Purpose:

To examine the effect of exercise training on functional capacity and hemodynamic responses in cardiac patients.

Methods:

Two hundred and twenty six cardiac patients (age = 58.0 ± 13 years, height = 1.67 ± 0.9 m, weight = 75.0 ± 12.0 kg, BMI = 26.7 ± 3.7 kg/m2, VO2máx = 13.4 ± 4.9 ml/kg/min), resting heart rate = 71 ± 13 bpm, systolic blood pressure (SBP) = 112 ± 18, diastolic blood pressure (DBP) = 69 ± 10) from our University-based CR program performed a 6-minute walking Test (6MWT) before and after completing a twelve-week exercise program. Functional capacity and VO2máx were estimated based on the 6MWT. Paired t-test was used to determine pre-and post rehabilitation outcomes differences. Effect sizes were also calculated P≤ 0.05 a priori.

Results:

Patients improved their functional exercise capacity using the 6MWT by 31%, from (410 ± 100 to 539 ± 93 m, CI 95% -138.4 to -118.8, P<0.001), and VO2max by 25% from (13.4 ± 5.0 to 16.8 ± 5.2 ml/kg/min, CI 95%-3.7 to -3.1, P< 0.001). Resting SBP was reduced by 3.6 %, from (112 ± 18 to 108 ± 17 mmHg, CI 95% 1.48 to 5.98, P= 0.001) and resting DBP was reduced by 2.9 %, from (69 ± 10 to 67 ± 9.0 mmHg, CI 95% 0.82 to 3.6, P= 0.002). Mean arterial pressure (MAP) was also reduced by 3.6 %, from (83 ± 11 to 80 ± 10 mmHg, CI 95% 1.2 to 4.2, P< 0.001). Effect sizes for 6MWT, VO2max, SBP, DBP and MAP were (1.29, 0.68, 0.22, 0.22 and 0.27 respectively). Patients exhibited a greater five minute heart rate recovery after post 6MWT 35 beats per minute, (CI 95% 20.9 a 24.8, P<0.001) versus 23 beats per minute, (IC 95% 33.3 a 37.7, P<0.001) at the beginning of the CR. We also had a greater SBP recovery 29 mmHg (CI 95% 15.06 a 19.25, P<0.001) than 17 mmHg at, (IC 95% 25.01 a 32.6, P<0.001) at the initial of the CR program. The effect sizes for heart rate and SBP recovery after the 6MWT were 0.85 and 0.73 respectively.

Conclusion:

Our twelve-week cardiac rehabilitation program improved functional capacity and enhanced hemodynamic responses after exercise. These findings provide plausible evidence that CR may contribute to improved survival and quality of life in Costa Rican CR patients.