Reduced Long-Term Relative Survival in Females and Younger Adults Undergoing Cardiac Surgery: A Prospective Cohort Study

Abstract

ObjectivesTo assess long-term survival and mortality in adult cardiac surgery patients.Methods8,564 consecutive patients undergoing cardiac surgery in Trondheim, Norway from 2000 until censoring 31.12.2014 were prospectively followed. Observed long-term mortality following surgery was compared to the expected mortality in the Norwegian population, matched on gender, age and calendar year. This enabled assessment of relative survival (observed/expected survival rates) and relative mortality (observed/expected deaths). Long-term mortality was compared across gender, age and surgical procedure. Predictors of reduced survival were assessed with multivariate analyses of observed and relative mortality.ResultsDuring follow-up (median 6.4 years), 2,044 patients (23.9%) died. The observed 30-day, 1-, 3- and 5-year mortality rates were 2.2%, 4.4%, 8.2% and 13.8%, respectively, and remained constant throughout the study period. Comparing observed mortality to that expected in a matched sample from the general population, patients undergoing cardiac surgery showed excellent survival throughout the first seven years of follow-up (relative survival ≥ 1). Subsequently, survival decreased, which was more pronounced in females and patients undergoing other procedures than isolated coronary artery bypass grafting (CABG). Relative mortality was higher in younger age groups, females and patients undergoing aortic valve replacement (AVR). The female survival advantage in the general population was obliterated (relative mortality ratio (RMR) 1.35 (1.19–1.54), p<0.001). Increasing observed long-term mortality seen with ageing was due to population risk, and younger age was independently associated with increased relative mortality (RMR per 5 years 0.81 (0.79–0.84), p<0.001)).ConclusionsCardiac surgery patients showed comparable survival to that expected in the general Norwegian population, underlining the benefits of cardiac surgery in appropriately selected patients. The beneficial effect lasted shorter in younger patients, females and patients undergoing AVR or other procedures than isolated CABG. Thus, the study identified three groups that need increased attention for further improvement of outcomes.

Short- and long-term survival after isolated coronary artery bypass grafting, the impact of gender and age

“…A study from Trondheim, Norway from 2016 followed patients that had undergone CABG, aortic valve replacement (AVR) or both. This study reported that female patients and patients in the age groups under 60 years and 60-69 years had reduced long-term survival compared to the general population, while male patients older than 70 years had improved survival [20]. The findings regarding female patients, male patients older than 70 years and patients in the age group 60-69 years differs from the findings in our study.…”

Long-term results after aortic valve replacement for bicuspid or tricuspid valve morphology in a Swedish population

“…There was a clear negative impact of known risk factors [ 14 ], such as diabetes, COPD, heart failure, reduced renal function and smoking at the time of surgery, both for observed and relative survival. Observed and relative survival were reduced in patients with atrial fibrillation.…”

“…Studies in coronary surgery without AVR have repeatedly shown that surgery has a substantial effect on the mortality risk of CAD. In a Norwegian population, Enger et al [ 14 ] showed that CABG conveyed persistently better relative survival than that in the general population.…”

Gender and intraoperative blood transfusion: analysis of 54,122 non-reoperative coronary revascularization procedures

“…41,42 The benefit of female gender for longer life expectancies than men is lost when they undergo cardiac surgery. 43 It is difficult to determine the reason why women experience higher mortality than men post-cardiac surgery. Although some studies have stated that transfusion or RBC is an independent risk factor for mortality, others have shown that transfusion may play a secondary role and that other undetermined factors related to gender may also be important.…”