BAV study

[PathFinder]

Looks like by the BAV's the dilating aorta means longer survival, becouse of more rare ilnesses of CAD?!? Or I don't decode the study very well?

Division of Cardiology, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA.

BACKGROUND: We aimed to determine the risk factors associated with mortality in patients with congenitally bicuspid aortic valve disease and dilation (<5 cm) of the ascending aorta after aortic valve replacement. METHODS: We reviewed 252 patients with bicuspid aortic valve undergoing aortic valve replacement at our institution from 1971 through 2000. Patients undergoing concomitant replacement of the ascending aorta were excluded. RESULTS: The average patient age was 61 +/- 15 years; 66.3% were male, and 40.5% of patients had coronary artery disease. The ascending aorta was normal (<4.0 cm) in 60.3%, mildly dilated (4.0 to 4.4 cm) in 24.2%, and moderately dilated (4.5 to 4.9 cm) in 15.5% of patients. Patients with moderate aortic dilatation had significantly lower prevalence of coronary artery disease compared with patients with normal ascending aortas (20.5% and 45.4%; p = 0.006). Mean follow-up was 8.9 +/- 6.3 years. Long-term survival was significantly different across the three groups (p = 0.004). The 5-, 10-, and 15-year estimates were 78%, 59%, and 37%, respectively, in the normal aorta group; 88%, 77%, and 46%, respectively, in the mild aortic dilation group; and 92%, 83%, and 70%, respectively, in the moderate aortic dilation group. No significant difference in cardiac death was found among the groups (p = 0.08). The significant predictors of survival using the Cox regression model were coronary artery disease, age, decade of surgery, and ejection fraction. Aortic dilation was not significant after adjusting for these other variables. At follow-up, 18 patients required reoperation, 17 for aortic valve prosthesis failure and 1 for ascending aorta aneurysm. CONCLUSIONS: The present study highlights the important adverse effect of concomitant coronary artery disease, advanced age, earlier decade of surgery, and reduced left ventricular ejection fraction on survival after aortic valve replacement for bicuspid aortic valve in patients with no or mild and moderate (<5 cm) dilation of the ascending aorta.

Ivo

 

[MrP]

This result is similar to the Yale study that shows an association between ascending aortic aneurysms and protection against coronary artery disease despite high cholesterol. However, the Cedar Sanai study associates moderate dilatation with less CAD. Also interesting, this study showed only 1 reoperation (during followup period of almost 9 yrs on avg.) for ascending aortic aneurysm after valve replacement in 252 BAV patients of which 15.5% (39 patients) had moderately dilated ascending aorta. I would've expected more ascending aortic aneurysms after valve replacement in BAV patients. So for those with moderate dilatation less than 5cm, this study seems to suggest one should delay surgery as long as possible. Am I correct?

 

[ptoddy]

I hope you are Mr P

It is a interesting study you talk about.What I have always thought and what I have read suggests that the Ascending Aorta increases at the same rate after AVR.This study perhaps suggests otherwise.

A possible reason for this could be that people with BAV also have large Ascending Aorta's to start with.Because they have a larger starting point they have not dilated as much because they were big to start with.This is what my cardio thinks could be the case with me.

Or another reason could be that the smaller orrifice on the damaged original valve cause dilation of the aorta,due to the way the blood comes out of the valve.When it is replaced the flow is normal again causing less stress on the aorta therfore less dilatation.

Any thoughts out there.

Paul

 

[Susan BAV]

I keep looking at it -- I hope you're right, Mr. P -- but I'm also surprised at how much CAD there is; because most of us with BAV had clean arteries noted during our angiograms, albeit most of us are relatively young when receiving that diagnosis. Are there degrees of CAD -- there must be -- or is CAD either a positive or negative diagnosis from testing?

 

[PJmomrunner]

Yes, Susan, my understanding of CAD is that there are varying degrees. In my husband's case, at least, his calcium score is being monitored annually. The calcium score is generated using computed tomography and the score is compared to the scores of others of his age. I'm not sure how much more than the mean amount one has to have to receive the diagnosis of CAD, but certainly the degree varies.

What I take away from the study pathfinder posts is that in one who has BAVD, while greater aortic dilation is generally associated with less CAD, one should takes steps to ensure that CAD risk remains low; and, one should wait as long as possible to replace the AV without waiting so long as to become so old as to decrease one's chances of surviving the surgery or permanently impair ejection fraction.

The study also reinforces the 2006 ACC/AHA Guideline for the Treatment of Valvular Heart Disease that recommends concommitant replacement of the ascending aorta during AVR only if it is 4.5cm or greater at the time of replacement--assuming the one in the study that required re-op for the aneurysm had been in the moderately dilated group at the time of AVR. It still leaves me uneasy with the idea of not replacing a, say, 4.3cm ascending aorta at the time of AVR since there are so many variables (and unknowns) involved in determining when it's gonna "blow". A study of 252 cases is a great start, but I doubt it represents every possible scenario.

PToddy, I have definitely read studies that confirm that BAV's come with aortas that are, on average, bigger than those that accompany TAV's. I'm not sure how that should comfort me though, since the consensus seems to be that they're bigger because the tissue is messed up.

 

[ptoddy]

PJ-Yes i agree the tissue is messed up,but perhaps our aorta's have been the size they are now for perhaps 10 or 15 years and could stay that size for another 10 years perhaps,who knows.

I think we automatically think they are going to grow,but there are a lot of people on this site who's aneurysm's are remaing stable with beta blocker control.

I think from a personal point of view I would prefer to leave my aneurysm alone IF it remains stable.

The more research I do about BAVD the more opinions there are about it.

Paul

 

[tobagotwo]

From the quote: "Patients with moderate aortic dilatation had significantly lower prevalence of coronary artery disease compared with patients with normal ascending aortas"

This site has long recognized a relationship between Bicuspid Aortic Valves and a lower incidence of Coronary Artery Disease. This seems to point to a further refinement, which indicates that a moderately dilated aorta leads to a likelihood longer of a longer lifespan (average age was 61: the likelihood of 15 more years was 37% for normal ascending aortas, 46% for mildly dilated aortas, and 70% for moderately dilated aortas). However, in perusing the results, the probability difference is based on the greater prevalence of CAD in those with normal aortas, and not the dilated aorta, BAV, replacement valve, or surgery itself. So, if you don't have CAD, your odds are more like the 70%, dilated aorta or not, assuming you are about age sixty.

So, take care of your coronary arteries.

It's significant that of the 232, only one was reoperated for an aneurysm. One sensible interpretation might be that if you are BAV and reach the age of sixty with an aorta of less than 5cm, you have only .05% chance of needing an aortic aneurysm repair in your lifetime. From what's presented, this doesn't indicate either way whether this average would be applicable to those who present with dilation at a much earlier age. My belief is that it's not, and that people who present with dilation when younger will have a higher rate of aneurysm repairs.

Best wishes,

 

[PJmomrunner]

perhaps our aorta's have been the size they are now for perhaps 10 or 15 years and could stay that size for another 10 years perhaps,who knows.

Yes, this is pretty much the perspective my surgeon has put forth and that I have adopted. It's taken sometime to feel at all comfortable with it though. I still feel like a ticking time bomb at times--largely, I suppose, because I live in a rural area where it would take hours to get to a hospital that could surgically intervene in the case of a dissection.

I think we automatically think they are going to grow,but there are a lot of people on this site who's aneurysm's are remaing stable with beta blocker control.

I know I do, even though mine has been stable for 2.5 years under beta blockade with a side of ace inhibitor for good measure!

I think from a personal point of view I would prefer to leave my aneurysm alone IF it remains stable.

Again, my view is the same. Although, if my valve were to require replacement I'm pretty sure there would be a measure of relief that I was finally going to be rid of the time bomb.

I am reminded of how nice it is to have company in my misery.

 

[Susan BAV]

This just puzzles me more...

This just puzzles me more...

"40.5% of patients had coronary artery disease..." Is this percentage higher or lower than the average person who might be, "61 +/- 15 years?" And does that statistic fit with the usual lower incidence of CAD in BAV patients? Or, could this better represent patients who have more heart issues than just BAV?

I thought the 66.3% male patient ratio was interesting also. That does not represent the typical male:female ratio of BAV patients, as per previous studies. It brings a lot more possibilities/puzzles to the mind.

 

[ptoddy]

Thanks PJ.It has taken me a while aswell but I think we are doing the correct thing in watching and waiting and carefully running.

Paul

 

[MrP]

One must keep in mind the true purpose of this study, as Tobaqotwo points out, with respect to measuring mortality risk factors such as CAD in BAV patients with varying degrees of aortic dilation. One must remember also that this study excluded all those BAV patients who had aneurysms resected. So we can't really draw conclusions from this study regarding how many BAV patients eventually develop life-threatening aortic aneurysms and how many BAV patients with enlarged aortas remain stable, as well as the rate of dilation at various aortic demensions with or without beta blocker. There are other studies that clearly show connective tissue disease in BAV patients and added risks for aortic dissection and rupture beyond that explained by hemodynamic factors introduced because of regurgitation from the faulty bicuspid aoric valve. For example, I recall two studies that showed risk of dissection at 9 to 10% higher in BAV patients than in the normal population. I also have firsthand experience and know results of examination of my diseased aorta post surgery. I do believe we should emphasize BAV patients need to be very careful when interpreting these studies and applying statistical results to their unique situation and when in the danger zone or borderline aortic demensions at or near the inflection point of aneurysmal rupture and dissection.

 

[ptoddy]

Yes I take your point Mr P and agree with what you say.

The point I am trying to make is if one's aneurysm is stable and continues to remain stable it may have been that size for quite a few years before it had started to be measured. I think that surely these type of anuerysms must be less likely to dissect than the ones which are growing.

Thanks

Paul

 

[MrP]

Paul, I hope you are right and surgery is something that can wait in many with BAV. Growth will occur in even normal patients' aortas as part of the aging process, and this rate of growth is very hard to measure year to year given the lack of precision in measurements.
I think we need more focused and controlled studies on BAV to develop better understandings of risk factors.

 

[Susan BAV]

"40.5% of patients had coronary artery disease..." Is this percentage higher or lower than the average person who might be, "61 +/- 15 years?" And does that statistic fit with the usual lower incidence of CAD in BAV patients? Or, could this better represent patients who have more heart issues than just BAV?

I thought the 66.3% male patient ratio was interesting also. That does not represent the typical male:female ratio of BAV patients, as per previous studies. It brings a lot more possibilities/puzzles to the mind.

I'm puzzled because some basic commonalities that we have learned about BAV tendencies don't seem to be clearly reflected in these study participants. There may be much more to learn.

 

[PathFinder]

abnormalities

abnormalities

Hi,folks!

Has anybody any data of the thesis, that we - young people with BAVD probably have abnormalities of the heart muscle, occuring years later in life in cardiac morbidity and mortality?

Ivo

 

[MrP]

No Ivo I have not but am interested in what you've learned.

Also I should've said earlier the rate of dissection is 9 to 10 TIMES higher in BAV patients than the normal population.

For example, I recall two studies that showed risk of dissection at 9 to 10% higher in BAV patients than in the normal population.

 

[PathFinder]

lost it

lost it

I found one, but I have lost it. However, it shows the heritability of BAV as a primary to a valvular disease and secondary as accompaning to another cardiodisease. That means, that the BAV by it self doesn't lead to a defects of the cardiac muscle, but in some cases (not rare) it is a secondary affect to another congenital heart disease.

The study comes from 2004 and I found it in www.pubmed.com

Ivo

 

[PathFinder]

found it

found it

here it is

Department of Pediatrics, Division of Cardiology, Cincinnati Children's Hospital, Ohio 45229, USA.

OBJECTIVES: Previous studies have established familial clustering of bicuspid aortic valve (BAV), presumably indicating genetic inheritance. Our objective was to statistically test whether the segregation pattern of BAV is consistent with genetic inheritance and to obtain an estimate of the size of the genetic effect (heritability). BACKGROUND: Bicuspid aortic valve occurs in 1% of the population, making it the most common cardiovascular malformation (CVM). Bicuspid aortic valve is frequently an antecedent to aortic valve stenosis or insufficiency and is often associated with other CVMs, including aortic root dilation. The genetic and developmental significance of these findings remains obscure. METHODS: In 50 probands with BAV, we obtained a three-generation family history and echocardiograms on first-degree relatives. Heritability (h2) of BAV and BAV and/or other CVMs were estimated using maximum-likelihood-based variance decomposition extended to dichotomous traits implemented in the computer package Sequential Oligogenic Linkage Analysis Routines (SOLAR, San Antonio, Texas). RESULTS: A total of 309 probands and relatives participated. Bicuspid aortic valve was identified in 74 individuals (prevalence = 24%). A total of 97 individuals had BAV and/or other CVM (prevalence = 31%), including aortic coarctation, ventricular or atrial septal defect, abnormal mitral valve, aortic root dilation, or hypoplastic left heart syndrome. The heritability (h2) of BAV and BAV and/or other CVMs were 89% and 75%, respectively. CONCLUSIONS: The high heritability of BAV suggests that in this study population BAV determination is almost entirely genetic. The heritability of BAV plus other cardiovascular anomalies suggests that valve malformation can be primary to defective valvulogenesis or secondary to other elements of cardiogenesis.

PMID: 15234422 [PubMed - indexed for MEDLINE]

 

[rtblount]

Ascending aortic aneurysm growth after aortic valve replacement

Ascending aortic aneurysm growth after aortic valve replacement

I have much conflicting information about the growth of the ascending aorta after valve replacement surgery. My bicuspid aortic valve was replaced about 10 years ago with a St Judes valve. No mention at that time of a dilated aorta.

About 2 years ago I was diagnosed by CT scan with an ascending aortic aneurysm measuring 5.3 cm. It has been monitored every 6 months since and hasn't changed at all. My cardiologist says we should not bother it unless it starts growing. I am 68 years old and about 5'5" tall (or short). I don't understand why the aneurysm is not increasing in size although I am grateful that it isn't. This seems contrary to almost everything I have read about the normal growth rate. The only medication I take other than coumadin is Benicar for lower blood pressure.
I am also aware that the aneurysm size is above the recommended size for surgery according to ACC/AHA guideline even for taller persons. My doctor seems to believe that the aneurysm growth rates don't really apply after the bicuspid aortic valve has been replaced.
I have had a second opinon as to surgery. The surgeon agreed with my cardiologist that we should wait. I am very uncomfortable about that.
Does anyone have any experience or advice relative to my situation?

 

[MrP]

Here's a good research article that may prove useful to you, rtblount.

http://circ.ahajournals.org/cgi/content/full/circulationaha;108/10_suppl_1/II-291

The patients with bicuspid aortic valve showed progressive dilation of the proximal ascending aorta even after AVR. Thus, AVR could not prevent progressive aortic dilation in those patients. Since the aorta did not dilate in patients with tricuspid aortic valve undergoing AVR, aortic dilation in patients with bicuspid aortic valve seems mainly due to the fragility of the aortic wall rather than hemodynamic factors caused by aortic stenosis or aortic regurgitation.

I assume that your ascending aorta has increased in size since your initial AVR, or otherwise your surgeon would've said something about your large aorta 10 yrs ago. I think the rate of growth is very slow and measureable over the course of many measurements, not unlike being unable to measure growth of your children day to day ... over time this growth becomes easier to recognize. The lack of precision or the margin of error of the CT scan machine used in your measurements may also "overshadow" your growth rate over such a short time interval of two years. Waiting for these results at this size is worrisome and a gamble in my opinion, as the 6.0cm diameter has been shown in other studies to be the "hinge point" for bad things to happen...you'll want to resect the aneurysm well ahead of this statistical hinge point. You may want to consider a second or third opinion from an aorta center.
All my best,
MrP