Background: It has been demonstrated that pre-frailty has more adverse outcomes after cardiac surgery, however, data on prognosis and long-term evolution in pre-frailty patients after cardiac surgery without postoperative complications are still scarce. Design: To evaluate the impact of pre-frailty on functional survival in patients after cardiac surgery without complications.

A three-year retrospective study based on a physiotherapy database was conducted, and a sample of 453 patients over 65 years of age was enrolled. All of them had an established diagnosis of cardiovascular disease (myocardial infarction, valve regurgitation or stenosis) determined by previous electrocardiogram and/or Doppler echocardiography, and all had surgical interventions (coronary artery bypass [CAB], valve replacement or valve repair). Patients with prior neurological/muscular disease (previous stroke or muscular dystrophies), cognitive impairment resulting from previous injury, frailty score ≥ 5, non-elective/emergency surgery procedures or incomplete data were excluded.

According to the hospital protocol, frailty was assessed by the Clinical Frailty Score (CFS) 24 hours before the scheduled elective surgery. We assigned patients into two groups based on this score: non-frail (frailty score 1~3) and pre-frail (frailty score 4) according to their CFS.

If patients experienced adverse cardiovascular events-both during surgery or at the ICU- such as stroke, infection, prolonged mechanical ventilation time of more than 24 hrs, ICU stay of more than 48 hrs or in-hospital death, they were excluded. We decided to exclude these patients as our objective was to evaluate patients without any surgical complications as our group recently had demonstrated that pre-frail patients had worse outcomes after cardiac surgery in a short period of time.

All included patients were analysed for 3 years using data from the hospital and physiotherapy database, which included medical appointments every 6 months after hospital discharge and major adverse cardiovascular events (atrial fibrillation, pneumonia, pleural effusion, acute myocardial infarction, heart failure, stroke and death).

This retrospective study was approved by the Institutional Ethics Committee (number 2.352.465).

Inclusion Criteria:

• established diagnosis of cardiovascular disease (myocardial infarction, valve regurgitation or stenosis) determined by previous electrocardiogram and/or Doppler echocardiography, and all had surgical interventions (coronary artery bypass [CAB], valve replacement or valve repair).

Exclusion Criteria:

• neurological/muscular disease (previous stroke or muscular dystrophies), cognitive impairment resulting from previous injury, frailty score ≥ 5, non-elective/emergency surgery procedures or incomplete data

established diagnosis of cardiovascular disease (myocardial infarction, valve regurgitation or stenosis) determined by previous electrocardiogram and/or Doppler echocardiography, and all had surgical interventions (coronary artery bypass [CAB], valve replacement or valve repair).

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