Systemic Diseases and Heart Block

Descriptive study of the clinical and myocardial status of a population with anatomopathological aortic valve amyloidosis

BACKGROUND

Aortic stenosis (AS) and transthyretin (ATTR) cardiac amyloidosis (CA) share the same clinical profiles and cardiac phenotype. Amyloid deposits have been frequently reported in aortic valves of patients with severe AS referred for surgical aortic valve replacement (SAVR). The aim of this study was to determine the clinical and myocardial status of patients with aortic valve amyloidosis after aortic valve surgery.

METHODS AND RESULTS

We performed a retrospective descriptive study of 46 patients who underwent SAVR for severe AS with amyloid deposits upon histological analysis. All patients were screened for cardiac involvement. Amyloid deposits typing was successful in 35 (76%) patients and 28 (80%) were ATTR. Two (4%) had positive bone scintigraphy and among the 5 myocardial biopsies performed during surgery, 80% were positive for ATTR deposits.

CONCLUSION

ATTR is the predominant type in the presence of amyloid deposits on the aortic valve after surgery for severe AS but is only rarely accompanied by cardiac uptake on bone scintigraphy. Early stages of myocardial involvement are frequent and myocardial biopsy is more sensitive for detection of mild amyloid deposits than bone scintigraphy.

The Combination of Hyperuricemia and Elevated High-Sensitivity C-Reactive Protein Increased the Risk of Cardiac Conduction Block

Objective

This study aimed to explore the impact of a combination of hyperuricemia (HUA) and excessive high-sensitivity C-reactive protein (hs-CRP) levels on the likelihood of developing cardiac conduction block (CCB). Additionally, it sought to assess whether the influence of uric acid (UA) on CCB is mediated by hs-CRP.

Methods

A prospective study was executed utilizing data from the Kailuan cohort, including 81,896 individuals initially free from CCB. The participants were categorized into four groups depending on the existence of HUA and low-grade inflammation (hs-CRP>3 mg/L). Cox regression analysis was employed to ascertain hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk of incident CCB. A mediation analysis was performed to determine if hs-CRP functioned as a mediator in the connection between UA levels and the incidence of CCB.

Results

During a median observation period of 11.8 years, we identified 3160 cases of newly occurring CCB. Compared with the low UA/low CRP group, the combination of HUA and low-grade inflammation elevated the CCB risks (HR:1.56, 95% CI:1.22-1.99), atrioventricular block (AVB) (HR:1.88, 95% CI:1.27-2.77), and right bundle branch block (HR:1.47, 95% CI:1.02-2.12), respectively. Mediation analysis revealed that in the HUA group, compared with the non-HUA group, the risk of CCB elevated by 14.0%, with 10.3% of the increase mediated through hs-CRP.

Conclusion

HUA combined with elevated hs-CRP increased the risk of CCB, especially AVB. The connection between UA and the CCB risk was partly mediated by hs-CRP.

Lesions of the Cardiac Conduction System and Sudden Death

ABSTRACT

When a young previously healthy person dies suddenly, occasionally, the scene is noncontributory and the autopsy and drug screen are negative. In such cases, additional studies, including genetic assessment and cardiac conduction system examination, should be performed. We performed a literature search and reviewed our own material to identify possible or definite conduction system anomalies that may cause death. We identified intrinsic conduction system disease including cystic tumor of the atrioventricular node, atrioventricular node (cystic tumor of the AV node), and fibromuscular dysplasia of the atrioventricular node artery to be likely causes of death. Extrinsic causes, in which a generalized disease affects the conduction system, include tumors, autoimmune disease, infiltrative disorders, and others, are a second category of diseases that can affect the conduction system and cause atrioventricular block and sudden death.

Distinct uric acid trajectories are associated with incident cardiac conduction block

BACKGROUND

The association of longitudinal uric acid (UA) changes with cardiac conduction block risk is unclear. We aimed to identify the trajectories of UA and explore its association with cardiac conduction block.

METHODS

A total of 67,095 participants with a mean age of 53.12 years were included from the Kailuan cohort in Tangshan, China, who were free of cardiac conduction block and with repeated measurements of UA from 2006 to 2012. UA trajectories during 2006 to 2012 were identified by group-based trajectory modeling. Cox proportional hazard regression models were used to assess the association of UA trajectories with cardiac conduction block.

RESULTS

We categorized three observed discrete trajectories of UA during 2006-2012 period: low-stable, moderate-stable, and high-stable. Over a median follow-up of 6.19 years, we identified 1405 (2.09%) incident cardiac conduction block. Compared to those in the low-stable trajectory, the adjusted hazard ratios (HRs) (95% confidence interval [CI]) of cardiac conduction block in the moderate-stable and high-stable trajectory were 1.30 (1.16-1.47) and 1.86 (1.56-2.22), and HRs of atrioventricular block were 1.39 (1.12-1.72) and 2.90 (2.19-3.83), and HRs of bundle branch blocks were 1.27 (1.10-1.47) and 1.43 (1.13-1.79). Notably, although the average UA level in the moderate-stable UA trajectory group is within the normal range, the risk of cardiac conduction block has increased.

CONCLUSIONS

The moderate-stable and high-stable trajectories are associated with increased risk for new-onset cardiac conduction block. Monitoring UA trajectories may assist in identifying subpopulations at higher risk for cardiac conduction block.