Patient Prosthesis mismatch / effective opening area

[realkarl]

I am researching possible reasons why I am not recovering quite as well back to my pre-symptom aerobic capacity, have too low ejection fraction, and still too high resting pulse (~90).

One thing I have been wondering about is the relatively small 21mm On-X valve which was all that would fit my aortic root.

I found a few articles about "Patient Prosthesis mismatch" (PPM), for example http://eurheartj.oxfordjournals.org/content/27/6/644.full, which discusses EOIA (Effective Opening Index Area, which is the effective opening area of the valve divided by the Body Surface Area, so cm^2 / m^2).

Now, according to my 3 month echo, the calculated aortic opening area is only 1.4 cm^2. This is based on measured pressure gradients across the valve (mine were peak of 17 and mean of 12 mmHg, which my cardio says is normal. That's while lying down though)

If I calculate my EOIA based on the above number, I get only 1.4 / 1.92 = 0.72, placing me in the Moderate category for PPM (< 0.9 for aortic valve). My Body Surface Area is ~ 1.92 m^2 (from this calculator). The Geometric Opening Area (GOA) of my On-X 21mm is 2.53 cm^2.

Has anyone with a small valve had any trouble with Patient Prosthesis mismatch, during rest or exercise? Articles say it's a frequent problem after valve replacement (up to 70% prevalence). I was also initially wondering why the EOA is so much smaller than the GOA, but found a good article on this topic.

The research I did while writing this was reassuring. I found I have normal pressure gradients across the valve while resting. Perhaps though there is still some PPM present during exercise, and one reason why improvement has been slow the last few months.

Adjusting my expectations is a process. I was in pretty good shape on my bicycle before my symptoms, and it's sometimes a struggle to keep my motivation up when I haven't noticed much improvement in a while. I have to keep in mind that I am better off than before my surgery, and that it is after all improving, not going downhill as it did. Has anyone else been through periods of slow improvement, or recovery to where to were has been very slow?

Karl.

 

[Doug]

You didn't say what your EF is or was in this note. I can't say anything about your calculations (looks like work to me), but the rehab nurses have said that plateauing is normal. Have you asked your cardiologist about it?

Even when I was an athlete I hit plateaus. It is like the body needs time to adjust to the new levels of activity.

 

[Luana]

I'm curious what your EF is also. Almost 70% rate of patient prosthesis mismatch? <gasp> That's like almost 3 out of 4 people; maybe I read something wrong?

Curious what cardio and/or CT have to say about your recovery so far.

My recovery has been slower than I anticipated, but has shown steady improvement, for which I'm grateful. I hope whatever is going on with you can be resolved soon.

I was supposed to get an On-X valve, but apparently it wasn't a good fit, so I got St. Jude Regent 21 mm.

All the best to you Karl,
Luana

 

[ottagal]

Hi Karl,

Sorry that I can't help you with the patient prosthesis mismatch question. My peak gradient post surgery is 20mmHG (maximum peak) and 9 mmHG (medium peak) so we are about the same. My ejection fraction is normal, but I can tell you that I, too am slow in 'recovering'. I am exercising at rehab but have days when I exercise on my own where I am having difficulty, my heart rate shoots up early and I am short of breath. I keep blaming it on post op complications and the lung issues.

As others have said, even though it is discouraging being 'slower' in recovery than anticipated (I am 4 months out) I am slowly but surely moving in the right direction. I, too was very active prior to surgery, so I am trying to be a 'patient' patient (which is not easy) .
I hope you get some resolution soon and my ver best wishes to you.

P.S. thanks for the good info on patient-prosthesis mismatch.

 

[realkarl]

Doug, Indeed, I know about plateauing. I have been an active hobby bicyclist all my life, years 5-9 after my radiation I took part in 350 mile one stage races back in Norway (best time 17hr 14min). Since then both on and off road, and the 5 years before my symptoms at age 38 I bicycled to and from work every day.

So now I try my best to vary the exercises between bicycling and strength, as well as simply rest, which has really helped as well. In fact, tonight on my indoor rollers I felt great after a whole 4 days without exercise (but being outdoors on the weekend).

It's funny, my new pacemaker is probably increasing my EF without any exercise at all. According to my cardiologist, exercise does not increase EF, but having a biventricular PM for a Left Bundle Branch Block does for 2/3 of patients with LBBB and low EF. Mine was 43% after surgery and up until the PM. It has not been measured since then. Exercise improves a lot of other factors of course, so I am not stopping the exercise, and just hope the PM will do the job for me...

What I need to do is relax the training a little, I always have and still keep comparing with how I did this exercise/hill/stretch the last time, and before my CHF. Instead I should practice just accepting things as they are and enjoy that I am able to work out as well as I am, after all

Hey, Doug, I see you have the same valve as me. Maybe radiation causes a narrow aortic root as well, especially when done at a young age. Have you had your valve's Effective Opening Area calculated at an echo post-surgery yet? I read it can vary quite a bit even with the same valve, due to other physiological effects.

Karl

 

[ks1490]

I think you should give it a little more time before worrying. Both my cardiologist and my "2nd opinion" cardiologist told me separately that, with a leaky valve, your heart is used to pumping away with little resistance from the valve. Once a new valve is put in, suddenly your heart has to push up against a robust valve - as a result, your ejection fraction can be lower for awhile until the heart gets used to it and returns back up to a normal EF. They recommend having surgery when your EF is still in "normal" range so that post-surgery it won't fall below or too far below the bottom end of the normal range. This sounded like a reasonable explanation to me.

 

[realkarl]

I'm curious what your EF is also. Almost 70% rate of patient prosthesis mismatch? <gasp> That's like almost 3 out of 4 people; maybe I read something wrong?

My recovery has been slower than I anticipated, but has shown steady improvement, for which I'm grateful. I hope whatever is going on with you can be resolved soon.

I was supposed to get an On-X valve, but apparently it wasn't a good fit, so I got St. Jude Regent 21 mm.

Thanks, Luana. Yes the prosthetic valves all result in a narrower effective valve opening than your natural valve, which is why so many end up with mild PPM. The papers did indicate though, that even with mild to moderate PPM, it has little effect on the life quality and outcome for most patients, which is good news. I, too, was surprised when I read about it. I am sure it was not mentioned beforehand, simply because it usually works out fine. But it also explains why many end up taking at least some CHF medications even after surgery. The valve simply isn't as good as your natural valve used to be.

My surgeon said that he probably could have fitted a 23mm St Jude, but due to the On-X design it is a tighter fit, so it ended up a 21mm.

My cardiologist isn't much help. I have already asked too many questions, and he doesn't have (m)any patients in my category.

And I am very grateful when I notice improvement, like tonight. Co-incidence, after starting this thread

Karl.

 

[realkarl]

I think you should give it a little more time before worrying. Both my cardiologist and my "2nd opinion" cardiologist told me separately that, with a leaky valve, your heart is used to pumping away with little resistance from the valve. Once a new valve is put in, suddenly your heart has to push up against a robust valve - as a result, your ejection fraction can be lower for awhile until the heart gets used to it and returns back up to a normal EF. They recommend having surgery when your EF is still in "normal" range so that post-surgery it won't fall below or too far below the bottom end of the normal range. This sounded like a reasonable explanation to me.

Thanks for the advice. I will add more patience to my mindset.. When I was diagnosed, my EF was below 20%. I think almost emergency level, so I was put on all the usual medication, full strength right away. It worked so well, I was stable at ~40% for about a year before surgery. It did not change much after surgery either, echos showed ~40%. Kind of strange. The 43% number is from a more accurate radionuclide measurement.

Karl.

 

[realkarl]

As others have said, even though it is discouraging being 'slower' in recovery than anticipated (I am 4 months out) I am slowly but surely moving in the right direction. I, too was very active prior to surgery, so I am trying to be a 'patient' patient (which is not easy) .
I hope you get some resolution soon and my ver best wishes to you.

Thanks for the encouragement, and I wish you a continued steady recovery as well!

 

[Ross]

I'll have to go dig out my last echo report. There was a mention of possible valve mismatch in it, but I don't remember the EF, but I do know the surface area was rather small for a 25mm valve.

 

[mainframe]

Yes the prosthetic valves all result in a narrower effective valve opening than your natural valve

Not always. My surgeon felt the 23 mm tissue valve I had was too small and instead put in a Top Hat valve. The different design doesn't have to fit in the opening, but rather sits on top. He put in a 27 mm valve.

 

[Doug]

Hey, Doug, I see you have the same valve as me. Maybe radiation causes a narrow aortic root as well, especially when done at a young age. Have you had your valve's Effective Opening Area calculated at an echo post-surgery yet? I read it can vary quite a bit even with the same valve, due to other physiological effects.

Karl

No, I have not taken a look at those calculations. My focus has been on strengthening the heart muscle. I figured that was working so poorly before the surgery that it will take awhile to build it back up. My EF was around 25% 6 weeks before surgery and 35 to 40% about 4 weeks after surgery, so I am happy.

In rehab they use METS to show progress, I will have to get the chart of my progress. It does show improvement each week, but there have been a couple of plateaus and a couple of slip backs. The nurses say when you change equipment or difficulty level that can result in some of the back slides.

 

[realkarl]

OK. That's great progress! I am glad to hear.

I did only 4 sessions of cardiac rehab that I paid myself at $100 a pop to verify with their EKG that my heart was working as expected at the indoor exercise level I was using on my own. Other than that it wasn't much use for me. I use various forms of measurements, total calories burned in 30 minutes on a stationary, how fast I can go on indoor rollers before lactic acid buildup, etc. I prefer interval training, 9 to 1 minute push really hard, 1 minute recovery. The shorter interval, the higher intensity. Sometimes I force myself not to compare though. I think I am limited by the 2 x 25mg Carvedilol, since my heart rate is only 145-150 when I push really hard, whereas I would get to 165-170 before. I have a really nice Garmin Forerunner HRM/GPS that graphs my HR and downloads each workout to the computer for later comparisons/reference.

However, what concerns me the most, I think, is my high resting pulse, 80-90, and it has hardly moved since 1 month after surgery. My cardiologist has not been concerned about this, which is reassuring, but I will mention it again next appt. I find it somewhat stressful to get to sleep and wake up to such a heart rate. I am maxed out on the beta blocker (Carvedilol).

Karl.

 

[acr]

Well I got a 29mm, thats the biggest St Jude Regent. So it's a bit tough if there is any mismatch as it can't go any bigger. Must admit I'd be worried about an 80-90 resting HR, but then I'm a worrier. Mine is 60-ish which is pretty much where it was prior to surgery.

 

[Mileena46]

As the months go by, my resting HR has continued to drop. I went from the 90s right out of the hospital to upper 60s now. I will be 8 months out on the 16th. Maybe you need to take a different kind of beta blocker. I am on a very low dose of Lisinapril....not sure about the sp?. It seems to working well. I hate it when my HR goes up and stays up for no reason so I feel for you. I would be looking for the doctor to change my meds.

Mileena

 

[Doug]

I don't have a lot of experience with Coreg (carvedilol), I was put on it shortly before surgery. I was on Metoprolol and my heart rate would not exceed 120 no matter how hard I pushed. It made it quite interesting for stress tests.

My resting heart rate has been between 75 and 80 since surgery and depending on the time of day my bp is 130 something over 70 something.
I am on 40 mg of Coreg CR. I take my meds about an hour before rehab, when I get there my BP is normal and HR is around 80. Starting the warmup my HR goes up to 90 - 94 range and then on the treadmill I finally get it up to about 106. I haven't checked it on the aerobic machines, I will ask them tomorrow, I can't see the display on any of the machines except for the treadmill.

 

[karen14]

Hi Karl,
I was officially diagnosed recently with prothesis mismatch, although my numbers are not similar to yours. Mine is most notable with the pressure gradient passing through the aortic valve being too high (even at rest). I am now 1 1/2 years post-surgery. Although I don't know what ALL the numbers mean, I know enough to help myself in my own healthcare. Here's another article for you to check out on valve sizing, that I found interesting as well: from The Society Of Thoracic Surgeons. Hope all turns out well for you! ~Karen

 

[Gail in Ca]

My surgeon found my aortic annulus was small, at 19mm, so instead of using the St Jude valve graft, he constructed a CVG utilizing a 25mm top-hat valve within a 30mm graft, which was secured to the heart in a supra-annular location in order to provide me with the largest mechanical valve that they could. He told be this would help my heart function at a better level.

 

[realkarl]

The plateauing has been very obvious for me, but my progress came to a halt a few months before the pacemaker implant. I am very glad to notice now that improvement has continued, with the LBBB being corrected by the PM and synchronous left/right ventricle contractions. Before I wrote the first post in this thread, I had been at a standstill again for a couple of weeks and was a little frustrated and depressed, and had taken almost a week's rest. Fortunately, this posting and your responses motivated me to get going again, on indoor rollers for my road bike, instead of the recumbent stationary. It was a welcome change in pace, and I have been feeling great and much stronger! I can almost feel my EF has increased... Resting heart rate not much changed though, but even in my best days, I always averaged higher than normal for my age/physical ability, rarely below 70 in fact. Maybe an artifact of the radiation as well. Who knows. That's probably why it's so high still (80-90).

And here's my HR chart for tonight's exercise. I did long intervals. Interesting to keep track of, and to see how fast HR recovers during one minute recovery. Don't worry, I won't keep posting these.

 

[Bill B]

Karl:

There are multiple possible reasons for low or no rise in EF after surgery. I have a similar concern as my EF was 55% immediately before surgery and 39% 5 days post-op. It has taken me a long time to get even back to my pre-op exercise tolerance. I was expecting immediate improvement from replacement of my tiny 0.7 cm^2 AV and to pretty quickly exceed my pre-op tolerance, but that has not happened. I've asked the surgeon and my cardiologist about this. The surgeon didn't actually give me any understandable explanation but just encouraged me to exercise hard and give it 6 months. My cardiologist offered that the cardioplegic solutions do not offer perfect protection during the period of time the heart is bypassed and said the 6 month echo, coming up soon, will be telling. If my EF is still around 39% we will both be very disappointed. The usual response to AVR for stenosis is a DRAMATIC rise in EF. The only study I could find about EF changes after AVR showed all patients going way up EXCEPT for one patient who suffered an intraoperative MI. However, none of the post-op echo were done in the immediate post-op period. They were all 8-22 months out.

My resting HR was historically around 60, but after surgery it rose into the 90s, and I found it very annoying like you have found it. I was started on Metoprolol and Lisinopril for BP control and my heart rate came down over a period of a few weeks to now 60. Metoprolol and other classic beta blockers reduce the rate and force of cardiac muscle contraction, which doesn't sound like it would be good for a low EF or CHF, but paradoxically these beta blockers can improve both. I think my resting HR would be higher without the metoprolol. You say you think you have reached the limit for Carvedilol dose based on a peak HR of 145-150, down from 180. I would reconsider that and consider a trial of higher dosage or perhaps metoprolol which has greater effects on heart rate than Carvedilol. It may bring down your resting pulse while not greatly effecting your exercise response or EF. It has helped me and although my peak HR rarely exceeds 150 I have been improving steadily of late in terms of exercise capacity. I presume you know more about exercise physiology than I do, but I wonder if there is any additional benefit to HR greater than 150 or so. At some point, the filling of the ventricles falls off. Even though your cardiologist is not concerned with your high resting heart rate, the fact that it bothers you should be a concern. I could not have tolerated my resting HR of 90+ had it remained so. I am much more comfortable at 60 and notice no adverse effects at all.

Although I am satisfied that I am back to pre-op level, despite my disappointment that it's not better, I did have an up-and-down struggle with it too. Until I get my echo later this month I won't know if my returned exercise capacity is just improved peripheral muscle efficiency and/or improved EF. I've heard the same comment that exercise does not improve EF, which sounds very discouraging, but I'm not sure that is always true or applies more specifically to people with underlying damaged myocardium, say, from an MI.