A novel mutation in the TTN gene resulted in left ventricular noncompaction: a case report and literature review.

BACKGROUND: Left ventricular noncompaction (LVNC) is a specific type of cardiomyopathy characterized by coarse trabeculae and interspersed trabecular crypts within the ventricles. Clinical presentation varies widely and may be nonsignificant or may present with progressive heart failure, malignant arrhythmias, and multiorgan embolism. The mode of inheritance is highly heterogeneous but is most commonly autosomal dominant. The TTN gene encodes titin, which is not only an elastic component of muscle contraction but also mediates multiple signalling pathways in striated muscle cells. In recent years, mutations in the TTN gene have been found to be associated with LVNC, but the exact pathogenesis is still not fully clarified. CASE PRESENTATION: In this article, we report a case of an adult LVNC patient with a TTN gene variant, c.87857G > A (p. Trp29286*), that has not been reported previously. This 43-year-old adult male was hospitalized repeatedly for heart failure. Echocardiography showed reduced myocardial contractility, dilated left ventricle with many prominent trabeculae, and a loose texture of the left ventricular layer of myocardium with crypt-like changes. During the out-of-hospital follow-up, the patient had no significant signs or symptoms of discomfort. CONCLUSION: This case report enriches the mutational spectrum of the TTN gene in LVNC and provides a basis for genetic counselling and treatment of this patient. Clinicians should improve their understanding of LVNC, focusing on exploring its pathogenesis and genetic characteristics to provide new directions for future diagnosis and treatment.

Clinical characteristics, predictors, and outcomes of heart failure with improved ejection fraction.

AIMS: Improvement in ejection fraction (EF) was observed in a subset of patients with heart failure (HF) and reduced ejection fraction (HFrEF). We analyzed and compared these patients with other HF phenotypes. METHODS: Based on left ventricular ejection fraction(LVEF) at baseline and follow-up, the 561 HF patients were divided into 4 groups: HF preserved EF (HFpEF, LVEF ≥ 50% on both occasions, n = 258), HF mid-range EF (HFmrEF, fluctuating between LVEF 40 and 49% on both occasions, n = 61), HFrEF (LVEF < 40% on both occasions, n = 141), and HF improved EF (HFimpEF, defined as LVEF < 40% at baseline and LVEF ≥ 40% at follow-up with ≥10% absolute improvement, n = 101). The composite of HF readmission and all-cause mortality was considered the primary endpoint, and the secondary endpoint was all-cause mortality. RESULTS: The characteristics of HFimpEF differed from other HF phenotypes. ß-blockers and aldosterone receptor antagonists were associated with improved LVEF. Kaplan-Meier curves showed the lowest incidence of the composite endpoint (p < 0.001) and all-cause mortality (p < 0.001) in HFimpEF. The risk of cardiovascular death was lowest in HFimpEF after controlling for competing events (p < 0.001), as were competing events (p < 0.001). Valvular heart disease (VHD) (HR 8.555, 95 CI% 2.126-34.420, p = 0.003) increased the risk of all-cause death, and anemia increased the risk of all-cause death (HR 5.533, 95 CI% 1.592-19.530, p = 0.007) and cardiovascular death in HFimpEF patients (HR 5.840, 95 CI% 1.088-31.356, p = 0.040). CONCLUSIONS: HFimpEF is an independent HF phenotype with a prognosis similar to HFmrEF and superior to HFpEF and HFrEF. When HFimpEF patients had VHD and anemia, the endpoint event rate was increased.