Assessment and medium-term follow up of heart transplant candidates undergoing low-intensity exercise

To study cardiovascular behavior and safety regarding a low-intensity exercise program for heart transplant candidates with severe heart failure.

Twenty-one patients with severe heart failure on the transplant list of the UNIFESP university hospital (Brazil) were studied. Following evaluation, the patients were monitored during an exercise program with six progressive phases (1--upper limbs; 2--lower limbs; 3--walking; 4--½ flight of stairs; 5--walking 200 m; and 6--whole flight of stairs), with the intensity estimated at two to six metabolic equivalents (1 MET = 3.5 ml of O2/kg/min.). The patients were prospectively followed up for approximately 17 months for the occurrence of clinical complications and death.

Three patients were unable to perform the complete program; BMI, maximal respiratory pressure (Pimax and Pemax, cmH2O) and number of previous hospitalizations were considered predictors for this subgroup. Heart rate (HR, bpm), double product (DP, bpm x mmHg) and Borg perceived exertion scale (PE) underwent the greatest oscillation during exercise, especially in phase 5 (H"METS), and are considered the best markers related to exertion. Blood pressure (BP, mmHg) oscillated little. There was no increase in the incidence of arrhythmia (Kappa = 0.552) during exercise. There was a moderate positive correlation between PE and BP (r = 0.4; P = 0.02) in phase 5 (walking 200 m). The patients who died had low Pimax values upon the initial evaluation. During the exercise program, there was a reduction in BP response and an increase in HR response.

Regarding cardiovascular behavior, the exercise program proved safe and well tolerated, but there is a need for monitoring. Information obtained upon the initial evaluation and during exercise program is associated to decompensation and death. Such information could assist in determining the stage of the disease.