Project description:This study will report the incidence of atrial fibrillation after elective colorectal cancer resection in the over 65 age group. This will be used to validate a risk model for the development of post-operative atrial fibrillation.
Eligible patients will undergo electrocardiogram based screening for atrial fibrillation, as well as brain natriuretic peptide tests prior to surgery. They will undergo 24 hour holter monitor prior to surgery, and at 30 and 90 days following surgery.
The primary outcome will be occurrence of atrial fibrillation within 90 days of surgery. Secondary outcomes include quality of life change, use of hospital services for atrial fibrillation, and complications of atrial fibrillation. This will be used to validate the pre-existing model for prediction of atrial fibrillation.
Project description:Atrial fibrillation (AF) is the most common heart arrhythmia disease. The greatest risk of atrial fibrillation is stroke, and stroke caused by valvular heart disease with atrial fibrillation (AF-VHD) is more serious. the development mechanism from VHD to AF-VHD is not yet clear. The research on expression profiles of lncRNA and mRNA is helpful to explore molecular mechanism in patients with valvular heart disease who develop atrial fibrillation.
Project description:In atrial fibrillation, disturbed electrical conduction disrupts the coordinated contraction of the heart’s antechambers, increasing the risk of stroke and heart failure. The rising prevalence of this disease approaches 9% in patients >65 years. Studying freshly isolated human atrial tissue and a new mouse model, we here decipher how immune and stromal cells contribute to the structural tissue remodeling that underlies atrial fibrillation. Single-cell transcriptomes from control and diseased human atria documented macrophage doubling at the expense of endothelial and mural cells. An inflammatory monocyte and a pro-fibrotic SPP1+ macrophage cluster expanded in patients with atrial fibrillation. To experimentally perturb pathways observed in patients, we matched their risk factors Hypertension, Obesity and Mitral valvE Regurgitation (HOMER) in mice. Atrial single-cell transcriptomes obtained in HOMER mice, which developed enlarged, fibrillation-prone atria, recapitulated human cell composition and transcriptome variations. Recruitment drove the expansion of atrial macrophages; accordingly, inhibition of monocyte migration reduced arrhythmia in Ccr2-/- HOMER mice. Deleting Spp1 established macrophage-derived osteopontin as a pleiotropic signal that promotes atrial fibrillation through pro-fibrotic, inflammatory crosstalk with an arsenal of local immune and stromal cells. Taken together, we identify SPP1+ macrophages as targets for immunomodulatory therapy in atrial fibrillation.
