title: Impact of exercise-induced mitral regurgitation on hypertrophic cardiomyopathy outcomes.
abstract: OBJECTIVE
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Service de Cardiologie et CIC-IT U 804, Centre Hospitalier Universitaire de Rennes, Hôpital Pontchaillou - CHU Rennes, F-35033 Rennes, France LTSI, Université Rennes 1, INSERM 1099, Rennes, France.
authors.forename: Damien
authors.initials: D
authors.lastname: Feneon
authors.affiliation: LTSI, Université Rennes 1, INSERM 1099, Rennes, France Service des Explorations Fonctionnelles et Médecine du Sport, CHU RENNES, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Schnell
authors.affiliation: Service de Cardiologie et CIC-IT U 804, Centre Hospitalier Universitaire de Rennes, Hôpital Pontchaillou - CHU Rennes, F-35033 Rennes, France LTSI, Université Rennes 1, INSERM 1099, Rennes, France.
authors.forename: Elena
authors.initials: E
authors.lastname: Galli
authors.affiliation: LTSI, Université Rennes 1, INSERM 1099, Rennes, France Service de Cardiologie, CHU Tours, F-37000, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Bernard
authors.affiliation: Service de Cardiologie et CIC-IT U 804, Centre Hospitalier Universitaire de Rennes, Hôpital Pontchaillou - CHU Rennes, F-35033 Rennes, France LTSI, Université Rennes 1, INSERM 1099, Rennes, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Mabo
authors.affiliation: Service de Cardiologie et CIC-IT U 804, Centre Hospitalier Universitaire de Rennes, Hôpital Pontchaillou - CHU Rennes, F-35033 Rennes, France LTSI, Université Rennes 1, INSERM 1099, Rennes, France.
authors.forename: J-Claude
authors.initials: JC
authors.lastname: Daubert
authors.affiliation: Service de Cardiologie et CIC-IT U 804, Centre Hospitalier Universitaire de Rennes, Hôpital Pontchaillou - CHU Rennes, F-35033 Rennes, France LTSI, Université Rennes 1, INSERM 1099, Rennes, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Leclercq
authors.affiliation: LTSI, Université Rennes 1, INSERM 1099, Rennes, France Service des Explorations Fonctionnelles et Médecine du Sport, CHU RENNES, France.
authors.forename: François
authors.initials: F
authors.lastname: Carre
authors.affiliation: Service de Cardiologie et CIC-IT U 804, Centre Hospitalier Universitaire de Rennes, Hôpital Pontchaillou - CHU Rennes, F-35033 Rennes, France LTSI, Université Rennes 1, INSERM 1099, Rennes, France erwan.donal@chu-rennes.fr.
authors.forename: Erwan
authors.initials: E
authors.lastname: Donal
mesh_terms: D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002423:Cause of Death; D015331:Cohort Studies; D025401:Echocardiography, Stress / Q000379:methods*; D005260:Female; D006323:Heart Arrest / Q000209:etiology / Q000401:mortality*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D012737:Sex Factors; D013318:Stroke Volume; D016019:Survival Analysis
keywords: exercise echocardiography; exercise-induced mitral regurgitation; hypertrophic cardiomyopathy; prognosis