Post-cardiac surgery mortality greatest after 75 years of age
medwireNews: The relationship between age and mortality after cardiac surgery is exponential rather than linear, with the greatest risk occurring in patients aged 75 years and older, research shows.
“The outcomes-driven age cutoffs derived and validated in this study are preferable to the arbitrary and variable age cutoffs currently used to define elderly in day-to-day practice and in clinical trials”, say Jonathan Afilalo (McGill University, Montreal, Canada) and colleagues.
They add: “Although advanced age should not be overemphasized as a sole predictor for risk stratification, it remains the starting point for many clinical decisions in cardiovascular medicine, which, to-date, had yet to be objectively defined.”
Afilalo and team characterised the relationship between age and adverse outcome in 6571 consecutive patients aged 50 years and older (mean age 69.1 years, 30.3% women) undergoing isolated coronary artery bypass grafting (CABG; 50.1%), isolated valve repair or replacement (30.6%) or combined CABG plus valve repair or replacement (19.3%) at three hospitals in the USA and Canada.
At 30 days postsurgery, the overall mortality was 2.1%. The researchers found that after controlling for gender and type of operation, the relationship between age and 30-day operative mortality was nonlinear.
Indeed, when age was categorised in 5-year increments, the odds of mortality was only significantly increased for patients aged 75 years and older, compared with those younger than 60 years. Specifically, the odds ratios for mortality were 3.08, 4.66 and 4.32 in patients aged 75–79, 80–84 and 85 years and older.
Receiver operating characteristic analysis, conducted in derivation (n=3220) and validation (n=3351) subsets, showed that the optimal cutoffs to discriminate between survivors and nonsurvivors were greater than 74, 78 and 75 years for isolated CABG, isolated valve surgery, and CABG plus valve surgery, respectively.
The researchers also observed a sharp decline in initial survival for the patients aged 75–79, 80–84 years and 85 years and older during the first 3 to 6 months after surgery. In the former two groups, this stabilised and followed a more gradual decline parallel to the younger age groups thereafter.
However, for the patients aged 85 years and older, the initial sharp decline continued for up to 2 years, indicating that these patients have “the most marked risk profile”, Afilalo and co-authors remark.
The researchers conclude in Circulation: Cardiovascular and Quality Outcomes: “[T]he implications of our findings are to equip clinicians and researchers with a prognostically meaningful definition of elderly in the context of cardiac surgery, which they can use as an upfront screening criterion to broadly identify older adults at higher risk of operative mortality that benefit from comprehensive geriatric assessment to better assess their risk and individualize their therapeutic plan.”
By Laura Cowen
medwireNews is an independent medical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2016