Determinants of peak oxygen uptake in patients with hypertrophic cardiomyopathy: a single-center study.
Most patients with hypertrophic cardiomyopathy (HCM) usually complain of a reduced exercise capacity, and several factors have been advocated as possible causes of this clinical feature. The present single-center study was designed to investigate exercise capacity and its main clinical determinants in HCM patients. One hundred ninety seven patients of 223 evaluated underwent a complete clinical assessment, including Doppler echocardiography, cardiopulmonary exercise test (CPET) and, in most cases, cardiac magnetic resonance. The HCM population (male 75 %; age 47 ± 16 years; NYHA class I or II 95 %; left ventricular ejection fraction 61 ± 3 %; resting left ventricular outflow tract gradient ≥30 mmHg 22 %; late gadolinium enhancement presence 58 %) showed slightly reduced mean peak oxygen uptake values (pVO2 75 ± 15 %, 23.2 ± 6.7 ml/kg/min) with a significant reduction of the achieved percentage of peak heart rate reserve (%pHRR 65 ± 20 %). Adopting a pVO2 <80 % cut-off value, 59 % of HCM patients showed a reduced exercise capacity. Age, male gender, left atrial size, chronotropic and systolic blood pressure response, ventilatory efficiency, late gadolinium enhancement presence and β-blocker therapy were independently associated with pVO2 (R (2)-adjusted index 0.738). A %pHRR cut-off value of 74 % appeared to most accurately predict an impaired exercise capacity (area under curve 0.90). A great prevalence of reduced exercise capacity is present in NYHA class I-II HCM patients. Notwithstanding its multifactorial genesis, few parameters might be adopted in identifying this feature. In this context, %pHRR value might represent a reliable and easy-to-obtain tool for the clinical evaluation of HCM patients.
Cardiology Unit, Department of Clinical and Molecular Medicine, Sapienza University, Rome, Italy.
Damiano
D
Magrì
Piergiuseppe
P
Agostoni
Filippo Maria
FM
Cauti
Beatrice
B
Musumeci
Gabriele
G
Egidy Assenza
Carlo Nicola
CN
De Cecco
Giuseppe
G
Muscogiuri
Antonello
A
Maruotti
Agnese
A
Ricotta
Erika
E
Pagannone
Laura
L
Marino
Daria
D
Santini
Giulia
G
Proietti
Andrea
A
Serdoz
Francesco
F
Paneni
Massimo
M
Volpe
Camillo
C
Autore
D002312:Cardiomyopathy, Hypertrophic / Q000378:metabolism* / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism*
D010100:Oxygen