Degenerative AS usually evolves slowly over the years. There is a long latent period, during which the patient remains asymptomatic. Angina pectoris is a frequent first clinical manifestation of advanced AS. Angina usually results from the increased oxygen need of the hypertrophied myocardium and a reduced oxygen delivery due to secondary coronary vessel compression. Concurrent coronary artery disease is not mandatory but is often present in older patients with AS. Syncope due to cerebral hypoperfusion is another frequent clinical manifestation of AS. It typically occurs upon exertion when arterial pressure decreases secondary to systemic vasodilation. Elderly patients are more likely to suffer syncope in advanced AS than younger patients are, because they often have concurrent atherosclerotic changes in the cerebral vasculature facilitating cerebral hypoperfusion. Furthermore, the baroreceptor function, which counteracts the systemic hypotension, may be impaired at old age. Another important clinical manifestation of AS is exertional dyspnea and/or heart failure. While in younger patients these symptoms usually do not develop until very late in the progression of AS, dyspnea and signs of heart failure may develop earlier in elderly patients who have further comorbid conditions of the heart or lungs.

All these symptoms are of great relevance in old patients. Symptoms such as angina or dyspnea not only adversely affect life quality but may also lead to disability. Due to the high prevalence of other comorbid conditions, such as sarcopenia, arterial pressure decrease upon exertion may strongly affect gait and physical function. The risk of deleterious consequences after a syncope is also higher in old vs. young patients, because elderly patients more frequently (i.e., about 5 %) suffer fractures after a syncope due to concurrent osteoporosis.

Degenerative AS is a chronic progressive disease. When symptoms develop, the prognosis is poor in the absence of a specific treatment, with impaired quality of life and high short-term mortality. Data from the PARTNER trial show that without aortic valve replacement, the 2- and 3-year mortality rate were 68.0 % and 80.9 %, respectively, despite an up-to-date standard therapy with drugs and, if indicated, balloon aortic valvuloplasty [5, 6].

Open-heart surgical aortic valve replacement (sAVR) was the standard treatment for severe aortic stenosis up until a few years. The results of sAVR were satisfactory in old patients with degenerative AS, with improved survival and quality of life [7]. However, it has to be realized that evidence regarding sAVR was mainly based on retrospective studies and registries conducted in younger patients. In fact, the decision to perform sAVR in octogenarians remains a challenge, mainly due to increased operative morbidity and mortality. It is estimated that approximately one third of patients were denied sAVR, typically due to a high surgical risk [8]. Moreover, many elderly patients with severe AS either refuse or are not referred for sAVR evaluation, despite evidence that sAVR can be performed safely in selected octogenarians.

Transcatheter aortic valve implantation (TAVI) is a new therapeutic option that involves providing aortic valve replacement through a catheter. The tip of the catheter wears the replacing valve, which was squeezed down on an inflatable balloon or a self-expandable system. The catheter is usually inserted through the femoral artery or through a small incision in the chest over the heart. The replacing valve is subsequently positioned inside the faulty aortic valve and unfolded. This procedure is believed to be associated with less interventional risk than sAVR and, therefore, was first used in older patients with high surgical risk.

Successful TAVI results in substantial hemodynamic and clinical improvement in patients with severe AS and high surgical risk. The PARTNER trial found a markedly lower 2-year and 3-year mortality rates of 43.3 % and 54.1 %, respectively, with TAVI as compared to the standard therapy (mortality rates of 68.0 % and 80.9 %, respectively) [5, 6]. The PARTNER trial also showed that mortality rates of TAVI and sAVR were similar [9]. TAVI not only dramatically improved survival as compared to a standard therapy but also markedly improved dyspnea functional class as well as quality of life. At 1 year after TAVI, 74.8 % of the surviving patients who had undergone TAVI, as compared with only 42.0 % of the surviving patients who had received standard therapy, were asymptomatic or had mild symptoms (New York Heart Association class I or II) (Fig. 9.2) [10].

Current guidelines recommend TAVI in patients with severe symptomatic AS, who are not suitable for sAVR as assessed by a multidisciplinary heart team involving cardiologists, cardiac surgeons, and other specialists [11, 12]. Also, TAVI can be considered in high-risk patients who may still be suitable for sAVR, but in whom TAVI is favored by the heart team based on an individual benefit-to-risk assessment [11]. Elderly patients are often included in this high-risk group, mostly due to associated comorbidity. Comorbidity has great influence on the prognosis of these patients. In fact, the real benefit in terms of survival of TAVI in elderly patients with high comorbidity is controversial. Consequently, it is essential to enhance risk prediction of patients scheduled for TAVI and to identify those most likely to benefit from TAVI [13, 14]. Current guidelines recommend that TAVI should not be performed, if comorbid conditions reduce life expectancy to less than 1 year [11].

According to the aforementioned selection criteria, TAVI is mainly performed in elderly patients. Therefore, concurrent geriatric problems are frequently found. A recent study found cognitive impairment in approximately one of three patients undergoing TAVI, and approximately two of five patients had mobility impairment and/or were malnourished (Table 9.1) [15]. Comprehensive geriatric assessment (CGA) is a process suitable to detect these problems. CGA differs from the standard medical evaluation in its concentration on older people with their complex problems and its emphasis on functional status [16]. It is important to perform CGA routinely and systematically in every patient, as it is well known that the geriatric problems often go undetected, if patients are not routinely screened for their presence [17].