Saturday, February 20, 2016

Post-Op



When I was first diagnosed with severe aortic regurgitation, there was a great deal of disagreement about what to do. A significant majority of cardiologists and surgeons I saw recommended surgery within 6 months, while a small minority suggested that I could safely wait several years, perhaps even ten (or more), before requiring my valve operation.

As I wrote before, the advantage to early operation is that it minimizes the chances of waiting too long. At a certain point, as the left ventricle undergoes chronic volume overloading, irreversible contractile dysfunction develops, and I certainly didn't want to be left with a weak heart after surgery that would last the rest of my days. Not only that, we know that if one operates too late, survival is reduced.

The advantages to waiting are numerous. Firstly, it delays an event that has a mortality of about 1%. Secondly, it delays the onset of life with a mechanical valve, meaning that it delays the risks of valve clot and stroke, infection, as well as the risks of anticoagulation with warfarin. Thirdly, as soon as a valve is put in, a clock starts ticking until it will need to be replaced, too. The later one can operate, the higher the chances are that only one operation will be needed.

So whom to listen to among the disagreement was one of the early conundrums I faced after diagnosis. I decided to go with the available data which coincided with the opinion of the cardiologist most experienced in timing such operations, both indicating that I should not undergo surgery at that time but rather delay delay it as long as possible, possibly for years.

Well, after three years of following my heart size and function closely with serial ultrasound and MRI examinations, my ventricle showed clear signs of increasing in size just a little bit too much, and the opinions of all involved aligned: it was time to operate. Now we get a chance to see if my initial choice of waiting was a mistake, or not.

Three years ago, when I was diagnosed, the relevant parameters were as follows:
Left ventricular diastolic dimension: 63 mm
Left ventricular systolic dimension: 42 mm
Left ventricular ejection fraction: 54%

Pre-operatively, those parameters were:
Left ventricular diastolic dimension: 67-70 mm
Left ventricular systolic dimension: 44 mm
Left ventricular ejection fraction: 60%

What do you think those parameters are on my post-op echo? If my LV remains large and my function (ejection fraction) drops dramatically, then I probably made a mistake (though, to be fair, we must give my heart some time to remodel and get used to the new conditions of a fully competent mechanical valve). On the other hand, if my left ventricle has shrunk, and my function remains good, then we can only expect improvement over time, and I probably made the right choice to wait and enjoy three years without the burdens of a mechanical valve. (And they were three very good years.)

Chime in below with your predictions. In a few days, I'll reveal what the numbers actually are.

4 comments:

  1. If mortality is 1% today, we have to assume that as medical technology improves, that will be dramatically lower in the years/decades before the valve needs to be replaced. Who knows how the surgery will be done that far down the road. We can know with certainty that the future surgery will not be any MORE dangerous than the current surgery.

    Far be it for me to disagree with a cardiac surgeons advice but I would have opted for surgery early to eliminate the very real danger of long term heart damage.

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    1. I certainly appreciate that perspective, Richard. My attitude was always to err on the side of operating a little too early rather than a little too late. However, There are a variety of good follow up studies that all indicate that the risk of irreversible cardiac dysfunction is extremely low when operating with the LV indices I had at the time of diagnosis and pre-operatively and that data serves as the foundation for the current guidelines, which I followed to a T.

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  2. I don't think you waited to long, but I was wondering if there is a role for cMRI here? I predict 60 mm LVEDV - 43 mm LVESV and EF of 60%

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    1. I had an echo at 6 month intervals and a cMRI at 6 month intervals, so that each year, I had at least one echo and one cMRI 6 months apart.

      The increase in my LV size was most apparent on the volume renderings the cMRI and really, the decision to operate was based on the cMRI rather than the echo data. I think that cMRI was very valuable in my case.

      It makes sense that the cMRI was more sensitive to my LV enlargement. A 3-d volume should be more sensitive than a single dimension measurement.

      I'm very grateful to my cardiologist, a cMRI specialist, for offering me this modality for follow up.

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