Cardiac rehabilitation outcome after transcatheter aortic valve implantation.

Patients with severe aortic stenosis are increasingly treated with transcatheter aortic valve implantation (TAVI) as a safer option to surgical aortic valve replacement (sAVR).  Similar to many other heart diseases, after the specific therapeutic intervention patients are eligible for cardiac rehabilitation (CR) for the purpose of functional recovery. Thus far, CR after both sAVR and TAVI has been used to a limited extent, as shown by the availability of only two meta-analyses including 5 studies and 6 studies, respectively. Recent observational studies reported a significant improvement in functional indexes such as the Barthel scale and the 6-minute walk test (6MWT). We evaluated the outcome of CR in patients after TAVI treatment by measuring changes in the commonly used Barthel scale and 6MWT and adding the short physical performance battery (SPPB) scale as an index to assess lower extremity function. All indexes demonstrated a significant improvement, namely p<0.001 with the Barthel scale, p=0.043 for the 6MWT, and p=0.002 for SPPB. These results confirm the significant improvement of the Barthel scale and 6MWT reported in the previous meta-analysis and suggest the utility of SPPB as a further index of efficacy of CR in patients with severe aortic stenosis treated with TAVI.

Training prescription in patients on beta-blockers: percentage peak exercise methods or self-regulation?

BACKGROUND: Exercise prescription based on percentage of peak exercise variables has many limitations in patients taking beta-blockers. The aim of this study was to evaluate efficacy and safety of a training protocol based on the rating of perceived exercise (RPE) in patients taking beta-blockers after cardiac surgical revascularization. DESIGN AND METHODS: 71 patients treated with beta-blockers after recent coronary artery bypass grafting were randomly allocated to two different programmes with training intensity adjusted to keep heart rate close to first ventilatory threshold (36 subjects, AeT group) or RPE between grades 4 and 5 of 10-point category-ratio BORG scale (35 subjects, RPE group). RESULTS: In the RPE group, mean training workloads and heart rate values were significantly higher than in the AeT group; during the last week of the programme, six RPE patients were training very close to anaerobic threshold. Aerobic peak capacity increased similarly in the two groups. Considering the potential effects on training intensity of prescriptions based on percentages of peak exercise variables, we found that only percentage heart rate reserve and peak workload methods were reliable in defining a safe upper limit of training intensity, with values of 50% and 65% respectively. CONCLUSIONS: Self-regulation of exercise training intensity between grades 4 and 5 of the 10-point category-ratio BORG scale is effective but may promote overtraining in some patients without significant functional advantages. For these reasons, RPE method should be integrated with objective indices based on percentage of heart rate reserve or of peak workload.