Epicardial Adipose Tissue and Postoperative Atrial Fibrillation

Background

Atrial fibrillation (AF) often occurs after cardiac surgery and is associated with increased risk of stroke and mortality. Prior studies support the important role of inflammation in the pathogenesis of postoperative atrial fibrillation (POAF). It is known that an increased volume and a pro-inflammatory phenotype of epicardial adipose tissue (EAT) are both associated with AF onset in non surgical context. In the present study, we aim to evaluate whether also POAF occurrence may be triggered by an increased production of inflammatory mediators from EAT.

Methods

The study population was composed of 105 patients, with no history of paroxysmal or permanent AF, undergoing elective cardiac surgery. After clinical evaluation, all patients performed an echocardiographic study including the measurement of EAT thickness. Serum samples and EAT biopsies were collected before surgery. Levels of 10 inflammatory cytokines were measured in serum and EAT conditioned media. After surgery, cardiac rhythm was monitored for 7 days.

Results

Forty-four patients (41.3%) developed POAF. As regard to cardiovascular therapy, only statin use was significantly lower in POAF patients (65.1% vs. 84.7%; p-0.032). Levels of Monocyte Chemoattractant Protein-1 (MCP-1), in both serum and EAT, were significantly higher in POAF patients (130.1 pg/ml vs. 68.7 pg/ml; p = <0.001; 322.4 pg/ml vs. 153.4 pg/ml; p = 0.028 respectively). EAT levels of IL-6 were significantly increased in POAF patients compared to those in sinus rhythm (SR) (126.3 pg/ml vs. 23 pg/ml; p = <0.005).

Conclusion

Higher EAT levels of IL-6 and MCP-1 are significantly associated with the occurrence of POAF. Statin therapy seems to play a role in preventing POAF. These results might pave the way for a targeted use of these drugs in the perioperative period.

Anabolic hormones and heart failure with preserved ejection fraction: looking for Ariadne's thread

Heart failure with preserved ejection fraction (HFpEF) is a complex clinical syndrome that accounts for more than half of all heart failure patients. Identification, early diagnosis and management of patients are still complex, and no targeted treatment is available, since all tested drugs were not able to lower hard clinical outcomes. A multi-hormonal deficiency syndrome has been described in HFpEF patients suggesting that different hormones may represent new biomarkers of the disease, but their clinical utility is still debated. The natriuretic peptides are the cornerstone biomarker in heart failure, predicting cardiovascular death and heart failure hospitalization. Testosterone and DHEA-S deficiencies have been reported in HFpEF and associated with right ventricular impairment and diastolic dysfunction. IGFBP-1/IGF-1 axis correlates with echocardiographic parameters of HFpEF patients and with several prognostic biomarkers including NT-proBNP and C reactive protein. Low triiodothyronine syndrome is frequently found in HFpEF and thyroid hormones should represent a potential biomarker of risk stratification and prognosis.