Aortic Stenosis: More patients need surgery


An interesting new article on the use of echocardiography (cardiac ultrasound imaging) to determine the optimal timing of aortic valve replacement is re-posted below.  This article is helpful for several reasons, but first a quick summary of Aortic Stenosis.

The timing of aortic valve replacement surgery for aortic stenosis (here after referred to as AS) has always been a complicated issue.  Not all stenotic valves need to be replaced at the time of diagnosis; in fact, most don’t since AS is usually diagnosed early (from the presence of a new heart sound on physical examination.)

Patients may not need surgery for ten or twenty years after AS is initially detected, and performing surgery at the RIGHT time is important.  Performing surgery too early has almost as many drawbacks as performing surgery too late.

Ideally, surgery is performed before the patient becomes symptomatic (fainting/ near fainting, chest pain or the development of heart failure) AND before the development of heart damage from AS.

Article re-post:  [my comments in bracketsI have also italicized certain portions for emphasis.

Echo predicts mortality in untreated

 Aortic stenosis with normal LV

function

Article authored by Marlene Busko, Heartwire.com  (June 17th, 2011)

Montreal, QC – Researchers have identified four  echo markers that predicted mortality in elderly patients with severe aortic  stenosis but preserved LV function who did not undergo surgical valve  replacement [1].
Dr Eddy Barasch (St Francis Hospital, Roslyn, NY) presented the  study here at the American Society of Echocardiography (ASE) 2011 Scientific  Sessions.

The four echocardiographic markers that predicted poor  survival were greater left ventricle (LV) concentric remodeling, lower stroke  volume, elevated LV filling pressures, and mildly elevated pulmonary artery pressure.

“Our findings may not be generalizable, but they suggest that in [elderly, symptomatic patients with untreated aortic stenosis] with normal LV function, no other valve disease, and normal sinus rhythm, these  echocardiographic parameters may be useful for risk stratification,”
Barasch told heartwire. Being able to predict mortality with surgery vs medical therapy in patients such as these—who are typical of patients seen in clinical practice—will become even more important when  transcatheter aortic-valve implantation (TAVI) becomes available, he added.

The data suggest that “not operating on symptomatic  patients like this—with these markers—is really a death sentence,” said Dr Malissa Wood (Massachusetts General Hospital Heart Center, Boston), when asked to comment on the study.”When you are managing patients who may in  fact be good candidates for surgery, looking at their echo and figuring out if
they have these risk factors can help determine the patients’ overall risk of
mortality with surgery vs medical therapy,” she added.  [I completely agree with Dr. Woods, which is why we need to be frank in our discussions of the real risks of surgery and the risks of NOT having surgery.]

Surgery seen as “too risky”

The prevalence of aortic stenosis increases with age, and it is estimated that among 80-year-olds, as many as one in four have aortic stenosis, and about 3% to 5% have severe aortic stenosis, Barasch explained.   However, a significant proportion of patients with aortic stenosis—30% to  40%—are denied surgery for various reasons, he noted. The patients may have
multiple comorbidities, be too old and frail, or may not want to have surgery.

In some cases, a primary-care physician may not refer a patient for surgery due to perceptions that the procedure is too risky, while in others, a surgeon may decide that a referred patient is not a good candidate for surgery, Wood added.
[The wording here is deceptive – if a patient decides not to have surgery – they weren’t ‘denied surgery’.  People have the right to decide for themselves – as long as we ensure that we explain everything to them in terms they can understand.  This phrasing is concerning now that many cardiologists are performing experimental transcutaneous valve procedures – sounds like cardiologists are opening the door to doing this procedure in patients that may not otherwise be candidates under “the patient was denied surgery/ patient refused surgery” model which we’ve seen many times before with stent patients.]

[The other issue that we will talk about in a future post is the “primary care provider (PCPs)” not  referring patients that he/she doesn’t think are good candidates.  Frankly, most PCP  and cardiologists, for that matter, are not qualified to make that determination.  As you will read further into the article and see – the outcomes of untreated AS are quite grim, so the
decision on whether or not to refer a patient for evaluation, is not one to be taken likely.]

“On the other hand, if you don’t treat these patients surgically, mortality is increased twofold,” said Barasch.

Although most elderly patients with severe aortic stenosis have preserved LV function, few studies have examined how risk factors  affect survival in this patient subset. To identify echo variables associated  with mortality in these patients, the team reviewed the charts of 443
consecutive patients with severe aortic stenosis and preserved LV ejection fraction who had echo Doppler in their center from 2003 to 2010.

After patients who underwent surgical aortic-valve replacement were excluded, the study population comprised 274 patients with a mean age of 79.5 years (51% men). [this is quite a large subset of patients that didn’t/ couldn’t/ didn’t want surgery.  I’d like to know why, and who decided (other than the patients themselves). We successfully do aortic valve replacement in many patients over 80 (age itself should NEVER be a factor – as discussed in numerous previous posts.]

All but two patients had symptoms of heart failure (45%), angina (33%), syncope (5%), or multiple or other symptoms (17%).  All patients had normal sinus rhythm, and their mean LVEF was 64.5%+9.4%.

After a mean follow-up of 3.2+2.7 years, 50.5% of the patients had died.

The patients who survived were younger, had a higher body-mass index (BMI), and were less likely to have hypertension, renal insufficiency, diabetes, or heart failure, and more likely to have CAD.

Of the multiple echo-Doppler variables that were examined, only four parameters—LV concentric remodeling (increased LV wall thickness), lower stroke volume, elevated LV filling pressures, and mildly increased pulmonary artery pressure—were moderately associated with mortality,  after researchers adjusted for age, gender, and BMI.

No surgery also ups risk

“The biggest take-away message is that we are still grossly undertreating symptomatic aortic stenosis, and many patients who would benefit from surgery are not getting it,” Wood summarized.  The study helps identify the magnitude of the risk of not having surgery, among these elderly patients.  [Actually, we’ve known these statistics for at least twenty years – I had to memorize them for student rounds when I was graduate school, as standard fare for grilling by the cardiac surgeon.]
“It is a strong study—useful for risk/benefit analysis,” she concluded.

Unfortunately, much of this article seems to state that the biggest obstacle to patient care, safety and welfare seems to be the referring physicians themselves.  In my opinion, ALL patients with AS should be referred to a cardiac surgeon (not because I work for one) but because ONLY the surgeon and the patient can truly decide whether its’ time for surgery/ and if the benefits outweigh the risks.

So, if you have Aortic stenosis, symptoms or not – get your more recent echocardiogram, a list of all your medications, and as many medical records as you can get – and schedule an appointment with a cardiac surgeon for a second opinion.

I’ll be posting some additional articles and references for interested readers soon.

 

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