Magnetic Resonance Left Ventricle Mass-Index/Fibrosis: Long-Term Predictors for Ventricular Arrhythmia in Hypertrophic Cardiomyopathy-A Retrospective Registry.

Objective: We aimed to study the long-term association of LV mass index (LVMI) and myocardial fibrosis with ventricular arrhythmia (VA) in a population of patients with confirmed hypertrophic cardiomyopathy (HCM) using cardiac magnetic resonance imaging (CMR). Methods: We retrospectively analyzed the data in consecutive HCM patients confirmed on CMR referred to an HCM clinic between January 2008 and October 2018. Patients were followed up yearly following diagnosis. Baseline demographics, risk factors and clinical outcomes from cardiac monitoring and an implanted cardioverter defibrillator (ICD) were analyzed for association of LVMI and LV late gadolinium enhancement (LVLGE) with VA. Patients were then allocated to one of two groups according to the presence of VA (Group A) or absence of VA (Group B) during the follow-up period. The transthoracic echocardiogram (TTE) and CMR parameters were compared between the two groups. Results: A total of 247 patients with confirmed HCM (age 56.2 ± 16.6, male = 71%) were studied over the follow-up period of 7 ± 3.3 years (95% CI = 6.6-7.4 years). LVMI derived from CMR was higher in Group A (91.1 ± 28.1 g/m2 vs. 78.8 ± 28.3 g/m2, p = 0.003) when compared to Group B. LVLGE was higher in Group A (7.3 ± 6.3% vs. 4.7 ± 4.3%, p = 0.001) when compared to Group B. Multivariable Cox regression analysis showed LVMI (hazard ratio (HR) = 1.02, 95% CI = 1.001-1.03, p = 0.03) and LVLGE (HR = 1.04, 95% CI = 1.001-1.08, p = 0.04) to be independent predictors for VA. Receiver operative curves showed higher LVMI and LVLGE with a cut-off of 85 g/m2 and 6%, respectively, to be associated with VA. Conclusions: LVMI and LVLGE are strongly associated with VA over long-term follow-up. LVMI requires more thorough studies to consider it as a risk stratification tool in patients with HCM.

Invasive Assessment of Microvascular Resistance in Hypertrophic Cardiomyopathy With Echocardiographic Correlates.

INTRODUCTION: Hypertrophic cardiomyopathy (HCM) is often associated with ischaemia despite lack of focal epicardial coronary stenosis. Our aim was to assess invasive coronary microvascular circulation and correlate findings with echocardiography. METHODS: We prospectively enrolled patients with HCM and controls who were referred for diagnostic coronary angiography. A pressure-temperature sensor coronary guidewire was used with intracoronary injections of room-temperature saline to measure mean coronary transit time during rest and hyperaemia induced with intravenous adenosine. The index of microvascular resistance (IMR) was calculated. Left ventricular mass was calculated during echocardiographic studies. RESULTS: Patients with HCM (n=12) and controls (n=7), had similar demographics. Left ventricular ejection fraction was higher in HCM (76.7%±11.0% vs 55.0%±15.9%, p=0.003). IMR was non-significantly higher in HCM (21.7±10.2 vs 15.3±4.8, p=0.16). Only patients with HCM had abnormal IMR (>25). Coronary flow reserve was non-significantly higher in HCM (2.7±1.6 vs 2.1±1.2, p=0.34). IMR correlated with left ventricular mass in hypertrophic cardiomyopathy subjects (Pearson r=0.68, p=0.02). CONCLUSIONS: Microvascular dysfunction as assessed by IMR may be abnormal in HCM and is correlated with left ventricular mass.

Shared genetic pathways contribute to risk of hypertrophic and dilated cardiomyopathies with opposite directions of effect.

The heart muscle diseases hypertrophic (HCM) and dilated (DCM) cardiomyopathies are leading causes of sudden death and heart failure in young, otherwise healthy, individuals. We conducted genome-wide association studies and multi-trait analyses in HCM (1,733 cases), DCM (5,521 cases) and nine left ventricular (LV) traits (19,260 UK Biobank participants with structurally normal hearts). We identified 16 loci associated with HCM, 13 with DCM and 23 with LV traits. We show strong genetic correlations between LV traits and cardiomyopathies, with opposing effects in HCM and DCM. Two-sample Mendelian randomization supports a causal association linking increased LV contractility with HCM risk. A polygenic risk score explains a significant portion of phenotypic variability in carriers of HCM-causing rare variants. Our findings thus provide evidence that polygenic risk score may account for variability in Mendelian diseases. More broadly, we provide insights into how genetic pathways may lead to distinct disorders through opposing genetic effects.

A Case of Systolic Anterior Motion After Mitral Valve Repair Causing Hemolytic Anemia: Mechanism and Treatment.

Hemolytic anemia after mitral valve repair and ring annuloplasty is uncommon when compared with mitral valve replacement. In this report we present the case of a 67-year-old woman who had undergone mitral valve repair with a Duran band and developed hemolytic anemia. Most patients with severe hemolysis after mitral valve repair undergo reoperation. However, in the present case, the hemolysis was found to be secondary to systolic anterior motion of the mitral valve and left ventricular outflow tract obstruction and was treated without the need for reoperation.

Multimodal imaging of aortic annulus and root geometry after valve sparing root reconstruction.

BACKGROUND: Controversy exists regarding the optimal annular stabilization technique following valve sparing aortic root reconstruction (VSRR) with no comprehensive imaging data to evaluate the natural history of aortic root graft geometry, aortic valve competency and patient prognosis post-reconstruction. METHODS: Between 2008-2017, 70 consecutive patients (mean age 56.4±16.4 years, 19.7% females) underwent VSRR. All patients were prospectively evaluated annually with clinical follow-up, echocardiography and CT imaging. Patients were assessed for survival, freedom from reoperation, degree of regurgitation, New York Heart Association (NYHA) status and graft complications and followed up to nine years post-operatively (mean 36±21 months). RESULTS: The largest increase of the aortic annulus diameter observed during the surveillance period was 2.64%±5.4% which occurred between the second and third years of follow-up and the aortic sinuses, sinotubular junction and ascending aorta all remained relatively stable based on annual CT imaging. Echocardiographic data showed far more variability in measurements at each annual post-operative visit with far less precision compared to the CT measurements taken at the same time. Due to the large variability and greater standard deviations, no significant difference was detected between the more precise CT measurements and those from the echocardiogram images. The overall survival rate was 94.3% (66 patients) at one year. Freedom from reoperation was 98.6% (69 patients). Throughout the entire duration of follow-up, aortic insufficiency was identified as 0 in 46 (65.7%), 1+ in 19 (27.1%), 2+ in 4 (5.7%), 3+ in 0 (0%) and 4+ in 1 (1.4%). Mean NYHA status was 1.1±0.3 at most recent follow-up for all patients. CT evidence showed 97.0% (64 patients) freedom from graft complication including: endocarditis, thrombosis, embolism, aneurysm, pseudoaneurysm, dehiscence, dissection and kinking. CONCLUSIONS: The annual imaging data presented here demonstrates stability of the Dacron aortic annuloplasty reconstruction over time, without the need for internal or external annular stabilization. CT imaging proved to be far more reliable than echocardiographic images, however given the stability, annual CT imaging is of little benefit. This is the first prospective study to compare echocardiographic, CT and clinical data following VSRR.

Mediastinal monophasic synovial sarcoma with pericardial extension causing hemodynamic instability.

A 46-year-old man presented with mass on chest x-ray along with a 6-month history of weight loss, dyspnea and cough. He was hypotensive and an echocardiogram showed large extra-cardiac mass compressing the right ventricular outflow tract resulting in features of cardiac tamponade. Chest computed tomography revealed a mediastinal mass invading the pericardium adjacent to right ventricular outflow tract. Biopsy of the mass confirmed primary monophasic synovial sarcoma. Chemotherapy and radiotherapy along with anti-inflammatories were given as surgery was too high risk due to the location of the tumour and pericardial involvement. Patient responded briefly to the treatment with improvement in hemodynamic parameters but over next weeks he became less responsive to treatment with increasing size. He died 2 months after treatment commenced.