Safer cardiac surgery is being offered to more high-risk and frail patients, improving both survival and quality of life (QoL) for most. The QoL After Cardiac Surgery Study (QUACS) evaluated QoL changes postoperatively to identify those who do not benefit from and may be harmed by intervention.

Moderate- and high-risk cardiac surgery patients enrolled in a prospective, national multicentre study (2019-2023). Mortality risk, frailty, outlook, affect, and socio-economic status were objectively measured. Quality of life was assessed preoperatively and to 12-24 months postoperatively.

Participants were 2948 patients (EuroSCORE II ≥3 or logistic EuroSCORE ≥6, mean age 72.9 years, female 39.6%). Inclusion criteria were not met in 186 patients, leaving 2762 for analysis. Hospital mortality was 3.93% and 5.86% died after discharge. At 1 year after surgery, net QoL benefit was achieved in 74% of symptomatic patients and in 18% of patients thought asymptomatic. Risk factors for failure to achieve a net QoL benefit were identified, and a preoperative QoL calculator was developed to quantify the likelihood of QoL benefit.

This first study examining QoL changes over time after complex major intervention such as cardiac surgery confirms that some patients do not obtain QoL benefit and helps to identify them. Findings and methodology are applicable to a wide range of major operations. The QUACS Study will improve the process of informed consent and decision-making by patients contemplating such procedures and reduce harmful interventions.