Associations between sinus tachycardia and adverse cardiovascular outcomes and mortality in cancer patients.

BACKGROUND: Sinus tachycardia in cancer reflects a significant multi-system organ stressor and disease, with sparse literature describing its clinical significance. We assessed cardiovascular (CV) and mortality prognostic implications of sinus tachycardia in cancer patients. METHODS: We conducted a case-control study of 622 cancer patients at a U.S. urban medical center from 2008 to 2016. Cases had ECG-confirmed sinus tachycardia [heart rate (HR) ≥100 bpm] in ≥3 different clinic visits within 1 year of cancer diagnosis excluding a history of pulmonary embolism, thyroid dysfunction, left ventricular ejection fraction <50%, atrial fibrillation/flutter, HR >180 bpm. Adverse CV outcomes (ACVO) were heart failure with preserved ejection fraction (HFpEF), HF with reduced EF (HFrEF), hospital admissions for HF exacerbation (AHFE), acute coronary syndrome (ACS). Regression analyses were conducted to examine the effect of sinus tachycardia on overall ACVO and survival. RESULTS: There were 51 cases, age and sex-matched with 571 controls (mean age 70±10, 60.5% women, 76.4% Caucasian). In multivariate analysis over a 10-year follow-up period, sinus tachycardia (HR ≥100 vs. <100 bpm) was an independent predictor of overall ACVO (OR 2.8, 95% CI: 1.4-5.5; P=0.006). There was increased incidence of HFrEF (OR 3.3, 95% CI: 1.6-6.5; P=0.004) and AHFE (OR 6.3, 95% CI: 1.6-28; P=0.023), but not HFpEF or ACS (P>0.05) compared with controls. Sinus tachycardia was a significant predictor of overall mortality after adjusting for significant covariates (HR 2.9, 95% CI 1.8-5; P<0.001). CONCLUSIONS: Independent of typical factors that affect cardiovascular disease, sinus tachycardia around the time of cancer treatment is associated with increased ACVO and mortality in cancer patients at 10 years of follow-up.

Deletion of Asxl1 results in myelodysplasia and severe developmental defects in vivo.

Somatic Addition of Sex Combs Like 1 (ASXL1) mutations occur in 10-30% of patients with myeloid malignancies, most commonly in myelodysplastic syndromes (MDSs), and are associated with adverse outcome. Germline ASXL1 mutations occur in patients with Bohring-Opitz syndrome. Here, we show that constitutive loss of Asxl1 results in developmental abnormalities, including anophthalmia, microcephaly, cleft palates, and mandibular malformations. In contrast, hematopoietic-specific deletion of Asxl1 results in progressive, multilineage cytopenias and dysplasia in the context of increased numbers of hematopoietic stem/progenitor cells, characteristic features of human MDS. Serial transplantation of Asxl1-null hematopoietic cells results in a lethal myeloid disorder at a shorter latency than primary Asxl1 knockout (KO) mice. Asxl1 deletion reduces hematopoietic stem cell self-renewal, which is restored by concomitant deletion of Tet2, a gene commonly co-mutated with ASXL1 in MDS patients. Moreover, compound Asxl1/Tet2 deletion results in an MDS phenotype with hastened death compared with single-gene KO mice. Asxl1 loss results in a global reduction of H3K27 trimethylation and dysregulated expression of known regulators of hematopoiesis. RNA-Seq/ChIP-Seq analyses of Asxl1 in hematopoietic cells identify a subset of differentially expressed genes as direct targets of Asxl1. These findings underscore the importance of Asxl1 in Polycomb group function, development, and hematopoiesis.

Recurrent somatic TET2 mutations in normal elderly individuals with clonal hematopoiesis.

Aging is characterized by clonal expansion of myeloid-biased hematopoietic stem cells and by increased risk of myeloid malignancies. Exome sequencing of three elderly females with clonal hematopoiesis, demonstrated by X-inactivation analysis, identified somatic TET2 mutations. Recurrence testing identified TET2 mutations in 10 out of 182 individuals with X-inactivation skewing. TET2 mutations were specific to individuals with clonal hematopoiesis without hematological malignancies and were associated with alterations in DNA methylation.