Background
Left ventricular noncompaction cardiomyopathy (
LVNC
) is a genetically and phenotypically heterogeneous disease. This study aims to investigate the genetic basis and genotype‐phenotype correlations in a cohort of Chinese patients with
LVNC
.
Methods and Results
A total of 72 cardiomyopathy‐associated genes were comprehensively screened in 83 adults and 17 children with
LVNC
by targeted sequencing. Pathogenicity of the detected variants was determined according to their prevalence and American College of Medical Genetics and Genomics recommendations. Baseline and follow‐up clinical data were collected. The primary end point was a composite of death and heart transplantation. Overall, 42 pathogenic variants were identified in 38 patients (38%), with
TTN
,
MYH
7
,
MYBPC
3
, and
DSP
being the most commonly involved genes. At baseline, genotype‐positive adults had higher rates of atrial fibrillation and family history, and lower left ventricular ejection fraction, compared with genotype‐negative adults. During a median follow‐up of 4.2 years, more primary end points occurred in genotype‐positive adults than in genotype‐negative adults (50.0% versus 23.5%;
P
=0.013). Multivariable analysis demonstrated that genotype‐positive status was associated with higher risks of death and heart transplantation, independent of age, sex, and cardiac function at baseline in patients with
LVNC
(adjusted hazards ratio, 2.49; 95% confidence interval, 1.15–5.37;
P
=0.020).
Conclusions
Our study revealed a distinct genetic spectrum in Chinese patients with
LVNC
, with variants in
TTN
,
MYH
7
,
MYBPC
3
, and
DSP
being the most common. The presence of pathogenic variants is an independent risk factor for adverse outcomes and may aid in risk stratification in adult patients. Larger studies are needed to confirm these findings.
Background
Intra‐ventricular blood flow dynamics is considered as an important component of left ventricular (LV) function assessment. The purpose of this study was to evaluate the LV diastolic function in chronic kidney disease (CKD) with different degrees of LV diastolic dysfunction (LVDD) by using flow energetic parameters.
Methods
In this study, a total of 96 cases were recruited, including 58 CKD patients and 38 healthy controls. CKD patients were divided into 2 groups according to LVDD severity, named as DD1 and DD2. Vector flow‐mapping (VFM) analysis was executed to calculate left ventricle average energy loss (EL) during early filling phase (E‐EL_ave), atrial filling phase (A‐EL_ave), diastole phase (D‐EL_ave), and ejection phase (S‐EL_ave). Moreover, the average vortex circulation during early filling phase (E‐cir_ave) and atrial filling phase (A‐cir_ave) was also assessed in the apical three‐chamber view. The rate of average EL during early filling and atrial filling was expressed as E/A‐EL.
Result
Compared to the control group, A‐EL_ave, S‐EL_ave, and A‐cir_ave in the DD1 group were higher (P < 0.05), and all parameters were obviously higher in the DD2 group (P < 0.05). In the control group and the DD2 subgroup, the E‐EL_ave value was significantly higher than A‐EL_ave value, which was opposite to the DD1 group. As diastolic dysfunction worsened, E‐EL_ave and D‐EL_ave risen gradually (P < 0.05), and A‐EL_ave and S‐EL_ave were slightly elevated with no significance. There were significant correlations between LV diastolic function and flow energetic parameters. Stepwise multiple regression analysis revealed that various LV function parameters could be regarded as independent predictors of average diastolic EL (all P < 0.01).
Conclusions
For CKD patient with LVDD and LVEF > 50%, effective LV filling and systolic ejection with optimized energy consumption have been impaired. As a new flow‐derived index, EL can quantitatively evaluate LV diastolic function in terms of blood fluid dynamics in CKD with various LVDD.
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