Aims We sought to investigate the association of obesity and metabolic health status with the incidence of clinical hypertrophic cardiomyopathy (HCM) diagnosis in the general population. Our goal was to identify modifiable risk factors to attenuate clinical expression of HCM, enabling management evolution from a mostly passive strategy of risk stratification to a proactive strategy of modifying disease expression. Methods Using nationwide population-based data from the Korean National Health Insurance Service, 28,679,891 people who were free of prevalent HCM and who underwent health examinations between 2009 and 2015 were followed until 31 December 2016. The primary outcome was clinical HCM that was defined as incident diagnosis of HCM during the follow-up, after a blanking period of 12 months. Results Over a median follow-up of 5.2 years, 0.027% (n = 7851) of the study participants were diagnosed as incident HCM. The incidence rate per 1000 person-years was 0.059. A significant association was found between body mass index (BMI) and the incidence of clinical HCM after multivariate adjustment, with a hazard ratio per 1 kg/m2 increase in BMI of 1.063 (95% confidence interval 1.051–1.075). Metabolically unhealthy participants had a greater incidence of HCM than metabolically healthy participants, regardless of obesity status. The effect of BMI was more pronounced in several subgroups, including participants with no hypertension, those aged less than 65 years and men. Conclusion We found that individuals with obesity and/or metabolic abnormalities had a significantly higher incidence of clinical HCM diagnosis than their counterparts. Efforts to manage obesity and metabolic abnormalities may be important in modifying clinical expression of HCM.
Echocardiographic diagnosis of total or left congenital pericardial absence with positional change
Objectives Congenital absence of the pericardium (CAP) is often confused with other conditions presenting with right ventricular dilatation and usually warrants CT or cardiac MR (CMR) to confirm. It would be desirable to have more specific echocardiographic criteria to provide a conclusive diagnosis. Methods 11 patients who were diagnosed with CAP (four patients with total CAP) based on CT/CMR were consecutively enrolled. Thirteen patients with atrial septal defect (ASD) and 16 normal subjects served as controls. To investigate spatial changes of heart in the thoracic cavity in CAP, following echocardiographic measurements were made in the left and right decubitus positions: the angle between the ultrasound beam and the left ventricular posterior wall (Angle-PW) in end-diastole at the parasternal long axis, and the distance between the chest wall and the most distal part of the left ventricular posterior wall (Distance-PW) at the parasternal mid-ventricular short axis. Results Angle-PW in patients with CAP were significantly greater than in those with ASD (100.1±12.5° vs 74.5±8.6°, p<0.017) or in normal subjects (100.1±12.5° vs 69.9±7.6°, p<0.017) at the left decubitus, and the difference in Angle-PW according to posture (left vs right) was significantly greater in CAP compared with the other groups (CAP 20.7±12.7°, ASD 0.31±1.80°, normal 0.31±1.40°, all p<0.017). The differences in Distance-PW according to patient position (CAP 2.43±0.77°, ASD 0.42±0.45°, normal 0.26±0.55°) or cardiac cycle in each position (left: CAP 1.60±0.76°, ASD 0.41±0.27°, normal 0.17±0.12°; right: CAP 0.70±0.32°, ASD 0.22±0.19°, normal 0.22±0.13°) were significantly higher in the CAP group than in the other groups (all p<0.017). Conclusions Patients with CAP have dynamic alteration in cardiac position depending on posture, which is not observed in ASD or in normal controls. Hence, total or left-sided CAP can be reliably diagnosed with positional changes during routine echocardiography.