Evaluation of the cardiac amyloidosis clinical pathway implementation: A real-world experience

AIMS: The aim of this study is to evaluate the implementation of the cardiac amyloidosis (CA) clinical pathway on awareness among referring cardiologists, diagnostic delay, and severity of CA at diagnosis. METHODS AND RESULTS: Patients with CA were retrospectively included in this study and divided into two periods: pre-implementation of the CA clinical pathway (2007–18; T1) and post-implementation (2019–20; T2). Patients’ and disease characteristics were extracted from electronic health records and compared. In total, 113 patients (mean age 67.8 ± 8.5 years, 26% female) were diagnosed with CA [T1 (2007–18): 56; T2 (2019–20): 57]. The number of CA diagnoses per year has increased over time. Reasons for referral changed over time, with increased awareness of right ventricular hypertrophy (9% in T1 vs. 36% in T2) and unexplained heart failure with preserved ejection fraction (22% in T1 vs. 38% in T2). Comparing T1 with T2, the diagnostic delay also improved (14 vs. 8 months, P < 0.01), New York Heart Association Class III (45% vs. 23%, P = 0.03), and advanced CA stage (MAYO/Gillmore Stage III/IV; 61% vs. 33%, P ≤ 0.01) at time of diagnosis decreased. CONCLUSION: After implementation of the CA clinical pathway, the awareness among referring cardiologists improved, diagnostic delay was decreased, and patients had less severe CA at diagnosis. Further studies are warranted to assess the prognostic impact of CA clinical pathway implementation

Increase of sural nerve T cells in progressive axonal polyneuropathy and monoclonal gammopathy

The authors investigated whether T cells have a role in the pathogenesis of axonal polyneuropathy and monoclonal gammopathy by comparing the presence of T cells in sural nerves of 23 patients with axonal polyneuropathy and monoclonal gammopathy (12 IgM, 11 IgG), of 15 patients with chronic idiopathic axonal polyneuropathy, and of 10 autopsy cases. Seven patients with an increased T-cell density had a progressive disease course, and four of these patients were treated with prednisone with a good response, suggesting that vasculitis plays a role in the pathogenesis

Mutations in RYR1 are a common cause of exertional myalgia and rhabdomyolysis

Mutations in the skeletal muscle ryanodine receptor (RYR1) gene are a common cause of neuromuscular disease, ranging from various congenital myopathies to the malignant hyperthermia (MH) susceptibility trait without associated weakness. We sequenced RYR1 in 39 unrelated families with rhabdomyolysis and/or exertional myalgia, frequent presentations in the neuromuscular clinic that often remain unexplained despite extensive investigations. We identified 9 heterozygous RYR1 mutations/variants in 14 families, 5 of them (p.Lys I 393Arg; p.Gly2434Arg; p.Thr4288_Ala4290dup; p.Ala4295Val; and p.Arg4737Gln) previously associated with M H. Index cases presented from 3 to 45 years with rhabdomyolysis, with or without exertional myalgia (