Editorial Comment: Aortic stenosis in octogenarians and other high-risk groups: what can surgical valve replacement offer?

Abstract

The paper published in this issue of the Journal by Molstad et al. [1] from Feiring, Norway, deals with the long-term survival after aortic valve replacement (AVR) in octogenarians and high-risk subgroups. A total of 1525 patients were submitted to AVR in their institution over a period of approximately 11 years. Included were 361 patients (24%) older than 80 years of age (mean 83.1 ± 2.4 years). The main aim of the study was to assess survival, and the accuracy of the outcome analysis is guaranteed by the Norwegian National Registry, assuring a complete follow-up. This comes at the time when there is great enthusiasm around for percutaneous aortic valve implantation (TAVI), which some now call, in my view inappropriately, transcatheter aortic valve replacement (TAVR). This novel technique was initially implemented specifically for use in patients to whom conventional AVR was denied because it was either not possible or considered too high risk. This issue was triggered by the initial reports derived from the Euro Heart Survey, conducted one decade ago, which showed that approximately one third of the patients with severe symptomatic aortic valve stenosis were never offered surgery [2]. Since then, this subgroup of patients have been given an opportunity for treatment of a pathology that cannot be treated by medical means alone, with a well-known natural history of up to 50% mortality within 1 year in patients with severe symptoms. Some studies have shown early TAVI results to be at least similar to those obtained with AVR. These preliminary results have had the effect of potentiating the implantation rate and in the last few years over thirty thousand patients have received the percutaneous valves in Europe, in an unprecedented surge of a new technique, massively driven by a multi-million dollar industry. In 2011, TAVI constituted 30.5% of all interventions in patients with aortic stenosis in Germany, where 40% of the TAVI performed in Europe is done [3]. It is evident that this intervention has an important role to play in the future and there are already studies under way involving younger and less risky patients. However, the majority, if not all, of the comparative studies thus conducted are based on risk-predicting models, such as the original EuroSCORE, which are now overwhelmingly recognized to overpredict risk, especially mortality. The new EuroSCORE II was launched very recently, and has not yet been widely used. Strangely, very few of these comparative studies used the Society of Thoracic Surgeons (STS) risk score, recognized as being more accurate to predict surgical mortality. It is here that the current study by Molstad and colleagues becomes important. Not so much because of the number of patients included, as much larger series have been published, but because of the results reported. Importantly, the patients in the cohort were treated during the same period of use of the percutaneous valves, but with a mean follow-up of almost 5 years, which is important when referring to over 80-year olds. And this study includes all comers, comprising 58% of patients with associated coronary diseases requiring coronary artery bypass grafting. The logistic EuroSCORE of the latter group was 15.2 and 17.5% of the patients had an EuroSCORE over 20. Short-term (30-day) mortality was 2.2% in the whole population and 3.9% in the over 80-year group. Five-year survival was 83.1% for the whole population and 68.1% for the over 80-year old group where the median survival time was 7.3 years, which parallels the mean expected survival time for the general Norwegian population matched for age and gender in the octogenarian group (7.4 years). Other authors have recently reported equally good results with AVR in the elderly. El Bardissi and associates from Boston reported operative mortality of 3% and 1-, 5-, and 10-year survival of 91, 77 and 56%, respectively, in 249 octogenarians (mean age: 84 years; EuroSCORE: 11) undergoing AVR during this modern era, ‘who might otherwise have been considered candidates for TAVI’ [4]. And even more recently, Langanay et al. reported on 1193 AVR in octogenarians, with a mortality of 5.5% for isolated valve procedures [5]. Of interest, by comparison, 1-year survival after TAVI was 76.1% in the SOURCE Registry and 69% in the PARTNER trial, although both studies concluded that the survival was similar to surgical AVR in the populations studied. These results, and not those predicted by the most popular risk scores, should constitute the benchmark for both TAVI and AVR. Our Journal still receives reports of series of AVR with mortality figures approximating two digits, which should no longer be considered acceptable. Not even the usual presence of some of the risk factors so far identified should constitute a justification for higher mortality. Unequivocally, AVR in the elderly patient with