Background and objectives: Multivessel atherosclerosis and its genetic background are under-investigated, although atherosclerosis is seldom local and still causes high mortality. Alternative methods to assess coronary calcification (CAC) might incorporate genetic links between different arteries’ atherosclerotic involvement, however, co-occurrences of coronary calcification have not been investigated in twins yet. Materials and Methods: We assessed the heritability of radio morphologically distinct atherosclerotic plaque types in coronary (non-enhanced CT, Agatston score), carotid, and femoral arteries (B-mode ultrasound) in 190 twin subjects (60 monozygotic, 35 dizygotic pairs). Four-segment scores were derived in order to assess the dissemination of the distinct plaque types in the carotid and femoral arteries taking bilaterality into account. We calculated the genetic correlation between phenotypically correlating plaque types in these arteries. Results: CAC and dissemination of calcified plaques in the carotid and femoral arteries (4S_hyper) were moderately heritable (0.67 [95% CI: 0.37–1] and 0.69 [95% CI: 0.38–1], respectively) when adjusted for age and sex. Hypoechoic plaques in the carotid and femoral arteries showed no heritability, while mixed plaques showed intermediate heritability (0.50 [95% CI: 0–0.76]). Age and sex-adjusted phenotypic correlation between CAC and 4segm_hyper was 0.48 [95% CI: 0.30–0.63] and the underlying genetic correlation was 0.86 [95% CI: 0.42–1]. Conclusions: Calcification of atherosclerotic plaques is moderately heritable in all investigated arteries and significant overlapping genetic factors can be attributed to the phenotypical resemblance of coronary and carotid or femoral atherosclerotic calcification. Our findings support the idea of screening extracoronary arteries in asymptomatic individuals. We also propose a hypothesis about primarily carotid-coronary and femoral-coronary atherosclerosis as two distinct genetic predispositions to co-localization.
1 January 2013 in Arteriosclerosis, Thrombosis, and Vascular Biology
Objective—Altered venous biomechanics may contribute to the pathogenesis of venous diseases, and their heritability is less known. Methods and Results—Seventy-eight monozygotic twin pairs (aged 42.4±16.8 years) and 24 same-sex dizygotic twin pairs (aged 50.5±16.1 years) were examined. Anteroposterior and mediolateral diameters of the common femoral vein were measured by ultrasonography. Measurements were made both in supine and in standing body positions, with or without controlled forced expiration (Valsalva test). High correlation of diameter, capacity, and distensibility values was found between twin pairs. The univariate heritability (A), shared (C), and unshared (E) environmental effects model has shown 39.3% genetic component of the variance of low pressure, 37.9% of high-pressure venous capacity, and 36.4% of maximal capacity changes, even after elimination of sex, age, and body weight effects. Bivariate Cholesky analysis revealed substantial covariance of inherited body weight and venous capacity components (57.0%–81.4%). Conclusion—Femoral vein capacity and elasticity depend ≈30% to 40% on genetic factors, and this value in the standing body position can reach 50%. A relatively high genetic covariance was found between weight and femoral vein capacity and elasticity. Our work might yield some new insights into the inheritance of venous diseases that are associated with altered venous biomechanics and help elucidate the involved genes.
1 June 2017 in European Journal of Internal Medicine
Transthoracic (TTE) and transesophageal echocardiography (TEE) is the standard imaging method for atrial septal defect (ASD) and patent foramen ovale (PFO) detection, for patient selection for transcatheter ASD/PFO closure, for intraoperative guidance and for long-term follow-up. The size, shape, location and the number of the atrial communications schould be determined. The accuracy of PFO detection can be improved by using agitated saline together with maneuvers to transiently increase the right atrial (RA) pressure. The appearance of microbubbles in the left atrium (LA) within 3 cardiac cycles after opacification of the RA is considered positive for the presence of an intracardiac shunt. Three dimensional TEE identifies further septal fenestrations and describes the dynamic morphology of ASD/PFO and atrial septal aneurysm. Follow-up evaluations with TTE is recommended at 1, 6, and 12 months after the procedure, with a subsequent evaluation every year. Previous studies showed an increased incidence of atrial arrhythmias early after device closure. Speckle tracking analysis may help to understand functional left atrial remodeling following percutaneous closure and its impact on atrial arrhythmias.
Valvular heart disease is a multifactorial disorder. Twin studies may help to better understand both genetic and environmental determinants contributing to the development of valve lesions. We describe the case of a 45-year-old female asymptomatic triplet with multiple valvular heart lesions, with a somewhat different pattern between the dizygotic twin pairs compared with the monozygotic twin pair. After thorough assessment of medical history and physical examination, the triplet underwent two- and three-dimensional transthoracic and transesophageal echocardiographic examinations to assess the pathomechanism and severity of their heart valve lesions. The monozygotic twin pair (second-born twin B and third-born twin C) showed the same pattern of valvular lesions: mild mitral, tricuspidal, and aortic regurgitation of the same pathomechanism (posterior mitral valve cleft and aortosclerosis). Interestingly, the examination of first-born twin (twin A), who was dizygotic to twins B and C, revealed mild protosystolic mitral and mild tricuspidal regurgitation, but neither aortic insufficiency nor mitral cleft or indentation could be detected. Beyond the genetic effect, we presume that the intrauterine twinning process might also play a role in the development of congenital valvular heart disease. In order to verify this, further investigation should be performed on larger twin populations. Nevertheless, when one twin is affected, the other asymptomatic twin should also be examined for valvular heart disease.