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Completed

NCT Number: NCT01593007

Inspiratory Muscular Training

Objectives: To evaluate regional lung ventilation distribution in patients suffering from chronic heart failure (CHF) after completing inspiratory muscle training (IMT) and correlate it with functional capacity and quality of life among these individuals. Methods and Results: Nineteen CHF patients were randomly assigned to two groups: Control and IMT. Before and after muscle training, subjects were submitted to assessment protocol for respiratory muscles, digital spirometry, optoelectronic plethysmography (OEP), the six-minute walk test (6MWT) and a quality of life questionnaire (MLHFQ). There was no difference in lung function following the 12-week training period in either group. However, the IMT group showed an increase in actual and predicted MIP, higher MLFHQ score and greater distance walked in the 6MWT, as well as a reduction in the Borg scale after the 6 MWT in relation to the control. For the OEP, IMT group members exhibited higher values for total chest wall volume (Vcw), abdominal rib cage volume (Vrc,a) and abdominal volume (Vab) when compared to the control. Conclusions: For patients with CHF, IMT proved efficient in improving muscle strength, functional capacity and quality of life. The present study also analyzed the distribution behavior of lung volumes for the thoracoabdominal system in this population, showing that larger abdominal rib cage and abdomen volumes may result in more effective diaphragmatic contraction.

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Key information

Conditions

Heart Failure Cardiovascular Diseases Heart Diseases

Age range

21 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Departamento de Fisioterapia-Universidade Federal de pernambuco

Recife, Pernambuco, Brazil

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • sedentary adults diagnosed with functional class II and II CHF in accordance with the New York Heart Association (NYHA);
  • in stage B or C according to American College of Sports Medicine guidelines;
  • with left ventricle ejection fraction lower than 45% (evaluated by echocardiogram in a period ≤ 1 year);
  • cardiomegaly confirmed by increased left ventricle end-diastolic (LVDD) and end-systolic diameter (LVESD) associated with a cardiac index (CI) >0.5 according to chest X-rays;
  • inspiratory muscle weakness (MIP <70% of predicted values);
  • clinical stability with no change in medication for at least three months and sedentary (no regular physical activity performed in the previous six months or not accumulating 30 minutes or more of moderate physical activity - 3 to 6 METs - on most week days).

Exclusion criteria

  • patients exhibiting unstable angina, myocardial infarction or prior heart surgery up to three months before beginning the investigation;
  • orthopedic, infectious or chronic metabolic diseases;
  • treatment with steroids, hormones or chemotherapy;
  • ratio between forced expiratory volume in one second and forced vital capacity (FEV1/FVC) < 70% of predicted, characterizing an obstructive respiratory disorder;
  • respiratory diseases, smokers and ex-smokers with a history of cigarettes/day for more than 10 years.

Treatment and study plan

Inspiratory Muscle Training

Other

All participants were instructed to use a Threshold® trainer for 30min a day, seven times a week over 12 consecutive weeks.10 Patients in the Control Group used a Threshold ® device without resistance, making them blind to the treatment. For the treatment group, inspiratory resistance of the Threshold® trainer was 30% of MIP, adjusted on a weekly basis to remain constant.

Control Group

Other

Patients from the control group were also assessed weekly to ensure homogenization of the learning effect for the manometer maneuver.

Primary outcomes

  1. Respiratory muscles

    Time frame: 3 months

    In order to evaluate inspiratory muscle strength, a digital manometer was used (MVD-300, Globalmed, Brazil) connected to a mouthpiece with a 2mm opening to reduce the influence of pressure caused by glottal closure. In a sitting position, each patient performed up to six maneuvers to obtain MIP, from residual volume (RV) to total functional capacity (TFC), considering the best of three maneuvers with < 10% variation between them

Secondary outcomes

  1. Assessment of respiratory mechanics by Optoelectronic Plethysmography

    Time frame: 3 months

    The optoelectronic plethysmography system (OEP) of BTS Bioengineering (Italy) was employed in this study. To that end, a calibration instrument was used, containing three axes connected to reflective markers. This phase does not require participation by the individual to be examined. This creates a three-dimensional model, dividing the thoracoabdominal system into three parts: pulmonary rib cage (RCp), abdominal rib cage (RCa) and the abdomen (AB).

  2. Evaluation of submaximal functional capacity

    Time frame: 3 mounths

    Functional capacity was assessed by the six-minute walk test (6MWT), according to the protocol published by the American Thoracic Society (ATS).

  3. Quality of Life Questionnaire: Minnesota Living With Heart Failure Questionnaire (MLHFQ)

    Time frame: 3 months

    The MLHFQ is a questionnaire validated for the Brazilian population, consisting of 21 questions regarding limitations frequently associated with the extent to which heart failure has affected patient's lives in the previous month. Each question is attributed a value from 0 (zero) to 5 (five), with the highest score indicating worse quality of life. The total score is calculated by adding the 21 items, with a possible interval between 0 and 105.

Sponsors and collaborators

Lead sponsor

Universidade Federal de Pernambuco

Other

Collaborators

  • Conselho Nacional de Desenvolvimento Científico e Tecnológico
  • Fundação de Amparo à Ciência e Tecnologia de Pernambuco

Registry information

Official study title

REGIONAL LUNG VENTILATION DISTRIBUTION AMONG INDIVIDUALS WITH CHRONIC HEART FAILURE AFTER AN INSPIRATORY MUSCLE TRAINING PROGRAMM: A RANDOMIZED CONTROLLED CLINICAL TRIAL

Important dates

Study start
2010
Primary completion
2011
Study completion
2011
First posted
May 7, 2012
Registry last updated
Jun 13, 2012

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

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This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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