Incidental cardiac uptake of 99mTc-diphosphonates is predictive of poor outcome: data from 9616 bone scintigraphies.

BACKGROUND: Bone scintigraphy (BS) is highly diagnostic for amyloid transthyretin (ATTR) cardiomyopathy. Prevalence and prognostic value of BS cardiac uptake is not well established. Our aim was to assess the prevalence of subclinical cardiac ATTR amyloidosis in patients undergoing [99mTc]MDP/DPD scintigraphy and to define their phenotype and prognosis. METHODS AND RESULTS: BS scans performed for any clinical indications from 2009 to 2020 were reviewed. Patients were stratified according to Perugini visual score of cardiac uptake. Follow-up data were collected. Among 9616 BS scans, 0.7% (n = 67) showed cardiac uptake. In 47 (70%) patients, Perugini score was 1 and in 20 (30%) patients uptake was ≥ 2, suggesting cardiac ATTR amyloidosis. Forty subjects (61%) died during the follow-up (mean 47 ± 30 months). Compared with patients with Perugini score 1, those Perugini score ≥ 2 showed increased death rate (P = .018). Two (2/67) subjects were investigated for TTR gene mutations resulting negative. CONCLUSIONS: In patients undergoing BS for different clinical indications, cardiac uptake suggesting cardiac ATTR amyloidosis is a rare, but still neglected finding, thus preventing possible diagnosis of ATTR cardiomyopathy. Importantly, cardiac uptake negatively affects the survival. Physicians should be aware of this rare, but crucial finding for timely diagnosis and treatment.

Arrhythmogenic right ventricular cardiomyopathy. Contribution of cardiac magnetic resonance imaging to the diagnosis.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited disease of the heart muscle, mostly due to genetically defective desmosomal proteins. The disease is characterized by fibrofatty replacement leading to ventricular arrhythmias and sudden death in young people and athletes. There is no single clinical gold standard examination for making a definitive diagnosis. The diagnosis is based on multiple parameters, including: (1) global or regional dysfunction and structural alteration of the right ventricle demonstrated on imaging; (2) tissue characterization by endomyocardial biopsy; (3) repolarization and (4) depolarization electrocardiographic abnormalities; (5) arrhythmias; and (6) family history. The so-called phenocopies must be included in the differential diagnosis, always taking into account that there is no single criterion sufficiently specific for a reliable diagnosis of ARVC. Contrast-enhanced cardiac magnetic resonance imaging (CE-CMR) is not yet included in the revised diagnostic criteria, although this is the only imaging modality able to depict fibrosis as late gadolinium enhancement (LGE) deposition. This review analyzes the role of CMR imaging in the diagnostic work-up of ARVC. The lack of specific diagnostic criteria contributes to the under-recognition of the nonclassic variants of ARVC, i.e., dominant or isolated left ventricular disease.

Arrhythmogenic right ventricular cardiomyopathy. What is needed for a cure?

There have been major advances in recent years in the clinical setting of arrhythmogenic right ventricular cardiomyopathy, including new diagnostic criteria, a changing spectrum of the disease with even left dominant forms, the role of cardiac magnetic resonance and electroanatomic mapping, the expanding use of genetic screening and the existence of overlapping phenotypes. Moreover, early diagnosis at pre-participation screening with sports disqualification and risk stratification for the indication of ICD have been shown to be life-saving. In addition to traditional therapies targeting arrhythmias and congestive heart failure, an effective treatment of the disease could be based on the discovery of the molecular mechanisms involved in the pathobiology of the disease in order to block the onset and progression of cell death.