Longitudinal Changes in Exercise Capacity in Patients Who Underwent Ross Procedure and Mechanical Aortic Valve Replacement: Does the Type of Surgery Matter?
Takajo D, Kota V, Balakrishnan PPL, Gayanilo M, Sriram C, Aggarwal S.Pediatr Cardiol. 2021 Jun;42(5):1018-1025. doi: 10.1007/s00246-021-02575-4. Epub 2021 Mar 8.PMID: 33682063
Take Home Points:
- Young children who undergo aortic valve replacement experience a decrease in exercise capacity in long term follow-up.
- On the other hand, young children who had undergone the Ross procedure have a preserved exercise capacity.
- This was due to a prosthesis-patient-mismatch, in patients who underwent aortic valve replacement, as they grow; while patients who had the Ross procedure had a preserved exercise capacity due to the growing autograft.
Commentary from Dr. MC Leong (Kuala Lumpur), section editor of ACHD Journal Watch:
The Ross procedure (RP) and aortic valve replacement (AVR) are two commoner procedures employed in the treatment of severe aortic valve disease in children. In the former, the single valve disease is converted into a two-valve disease and often the long-term outcome depends heavily on the surgical expertise. However, the autograft grows with the growing child and it is favoured over AVR in the treatment of very young children due to the concerns of prosthesis-patient mismatch and the warfarin treatment, diet restrictions, and the inherent complications that come along with a mechanical AVR.
In this study, the authors retrospectively examined the exercise capability between children who underwent RP and AVR as well as the longitudinal changes in exercise performance after these procedures in their institution from 2005 and 2020. Patients with other concomitant congenital heart disease or pacemaker/defibrillator were excluded. Patients were considered to have a longitudinal assessment if there is more than one cardiopulmonary exercise tests after the initial aortic valve intervention.
A total of 47 patients were included – RP [n=23, 73.9% male, age at surgery 11.2 (4.5–15.9) years] vs. AVR [n=24, 88% mechanical AVR, 60.9% male, age at surgery 15.1 (12.8–19.4) years] (Table 1). At baseline, the cardiopulmonary exercise parameters were largely comparable between groups except for the % VO2. Only 23 patients had longitudinal assessments – 12 patients in the RP group [58.3% male, inter-test duration 7.1 (5.8–9.5) years] (Table 3) vs n 11 patients in the AVR group [54.5% male, inter-test duration 5 (3.7–7.1) years] (Table 4). In the RP group, there was a significant improvement in the VE/VCO2 at anaerobic threshold during follow-up. The other parameters showed no significant change. However, in the AVR group, there was a decrease in (i) peak exercise capacity or VO2 (34.2 vs. 26.2 vs., p=0.006), (ii) %VO2 (85 vs. 59, p=0.003) (Figure 2), (iii) METS (9.8 vs.7.5, p=0.006), and (iv) % oxygen pulse (111 vs. 94, p=0.04). There were more patients with abnormal %VO2 at follow-up (45% vs. 100% of patients). The drop in the CPET parameter, according to the authors, was likely attributed to the prosthesis-patient mismatch in these growing patients. This drop was not seen in the RP group underscoring the growth potential of the autograft.
One of the biases in this study was the presence of a higher number of patients in the AVR group who were on beta blockers (8, 33.3%) and Digoxins (4, 16.7%) compared to the that of the RP (5, 21.7% and 1, 4.3%) (Table 1). These patients may have chronotropic incompetence which may lower the cardiac output, thus affecting exercise capacity.