Comparison of resting and exercise echocardiographic parameters as indicators of outcomes in hypertrophic cardiomyopathy.

Both resting echocardiography and exercise echocardiography produce variables predictive of outcomes in patients with hypertrophic cardiomyopathy (HCM). The aim of the present study was to compare the respective value of resting and exercise echocardiographic parameters as indicators of clinical outcomes in patients with HCM. Resting and exercise echocardiography was performed prospectively in patients with HCM evaluated at the HCM Competence Center of Bordeaux and followed up every 6 months. A composite cardiac event was defined. One hundred fifteen patients (mean age, 51.9 ± 15.2 years; 66% men) were evaluated by echocardiography and followed for a mean period of 19 ± 11 months. Eighteen patients (16%) reached the composite end point, including 10 progressions to New York Heart Association functional class III or IV. On rest echocardiography, in patients with cardiac events during follow-up, left atrial volume index was significantly more increased, as were lateral E/E' ratio and left ventricular outflow tract (LVOT) gradient, whereas mean global longitudinal strain (GLS) expressed in magnitude (14.0 ± 2.6% vs 17.0 ± 3.6%, P < .001) and peak velocities at the lateral annulus by Doppler tissue imaging were significantly reduced compared with patients without events. At peak exercise, patients who developed cardiac events were characterized by lower ejection fractions and greater LVOT gradients (76 ± 55 mm Hg vs 40 ± 40 mm Hg, P < .002). A Cox backward-entry selection model revealed that GLS ≤ 15% at rest and LVOT gradient ≥ 50 mm Hg at peak exercise were independently associated with an increased risk for poor outcomes in patients with HCM (hazard ratios, 3.8 [P = .017] and 3.3 [P = .028], respectively). On Kaplan-Meier survival analyses, peak exercise LVOT gradient evaluation showed additive value to predict outcomes, particularly in patients with rest GLS > 15% (log-rank P = .001) and despite a resting LVOT gradient ≥ 30 mm Hg (log-rank P = .001). This study supports the value of resting GLS and of peak LVOT gradient, measured during exercise echocardiography, in identifying patients with HCM at increased risk for adverse events during follow-up.

Reant P ，Reynaud A ，Pillois X ，Dijos M ，Arsac F ，Touche C ，Landelle M ，Rooryck C ，Roudaut R ，Lafitte S ... -  《-》

Exercise echocardiography in asymptomatic HCM: exercise capacity, and not LV outflow tract gradient predicts long-term outcomes.

This study sought to assess long-term outcomes in asymptomatic or minimally symptomatic patients with hypertrophic cardiomyopathy (HCM) who underwent exercise echocardiography, without invasive therapies for relief of left ventricular outflow tract (LVOT) obstruction. Many HCM patients present with LVOT obstruction, mitral regurgitation (MR), and diastolic dysfunction, often requiring invasive therapies for symptomatic relief. However, a significant proportion of truly asymptomatic patients can be closely monitored. In HCM patients, exercise echocardiography has been shown to be a useful assessment of functional capacity and risk stratification. We included 426 HCM patients (44 ± 14 years; 78% men) undergoing exercise echocardiography, excluding hypertensive heart disease of elderly, ejection fraction <50% and invasive therapy (myectomy or alcohol ablation) during follow-up. Clinical, echocardiographic (LV thickness, LVOT gradient, and MR) and exercise variables (percent of age-sex predicted metabolic equivalents [METs] and heart rate recovery [HRR] at 1 min post-exercise) were recorded. A composite endpoint of death, appropriate internal defibrillator discharge, and admission for congestive heart failure was recorded. Patients were asymptomatic or minimally symptomatic on history, but 82% of patients achieved <100% of age-sex predicted METs, and 43% had ≥II+ post-stress MR. The mean LV septal thickness, post-exercise LVOT gradient, and HRR were 2.0 ± 0.5 cm, 62 ± 47 mm Hg, and 31 ± 14 beats/min, respectively. During a mean follow-up of 8.7 ± 3 years, there were 52 events (12%). Patients achieving >100% of age-sex predicted METs had 1% event rate versus 12% in those achieving <85%. On stepwise multivariate survival analysis, percent of age-sex predicted METs (hazard ratio [HR]: 0.76; 95% confidence interval [CI]: 0.64 to 0.90), abnormal HRR (HR: 0.89; 95% CI: 0.82 to 0.97), and atrial fibrillation (HR: 2.73; 95% CI: 1.30 to 5.74) (overall, p < 0.001) independently predicted outcomes. In asymptomatic or minimally symptomatic HCM patients, exercise stress testing provides excellent risk stratification, with a low event rate in patients achieving >100% of predicted METs.

Desai MY ，Bhonsale A ，Patel P ，Naji P ，Smedira NG ，Thamilarasan M ，Lytle BW ，Lever HM ... -  《-》

Impact of exercise-induced mitral regurgitation on hypertrophic cardiomyopathy outcomes.

Rest echocardiography plays a role in hypertrophic cardiomyopathy (HCM) diagnosis and risk stratification because left atrial enlargement, severe left ventricle (LV) hypertrophy, and rest LV outflow tract (LVOT) gradients ≥50 mmHg are sudden cardiac death risk factors that have been highlighted in recent guidelines. Conversely, the lack of evidence makes that exercise-echocardiography findings play a limited role. In clinical practice, LVOT gradient, but also mitral regurgitation (MR) or pulmonary pressure, seems relevant parameters to look for, during the exercise. Therefore, we sought to determine whether exercise-induced changes in myocardial and valvular functions could improve HCM risk stratification. Consecutive primitive HCM patients with a preserved LV ejection fraction underwent standardized exercise echocardiography (including the assessment of myocardial function, dynamic left intraventricular gradient, and valvular regurgitations) at baseline and were clinically followed for a median of 29.3 months. The primary endpoint was a composite criterion that included death from any cause, cardiorespiratory arrest, and hospitalization for a cardiovascular event. A total of 126 patients were included. Eighteen patients reached the primary endpoint. According to univariate Cox regression analysis, exercise LVOT gradient ≥50 mmHg [hazard ratio (HR) = 3.31, P = 0.01] and significant (≥2/4) exercise MR (HR = 3.64, P < 0.01) were associated with the primary endpoint. Patients with significant MR had significantly higher rest and exercise LVOT gradients (P = 0.001 and P = 0.001) and larger left atria volumes (P < 0.001). Significant exercise-induced MR appears to significantly impact the prognoses of HCM patients, and it is also associated with higher LVOT rest and exercise gradients.

Feneon D ，Schnell F ，Galli E ，Bernard A ，Mabo P ，Daubert JC ，Leclercq C ，Carre F ，Donal E ... -  《-》

Tissue Doppler imaging during exercise stress echocardiography demonstrates a mechanism for impaired exercise performance in children with hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is associated with decreased exercise tolerance in children, presumably due to diastolic dysfunction. Modern imaging techniques to assess myocardial function during active exercise have not been applied to this population. We hypothesized that impaired contractile reserve, as assessed by tissue Doppler imaging (TDI) and strain, contributes to reduced exercise capacity in affected individuals. Children (<18 years) with HCM and healthy age- and sex-matched controls were prospectively enrolled. Resting echocardiograms and staged upright cycle ergometry with simultaneous echocardiograms were performed. During exercise, left ventricular outflow tract (LVOT) gradients and color Doppler maps of apical four-chamber and parasternal short-axis views were obtained. Post processing of images was performed to obtain TDI velocities, and measurements of strain were attempted. Exercise parameters and staged TDI values were compared. The study population consisted of 58 subjects (22 with HCM and 36 controls). Patients with HCM had significantly higher peak LVOT gradients compared to controls at baseline and at each exercise stage. TDI revealed that diastolic function, as assessed by E' velocities at septal and lateral mitral annuli, normalized with exercise in HCM patients. Further, systolic function (S' velocity) of HCM patients at rest was normal but failed to augment normally at peak exercise. Children with HCM have decreased TDI velocities at rest. With exercise, they may increase their E' velocities but fail to augment S' velocities, demonstrating decreased contractile reserve. In the patient with suspected HCM but equivocal findings, exercise TDI assessment may complement the diagnostic evaluation.

Ferguson ME ，Sachdeva R ，Gillespie SE ，Morrow G ，Border W ... -  《-》

Left ventricular and atrial functions in hypertrophic cardiomyopathy patients with very high LVOT gradient: a speckle tracking echocardiographic study.

Determination of myocardial deformation (strain) by two-dimensional (2D) speckle tracking echocardiography (STE) is a new method for evaluating left ventricular (LV) regional function in patients with hypertrophic cardiomyopathy (HCM). The aim of this study was to assess LV and left atrial (LA) functions with 2DSTE in HCM patients and to investigate relation between strain analysis and LV outflow tract (LVOT) gradient. Forty consecutive HCM patients (26 male, mean age: 47.7 ± 15.2 years), and 40 healthy volunteers (22 male, mean age: 46.6 ± 11.2 years) were included in the study. All subjects underwent a transthoracic echocardiography for evaluation of LV and LA functions with 2DSTE. The HCM patients were divided into 2 groups according to the presence of resting LVOT gradient >100 mmHg. Left ventricular global longitudinal strain (GLS), global radial strain (GRS), and global circumferential strain (GCS) were significantly lower in patients with HCM compared with controls (-20.3 ± 3.6% vs. -24.1 ± 3.4% P < 0.001, 38.1 ± 12.8% vs. 44.8 ± 10.2% P = 0.012, and -22.0 ± 4.4% vs. -23.9 ± 4.0% P = 0.045, respectively). Although basal and apical rotation were similar between the groups, mid-rotation was significantly clockwise in HCM patients (-1.53 ± 2.06° vs. 0.05 ± 1.7° P < 0.001). Both LA reservoir functions and LA conduit functions were significantly lower in HCM patients (21.6 ± 9.1% vs. 39.4 ± 10.6% P < 0.001, and 10.5 ± 4.3% vs. 15.7 ± 5.3%, P < 0.001). Fifteen patients had a resting LVOT gradient of >100 mmHg and they had significantly decreased GLS, twist and untwist compared to the HCM patients with lower resting LVOT gradient (-18.7 ± 2.3% vs. -21.2 ± 3.9% P = 0.016, 19.4 ± 4.3° vs. 23.5 ± 7.4° P = 0.038 and -94.0 ± 29.1°/sec vs. -134.9 ± 55.8°/sec, 0.005, respectively). Although basal and apical rotation were similar between the 2 groups, mid-rotation was significantly clockwise in HCM patients with higher LVOT gradient (-2.52 ± 1.76° vs. -0.96 ± 2.03°, P = 0.018). Correlation analysis revealed that LVOT peak velocity was associated with GLS (r = -0.358, P = 0.023), LV mid-rotation (r = -0.366, P = 0.024), and LV untwist (r = -0.401, P = 0.013). Left ventricular and LA functions are impaired in patients with HCM. 2DSTE is useful in determining patients with impaired myocardial mechanics. High LVOT gradient may be one of the responsible factors that trigger deterioration of LV longitudinal strain and twist mechanics in patients with HCM. Further studies are required to clarify the preliminary results of this study.

Tigen K ，Sunbul M ，Karaahmet T ，Dundar C ，Ozben B ，Guler A ，Cincin A ，Bulut M ，Sari I ，Basaran Y ... -  《-》