An Evaluation of Phase IV Participants

Aims To evaluate the health and fitness of long-term Phase IV cardiac rehabilitation (CR) participants.

Introduction Exercise training is considered a cornerstone intervention in Phase III and Phase IV CR. The benefits of exercise are only retained with adherence. Very little evaluative work has been conducted on those who remain involved in Phase IV to investigate their health and functional status in relation to key risk management criteria (i.e. BMI, waist circumference, blood pressure and functional status).

Methods 34 Phase IV participants (male = 24; female = 10; mean age 72.74 ±5.71 years) with at least 6 months engagement in a once weekly CR circuit exercise class completed anthropometric (BMI and waist circumference), health measurements (resting blood pressure), and 6-minute shuttle walking distance (6MWD) for functional capacity. Comparison was made to a Phase III dataset (n= 669) obtained from the local CR team to evaluate health and functional status of long-term Phase IV participants.

Results There was a 10% increase in those with a BMI > 25kg.m2 from Phase III to Phase IV (66% - 76% of the group). The mean BMI in the Phase IV cohort was 27.33 ±3.57kg.m2 and regional weight distribution measured by waist circumference was 99.72±11.92cm and 87.25 ±8.27cm in males and females respectively. Blood pressure remained in a normotensive range. 6MWD improved from a mean of 437.38 ±91.16m to 488.26 ±89.61m (11.62% improvement). Using the ACSM (2014) formula based on walking speed (m.min-1) in the 6MWD test, this represented a MET improvement from 3.08 to 3.32 METs for a sub-maximal walking effort.

Conclusion A small improvement in sub-maximal functional capacity achieved in this Phase IV CR population, as measured by 6MWD. However, the MET equivalent value for this effort was only just in the moderate intensity range and below the 5-MET threshold normally associated with higher risk stratification. There is scope for education reinforcement related to healthy weight management to control for the risk associated with overweight / obesity, as measured by BMI and waist circumference in both the male and female Phase IV CR population.