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 ... -  《-》

Predictors of long-term outcomes in patients with hypertrophic cardiomyopathy undergoing cardiopulmonary stress testing and echocardiography.

Patients with hypertrophic cardiomyopathy (HCM) have exercise intolerance due to left ventricular outflow tract (LVOT) obstruction, mitral regurgitation, and left ventricular dysfunction. We sought to study predictors of outcomes in HCM patients undergoing cardiopulmonary stress testing (CPT). We studied 1,005 HCM patients (50 ± 14 years, 64% men, 77% on β-blockers) who underwent CPT with echocardiography. Clinical, echocardiographic, and exercise variables (peak oxygen consumption [VO2] and heart rate recovery [HRR] at first minute postexercise) were recorded. End point was a composite of death, appropriate defibrillator discharges, resuscitated sudden death, stroke, and heart failure admission. Mean left ventricular ejection fraction (LVEF), postexercise LVOT gradient, and peak VO2 were 62% ± 6%, 92 ± 51 mm Hg, and 21 ± 6 mL kg(-1) min(-1), respectively. Despite 789 patients (78%) being in New York Heart Association classes I to II, only 8% achieved >100% age-gender predicted peak VO2, whereas 77% and 15% achieved 50% to 100% and <50%, respectively. Left ventricular outflow tract gradient ≥30 mm Hg was observed in 83% patients, whereas 23% had abnormal HRR. More than 5.5 ± 4 years, there were 94 (9%) events; 511 (50%) patients underwent surgery for LVOT obstruction. Multivariable Cox proportional analysis demonstrated % age-gender predicted peak VO2 (hazard ratio [HR] 0.96 [0.93-0.98]), normal vs abnormal HRR (HR 0.48 [0.32-0.73]), higher LVEF (HR 0.96 [0.93-0.98]), surgery (0.53 [0.33-0.83]), and atrial fibrillation (HR 1.65 [1.04-2.60]) were associated with outcomes (all P < .05). In HCM patients undergoing CPT, a higher % of achieved age-gender predicted VO2 and surgical relief of LVOT obstruction were associated with better outcomes, whereas abnormal HRR, atrial fibrillation, and lower LVEF were associated with worse outcomes.

Masri A ，Pierson LM ，Smedira NG ，Agarwal S ，Lytle BW ，Naji P ，Thamilarasan M ，Lever HM ，Cho LS ，Desai MY ... -  《-》

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 ... -  《-》

Predictors of long-term outcomes in patients with significant myxomatous mitral regurgitation undergoing exercise echocardiography.

Naji P ，Griffin BP ，Asfahan F ，Barr T ，Rodriguez LL ，Grimm R ，Agarwal S ，Stewart WJ ，Mihaljevic T ，Gillinov AM ，Desai MY ... -  《-》

Paradoxical response to exercise in asymptomatic hypertrophic cardiomyopathy: a new description of outflow tract obstruction dynamics.

The purpose of this study was to analyze left ventricular obstruction in patients with hypertrophic cardiomyopathy (HCM) during exercise echocardiography. Despite the association of symptoms with left ventricular outflow tract obstruction in HCM, there exist paradoxical situations in which significant intraventricular gradients (>50 mm Hg) at rest occur in conjunction with excellent exercise tolerance. To examine this phenomenon, we performed exercise echocardiography and analyzed the clinical status of 107 HCM patients with and without resting obstruction. At rest, 69 patients had no obstruction and 38 exhibited an intraventricular gradient, 9 of whom exhibited a decrease in gradient of at least 30 mm Hg (99.4 ± 35.5 mm Hg to 30.2 ± 14.3 mm Hg, p < 0.001) during exercise (paradoxical response to exercise [PRE]). The PRE patients presented with a significantly lower New York Heart Association clinical class and higher left ventricular volumes and arterial pressure both at rest and during exercise than HCM patients in whom the gradient increased or did not change during stress echocardiography. Finally, PRE patients exhibited a trend toward a reduced rate of cardiac events. Our study reports a subgroup of HCM patients, designated PRE based on a decreased intraventricular gradient during exercise. The reduced exertional obstruction may account for the better functional class and trend toward fewer clinical events in PRE patients.

Lafitte S ，Reant P ，Touche C ，Pillois X ，Dijos M ，Arsac F ，Peyrou J ，Montaudon M ，Ritter P ，Roudaut R ，Demaria A ... -  《-》