Aortic valve stenosis (AS) is the most common heart valve disease in developed countries,1 with an estimated prevalence of around 3% in patients aged 65 years or more, but gradually increases with age, reaching 4.3% between 76 and 85 years and 7.4% over 85.2

Mortality significantly increases with the onset of symptoms, with approximately a 50% risk of death in the first two years.3,4 Besides the higher risk of death, patients also present a considerably impaired quality of life.5 Prognosis can be modified with an aortic valve intervention, such as surgical aortic valve replacement (SAVR) or transcatheter aortic valve implantation (TAVI). Subsequently, more than 65000 and 67500 AVR are performed each year in Europe and the United States of America, respectively.6 Although AS already represents a considerable burden that requires intervention, the number of patients with AS will increase in the next decades due to an aging population.7,8 Moreover, both the proportion and absolute number of older patients being offered interventions will increase.

Elderly patients have a higher incidence of comorbidities and have been classically associated with a substantial increase in morbidity and mortality, with up to 78% of major complications and death after cardiac surgery occurring in patients over 75 years.9 Yet, improvements in patient selection, extracorporeal circulation, perioperative management and surgical techniques have significantly reduced morbidity and mortality over the past years, enabling safe aortic valve interventions in older patients. Mortality in octogenarians was reported to be as high as 24% in 1988, decreasing to 15.7% in 1991 and approaching 4% in 2015.10–12

In 2021, life expectancy in Portugal at the age of 65 was 19.6 years (17.8 years for males and 21 for females), and in the same year, approximately 23.8% of the Portuguese population were aged 65 or over.13 The percentage of elderly patients in Portugal will increase in the next decades, and the number of octogenarians being offered interventions will probably also rise, as predicted in other developed countries.11,12

The aim of this study was to assess the safety of SAVR in octogenarians, evaluating perioperative outcomes and in-hospital and long-term mortality, comparing patients with low surgical risk (EuroscoreII <4%) with patients with intermediate and high risk (EurosoreII ≥4%).

Our study shows that SAVR in octogenarians is associated with low mortality rate, with satisfactory perioperative morbidity and in-hospital mortality. Moreover, patients with low surgical risk have very acceptable five-year survival rates, similar to what is expected in general population.13 Surgery in octogenarians is associated with a considerable proportion of postoperative complications, which were significantly higher in patients with intermediate-high surgical risk.

Age is an important and established predictor of perioperative morbidity and mortality in cardiac surgery. It is one of the greatest contributors to postoperative mortality, at the level of urgent or emergent presentation.16 The risk increases with age, and Hannan et al. have demonstrated that the adjusted hazard ratio for 30-month survival in patients with aortic stenosis undergoing SAVR increases from 1.57 in 65–74 years to 3.96 in patients over 84 years.17 It is well known that the strong and clear association between age and surgical outcomes has a considerable impact on the decision to operate. In fact, age is one of the main reasons to decide against surgery and was one of the preponderant factors to deny intervention in 33% of elderly patients with severe symptomatic aortic stenosis in the Euro Heart Survey.18

However, even in elderly patients with severe symptomatic aortic stenosis, the negative impact of conservative treatment remains unacceptable. It has been shown that SAVR confers significant survival benefits in patients aged 80 and over, with patients denied surgery having up to 12-fold increased mortality risk.19 Thus, the decision to operate should not rely solely on preoperative risk estimation and should consider the risk-benefit ratio, potential improvement in quality of life, current life expectancy and patient decision. Thereby, current recommendations for SAVR in octogenarians should consider the available data for three factors we will explore further: (1) recent improvements in cardiac surgery that lead to low morbidity and mortality rates; (2) postoperative improvement in quality of life; and (3) cost-effectiveness.

First, recent advances in cardiac surgery have substantially reduced perioperative morbidity and mortality in all patients. Despite the increase in patient risk profile and comorbidities, mortality in cardiac surgery has been consistently reduced,20,21 enabling older patients to undergo surgery with acceptable risk. Mortality rates after SAVR in octogenarians are now low, ranging from 1.9% to 4.5%.22–25

Second, while survival is clearly important to measure the success of surgery, it may not be the major factor in clinical decision to operate older patients, since improvements in quality of life can be much more impactful. Current evidence shows that surgery in elderly patients clearly reduces cardiac symptoms, equals or increases quality of life (compared to age-matched general population and to younger patients submitted to SAVR) and significantly increases patients’ functional status.26 Quality of life in the elderly can be assessed by diverse questionnaires, with the Short-form 36 Health Status questionnaire (SF-36) being the most frequently used.27 It includes 36 health-related multiple-choice questions covering eight domains (physical functioning, role physical, bodily pain, general health, vitality, social functioning, role emotional and mental health) to measure both physical and mental components. Using the SF-36, Bento et al. reported significant improvements in all domains at three, six and 12 months after SAVR in 163 octogenarians in Portugal, identical to other reports in several other developed countries.24,28,29

Finally, even from an economic perspective, SAVR has advantages in octogenarians. One way to evaluate the economic impact of an intervention is the cost-effectiveness ratio (CER), which provides the cost for gaining one additional quality-adjusted life year (QALY). It is commonly used to compare treatments and/or interventions. Wu et al. reported that the overall CER for a SAVR is $13528 per QALY and increases with age, up to $19826 in octogenarians.30 Commonly accepted thresholds establish less than $20000 per QALY as very cost-effective,31 so SAVR is very cost-effective in all patients, including patients aged between 80 and 89 years old.30 Moreover, Wu et al. have also shown that the return on the investment for SAVR is enormous for patients of all ages, even in very elderly patients.30,32

Currently, it is essential to consider TAVI when analyzing surgical results in this particular population. The NOTION trial, the only low-risk randomized controlled trial involving an elderly population, did not reveal a statistically significant difference between TAVI and SAVR concerning the composite endpoint of death, stroke, or myocardial infarction.33 Subgroup analyses of elderly patients in two major low-risk randomized controlled trials did not demonstrate statistically significant differences compared to the overall population. In the analysis of the PARTNER-3 trial,34 which compared TAVI using a balloon-expandable bioprosthesis (Sapien 3) with SAVR at five years, there was no significant difference in the risk of death, stroke, or rehospitalizations. Although mortality curves crossed beyond three years, the difference in all-cause mortality was not statistically significant, with a higher incidence of non-cardiovascular deaths in the TAVI group. The Evolut Low-Risk trial illustrated TAVI's noninferiority to surgery at the four-year mark.35 Generally, lower evidence studies support these findings.

In October 2023, Thourani et al. presented the initial report linking the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database to the National Death Index (NDI).36 The long-term mortality of 42586 low-risk patients undergoing isolated SAVR is detailed. The patients had baseline characteristics similar to those in both the Evolut and PARTNER-3 low-risk trials. In the analysis of the subgroup aged 75–84 years, mortality at one, three, five, and eight years was 2.5%, 4.3%, 6.7%, and 12%, respectively, with survival rates of 97.5%, 95.7%, 93.3%, and 88%, respectively.34 These remarkable results, frankly better than those published in well-known trials, should establish a new gold standard for SAVR, underscoring the excellence in care provided through these well-established surgical procedures.

Overall, the data support TAVI as a meaningful alternative for low-risk patients with severe aortic stenosis. However, careful consideration of individual patient factors and longer-term outcomes is paramount. There is insufficient evidence to prioritize older age as the exclusive criterion for choosing between TAVI and SAVR in otherwise low-risk patients. The superiority of either technique in this specific subgroup remains uncertain, with each method presenting its advantages and drawbacks. Given the limited four- to five-year follow-up in the two largest low-risk trials, decisions should be guided by life expectancy rather than age. Considerations of risk scores and procedural risks, which may or may not be associated with age itself, play a critical role in the decision-making process. This perspective underscores the significance of heart team discussions in selecting the most appropriate approach for each patient.

Our results show that elderly patients can undergo surgery with low mortality rates and acceptable morbidity rates. The in-hospital mortality rate was low (0.5%), similar to that observed in younger patients. Long-term survival was similar to that expected in patients in this range, and similar to other studies with slightly younger populations, such as in the PARTNER-3 sub analysis. Although PARTNER-3 showed survival rates of 93.3% at five years in patients between 75 and 84 years, our group of low surgical risk patients were significantly older and presented a survival rate of 81.7% at five years. One important consideration in the survival analysis between low and intermediate-high risk groups is that there are no differences in the confidence intervals (CI) between both groups, with an important overlap of both CI. One may conclude that with 95% of confidence there are no differences up to 60 months. One possibility to explain the statistically significant difference at 60 months between the two groups is the unbalanced proportion of patients (149 vs. 46 patients). Moreover, patients at an intermediate-high surgical risk have more comorbidities that may significantly impact long-term survival. In terms of morbidity, our patients had a significantly high rate of AKI (47.7%), although the majority had a mild postoperative AKI with complete in-hospital recovery and only 1.5% had necessity of renal replacement therapy. Other complications had similar or lower rates compared to what is currently published.12,19,24 Although the occurrence of complications may not directly impact survival, since there were no survival differences comparing patients with and without any complication up to five years after surgery, patients with higher preoperative risk had a significantly increased proportion of complications. The impact of postoperative complications in this subset of patients warrants further investigation.

We have no doubt that the number of older patients undergoing cardiac surgery will increase in the following years and this type of retrospective analysis is the starting point to design more accurate programs to continue reducing postoperative morbidity in older patients. New surgical approaches, with minimally invasive surgeries and/or the use of rapid deployment valves, will certainly contribute to new surgical strategies in this specific but absolutely substantial surgical population.

It is important to highlight that our study has several limitations, many of them associated with the retrospective nature of its design. It is a single-center analysis and the results may not be translated to other populations. Moreover, patients who underwent surgery are discussed in the heart team, but are pre-operatively evaluated by our Department, evaluating comorbidities and frailty. Thereby, there is a selection bias and only patients fit for surgery and with good functional status were included. Other patients with indication for intervention are referred for percutaneous aortic valve replacement.

SAVR in octogenarians is associated with low in-hospital mortality, with a considerable proportion of patients developing postoperative complications, although the proportion is significantly lower in patients with EuroscoreII below 4%. The most frequent postoperative complication was the need for hemodynamic support, followed by AKI. However, most of the patients quickly recovered, with ICU and hospital LOS similar to younger patients. Furthermore, long-term follow-up to five years is acceptable in patients at a low risk, showing that the survival of these patients is closer to the average life expectancy of the general population. Octogenarians with low surgical risk can undergo surgery safely, with favorable results up to five years. Nevertheless, the survival proportion is lower in intermediate-high risk patients aged at least 80 years old, and the type of intervention in this subgroup should be discussed case by case by the heart team.

The authors state that they have no conflict of interests.