Arrhythmogenic right ventricular cardiomyopathy: severe structural alterations are associated with inflammation

Aim

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is a rare cardiomyopathy associated with sudden cardiac death. It is characterised by a progressive right ventricle (RV) fibrofatty replacement, although biventricular replacement (BV) is also common. Inflammation believed to be a key player in disease progression and outcome. Our study investigates the relationship between the presence of inflammatory infiltrates in myocardium and the severity of structural heart alterations in ARVC.

Methods

Our study included eight control and 36 ARVC postmortem human heart samples. We performed macroscopic assessment and microscopic analysis for different inflammatory cell types.

Results

Fibrofatty replacement of RV was present in all our cases. Thirteen cases showed sole RV involvement (36.11%). Of these, only one showed inflammatory infiltrates (7.69%). Sixteen cases showed severe ARVC phenotypic forms characterised by BV involvement and right auricular (RA) fatty accumulation plus RV dilation (44.44%); eight of them also showed inflammatory infiltrates (50%). Immunohistochemical studies revealed ventricular multifocal inflammatory infiltrates, showing seven T-lymphocytes as the main infiltrate cell types.

Conclusions

The presence of inflammatory infiltrates in ventricular myocardium of ARVC samples is associated with severe structural heart changes, indicating that an inflammatory process may be a modulator of severity in ARVC.