2 groups, assessed using the Wilcoxon signed rank test, was comparable (7.37% vs 11.37%; P = 0.27).

Figure 3

CHIP Exacerbates Cardiac Dysfunction of Mild DCM Mice With Ttn Truncating Variant (A) Experimental design for testing the effect of CHIP on the dilated cardiomyopathy (DCM) murine model. (B) The chimerism of transplanted CD45.1 cells was analyzed using flow cytometry at 5 weeks after bone marrow transplantation (BMT) (n = 7 for Ttn^F28051Ifs∗^15/WT with BMT of wild-type [WT] donor [Ttn^Mt-WT]; n = 11 for Ttn^F28051Ifs∗^15/WT with BMT of Asxl1^G643Wfs∗^12/WT donor [Ttn^Mt-Asxl1^Mt]) Data are shown as mean and SD. (C) Flow cytometry analysis of peripheral blood from Ttn^Mt-WT (n = 7) and Ttn^Mt-Asxl1^Mt (n = 9) shows that there were no detectable changes in myeloid populations. (D) Echocardiographic assessment of the heart in each group at 5 and 8 weeks after BMT (n = 10 and n = 8 for WT; n = 10 and n = 8 for Ttn^F28051Ifs∗^15/WT [Ttn^Mt]; n = 9 and n = 6 for Ttn^Mt-WT; n = 12 and n = 8 for Ttn^Mt-Asxl1^Mt). Data are shown as mean and SD. (E,F) Histochemical detection of collagen fibers by Sirius red/fast green dye staining in each group at 5 weeks after BMT. Results of quantitative analysis of fibrosis area are also shown (n = 12 for each group). Data are shown as mean and SD. (G) Flow cytometry analysis of cardiac immune cells from Ttn^Mt-WT (n = 3) and Ttn^Mt-Asxl1^Mt (n = 3) showed increased chimerism of donor-derived (CD45.1⁺) macrophages in Ttn^Mt-Asxl1^Mt, especially in the subset of proinflammatory Ccr2⁺, MHCII⁺ macrophages. (H) Messenger RNA (mRNA) expression levels of various proinflammatory cytokines and chemokines in the sorted donor-derived (CD45.1⁺) cardiac macrophages in Ttn^Mt-WT and Ttn^Mt-Asxl1^Mt at 8 weeks after BMT. (I) mRNA expression levels of various proinflammatory cytokines and chemokines in the bone marrow–derived macrophages generated from WT or Asxl1^Mt mice after stimulation by lipopolysaccharide. Statistical significance was evaluated using multiple unpaired Student’s t-tests with Holm-Šidák post hoc test (B,C,G), 2-way analysis of variance (ANOVA) with the Bonferroni post hoc test (D), 1-way ANOVA with the Tukey post hoc test (E,F), or unpaired Student’s t-tests (H,I). ∗P < 0.05, ∗∗P < 0.01, and ∗∗∗P < 0.001. Source data are provided as a Source Data file. B = B cells; Ly6C^hi = Ly6C-high monocytes; Ly6C^lo = Ly6C low monocytes; neut = neutrophils; T = T cells.