Imaging of programmed cell death in arrhythmogenic right ventricle cardiomyopathy/dysplasia

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a myocardial disease that predominantly affects the right ventricle (RV). Its hallmark feature is fibrofatty replacement of the RV myocardium. Apoptosis in ARVC/D has been proposed as an important process that mediates the slow, ongoing loss of heart muscle cells which is followed by ventricular dysfunction. We aimed to establish whether cardiac apoptosis can be assessed noninvasively in patients with ARVC/D. Six patients fulfilling the ARVC/D criteria were studied. Regional myocardial apoptosis was assessed with (99m)Tc-annexin V scintigraphy. Overall, the RV wall showed a higher (99m)Tc-annexin V signal than the left ventricular wall (p = 0.049) and the interventricular septum (p = 0.026). However, significantly increased uptake of (99m)Tc-annexin V in the RV was present in only three of the six ARVC/D patients (p = 0.001, compared to (99m)Tc-annexin V uptake in the RV wall of the other three patients). Our results are suggestive of a chamber-specific apoptotic process. Although the role of apoptosis in ARVC/D is unsolved, the ability to assess apoptosis noninvasively may aid in the diagnostic course. In addition, the ability to detect apoptosis in vivo with (99m)Tc-annexin V scintigraphy might allow individual monitoring of disease progression and response to diverse treatments aimed at counteracting ARVC/D progression.