Aortic Stenosis
Table 1: Overall Operative Mortality after Surgical Therapy
Procedure SAVR only
MVR only
SAVR + MVR SAVR + CABG MVR +CABG
Number of Patients 26,317
13,936 3,840
22,713 8,788
Mortality (%) 4.3
6.4 9.6 8.0
15.3
SAVR = surgical aortic valve replacement; CABG = coronary artery bypass grafting; MVR = mitral valve replacement. Source: adapted from Jamieson et al., 1999,6 with permission from the Annals of Thoracic Surgery.
reproduced
Table 2: Operative Mortality After Surgical Therapy by Age Group
Procedure
SAVR (%) SAVR
+ CABG (%) MVR (%) MVR+
CABG (%)
SAVR = surgical aortic valve replacement; CABG = coronary artery bypass grafting; MVR = mitral valve replacement. Source: adapted from Jamieson et al., 1999,6 with permission from the Annals of Thoracic Surgery.
reproduced 3.0 3.4 11.7 6.1 3.5 13.2 5.2 Patient Age (Years)
30–39 40–49 50–59 60–69 70–79 80–89 90–99 2.0
2.9 4.7
4.1 8.6
3.2 5.1
6.1
5.3 8.6
9.8 12.3 18.4 8.5 12.5
13.4 25.1
14.5 18.8
25.0 42.9
Clinicians at the Medical University of Vienna, Austria, presented data at the Euroecho meeting, showing that two subsets of patients need to be differentiated. On the one hand, there are patients who are symptomatic at the time of first presentation; strikingly, these patients have had symptoms for approximately one year before seeking medical help. On the other hand, there are patients enrolled in a follow-up programme who were asymptomatic when they first presented; among those who regularly attend their six-monthly visits, only 79 % report symptoms soon after they become symptomatic and 70 % report symptoms only at their next scheduled visit. Patients usually report their symptoms about three months after onset when they attend their next scheduled visit. Although they are instructed to report symptoms as soon as possible, only 21 % will call the clinic to do so soon after onset (typically 20 days later).
Considering late symptom reporting and subsequent late referral to surgery, the risk stratification of asymptomatic patients is an important step towards the identification of those who are likely to develop symptoms in the near future, which can occur very rapidly and warrant surgical intervention. In patients with severe AS (defined by a peak aortic jet velocity >4m/s) who have calcified aortic valves and a rapid haemodynamic progression (increase of the peak aortic jet velocity by ≥0.3 m/s within 12 months), the event-free survival rate at two years is only 20 %.12
The limitations of current risk scoring systems are mentioned in a recent ESC position paper on risk assessment before intervention in patients with valvular disease.5
Nonetheless, the Euro Heart Survey showed that one-third of patients with severe symptoms of valve disease (NYHA functional class III or IV), including patients without significant co-morbidities, are not referred for aortic valve intervention.9 A similar situation was observed in the US, where Pai et al. conducted a study and found that one third of symptomatic patients with severe AS were not referred for aortic valve replacement surgery, even though some of them had a low estimated operative risk (<5 %). Many of these untreated patients died of complications related to AS within 14 months. The reasons for not performing surgery included high surgical risk unrelated to AS and patient refusal.10
Although not deemed a contraindication for intervention,7 advanced
and the clinical decisions, mainly based on age and ejection fraction values, are often inconsistent and do not take into account risk:benefit ratios. Considering the estimated prevalence of AS in patients over 65 years and the actual numbers of patients referred to surgery, it might be extrapolated that a significant proportion of patients do not receive appropriate care. The significant ageing of the Western populations will accentuate this trend over the next decades, and some projections point to a doubling of the number of patients over 65 years.
age has a significant weight in patient selection. In clinical practice, 33 % of patients aged between 75 and 80 years are not referred to surgery,11
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In Europe as well as in the US, the life expectancy of 65-year-old AS patients is approximately 19 years. For 80-year-olds, it is around nine years. And in the absence of significant co-morbidities, 85-year-old AS patients still have a life expectancy of six years or more.15
Therefore,
the undertreatment of AS is also a concern in elderly patients, who can present with extensive co-morbidities and have different expectations towards therapy.
The causes behind the undertreatment of AS are multifactorial and include difficulty in determining disease severity based on peak aortic jet velocities, non-recognition of symptoms (by both patients and physicians)
EUROPEAN CARDIOLOGY
replacement who are deemed inoperable or at high risk from surgery.7 While the European System for Cardiac Operative Risk Evaluation (EuroSCORE) still successfully discriminates high-risk patients undergoing SAVR, it has become increasingly uncalibrated with absolute risk, resulting in an overestimation of the 30-day mortality rate.8
and peak aortic jet velocities of 4.0–5.0 m/s, 5.0–5.5 m/s or >5.5 m/s, the event-free survival rates at three years are 49 %, 33 % and 11 %, respectively. In addition to their importance with regard to risk stratification, these data suggest that the definition of ‘very severe’ AS should be based on a peak aortic jet velocity ≥5.0 m/s.13
The event-
free survival curve of ‘very severe’ AS matches that of ‘severe’ AS with valve calcification and rapid haemodynamic progression;12
hence
these parameters define high-risk subsets of patients in whom early elective surgery may be considered.
The failure to recognise and report symptoms also has implications for the symptomatic status of patients. More than 60 % of the mildest symptomatic cases (NYHA functional class II) undergo surgery. More than 50 % of patients presenting for the first time at a symptomatic stage with mainly severe symptoms are in NYHA functional class II-III or greater. The surgery waiting list death rate is approximately 13.5 % per year.14
For these patients at
high risk, the timing and choice of procedure are critical. According to the already mentioned ESC position paper, the patient’s life-expectancy and personal preferences, an individualised risk assessment, the natural history of the disease, the risk posed by intervention and the expected long-term post-procedural outcomes must all be taken into account in the treatment decision-making process.5
In patients with severe asymptomatic AS
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