Exercise capacity assessment before, after TAVR may improve patient risk stratification

Patient risk stratification may be improved by implementing exercise capacity assessment before and after transcatheter aortic valve replacement, according to data published in Circulation.

A combination of baseline and periprocedural factors was linked to exercise capacity after TAVR, and lack of improvement in exercise capacity after TAVR was linked to poorer clinical outcomes, according to the researchers.

“TAVR is an established therapeutic option for patients with severe aortic stenosis deemed at high risk for open-heart surgery. However, in a considerable portion of patients the intervention appears futile, largely due to a lack of functional status improvement or mortality during the first year post-TAVR,” Omar Abdul-Jawad Altisent, MD, from the Quebec Heart and Lung Institute at Laval University in Quebec City, and colleagues wrote. “Given the clinical and economic implications of TAVR, there is considerable interest in better identifying specific factors implicated in the lack of functional benefit post-TAVR.”

To describe changes in exercise capacity after TAVR and to identify factors linked to clinical outcomes of suboptimal improvement in exercise capacity after TAVR, Abdul-Jawad Altisent and colleagues conducted a prospective single-center study, enrolling 305 patients who underwent TAVR and completed baseline and follow-up exercise capacity assessments 6 months after TAVR.

Researchers evaluated exercise capacity using the 6-minute walk test (6MWT).

A comparison was conducted between patients who displayed greater than (n = 152; improving group) vs. lesser than (n = 153; nonimproving group) the median percentage change in distance walked between baseline and 6-month follow-up exams.

Reduced exercise capacity

The primary outcome measure was clinical event rates, which were measured from the 6-month post-TAVR period onward.

Additionally, researchers assessed further dichotomization according to baseline 6MWT distance ("slow walker" vs. "fast walker").

Mean overall distance walked was 204 ± 119 m before TAVR and 263 ± 116 m 6 months after TAVR (change in 6MWT = 60 ± 106 m). Seventy-two percent of patients demonstrated an increased walking distance, with a median overall increase of 20% (interquartile range, 0-80).

A range of baseline clinical characteristics (older age, female sex, chronic obstructive pulmonary disease; P < .05 for all), periprocedural major or life-threatening bleeding (P = .009) and new-onset anemia at 6 months after TAVR (P = .009) were independently correlated with reduced exercise capacity.

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There was an independent association between failure to improve the 6MWT distance by at least 20% and all-cause death (P = .002), and CV death or re-hospitalization for CV causes (P = .001).

There were better outcomes for baseline slow walkers able to improve 6MWT compared with those who did improve (P = .01 for all-cause death; P = .001 for CV endpoint).

According to the study, approximately one-third of patients failed to improve their exercise capacity after TAVR.

Improved risk stratification

"Implementing exercise capacity assessment pre- and post-TAVR may help to improve patient risk stratification augmenting the accuracy of the prognostic information given to patients and help to identify those patients requiring more intensive medical follow-up assessments,” the researchers wrote. “Among those patients with poor physical performance pre-TAVR, a lack of exercise recover postintervention could be considered an appropriate surrogate endpoint of futility.” – by Dave Quaile

Disclosures: Abdul-Jawad Altisent reports no relevant financial disclosures. Another researcher reports receiving research grants from Edwards Lifesciences and Medtronic.