Valvular heart disease
Exercise Capacity in Patients With Severe Symptomatic Aortic Stenosis Before and Six Months After Transcatheter Aortic Valve Implantation

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Few data exist on the use of the 6-minute walk test (6MWT) to measure the exercise capacity of patients with severe symptomatic aortic stenosis considered at very high surgical risk. The objectives of the present prospective study were (1) to determine the feasibility and safety of the 6MWT as a measure of exercise capacity before and after transcatheter aortic valve implantation (TAVI), and (2) to determine the clinical and hemodynamic parameters associated with the exercise capacity changes in such patients. A total of 64 patients (age 80 ± 8 years, logistic European System for Cardiac Operative Risk Evaluation score 21 ± 15%, Society of Thoracic Surgeons' score 7.5 ± 3.9%) who had undergone successful TAVI were included. The 6MWT was performed within the month before TAVI and at the 6-month follow-up visit. The mean distance walked increased from 165.3 ± 79.7 to 231.7 ± 88.9 m (p <0.0001); however, up to 25% of the patients did not improve or even decreased their exercise capacity. After adjustment for the baseline distance walked, multilinear regression analysis showed that a greater degree of renal dysfunction, as evaluated by the serum creatinine levels (r2 = 0.05, p = 0.03), lower postprocedural hemoglobin values (r2 = 0.13, p = 0.0012), and a longer hospitalization length (r2 = 0.08, p = 0.007) were associated with lower improvement in exercise capacity. In conclusion, exercise capacity, as evaluated by the 6MWT, was very poor in patients with severe symptomatic aortic stenosis considered at very high surgical risk. TAVI was associated with a significant increase in exercise capacity, although no improvement was observed in 1/4 of the patients. A greater degree in renal dysfunction, lower postprocedural hemoglobin values, and longer hospitalization stay were predictors of lower improvement in exercise capacity after TAVI. These results suggest that the 6MWT might become an important tool as a part of the evaluation process for TAVI candidates.

Section snippets

Methods

Of the 119 patients diagnosed with severe symptomatic AS who had undergone TAVI at our center, 64 patients, who had performed a 6MWT before and 6 months after the procedure, were included in the present study. Of the remaining 55 patients, 20 were unable to perform the 6MWT at baseline because of New York Heart Association (NYHA) class IV in 7, severely limited mobility in 3, oxygen dependency in 3, and logistical reasons in 7. Another 28 patients did not perform the 6MWT at follow-up because

Results

The clinical, echocardiographic, and procedural characteristics of the study population are listed in Table 1. All patients performed the 6MWT with no complications. The results of the 6MWT are summarized in Table 2. The mean distance walked improved from 165.3 ± 79.7 m at baseline to 231.7 ± 88.9 m at 6 months after TAVI, for a mean increase of 66.4 ± 81.7 m (Δ83%, 95% confidence interval 39 to 127) versus baseline (p <0.0001). However, this mean distance walked remained much shorter than the

Discussion

The present study showed the usefulness of the 6MWT in a high-risk population of octogenarian patients with severe symptomatic AS. The exercise capacity of these patients was very poor (mean distance walked <200 m), and TAVI was associated with a significant increase in the mean distance walked at 6 months after TAVI. However, up to 25% of the patients did not improve or even decreased their exercise capacity at 6 months after TAVI. A greater degree of renal dysfunction, lower postprocedural

Acknowledgment

We thank Jacinthe Aubé, RN, for her outstanding work on the 6MWTs and patient follow-up and Ms. Nathalie Boudreault for patient follow-up. Rodrigo Bagur, MD, received a 1-year scholarship from the “Centre de Recherche de l'Institute Universitaire de Cardiologie et Pneumologie de Québec.”

References (30)

  • M.A. Clavel et al.

    Predictors of outcomes in low-flow, low-gradient aortic stenosis: results of the multicenter TOPAS Study

    Circulation

    (2008)
  • D.P. de Arenaza et al.

    Preoperative 6-minute walk test adds prognostic information to Euroscore in patients undergoing aortic valve replacement

    Heart

    (2010)
  • R.C. Aitken

    Measurement of feelings using visual analogue scales

    Proc R Soc Med

    (1969)
  • D.A. Mahler et al.

    Comparison of clinical dyspnea ratings and psychophysical measurements of respiratory sensation in obstructive airway disease

    Am Rev Respir Dis

    (1987)
  • R.C. Wilson et al.

    A comparison of the visual analogue scale and modified Borg scale for the measurement of dyspnoea during exercise

    Clin Sci Lond

    (1989)
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    This study was supported in part by grant P57745 from the Canadian Institutes of Health Research, Ottawa, Ontario, Canada.

    Drs. Dumont and Rodés-Cabau are consultants for Edwards Lifesciences, Inc., Irvine, California. Dr. Pibarot has received honoraria for presentations and research grants from Edwards Lifesciences, Inc.

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