Efeito da correção cirúrgica nas variáveis do teste cardiopulmonar de exercício em pacientes com insuficiência mitral crônica. / Effect of surgical correction on cardiopulmonary exercise testing in patients with organic mitral regurgitation.

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

09/05/2012

RESUMO

Introduction: Chronic organic Mitral Regurgitation (MR) has a complex physiopathology. The symptoms of heart failure and functional capacity worsening may appear too late, when a left ventricle (LV) contractile dysfunction already exists. The cardiopulmonary exercise testing (CPET) may objectively assess the functional capacity and helps in the medical conduct concerning patients with MR, but little is known about the surgery effect on its variables. Objectives: To evaluate the effects of the MR surgical correction on the variables related to the CPET performed on stationary bicycle and treadmill. Methods: A total of 72 patients with severe MR were selected and underwent a surgery for valvulopathy correction and an echocardiogram (ECHO) and CPET were performed around 30 days before the surgery and then from six to 12 months after the surgery. Results: The patients were aged an average 49.9 ± 16.9 years. There was a predominance of male patients [41 patients (56.9%)], degenerative etiology [50 patients (69.4%)] and NYHA I or II functional class [51 patients (70.8%)]. Forty-seven (47) patients (65.3%) had their mitral valves repaired and 25 patients had them replaced. After the surgery, there was a reduction in the left atrial volume (LAV) from 124.4 ± 58.9 ml to 76.4 ± 34.0 ml (p<0.001), in the LV end-diastolic volume (LVEDV) from 151.7 ± 35.7ml to 109.6 ± 42.8 ml (p<0.001), in the LV end-systolic volume (LVESV) from 47.6 ± 18.0 to 43.9 ± 27.1ml (p<0.001), in the ejection fraction (EF) from 69.1 ± 6.3 to 61.30 ± 8.2% (p<0.001) and in the pulmonary artery systolic pressure (PASP) from 46.7 ± 15.9 to 35.4 ± 12.5 mm Hg (p<0.001). A reduction in the peak consumption of oxygen (VO2) was also observed in both types of exercise testing after the surgery (stationary bicycle: from 1356 ± 506 to 1269 ± 408 mL.min-1, p=0.015; treadmill: from 1618 ± 579 to 1536 ± 447 mL.min-1, p=0.06), as well as in the variable Oxygen Uptake Efficiency Slope (OUES) (stationary bicycle: from 1530 ± 516 to 1414 ± 415, p=0.001; treadmill: from 1761 ± 585 to 1691 ± 508, p=0.050). Pulse oxymetry readings (O2) increased after the surgery only for the CPET performed on the treadmill from 10.7 ± 4.0 to 11.5 ± 3.2 mL. heartbeat -1 (p=0.023). For the CPET performed on the treadmill, the OUES percent difference showed significant negative correlation with the percent difference of LVEDV (r=-0.277; p=0.034), LAV (r=-0.275; p=0.035) and PASP (r=-0.282; p=0.041), respectively. For the CPET performed on the stationary bicycle, the percent difference of the OUES showed a negative correlation only with the percent difference of PSAP (r=-0.359; p=0.010). Conclusion: The mitral valve surgery caused no increase in the peak VO2 or OUES despite the symptomatic improvement as assessed through the functional class (NYHA). However, the variable OUES showed negative correlation with the echocardiographic parameters of cardiac remodeling. The CPET is a useful and promising tool, and may help in the medical conduct concerning patients with MR.

ASSUNTO(S)

chronic mitral regurgitation cirurgia cardíaca exercício exercise insuficiência da valva mitral sintomas surgical cardiac symptoms

ACESSO AO ARTIGO

Documentos Relacionados