The 12-week progressive quadriceps resistance training improves muscle strength, exercise capacity and quality of life in patients with stable chronic heart failure

Abstract

Background: Abnormalities in the skeletal musculature underlie exercise intolerance in chronic heart failure (CHF). We investigated, whether in CHF selective resistance training without accompanying aerobic regime favourably affects muscle strength, muscle mass and improves exercise capacity.

Methods: Ten patients with stable ischaemic CHF in NYHA class III (9 men, age: 70+/-6 years [mean+/-SD], left ventricular ejection fraction: 30+/-5%, peak oxygen consumption [peak VO(2)]: 12.4+/-3.0 mL/min/kg) underwent the rehabilitation programme which consisted of a 12-week training phase (progressive resistance exercises restricted to the quadriceps muscles) followed by a 12-week detraining phase.

Results: All subjects completed a training phase of the programme with no adverse events. Resistance training markedly increased quadriceps strength (right leg: 260+/-34 vs. 352+/-28 N, left leg: 264+/-38 vs. 342+/-30 N, both p<0.01 - all comparisons: baseline vs. after training), but did not affect lean tissue mass of lower extremities (both p>0.2). It was accompanied by an improvement in clinical status (all NYHA III vs. all NYHA II, p<0.01), quality of life (Minnesota questionnaire: 44+/-15 vs. 33+/-18 points, p<0.05), exercise capacity assessed using a distance during 6-minute walk test (6MWT: 362+/-83 vs. 455+/-71 m, p<0.01), but not peak VO(2) (p>0.2). Plasma NT-proBNP remained unchanged during the training. At the end of detraining phase, only a partial improvement in quadriceps strength (p<0.05), a 6MWT distance (p<0.05) and NYHA class (p=0.07 vs. baseline) persisted.

Conclusions: Applied resistance quadriceps training is safe in patients with CHF. It increases muscle strength, improves clinical status, exercise capacity, and quality of life.