Dissecting functional impairment in hypertrophic cardiomyopathy by dynamic assessment of diastolic reserve and outflow obstruction: A combined cardiopulmonary-echocardiographic study.

Exercise limitation in hypertrophic cardiomyopathy (HCM) patients is often attributed to left ventricular outflow tract (LVOT) obstruction and diastolic impairment. However, these features assessed at rest fail to predict performance. To evaluate their variations and interplay during effort in HCM, we performed echocardiographic assessment of diastolic function and outflow obstruction during cardiopulmonary test (CPX). We included 197 HCM patients (mean age 45±15years, 129 males), undergoing CPX. Diastolic dysfunction (DD) grade was measured at baseline and at peak exercise. Oxygen consumption (VO2 max) values <75% of maximum predicted were considered abnormal. One hundred-seven patients (54%) had DD grade II-III at rest (Rest DD), 40 (20%) showed preserved diastolic function (grade 0/I) both at rest and on effort (No DD). The remaining 50 patients (25%) had a grade 0/I pattern at rest but exhibited impaired diastolic reserve on exercise (Latent DD). Latent DD was associated with higher prevalence of patients with VO2<75% in both the non-obstructive and the latent-obstructive group: at multivariate regression analysis, left atrium volume index, LV obstruction at rest and rest or latent DD were significantly associated with lower peak VO2. Excluding rest-obstructive patients from the analysis, rest- or latent DD were the only determinants of exercise impairment (latent-obstructive, OR 8.9; 95% CI 1.5-18.8; p=0.012; non-obstructive, OR 2.2; 95% CI 1.0-5.8; p=0.03). Latent DD is a major determinant of exercise intolerance in HCM. Comprehensive assessment of outflow obstruction and diastolic reserve during cardiopulmonary test represents an important adjunct to clinical management.

Re F ，Zachara E ，Avella A ，Baratta P ，di Mauro M ，Uguccioni M ，Olivotto I ... -  《-》

Rest and latent obstruction in hypertrophic cardiomyopathy: impact on exercise tolerance.

Re F ，Zachara E ，Avella A ，Baratta P ，Di Mauro M ，Penco M ，Musumeci F ，Tondo C ... -  《-》

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 ... -  《-》

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 ... -  《-》

Relationship between outflow obstruction and left ventricular functional impairment in hypertrophic cardiomyopathy: a Doppler echocardiographic study.

Araujo AQ ，Arteaga E ，Ianni BM ，Fernandes F ，Ramires FJ ，Buck PC ，Salemi VM ，Nastari L ，Mady C ... -  《-》