Alpha-protein kinase 3 (ALPK3) truncating variants are a cause of autosomal dominant hypertrophic cardiomyopathy.

AIMS: The aim of this study was to determine the frequency of heterozygous truncating ALPK3 variants (ALPK3tv) in patients with hypertrophic cardiomyopathy (HCM) and confirm their pathogenicity using burden testing in independent cohorts and family co-segregation studies. METHODS AND RESULTS: In a discovery cohort of 770 index patients with HCM, 12 (1.56%) were heterozygous for ALPK3tv [odds ratio(OR) 16.11, 95% confidence interval (CI) 7.94-30.02, P = 8.05e-11] compared to the Genome Aggregation Database (gnomAD) population. In a validation cohort of 2047 HCM probands, 32 (1.56%) carried heterozygous ALPK3tv (OR 16.17, 95% CI 10.31-24.87, P < 2.2e-16, compared to gnomAD). Combined logarithm of odds score in seven families with ALPK3tv was 2.99. In comparison with a cohort of genotyped patients with HCM (n = 1679) with and without pathogenic sarcomere gene variants (SP+ and SP-), ALPK3tv carriers had a higher prevalence of apical/concentric patterns of hypertrophy (60%, P < 0.001) and of a short PR interval (10%, P = 0.009). Age at diagnosis and maximum left ventricular wall thickness were similar to SP- and left ventricular systolic impairment (6%) and non-sustained ventricular tachycardia (31%) at baseline similar to SP+. After 5.3 ± 5.7 years, 4 (9%) patients with ALPK3tv died of heart failure or had cardiac transplantation (log-rank P = 0.012 vs. SP- and P = 0.425 vs. SP+). Imaging and histopathology showed extensive myocardial fibrosis and myocyte vacuolation. CONCLUSIONS: Heterozygous ALPK3tv are pathogenic and segregate with a characteristic HCM phenotype.

Role of TBX20 Truncating Variants in Dilated Cardiomyopathy and Left Ventricular Noncompaction.

BACKGROUND: Less than 40% of patients with dilated cardiomyopathy (DCM) have a pathogenic/likely pathogenic genetic variant identified. TBX20 has been linked to congenital heart defects; although an association with left ventricular noncompaction (LVNC) and DCM has been proposed, it is still considered a gene with limited evidence for these phenotypes. This study sought to investigate the association between the TBX20 truncating variant (TBX20tv) and DCM/LVNC. METHODS: TBX20 was sequenced by next-generation sequencing in 7463 unrelated probands with a diagnosis of DCM or LVNC, 22 773 probands of an internal comparison group (hypertrophic cardiomyopathy, channelopathies, or aortic diseases), and 124 098 external controls (individuals from the gnomAD database). Enrichment of TBX20tv in DCM/LVNC was calculated, cosegregation was determined in selected families, and clinical characteristics and outcomes were analyzed in carriers. RESULTS: TBX20tv was enriched in DCM/LVNC (24/7463; 0.32%) compared with internal (1/22 773; 0.004%) and external comparison groups (4/124 098; 0.003%), with odds ratios of 73.23 (95% CI, 9.90-541.45; P<0.0001) and 99.76 (95% CI, 34.60-287.62; P<0.0001), respectively. TBX20tv was cosegregated with DCM/LVNC phenotype in 21 families for a combined logarythm of the odds score of 4.53 (strong linkage). Among 57 individuals with TBX20tv (49.1% men; mean age, 35.9±20.8 years), 41 (71.9%) exhibited DCM/LVNC, of whom 14 (34.1%) had also congenital heart defects. After a median follow-up of 6.9 (95% CI, 25-75:3.6-14.5) years, 9.7% of patients with DCM/LVNC had end-stage heart failure events and 4.8% experienced malignant ventricular arrhythmias. CONCLUSIONS: TBX20tv is associated with DCM/LVNC; congenital heart defect is also present in around one-third of cases. TBX20tv-associated DCM/LVNC is characterized by a nonaggressive phenotype, with a low incidence of major cardiovascular events. TBX20 should be considered a definitive gene for DCM and LVNC and routinely included in genetic testing panels for these phenotypes.

Impact of SARS-Cov-2 infection in patients with hypertrophic cardiomyopathy: results of an international multicentre registry.

AIMS: To describe the natural history of SARS-CoV-2 infection in patients with hypertrophic cardiomyopathy (HCM) compared with a control group and to identify predictors of adverse events. METHODS AND RESULTS: Three hundred and five patients [age 56.6 ± 16.9 years old, 191 (62.6%) male patients] with HCM and SARS-Cov-2 infection were enrolled. The control group consisted of 91 131 infected individuals. Endpoints were (i) SARS-CoV-2 related mortality and (ii) severe clinical course [death or intensive care unit (ICU) admission]. New onset of atrial fibrillation, ventricular arrhythmias, shock, stroke, and cardiac arrest were also recorded. Sixty-nine (22.9%) HCM patients were hospitalized for non-ICU level care, and 21 (7.0%) required ICU care. Seventeen (5.6%) died: eight (2.6%) of respiratory failure, four (1.3%) of heart failure, two (0.7%) suddenly, and three (1.0%) due to other SARS-CoV-2-related complications. Covariates associated with mortality in the multivariable were age {odds ratio (OR) per 10 year increase 2.25 [95% confidence interval (CI): 1.12-4.51], P = 0.0229}, baseline New York Heart Association class [OR per one-unit increase 4.01 (95%CI: 1.75-9.20), P = 0.0011], presence of left ventricular outflow tract obstruction [OR 5.59 (95%CI: 1.16-26.92), P = 0.0317], and left ventricular systolic impairment [OR 7.72 (95%CI: 1.20-49.79), P = 0.0316]. Controlling for age and sex and comparing HCM patients with a community-based SARS-CoV-2 cohort, the presence of HCM was associated with a borderline significant increased risk of mortality OR 1.70 (95%CI: 0.98-2.91, P = 0.0600). CONCLUSIONS: Over one-fourth of HCM patients infected with SARS-Cov-2 required hospitalization, including 6% in an ICU setting. Age and cardiac features related to HCM, including baseline functional class, left ventricular outflow tract obstruction, and systolic impairment, conveyed increased risk of mortality.

Screening of Fabry Disease in Patients with Chest Pain Without Obstructive Coronary Artery Disease.

Identification of Anderson-Fabry disease (AFD) in cardiac patients has been restricted so far to patients with left ventricular hypertrophy. Coronary microvascular dysfunction has been described in AFD with and without cardiac hypertrophy and may represent the only manifestation in AFD patients, offering a possible earlier diagnosis. We studied the prevalence of AFD in 663 patients with chest pain with normal or non-obstructive coronary arteries. The overall prevalence of AFD in this cohort was only 0.15% (1/663). AFD is not a frequent cause of chest pain without obstructive coronary artery disease and screening efforts should not be conducted in this patient population.

Clinical Findings and Prognosis of Danon Disease. An Analysis of the Spanish Multicenter Danon Registry.

INTRODUCTION AND OBJECTIVES: Danon disease (DD) is caused by mutations in the LAMP2 gene. It is considered a multisystemic disease characterized by hypertrophic cardiomyopathy with pre-excitation and extreme hypertrophy, intellectual disability, myopathy, childhood presentation, and worse prognosis in men. There are scarce data on the clinical characteristics and prognosis of DD. METHODS: We analyzed the clinical records of patients with DD from 10 Spanish hospitals. RESULTS: Twenty-seven patients were included (mean age, 31 ± 19 years; 78% women). Male patients showed a high prevalence of extracardiac manifestations: myopathy (80%), learning disorders (83%), and visual alterations (60%), which were uncommon findings in women (5%, 0%, and 27%, respectively). Although hypertrophic cardiomyopathy was the most common form of heart disease (61%), the mean maximum wall thickness was 15 ± 7 mm and dilated cardiomyopathy was present in 12 patients (10 women). Pre-excitation was found in only 11 patients (49%). Age at presentation was older than 20 years in 16 patients (65%). After a median follow-up of 4 years (interquartile range, 2-9), 4 men (67%) and 9 women (43%) died or required a transplant. Cardiac disease and adverse events occurred later in women (37 ± 9 vs 23 ± 16 and 36 ± 20 vs 20 ± 11 years, respectively). CONCLUSIONS: The clinical characteristics of DD differ substantially from traditional descriptions: age at presentation of DD is older, the disease is not multisystemic in women, and pre-excitation is infrequent.

Unusual cause of central aortic prosthetic regurgitation during transcatheter replacement.

Transcatheter aortic valve replacement (TAVR) is an increasingly common procedure for the treatment of aortic stenosis in elderly patients with comorbidities that prevent the use of standard surgery. It has been shown that implantation without aortic regurgitation is related to lower mortality. Mild paravalvular regurgitation is inevitable in some cases due to calcification of the aortic annulus and its usually somewhat elliptical shape. Central regurgitation is less common, but has been associated with valve overdilatation in cases in which reduction of paravalvular regurgitation was attempted after the initial inflation. However, there are no reported cases of central prosthetic aortic regurgitation due to acute LV dysfunction. We report a case in which central aortic regurgitation occurred due to transient ventricular dysfunction secondary to occlusion of the right coronary artery by an embolus. The regurgitation disappeared after thrombus aspiration and normal ventricular function was immediately recovered.

Comparison of imaging techniques to assess appendage anatomy and measurements for left atrial appendage closure device selection.

BACKGROUND: The adequate device size selection for left atrial appendage closure is crucial to ensuring adequate implantation and for avoiding the need for multiple attempts that increase the risk of complications. Our aim was to evaluate the information obtained using different imaging techniques to select the size of the closure device in a clinical environment. METHODS: Thirty-seven patients who consecutively underwent implantation of Amplatzer cardiac plug (ACP) devices were studied. All patients were examined using computed tomography (CT) prior to intervention. Measurements were compared to those obtained using intraoperative transesophageal echocardiography (IOTEE) and angiography. Size was determined by the longest axis of the appendage ostium. The influence of all techniques on the correct selection of final size was assessed. RESULTS: The measurements taken using the three techniques agreed in only 21.6% of the cases, leading to accurate selection of device size. Two techniques coincided as follows: IOTEE-CT in 45.9%, angiography-CT in 35.13%, and angiography-IOTEE in 24.3%. Measurements using CT were definitive for ACP selection in 75.7% of cases, angiography in 48.6%, and echocardiography in 51.4%. Device size was undermeasured with angiography in 35.1% of cases, and with IOTEE in 24.3%; CT overmeasured 21.6% of cases. The combination of angiography-CT was the most accurate for selection of device size. CONCLUSION: CT most often predicts the appropriate device size. If it fails, it usually overestimates the size. Agreement of measurements with all three techniques is the most accurate situation; when two agree, the most accurate combination is angiography and CT.