Evaluation of Patients with Artificial Aortic Valves by Cardiopulmonary Exercise Testing According to Valve Size

OBJECTIVE
The aim of this study was to evaluate the effect of valve size on left ventricular function, functional status and exercise duration as assessed by cardiopulmonary exercise testing in patients with aortic valve replacement due to severe aortic stenosis.
METHODS
We studied on 40 asymptomatic patients (8 women, 32 men, mean age 46±12) in whom aortic prostheses had been implanted. M-mode, 2-D and, cardiopulmonary exercise testing parameters were evaluated in all patients at a mean of 5±4 years after operation.
RESULTS
Patients were classified in two groups; Group I consisted of 18 patients whose valve size was 21mm or smaller and Group II of 22 patients with a valve size greater than 21 mm. We did not observe any statistical difference between these two groups, according to age, left ventricular systolic and diastolic function, thickness of interventricular and posterior walls and mean aortic gradient. On the other hand, the maximal pressure difference between Group I and Group II was significant (40±15mmHg, 29±8mmHg, respectively; p<0,03). In addition, peak VO2 (p<0,003), anaerobic treshold VO2 (p<0,001), peak VO2 /kg (p<0,03), and peak PVO2/HR (p<0,001) were significantly higher in Group II.
CONCLUSION
Cardiopulmonary exercise parameters such as peak VO2, anaerobic threshold, peak VO2 /kg and peak PVO2/HR were significantly higher in patients with greater valve size. Therefore, patients with greater valve size had a better functional capacity and higher peak stroke volume.