AS is the third most frequent cardiovascular disease in the Western world, where its prevalence is around 18% in the octogenarian population [1,2]. Aortic valve replacement is currently the only definitive treatment for patients with AS, showing good long-term outcomes even for populations at high and intermediate risk [17,18]. Preoperative estimation of surgical risk is essential during the therapeutic decision-making process. Current risk models are based on demographic and clinical factors, and other measurable factors of comorbidity, but do not include a comprehensive assessment of frailty, which is known to affect morbidity and mortality.
The potential impact of a procedure on a patient’s long-term QOL must also be considered when selecting one surgical procedure over another. Preoperative measures of frailty appear to be predictive of postoperative QOL [21-23].
In the present prospective study, 200 patients undergoing aortic valve replacement were divided into 3 groups according to AVR surgical procedure. The study population was homogenous in terms of preoperative predictors of cardiovascular risk, but the TAVI group showed higher preoperative rates of peripheral arterial disease, kidney disease, hypoalbuminemia, anemia and preoperative admission rate. The sutureless and TAVI groups had higher scores for risk (STS) and frailty (FRAIL scale) than the stented prosthesis group. Overall survival at discharge, 6 months and 1 year was 96%, 97% and 89% respectively. At 1-year follow-up 26 patients had died.
Our results on preoperative features are similar to those reported in the European Cardiac Surgery Registry for stented/sutureless prosthesis implantation surgery in intermediate- to high-risk populations [24] and in the Spanish Cardiac Surgery Registry for TAVI.
Mortality rates at 6 months and 1 year were 2.6% and 11%, respectively, similar to other previously published series. However, the 4% 30-day mortality, was lower than that reported in various TAVI registries (Spanish, Canadian, French, British, Italian and German), which ranges between 8%-10% and 16%-24%/year [6,24,25-27].
The rate of postoperative complications was highest in the TAVI group, when compared to the SAVR group and higher than that described in other TAVI registries. This was mainly due to vascular and infectious complications, which may have been related to the high rate of peripheral vascular disease and transfemoral approach.
Complications during the follow-up period were related to the patients’ preoperative condition and comorbidities. Respiratory complications or cardiac failure occurred in over 8% of patients at 6 months and 18.2% to 23% at 1 year. The leading cause of death was progression of respiratory or renal disease, and the second was oncological disease.
Preoperative factors related to morbidity and mortality
As in other studies, our univariate analysis found that arterial disease, anemia, STS score, Barthel Index and gait speed were associated with morbidity. After adjusting for age, only STS score, Barthel Index and gait speed were significant. Aging generally involves a decrease in muscular strength, related to loss of muscle mass and protein reduction, a factor measured by handgrip, although no association with morbidity was found [13,14,28,29].
GS is an easily measured patient feature and has been shown to correlate with complications in patients with heart failure and cardiac surgery [13]. It is a useful tool for predicting morbidity in elderly patients and has been shown to be related to resilience. This association not only has clinical implications, but also has a bearing on long-term quality of life. In addition, there is also an overall economic impact to consider, which should take into account not only direct costs but also indirect costs incurred due to intraoperative and postoperative complications.
To date, gait speed has been used as an isolated parameter. In our study, gait speed combined with STS and Barthel score increased its predictive capacity for morbidity.
Quality of life at follow-up
Frailty increases surgical risk. Some studies have found that even with less invasive techniques, QOL outcomes are not necessarily improved in intermediate- to high-risk patients. One of the most widely-used and validated scales for measuring QOL in our setting is the EQ-5D which assesses patients’ physical and psychological condition [21,22]. In contrast to what is reported in other studies, the TAVI group in our study had a worse QOL at one year than those who had received a conventional or sutureless prosthesis. Furthermore, as in other studies, TAVI patients also reported a worse QOL in items related to their affective or psychological wellbeing, not just in the functional–motor sphere [30].
Some previous studies have found an association between preoperative factors such as peripheral arterial disease and mood and worse QOL. Nevertheless, there are no studies that assess the association between preoperative risk factors or frailty features with QOL at follow-up. In our univariate analysis, faster gait speed and higher STS and FRAIL scale scores were negatively correlated with QOL at 1-year follow-up, but in multivariate analysis of these 3 factors only STS and FRAIL score remained predictors of worse QOL [30].
Thus, regardless of the surgical procedure employed, only STS and FRAIL score were strong predictors of QOL at 1-year follow-up. The importance of this conclusion becomes evident on analysis of the individual prosthesis types: although in our study there were relatively few TAVI interventions compared with stented or sutureless valve replacements, TAVI did not appear to be associated with improved QOL. It is therefore important to emphasize that the use of risk and frailty scales improves the prediction of morbidity and, most importantly, quality of life.