RESUMEN
BACKGROUND: Transfusion-dependent beta thalassemia (TDT) is a genetic disorder characterized by low haemoglobin levels, often leading to myocardial iron overload (MIO) and myocardial fibrosis (MF). Cardiac Magnetic Resonance (CMR) represents the gold standard for MIO and MF assessment, although its limited availability and high costs pose challenges. Left Ventricular Global Longitudinal Strain (LV GLS) measured by Speckle Tracking Echocardiography (STE) could offer a valuable alternative. METHODS: A monocentric diagnostic accuracy study was conducted to compare the performance of LV GLS with CMR using T2* for evaluating MIO and late gadolinium enhancement (LGE) for detecting MF. Between January 2022 and January 2023, 44 consecutive patients with TDT were enrolled. For each participant was performed LV GLS with STE, including CMR with T2* technique and LGE sequences. RESULTS: CMR identified MIO in 8 patients (18 %) and MF in 5 (11 %). LV GLS STE was normal in patients without MIO (-20.6 ± 3.1 %) or MF (-20.6 ± 2.8 %), significantly differing from those with MIO (-18.2 ± 2.1 %, p = 0.043) and MF (-16.4 ± 1.7 %, p = 0.002). ROC analysis indicated an optimal LV GLS STE cutoff of -19.8 % for MIO (AUC = 0.76, 95 % CI: 0.59-0.93, p = 0.054) with an overall diagnostic accuracy of 64 % and an optimal cutoff of -18.3 % for MF (AUC = 0.93, 95 % CI: 0.85-1.00, p = 0.009) with an accuracy of 86 %. CONCLUSIONS: The findings of this pilot study indicate that LV GLS with STE, may be a cost-effective screening tool for the early detection of MIO and MF in TDT patients.
RESUMEN
Arrhythmic risk stratification in patients with Lamin A/C gene (LMNA)-related cardiomyopathy influences clinical decisions. An implantable cardioverter defibrillator (ICD) should be considered in patients with an estimated 5-year risk of malignant ventricular arrhythmia (MVA) of ≥10%. The risk prediction score for MVA includes non-missense LMNA mutations, despite their role as an established risk factor for sudden cardiac death (SCD) has been questioned in several studies. The purpose of this study is to investigate cardiac features and find gene-phenotype correlations that would contribute to the evidence on the prognostic implications of non-missense vs. missense mutations in a cohort of LMNA mutant patients. An observational, prospective study was conducted in which 54 patients positive for a Lamin A/C mutation were enrolled, and 20 probands (37%) were included. The median age at first clinical manifestation was 41 (IQR 19) years. The median follow-up was 8 years (IQR 8). The type of LMNA gene mutation was distributed as follows: missense in 26 patients (48%), non-frameshift insertions in 16 (30%), frameshift deletions in 5 (9%), and nonsense in 7 (13%). Among the missense mutation carriers, two (8%) died and four (15%) were admitted onto the heart transplant list or underwent transplantation, with a major adverse cardiovascular event (MACE) rate of 35%. No statistically significant differences in MACE prevalence were identified according to the missense and non-missense mutation groups (p value = 0.847). Our data shift the spotlight on this considerable topic and could suggest that some missense mutations may deserve attention regarding SCD risk stratification in real-world clinical settings.