Design: pilot randomised controlled trial (NCT06323317) with centre-based, home-based and online delivery over at least four weeks
Population: 51 adults with mild to moderate frailty awaiting elective coronary artery or valve surgery — 26 prehabilitation, 25 usual care
Primary outcome: functional capacity measured by the Short Physical Performance Battery
Effect: β = 0.99 (95% CI 0.08–1.90) the day before surgery and 1.04 (0.05–2.03) at three months; Fried frailty reduced at both points (Hedges' g 0.92–1.18); 89% adherence; no difference in readmission or length of stay

Prehabilitation before cardiac surgery is usually generic aerobic conditioning, which is not what the frailty literature recommends — frailty responds to resistance work. A pilot randomised trial tested a frailty-specific programme in 51 adults with mild to moderate frailty awaiting elective coronary artery or valve surgery, randomising 26 to prehabilitation and 25 to usual care. The programme ran at least four weeks and combined education, nutritional optimisation, stress management and individualised resistance-focused exercise, delivered through a mix of centre-based, home-based and online sessions.

Functional capacity improved. The Short Physical Performance Battery was higher in the prehabilitation group the day before surgery (β = 0.99, 95% confidence interval 0.08 to 1.90, P = 0.032) and three months after the intervention (β = 1.04, 0.05 to 2.03, P = 0.040). Fried frailty category fell at both time points with large effect sizes (Hedges' g 0.92 to 1.18), and quality of life improved at one and three months. Adherence was 89% and adverse events minimal. What did not differ were biomarkers, clinical events, unplanned readmission and length of stay.

A pilot of 51 patients was never going to move readmission or stay, and the authors do not claim it did. What it supports is the design principle: a resistance-focused, individualised programme shifted the frailty measure itself in four weeks, which generic aerobic prehabilitation has largely failed to do. Four weeks also happens to be available in most elective cardiac surgical waits, which is the practical reason this is worth setting up rather than waiting for the full-scale trial.

Make prehabilitation resistance-focused and individualised rather than generic aerobic conditioning.
Use the elective surgical wait — four weeks was enough to move the frailty measure.
Combine exercise with nutritional optimisation and education; the programme was multi-component.
Measure the Short Physical Performance Battery before and after so the effect is visible locally.
Do not promise shorter stay or fewer readmissions; this trial showed neither.

Why it matters

Frailty has been treated as the reason a patient does badly after surgery rather than as something the pre-operative weeks could change.

The statistics, in plain English

A Short Physical Performance Battery improvement of about one point is around the threshold usually considered clinically meaningful, but both confidence intervals reach close to zero (0.08 and 0.05), so the smallest effects compatible with the data would not be noticeable. The large Hedges' g values for frailty and quality of life should be read cautiously: in a 51-patient pilot, effect sizes are estimated imprecisely and tend to be inflated. The absence of difference in readmission and length of stay is not evidence of no effect — a trial this size could not have detected one.