Latent obstruction and left atrial size are predictors of clinical deterioration leading to septal reduction in hypertrophic cardiomyopathy.
BACKGROUND
Exercise echocardiography is a reliable tool to assess left ventricular (LV) dynamic obstruction in hypertrophic cardiomyopathy (HCM). The aim of this study was to determine the role of exercise echocardiography in the evaluation of latent obstruction and in predicting clinical deterioration in HCM patients.


RESULTS
We considered 283 HCM patients studied with exercise echocardiography. The end point was clinical deterioration leading to septal reduction (myectomy or alcohol septal ablation). LV latent obstruction was present at enrollment in 67 patients (24%). During a mean follow-up of 42 ± 31 months, 42 patients had clinical deterioration leading to septal reduction therapy: in 12/67 (22%) patients with a latent obstruction at enrollment, in 28/84 (33%) patients with obstruction at rest, and in 2/132 (1.5%) with obstruction neither at rest or during stress. Multivariate analysis identified the following variables as independently associated with the end point: LV gradient >30 mm Hg at rest (hazard ratio [HR] 2.56, 95% CI 1.27-5.14; P = .009), LV gradient >30 mm Hg during stress (HR 4.96, 95% CI 1.81-13.61; P = .002), and indexed left atrial volume (LAVi ) >40 mL/m(2) (HR 2.86, 95% CI 1.47-5.55; P = .002). In patients with a latent obstruction, the strongest independent predictor of outcome was LAVi >40 mL/m(2) (HR 3.75, 95% CI 1.12-12.51; P = .032).


CONCLUSIONS
Assessment of LV gradient during stress with exercise echocardiography is an important tool for the evaluation of latent obstruction in HCM and may have a role in risk stratification of these patients.
Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Palo Alto, California. Electronic address: gherardobis@yahoo.it.
Gherardo
G
Finocchiaro
Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Palo Alto, California; Stanford Cardiovascular Institute, Palo Alto, California.
Francois
F
Haddad
Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Palo Alto, California.
Aleksandra
A
Pavlovic
Cardiovascular Department, Ospedali Riuniti and University of Trieste, Trieste, Italy.
Gianfranco
G
Sinagra
Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Palo Alto, California.
Ingela
I
Schnittger
Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Palo Alto, California; Stanford Cardiovascular Institute, Palo Alto, California.
Joshua W
JW
Knowles
Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Palo Alto, California; Stanford Cardiovascular Institute, Palo Alto, California.
Marco
M
Perez
Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Palo Alto, California.
Emma
E
Magavern
Veterans Affairs Palo Alto Health Care System, Palo Alto, California.
Jonathan
J
Myers
Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Palo Alto, California; Stanford Cardiovascular Institute, Palo Alto, California.
Euan
E
Ashley
D006348:Cardiac Surgical Procedures / Q000379:methods*; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D015150:Echocardiography, Doppler; D025401:Echocardiography, Stress / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006346:Heart Septum / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome; D014694:Ventricular Outflow Obstruction / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery
Hypertrophic cardiomyopathy; exercise echocardiography; left ventricular obstruction