Impact of clinical frailty scale on postoperative outcomes in older adults undergoing cardiac surgery: a three-year real-world analysis

Background Frailty is a key determinant of adverse outcomes in older adults undergoing cardiac surgery, reflecting biological vulnerability beyond chronological age and conventional risk scores such as EuroSCORE and STS. The Clinical Frailty Scale (CFS), developed by Rockwood et al., is a validated 9-point measure from 1 (very fit) to 9 (terminally ill). Scores 1–3 indicate robustness, whereas ≥4 denotes increasing vulnerability, from loss of independence in instrumental activities of daily living to complete dependency and terminal illness. Despite evidence of its prognostic value, real-world data from Latin American surgical populations remain limited, particularly in tertiary referral centres managing complex valvular and coronary disease. Methods We performed a retrospective longitudinal study at a tertiary cardiology referral centre in Latin America receiving patients from secondary and community hospitals. Consecutive patients aged ≥60 years undergoing valve repair or replacement, coronary artery bypass grafting (CABG), or combined procedures over three years were included. Participants were stratified by CFS into low frailty (1–4) and high frailty (5–9). Sociodemographic characteristics, comorbidities, operative variables, and postoperative outcomes were extracted from medical records. Data are presented as medians (interquartile ranges) or absolute and relative frequencies. Group comparisons used chi-square, Fisher’s exact, or Wilcoxon rank-sum tests, as appropriate. Multivariable logistic and linear regression models were fitted adjusting for age and sex. Results A total of 305 patients were included; 59% were male, median age 66 (62–71) years. High frailty (CFS 5–9) was present in 18% (n=58). Baseline characteristics were comparable between groups except for type of surgery (p=0.016), with lower representation of isolated CABG in the high-frailty group (Table 1). Patients with high frailty had worse postoperative outcomes (Figure 1). Median hospital stay was significantly longer in frail patients (21.5 vs 17.0 days; p<0.001) (Figure 2). Frailty was independently associated with prolonged stay (β=5.9 days; 95% CI 0.7–11.0), increased risk of bleeding (OR 2.6; 95% CI 1.1–5.8), and reintervention (OR 2.6; 95% CI 1.2–5.4). Although mortality was numerically higher in frail patients (10.3% vs 6.5%) (Table 2), this difference did not reach statistical significance. No significant differences were observed in stroke (CVA), acute kidney injury, atrial fibrillation, or ventricular arrhythmias. Conclusions In this real-world cohort of older adults undergoing cardiac surgery, higher frailty burden assessed by the CFS was independently associated with prolonged hospitalisation, bleeding, and reintervention. These findings support routine frailty assessment in preoperative risk stratification to improve perioperative planning and optimise outcomes in older adults undergoing cardiac surgery.