Basal Septal Thickness Research Articles

Sex-based differences in anatomical and hemodynamic parameters and outcomes in patients with hypertrophic cardiomyopathy undergoing alcohol septal ablation

Abstract Background This study aimed to assess sex differences in anatomical and hemodynamic parameters, and in procedure related outcomes, in patients with hypertrophic obstructive cardiomyopathy (HOCM) undergoing alcohol septal ablation (ASA). Methods 154 patients that underwent ASA in at our university hospital, between 2009 and 2021, were retrospectively included. Anatomical and hemodynamic parameters were collected from invasive catheterization before and during ASA, and from echocardiography (ECHO) examinations at maximum one week before ASA. Follow-up was conducted one year after ASA. The parameters analyzed were left ventricular (LV) volume, basal septal wall thickness (BSWT), anterior (AML) and posterior mitral leaflet (PML) length, minimal left ventricle outflow tract (LVOT) diameter, and LVOT pressure gradient at rest, prior to ASA, and prevalence of atrioventricular block after ASA. Linear and logistic regression models were used to assess the sex differences between the parameters. Results 50% of the patients were women. At the time of ASA, women were significantly older, had lower LV volume indexed for BSA in end-diastole (44 vs. 54 ml, p<0.001) and end-systole (18 vs. 23 ml, p=0.021), longer AML length indexed for BSA (13.7 vs. 11.6 mm, p<0.001) and PML length indexed for BSA (8.8 vs. 8.1 mm, p=0.018), smaller minimal LVOT diameter (4.6 vs. 4.9 mm, p=0.042), and higher LVOT pressure gradient at rest (49.3 vs. 32.5 mmHg, p=0.014), compared with men. The median follow-up was 364 days. Atrioventricular block (II or III) was more common among women (n=20, 26%) compared with men (n=10, 13%, p=0.045). Conclusions ECHO and invasive catheterization prior to ASA showed that women with HOCM presented with less favorable anatomical and hemodynamic pre-conditions, compared with men. At follow-up, women had a greater incidence of atrioventricular block after ASA. This strongly emphasizes the need for a sex-specific approach to optimize care and improve outcomes in patients with HOCM.

Alcohol septal ablation for hypertrophic obstructive cardiomyopathy: do mitral valve leaflet length, septal thickness, or sex affect the outcome?

This retrospective cohort study aimed to assess whether basal septal wall thickness (BSWT), anterior (AML) and posterior (PML) mitral leaflet length, or sex were associated with remaining left ventricular outflow tract obstruction (LVOTO) in patients with hypertrophic obstructive cardiomyopathy (HOCM) undergoing alcohol septal ablation (ASA). One hundred fifty-four patients who underwent ASA at the Karolinska University Hospital in Stockholm, Sweden, between 2009 and 2021, were included retrospectively. Anatomical and hemodynamic parameters were collected from invasive catheterization before and during ASA, and from echocardiography (ECHO) examinations before, during, and at 1-year follow-up after ASA. Linear and logistic regression models were used to assess the association between sex, BSWT, AML, PML, and outcome, which was defined as the remaining LVOTO (≥ 30 mmHg) after ASA. The median follow-up was 364 days (interquartile range 334–385 days). BSWT ≥ 23 mm (n = 13, 12%) was associated with remaining LVOTO at follow-up (p = 0.004). Elongated mitral valve leaflet length (either AML or PML) was present in 125 (90%) patients. Elongated AML (> 24 mm) was present in 67 (44%) patients, although AML length was not associated with remaining LVOTO at follow-up. Elongated PML (> 14 mm) was present in 114 (74%) patients and was not associated with remaining LVOTO at follow-up. No significant sex differences were observed regarding the remaining LVOTO. ECHO measurement of BSWT can be effectively used to select patients for successful ASA and identify those patients with a risk of incomplete resolution of LVOTO after ASA.Graphical abstract

Morphology of hypertrophied basal septum contributes to left ventricular outflow tract obstruction in patients with hypertrophic cardiomyopathy: a retrospective case-control study.

Detailed assessment of basal septal morphology is essential for understanding the morphological mechanism of left ventricular outflow tract (LVOT) obstruction. We aimed to analyze the morphological alterations of the basal septum (BS) and its surrounding structures and explore their role in LVOT obstruction (LVOTO) in patients with hypertrophic cardiomyopathy (HCM). During January 2019 and December 2019, 239 patients were diagnosed with HCM at Fuwai Hospital. We retrospectively reviewed echocardiographic data sets from 105 consecutive patients with HCM [64 with hypertrophic obstructive cardiomyopathy (HOCM) and 41 with hypertrophic non-obstructive cardiomyopathy (HNOCM)] and 28 healthy controls. For quantitatively assessing the basal septal morphology, a novel measurement method was used to obtain the IVSa (the area of the BS protruding into the LVOT), LA (the largest distance of the BS protruding into the LVOT), LB (IVSa length in the direction perpendicular to the LA), and S-IVSa (IVSa divided by LB). Echocardiographic parameters associated with LVOTO were analyzed using multivariable logistic regression analyses. There was no significant difference in the maximal basal septal thickness between the HOCM and HNOCM patients (P>0.99). Among the three groups, there were significant differences in the length of the anterior and posterior mitral leaflets (AML and PML), the angle between the mitral valve orifice and ascending aorta (MV-AO) angle, IVSa, LA, LB, and S-IVSa (all P<0.001). Compared with HNOCM patients, HOCM patients had significantly longer AML and PML, as well as larger MV-AO angle, IVSa, LA, and S-IVSa (P<0.001, P<0.001, P<0.001, P=0.002, P<0.001, and P=0.03, respectively). In the multivariate analysis, AML, MV-AO angle, IVSa, and S-IVSa were associated with LVOTO {odds ratio (OR) [95% confidence interval (CI)]: 0.649 (0.462-0.911), P=0.01; 0.842 (0.768-0.923), P<0.001; 1.025 (1.001-1.049), P=0.04; and 0.276 (0.101-0.754), P=0.01, respectively}. Morphological alterations of the BS relative to the LVOT may provide additional value for estimating the extent of LVOTO. The length of AML, MV-AO angle, IVSa, and S-IVSa were associated with LVOTO.

Aorto-septal angle, isolated basal septal hypertrophy, and systolic murmur in 122 cats

Introduction/ObjectivesSystolic murmurs in the absence of cardiac structural abnormalities are common in cats. Narrow aorto-septal angle (AoSA) and septal remodeling can be a cause of a systolic murmur in elderly human beings. The aim of this study was to measure the AoSA in cats and to investigate the association between the AoSA and the presence of a murmur and isolated basal septal hypertrophy (IBSH). AnimalsThe study population comprised 122 cats. Materials and methodsA physical exam, blood pressure measurement, chest radiographs, and echocardiography were performed. ResultsA systolic murmur was audible in 39/122 cats. A difference between cats with and without a murmur was found for age (P=0.0001), interventricular basal septal thickness (BIVSd) (P=0.004), AoSA (P=0.003), aortic (P<0.0001), and pulmonic (P=0.021) flow velocity, the presence of IBSH (P<0.0001), and systolic anterior motion of the mitral valve (P=0.0002). More than 50% of cats with a murmur had an AoSA ≤122°. Less than 25% of the cats with an AoSA ≥137° had a murmur. The AoSA narrowed 0.55°/year of age (P<0.001), whereas the BIVSd increased 0.11 mm/year of age (P<0.0001); the BIVSd increased as the AoSA narrowed. In all cats with AoSA < 120°, IBSH was present. ConclusionsThis study demonstrates that the probability of having a systolic murmur in cats is increased by the presence of a narrow AoSA. Aging was associated with a narrower AoSA and a thicker basal septum; these findings might represent an age-related heart remodeling.

Association between basal septal hypertrophy and left ventricular geometry in a community population

BackgroundLeft ventricular (LV) geometry is closely associated with cardiovascular disease; however, few studies have evaluated the relationship between basal septal hypertrophy (BSH) and LV geometry. In this study, we examined the relationship between BSH and LV geometry in a Beijing community population.MethodsThe clinical and echocardiographic data of 1032 participants from a community in Beijing were analyzed. BSH was defined as a basal interventricular septal thickness ≥ 14 mm and a basal septal thickness/mid-septal thickness ≥ 1.3. On the basis of their echocardiographic characteristics, patients were described as having a normal geometry, concentric remodeling, concentric hypertrophy, or eccentric hypertrophy. Multivariable logistic regression was used to analyze the relationship between BSH, LV mass index (LVMI), and relative wall thickness (RWT).ResultsThe prevalence of BSH was 7.4% (95% confidence interval [CI] 5.8–9.0%). Basal and middle interventricular septal thickness, LV posterior wall thickness, and RWT were greater, while LVMI and LV end-diastolic dimension were lower in the BSH group than in the non-BSH group (p < 0.05). The BSH group accounted for the highest proportion of patients with concentric remodeling. A multivariable regression analysis showed that BSH increased by 3.99-times (odds ratio [OR] 3.99, 95% CI 2.05–7.78, p < 0.01) when RWT was > 0.42, but not when LVMI increased (OR 0.16, 95% CI 0.02–1.19, p = 0.07). There were no interactions between BSH and age, body mass index, sex, diabetes mellitus, coronary heart disease, stroke, and smoking in relation to an RWT > 0.42.ConclusionBSH was independently associated with an RWT > 0.42.

Ecocardiographic comprehensive evaluation of OHCM patients treated with percutaneous ASA

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Alcohol septal ablation (ASA) has been widely accepted as an alternative to surgical myectomy in patients with symptomatic obstructive hypertrophic cardiomyopathy (OHCM) despite optimal medical treatment. The aim of this study was to analyse the effect of ASA on anatomical and functional features analysed by echocardiography, as well as its clinical impact. We further evaluated the safety of procedure. Methods and results Retrospective analysis of consecutive patients submitted to ASA (2009 – 2019) in a single tertiary centre. A dedicated echocardiogram was performed at 3 and 6 months after procedure. Echocardiographic primary endpoint was a &amp;gt; 50% reduction in left ventricular outflow tract (LVOT) gradient (the definition used for successful procedure). Echocardiographic secondary endpoint was improvement in mitral regurgitation. Clinical primary endpoint was defined as a combined endpoint of cardiac death or hospitalization during follow-up (FU). 110 patients were included, 66.4% women, mean age 65.1 ± 12.2 years. Functional class NHYA class III/IV, angina CCS class II/III and syncope were present in 87.3%, 52.7% and 10.0%, respectively. Baseline LVOT gradients at rest and at Valsalva manoeuvre were 93.6 ± 39.8 mmHg and 118.9 ± 44.2 mmHg. Maximum septal thickness was 21.0 ± 3.3 mm, 24.5% had moderate mitral regurgitation and 52.7% showed systolic anterior motion of mitral valve. During hospitalization for ASA, peak creatine kinase after procedure was 1306 ± 816 U/l. 17 (17.1%) patients required permanent PM due to induction of permanent complete heart block. There was one case of inferior myocardial infarction and one case of cardiac tamponade. Echocardiographic primary endpoint was achieved by 83.6% of patients. At 3 and 6-months follow up, LVOT gradients was significantly decreased in successful comparing with unsuccessful procedure group (24.6 ± 23.9 vs 82.0 ± 28.7 mmHg, p = 0.003 and 31.8 ± 34.5 vs 68.6 ± 27.8 mmHg, p = 0.027, respectively). There was no difference in baseline clinical or echocardiographic parameters between both groups. Regarding the echocardiographic secondary endpoint, among patients with moderate mitral regurgitation, 80% improved to mild regurgitation. A significant reduction in basal septal thickness was achieved in most patients, from 21.0 ± 3.3mm to 16.4 ± 2.7 mm after ASA (p = 0.001). During mean FU of 3.4 ± 2.1 years, clinical primary endpoint occurred in 25.5%, mainly in unsuccessful procedure group (50.0% vs 20.7%, p = 0.013). Reintervention was performed for recurrence of symptoms in 14 (12.7%) patients, surgical myectomy in 3 (3.6%) and repeated ASA in 10 (9.1%). Conclusion ASA allows a significant reduction in LVOT gradient and improvement of mitral regurgitation in the majority of patients with OHCM. Systematic and comprehensive echocardiographic evaluation assumes a paramount importance for the evaluation of procedural success. Abstract Figure.

Hypertrophic obstructive cardiomyopathy with a basal septal thickness of 16mm or less: clinical characteristics and surgical results.

To characterize the clinical features and surgical outcomes of symptomatic hypertrophic obstructive cardiomyopathy (HOCM) in patients with only mild septal hypertrophy. The clinical characteristics and surgical outcomes of 53 HOCM patients with a basal septal thickness ≤ 16mm (mild group) were compared with those of 128 HOCM patients with a basal septal thickness > 16mm (control group). The mild group had a greater prevalence of mitral subvalvular anomalies than the control group (79.2% vs. 6.3%, p < 0.001). Neither iatrogenic septal perforation nor inadequate septal myectomy was observed after myectomy in the mild group. There were no deaths during a median follow-up of 10months. Transthoracic echocardiography 6months after myectomy revealed a significant decrease in maximum gradients in both groups, from baseline 90.5 ± 21.5mmHg to 10.3 ± 4.4mmHg in the mild group (p < 0.001) and from 95.0 ± 22.0mmHg to 12.0 ± 5.9mmHg (p < 0.001) in the control group. Neither residual obstruction nor residual mitral regurgitation was recorded in the mild group. Symptomatic patients with hypertrophic obstructive cardiomyopathy and mild septal hypertrophy may have a higher prevalence of mitral subvalvular abnormalities. Mitral subvalvular management during myectomy can achieve outstanding results for these patients.

Clinical and electrocardiographic differences between apical and midventricular stress cardiomyopathy

Abstract Background Stress cardiomyopathy (SCM) is a transient ventricular dysfunction frequently precipitated by acute emotional or physical stress. According to ventricular contractile pattern there are four SCM variants, being apical (80%) and midventricular (15%) the most frequents. Our aim is to describe the differences between these two SCM variants. Methods We performed an observational study of patients who were diagnosed with SCM in our centre from February 2010 to January 2020. We registered demographic information, medical history, clinical, echocardiographic and analytical data of our patients and we performed a digital analysis of the 12-lead electrocardiogram (ECG) recorded in the first 48 hours after the onset of symptoms. Patients were divided into two groups, those with apical LV ballooning and patients with midventricular SCM. Results We included 86 patients; baseline characteristics of the population are described in the table. The median age was 77 (IQR: 67.7–82.9), and 91.9% were female. Fifty-six patients (65.1%) had apical variant whereas thirty patients (34.9%) showed midventricular one. The most frequent antecedent trigger was an emotional stressor (36.3%) follow by physical stressor (identified in 23.8%). Chest pain was the most frequent clinical presentation (54.7%). Median LVEF was 35% (IQR 30.0–45.0) and mean basal septal thickness was 9.50 (IQR 9.0–11.0). Median peak of troponin level was 1.71 (IQR 0.6–3.4). Comparing apical and midventricular variants of SCM median age was 80.2 (IQR 68.9–84.5) in apical group and 71.6 (IQR 59.64–78.0) in midventricular variant (P=0.001). There were no other differences in the medical history, clinical, echocardiographic and analytical data between both groups (table). After comparative analysis of ECG we found differences in negatives T wave location and QT duration. Apical variant present more negative-T waves in leads II, III, AVF, V4, V5, V6, while in midventricular variant they are more present in AVR and AVL (figure 1). Mean QT duration was 508.0ms (IQR 470.0–552.0) in apical variant and 470.5ms (IQR 423.7–524.2) in midventricular group (p=0.026). There were no differences in Q waves between both groups. Conclusions In our group of patients, apical and midventricular stress cardiomyopathy variants exhibit clinical and electrocardiographic differences. Patient with apical stress cardiomyopathy are older. They present more negative T waves in inferior and precordial leads, and longer QT interval. These results suggest that the pathophysiology of both entities could be different. Funding Acknowledgement Type of funding sources: None. Negative T-Waves comparationPopulation characteristics.

ANALYSIS OF ECHOCARDIOGRAPHIC AND MRI ANATOMICAL CHARACTERISTICS AND HEMODYNAMIC CHARACTERISTICS OF LEFT VENTRICULAR OUTFLOW TRACT STENOSIS

Objective: To analyze the anatomical morphological and hemodynamic characteristics of left ventricular outflow tract stenosis (LVOTS) by echocardiography and MRI. Methods: The Echocardiography data of 112 patients with LVOTS were retrospectively analyzed by measuring the basal interventricular septal thickness (IVST-b), the left ventricle posterior wall thickness (LVPWT), and the peak pressure gradient of LVOTS, as well as by observing the characteristics of spectral pattern and the presence of systolic anterior motion of mitral valve leaflets. A Siemens 3.0T MRI scanner was used to scan the contrast-enhanced left ventricular (LV) volume of all cases. The obtained end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF) of LV were compared with the Echocardiography results. Results: The 112 patients were divided into four groups: hypertrophic obstructive cardiomyopathy (Group I, 42 cases), hypertensive left ventricular hypertrophy (Group II, 40 cases), basal septal hypertrophy in the elderly (Group III, 21 cases), and the subaortic membrane (Group IV, 9 cases). The continuous wave (CW) Doppler characteristic of Groups I, II, and III was broadsword-shaped jet, and that of Group IV was equilateral triangle-like spectrum. The IVST-b, IVST-b/LVPWT ratio and peak pressure gradient of LVOTS of Group I was significantly higher than those in Groups II and III ([Formula: see text]). The LVPWT of the first three groups was slightly correlated with the LVOTS peak pressure gradient ([Formula: see text], respectively, [Formula: see text]). There were no statistically significant differences between Echocardiography and MRI results regarding the LV EDV, ESV, SV, and EF ([Formula: see text]), and no statistically significant differences were found between Echocardiography and MRI results regarding the myocardial thicknesses of septal, anterior, lateral, and inferior walls ([Formula: see text]). The Pearson’s correlation analysis demonstrated correlations between MRI and Echocardiography results for LV EDV, ESV, SV, and EF ([Formula: see text], 0.002, 0.009, and [Formula: see text], respectively). The MRI enhancement was shown as delayed enhancement in 52 cases, localized enhancement in 8 cases, diffuse enhancement in 6 cases, and transmural enhancement in 3 cases, with abnormal enhancement lesions distributed in the area of ventricular septum free wall junctions and ventricular septum. Conclusion: Using MRI to evaluate LV function of hypertrophic cardiomyopathy is reliable and accurate. MRI enhancement can be used for the quantitative measurement of myocardial fibrosis. Echocardiography can distinguish the stenosis types of LVOTS. The IVST-b and existence of SAM may be important anatomical characteristics determining the degree of dynamic stenosis, and MRI combined with Echocardiography can provide important detailed information.

Outcomes in Patients With Obstructive Hypertrophic Cardiomyopathy and Concomitant Aortic Stenosis Undergoing Surgical Myectomy and Aortic Valve Replacement.

BackgroundHypertrophic cardiomyopathy (HCM) and aortic stenosis can cause obstruction to the flow of blood out of the left ventricular outflow tract into the aorta, with obstructive HCM resulting in dynamic left ventricular outflow tract obstruction and moderate or severe aortic stenosis causing fixed obstruction caused by calcific degeneration. We sought to report the characteristics and longer‐term outcomes of patients with severe obstructive HCM who also had concomitant moderate or severe aortic stenosis requiring surgical myectomy and aortic valve replacement.Methods and ResultsWe studied 191 consecutive patients (age 67±6 years, 52% men) who underwent myectomy and aortic valve (AV) replacement (90% bioprosthesis) at our center between June 2002 and June 2018. Clinical and echo data including left ventricular outflow tract gradient and indexed AV area were recorded. The primary outcome was death. Prevalence of hypertension (63%) and hyperlipidemia (75%) were high, with a Society of Thoracic Surgeons score of 5±4, and 70% of participants had no HCM‐related sudden death risk factors. Basal septal thickness and indexed AV area were 1.9±0.4 cm and 0.72±0.2 cm2/m2, respectively, while 100% of patients had dynamic left ventricular outflow tract gradient >50 mm Hg. At 6.5±4 years, 52 (27%) patients died (1.5% in‐hospital deaths). One‐, 2‐, and 5‐year survival in the current study sample was 94%, 91%, and 83%, respectively, similar to an age‐sex–matched general US population. On multivariate Cox survival analysis, age (hazard ratio [HR], 1.65; 95% CI, 1.24–2.18), chronic kidney disease (HR, 1.58; 95% CI, 1.21–2.32), and right ventricular systolic pressure on preoperative echocardiography (HR, 1.28; 95% CI, 1.05–1.57) were associated with longer‐term mortality, but traditional HCM risk factors did not.ConclusionsIn symptomatic patients with severely obstructive HCM and moderate or severe aortic stenosis undergoing a combined surgical myectomy and AV replacement at our center, the observed postoperative mortality was significantly lower than the expected mortality, and the longer‐term survival was similar to a normal age‐sex–matched US population.

Obesity in the absence of comorbidities is not related to clinically meaningful left ventricular hypertrophy

Obesity is associated with the development of left ventricular (LV) hypertrophy. Whether obesity in in the absence of comorbidities can cause LV hypertrophy to an extent which could create diagnostic uncertainty with pathological states (such as hypertrophic cardiomyopathy) is unknown. We used cine cardiovascular magnetic resonance imaging to precisely measure LV wall thickness in the septum and lateral wall in 764 people with body mass indices ranging from 18.5 kg/m2 to 59.2 kg/m2 in the absence of major comorbidities. Obesity was related to LV wall thickness across the cohort (basal septum r 0.30, P < 0.001 and basal lateral wall r 0.18, P < 0.001). Although no participant had hypertension, these associations remained highly significant after controlling for systolic blood pressure (all P < 0.01). Each 10 kg/m2 increase in BMI was associated with an increase in basal septal wall thickness of 1.0 mm males and 0.8 mm in females, with no statistically significant difference between genders (P = 0.1). Even in class 3 obesity (BMI > 40 kg/m2), no LV wall thickness > 13.4 mm in males or > 12.7 mm in females was observed in this cohort. We confirm that obesity in the absence of comorbidities is associated with LV hypertrophy, and establish that the magnitude of this change is modest even in severe obesity. LV hypertrophy > 14 mm cannot safely be attributed to obesity alone and alternative diagnoses should be considered.

Characteristics and Outcomes of Elderly Patients With Hypertrophic Cardiomyopathy.

BackgroundWe report characteristics and outcomes of elderly patients with hypertrophic cardiomyopathy (HCM) with basal septal hypertrophy and dynamic left ventricular outflow tract obstruction.Methods and ResultsWe studied 1110 consecutive elderly patients with HCM (excluding moderate or greater aortic stenosis or subaortic membrane, age 80±5 years [range, 75–92 years], 66% women), evaluated at our center between June 2002 and December 2018. Clinical and echocardiographic data, including maximal left ventricular outflow tract gradient, were recorded. The primary outcome was death and appropriate internal defibrillator discharge. Hypertension was observed in 72%, with a Society of Thoracic Surgeons (STS) score (8.6±6); while 80% had no HCM‐related sudden cardiac death risk factors. Left ventricular mass index, basal septal thickness, and maximal left ventricular outflow tract gradient were 127±43 g/m2, 1.7±0.4 cm, and 49±31 mm Hg, respectively. A total of 597 (54%) had a left ventricular outflow tract gradient >30 mm Hg, of which 195 (33%) underwent septal reduction therapy (SRT; 79% myectomy and 21% alcohol ablation). At 5.1±4 years, 556 (50%) had composite events (273 [53%] in nonobstructive, 220 [55%] in obstructive without SRT, and 63 [32%] in obstructive subgroup with SRT). One‐ and 5‐year survival, respectively were 93% and 63% in nonobstructive, 90% and 63% in obstructive subgroup without SRT, and 94% and 84% in the obstructive subgroup with SRT. Following SRT, there were 5 (2.5%) in‐hospital deaths (versus an expected Society of Thoracic Surgeons mortality of 9.2%).ConclusionsElderly patients with HCM have a high prevalence of traditional cardiovascular rather than HCM risk factors. Longer‐term outcomes of the obstructive SRT subgroup were similar to a normal age‐sex matched US population.

Outcomes in Guideline-Based Class I Indication Versus Earlier Referral for Surgical Myectomy in Hypertrophic Obstructive Cardiomyopathy.

BackgroundIn patients with obstructive hypertrophic cardiomyopathy, surgical myectomy (SM) is indicated for severe symptoms. We sought to compare long‐term outcomes of patients with obstructive hypertrophic cardiomyopathy where SM was based on guideline‐recommended Class I indication (Functional Class or FC ≥3 or angina/exertional syncope despite maximal medical therapy) versus earlier (FC 2 and/or impaired exercise capacity on exercise echocardiography with severe obstruction).Methods and ResultsWe studied 2268 consecutive patients (excluding <18 years, ≥ moderate aortic stenosis and subaortic membrane, 56±14 years, 55% men), who underwent SM at our center between June 2002 and March 2018. Clinical data, including left ventricular outflow tract gradient, were recorded. Death and/or appropriate internal defibrillator discharge were primary composite end points. One thousand three hundred eighteen (58%) patients met Class I indication and 950 (42%) underwent earlier surgery; 222 (10%) had a history of obstructive coronary artery disease. Basal septal thickness, and resting and maximal left ventricular outflow tract gradient were 2.0±0.3 cm, 61±44 mm Hg, and 100±31 mm Hg, respectively. At 6.2±4 years after SM, 248 (11%) had composite events (13 [0.6%] in‐hospital deaths). Age (hazard ratio [HR], 1.61; 95% CI, 1.26–1.91), obstructive coronary artery disease (HR, 1.46; 95% CI, 1.06–1.91), and Class I versus earlier SM (HR, 1.61; 95% CI, 1.14–2.12) were associated with higher primary composite events (all P<0.001). Earlier surgery had better longer‐term survival (similar to age‐sex‐matched normal population) versus surgery for Class I indication (76 [8%] versus 193 [15%], P<0.001).ConclusionsIn patients with obstructive hypertrophic cardiomyopathy, earlier versus surgery for Class I indication had a better long‐term survival, similar to the age‐sex‐matched US population.

Characteristics and Longer-Term Outcomes of Contemporary Patients

We describe characteristics and outcomes of contemporary pediatric hypertrophic cardiomyopathy (PHC) patients. We studied 398 consecutive pediatric HC patients (<18 years, median 14 years, 65% boys) seen at our center between 2002 and 2018. Baseline clinical and pediatric echocardiographic data was collected. Left ventricular outflow tract gradient (LVOTG), LV fractional shortening and Z-score for left ventricular (LV) wall thickness were calculated. Sudden cardiac death (SCD), appropriate internal defibrillator discharge (ICD), myectomy, and orthotopic heart transplant (OHT) were composite primary endpoint. A total of 133 (33%) had symptoms (71 [18%] dyspnea, 77 [19%] angina, and 19 [5%] syncope), 109 (27%) were on beta-blockers; 179 (45%) had family history of HC. A total of 146 (37%) underwent genetic testing (of which 91 (62%) were HC-gene positive). Basal septal LV thickness, septal LV z-score and fractional shortening were 1.2 ± 0.6 cm, 4.8 ± 5.6, and 42% ± 8, whereas 23% had extreme LV hypertrophy (z-score > 6) and 8% had LVOTG >30 mm Hg (range 0 to 139 mm Hg). At a median of 5.9 years (interquartile range 2.4, 9), there were 23 (6%) ICD's placed, and 47 (12%) primary composite events (9 [2%] deaths, 3 [1%] appropriate ICD discharge, 29 [7%] myectomy, and 8 [2%] OHT). There were no in hospital deaths following myectomy/OHT. Presence of symptoms (Hazard ratio or HR 2.45), ventricular tachycardia (HR 1.52), and higher basal septal LV z-score (HR 1.10) were independently associated with primary composite outcomes. LV septal z-score >4 was independently associated with events on spline analysis. Rate of SCD/appropriate ICD discharge was 0.5%/year. In conclusion, contemporary PHC patients seen at an experienced center have excellent outcomes with presence of symptoms and higher LV septal thickness associated with primary composite events.

Effect of Regional Upper Septal Hypertrophy on Echocardiographic Assessment of Left Ventricular Mass and Remodeling in Aortic Stenosis

Transthoracic echocardiography (TTE) is the reference method for evaluation of aortic stenosis (AS), and it is extensively used to quantitate left ventricular (LV) mass and volumes. Regional upper septal hypertrophy (USH) or septal bulge is a frequent finding in patients with AS and may lead to overestimation of LV mass when using linear measurements. The objective of this study was to compare estimates of LV mass obtained by two-dimensional transthoracic echocardiographic LV dimensions measured at different levels of the LV cavity with those obtained by cardiovascular magnetic resonance (CMR). One hundred six patients (mean age, 63±15years; 68% men) with AS were included in this subanalysis of the PROGRESSA study. Two-dimensional transthoracic echocardiographic measurements of LV dimensions were obtained at the basal level (BL; as recommended in guidelines), immediately below the septal bulge (BSB), and at a midventricular level (ML). Regional USH was defined as a basal interventricular septal thickness ≥ 13mm and >1.3 times the thickness of the septal wall at the ML. Agreement between transthoracic echocardiographic and CMR measures was evaluated using Bland-Altman analysis. The distribution of AS severity was mild in 23%, moderate in 57%, and severe in 20% of patients. Regional USH was present in 28 patients (26%). In the whole cohort, two-dimensional TTE overestimated LV mass (bias: BL,+60±31g; BSB,+59±32g; ML,+54±32g; P=.02). The biplane Simpson method slightly but significantly underestimated LV end-diastolic volume (bias -10±20mL, P<.001) compared with CMR. Overestimation of LV mass was more marked in patients with USH when measuring at the BL and was significantly lower when measuring LV dimensions at the ML (P<.025 vs BL and BSB). Two-dimensional TTE systematically overestimated LV mass and underestimated LV volumes compared with CMR. However, the bias between TTE and CMR was less important when measuring at the ML. Measurements at the BL as suggested in guidelines should be avoided, and measurements at the ML should be preferred in patients with AS, especially in those with USH.

Effectiveness of alcohol septal ablation for hypertrophic obstructive cardiomyopathy in patients with late gadolinium enhancement on cardiac magnetic resonance

BackgroundAccording to European guidelines, alcohol septal ablation (ASA) for hypertrophic obstructive cardiomyopathy (HOCM) may be less effective in patients with extensive septal scarring on cardiac magnetic resonance (CMR). This study aimed to analyze the impact of late gadolinium enhancement (LGE) on CMR on the effectiveness of ASA. MethodWe conducted an observational retrospective study involving adult patients with symptomatic drug-refractory HOCM who underwent CMR before ASA at two European centres from May 2010 through June 2019. Patients were compared in binary format based on LGE presence. Moreover, a subanalysis focused on patients with septal fibrosis was performed. The effectiveness of ASA was evaluated by echocardiographic, ECG and clinical findings. ResultsOf the 113 study patients, 54 (48%) had LGE on CMR. The LGE quantification performed in 29 patients revealed septal fibrosis in 17. The mean follow-up was 4.4 ± 2.6 years. Baseline parameters were similar between groups except for basal septal thickness that was greater in LGE+ group (21.1 ± 3.9 mm for LGE+ vs. 19.2 ± 3.2 mm for LGE-: p = .005). ASA improved symptoms in all groups and reduced left ventricular outflow tract obstruction (LVOTO) (delta gradient reduction: LGE+: 62 ± 37.3%; septal LGE+: 75.6 ± 20.8%; LGE-: 72.5 ± 21.0%). However, 13% of the LGE+ and 2% of the LGE- group had residual LVOTO above 30 mmHg (p = .027). ConclusionASA was effective in all patients with HOCM, whether they had LGE on CMR or not and whether they had septal fibrosis or not.

P1708 Analysis of ventricular mechanics in echo-guided endocardial radiofrequency septal ablation for hypertrophic obstuctive cardiomyopathy

Abstract Introduction Hypertrophic Obstructive Cardiomyopathy (HOCM) is an important cause of sudden death and heart failure, specially in young adults. Approximately 5% to 8% of patients are not suitable for transcoronary ablation, if myectomy is not feasible, Endocardial Radiofrequency Ablation of Septal Hypertrophy (ERASH) has shown acceptable efficacy and safety for left ventricular outflow tract (LVOT) gradient reduction. 20 ERASH cases have been reported in the literature. Case report 39 year old woman with diagnosis of HOCM, symptoms of dyspnea (NYHA III), and aborted sudden death as first clinical manifestation; a cardiac defibrillator was implanted. A transthoracic echocardiogram (TTE) revealed normal left ventricle (LV) ejection fraction, moderate mitral regurgitation (systolic anterior valve motion), basal inter-ventricular septal wall thickness of 20 mm generating a LVOT gradient of 51 mmHg. A coronary angiography showed inadequate septal branch anatomy to perform alcohol ablation. The patient refused myectomy. Heart Team decided to perform ERASH. Using a 3D Cardiac Mapping System and 2D Echocardiography, the basal interventricular septum received 50 Watts/50˚C radiofrequency ablation without any acute complication. Three days later, a TTE showed LVOT gradient 26 mmHg. The description of the LV mechanics is described on Table 1. Pre and post ERASH ventricular mechanics was analyzed including circumferential endocardial and mesocardial strain and strain rate, as well as longitudinal strain involved in the LV segments that received ERASH (Figure 1.) . Conclusion We report the analysis of ventricular mechanics after a successful case of ERASH, an alternative technique for treating HOCM. In our analysis, pre- ERASH longitudinal strain was significantly more negative at the basal anterior and anteroseptal segments than the other LV segments. This may be a predictor of focal LV remodeling at these segments in the future. Table 1. Pre ERASH Post ERASH Ventricular Segment Strain Strain Rate Strain Strain Rate Longitudinal Strain Basal Anteroseptal -14.4% -1.2 1/s -7% -0.6 1/s Endocardial Circumferential Strain Basal Anteroseptal -13.7% -1.9 1/s -32% -2.2 1/s Basal Anterior -44.6% -4.2 1/s -18.6% -1.6 1/s Mesocardial Circumferential Strain Basal Anteroseptal -7.7% -1.0 1/s -20.2% -1.2 1/s Basal Anterior -24.9% -1.7 1/s -13.8% -0.9 1/s Left ventricular mechanics pre and post ERASH. Abstract P1708 Figure 1.

Cardiac structural and functional findings in Persian cats with autosomal dominant polycystic kidney disease

ABSTRACT: Autosomal dominant polycystic kidney disease (ADPKD) has been related to left ventricular structural and functional abnormalities in human patients. The present study aimed to evaluate the cardiac structural and functional findings in Persian cats with ADPKD. Client-owned ADPKD (n=12) and non-ADPKD (n=12) Persian cats were enrolled in this study. The animals underwent echo- and electrocardiographic (ECG) examinations, and non-invasive measurements of systolic blood pressure (SBP) were obtained. Both groups were similar regarding hematological and biochemical parameters, including white blood cell count and levels of blood urea nitrogen, creatinine, total protein and thyroxine. There were no differences related to ECG parameters between ADPKD and non-ADPKD cats. Left ventricular hypertrophy (LVH) was demonstrated in 6/12 (50%) normotensive ADPKD cats with preserved renal function. There were no differences between animal groups regarding the echocardiographic parameters, including left ventricular ejection fraction and shortening fraction; however, basal interventricular septal thickness at end-diastole near the left ventricular outflow tract and aortic artery flow velocity showed slightly elevated values in ADPKD-cats. Our study revealed that Persian cats with ADPKD do not reproduce the functional and structural cardiac phenotype reported in human patients; however, large-scale cohort studies are necessary to distinguish the possibilities of a true linkage between ventricular myocardial hypertrophy and ADPKD in this breed.

226Earlier surgical myectomy vs. waiting for a Class I indication is associated with improved long-term survival in symptomatic hypertrophic obstructive cardiomyopathy patients

Abstract Background In patients with severe hypertrophic obstructive cardiomyopathy (HOCM), surgical myectomy (SM) is typically indicated for severe symptoms despite maximal medical therapy. Aims We sought to compare long-term outcomes of severe HOCM patients where decision for SM was based on guideline-recommended Class I indication (functional Class or FC ≥3 or exertional syncope despite maximal medical therapy) vs. earlier (FC II and/or impaired exercise capacity on exercise echo with medication intolerance). Methods The study included 2268 HOCM patients (excluding &lt;18 years, at least moderate aortic stenosis requiring valve replacement and subaortic membrane, age 56±14 years, 55% men), who underwent SM at our center between 1/02–3/18. Clinical and echo data, including left ventricular outflow tract gradient (LVOTG) were recorded. Cardiac death and/or appropriate internal defibrillator discharge were recorded as composite endpoints. Results 1318 (58%) patients met Class I indication for SM, while the rest underwent SM for FC II (due to medicine intolerance) or impaired exercise capacity. 535 (24%) and 408 (18%) had history of atrial fibrillation and a family history of HCM. All patients were on maximally tolerated medical therapy. European 5-year sudden death risk score was 3.7±2%. Baseline basal septal thickness, resting and maximal LVOTG were 2.0±0.3 cm, 61±44 mm Hg and 100±31 mm Hg. At 6.2±4 years of follow-up after SM, 248 (11%) had composite events (13 [0.6%] in-hospital deaths). Competing risk survival analysis for composite endpoint is shown in Figure 1a. Patients operated for Class I indication had significantly higher longer-term event rate vs. those operated earlier (182 [14%] vs. 66 [7%], p&lt;0.001, Figure 1B). Conclusions In patients with severe HOCM undergoing SM at an experienced center performed by experienced surgeons, delaying surgery till reaching Class I indication was associated with much worse survival than operating earlier for milder symptoms or impaired exercise tolerance on exercise echo.

Clinical Spectrum and Management Implications of Left Ventricular Outflow Obstruction With Mild Ventricular Septal Thickness in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HC) has historically been characterized as a disease of substantial left ventricular hypertrophy, often associated with dynamic left ventricular outflow tract obstruction. However, we have recently encountered patients with subaortic obstruction and only minimal basal septal thickness, raising important management implications. Thereby, we sought to characterize the natural history and treatment strategies for this under-recognized subgroup of HC patients with dynamic obstruction. Of 1,591 consecutive patients with a HC diagnosis, 113 (7%) were identified with outflow obstruction due to elongated mitral valve leaflets producing systolic anterior motion and septal contact typical of HC (gradient, 84 ± 29 mm Hg at rest or with exercise), with maximal ventricular septal thickness ≤15 mm, including 14 patients with only 10 to 12 mm. In addition to the mechanism of outflow obstruction, other evidence supporting a HC diagnosis prominently included: positive HC family history and/or pathogenic sarcomere mutation, arrhythmic sudden death event, typical histopathology of septal muscle, and characteristic mitral valve and papillary muscle anomalies. Over 3.8 ± 3.5 years, 41 patients (36%) developed severe heart failure including 36 who have undergone myectomy associated with reconstruction of the outflow tract and mitral valve apparatus, resulting in relief of gradient without iatrogenic ventricular septal defect or mitral valve replacement. Postoperatively, all 36 patients have survived with symptom relief to New York Heart Association classes I/II. In conclusion, these observations expand the HC clinical profile and phenotype to include an under-appreciated subgroup in which disease expression includes outflow obstruction due primarily to an elongated mitral valve, associated with only minimal (or normal) ventricular septal thickness. Such HC patients can develop marked functional limitation amenable to an operative strategy that effectively relieved symptoms due to outflow obstruction, but without mitral valve replacement.