Dilated Cardiomyopathy: Taking medications after heart function returns to normal range

Author: Dr Patricia Ding

Transcript:

Dr Patricia Ding:

Good morning, Warwick.

Dr Warwick Jaffe:

Good morning, Patricia.

Dr Patricia Ding:

Hi there. I'm Patricia Ding, cardiologist. I'm here with the experienced interventional cardiologist, Dr. Warwick Jaffe from Ascot Cardiology. So now, as a clinician, we always face this challenge about how to convince our patients to take medications. I heard you've got an interesting case today to tell us about it.

Dr Warwick Jaffe:

This is a woman that I've looked after for about 25 years. In 1994, she had a mitral valve replacement, mechanical one. Before the operation, her heart function was normal. After the operation, her heart was a little weak. The ejection fraction dropped from 55% down to 45%. She felt tired and she was put on an ACE inhibitor. She remained on this for many, many years. Around 2015, she became short of breath and was put on a beta blocker as well as an ACE inhibitor. At this time, her ejection fraction actually increased from about 45% to 55%, and she felt much better, although she still remained tired. The year before last, she was fed up with this fatigue. So she decided she was going to get a second opinion on her condition. She saw another cardiologist. The echo was repeated. Her ventricular function looked normal. Rejection fraction was recorded at 55%.

Dr Warwick Jaffe:

So at that stage, the doctor thought perhaps it was her medication that was causing her a problem and advised her to stop both her beta blocker and ACE inhibitor at the same time, within a few months of doing this, there'd been a dramatic deterioration in her condition. And she came back to see me to see what I thought about all of this and did her repeated her echo. And to my horror, her rejection fraction had dropped right down to about 35%. I wondered if the echocardiogram was incorrect. So I got an MRI scan done, which confirmed an ejection fraction of 34%, very similar. We restarted her medication, but unfortunately there wasn't too much improvement in her condition and she remained short of breath and tired. And her echocardiograms have shown that her ejection fraction hasn't improved.

Dr Patricia Ding:

So this is a valve patient with impaired LV function after surgery and put on medications. And after stopping the medications that LV function deteriorate back into moderately impaired range, what does that tell us? Do people need to keep on taking their medications when LV function improves back into the normal range?

Dr Warwick Jaffe:

Yeah it does. And I think that's the point of this, is that just because the hat looks normal on the echocardiogram, it looks normal because they're taking the medication and it can be very, very difficult to get the heart to pump well again, if that medication has stopped, that's a pretty risky thing to do.

Dr Patricia Ding:

And does that apply to all forms of heart failure?

Dr Warwick Jaffe:

Well it applies to most patients that you'll see, but there are some who have more acute forms of heart failure, such as rapid atrial fibrillation with impaired ventricular function, where you can stop the medication once the underlying condition is fixed. The key thing there is that the patients heart is usually not dilated or enlarged. They have a relatively normal size heart that just doesn't pump very well.

Dr Patricia Ding:

So in other words, if there's more acute reversible underlying causes for these types of heart failures, then it's relatively, we're more relaxed to stop their heart failure medications. Whereas dilated heart failure is quite different when it comes to stopping medications and it's unpredictable what the outcome is going to be. Are there any clinical studies to support, long-term management in these patients?

Dr Warwick Jaffe:

Well unfortunately, this is quite a hard thing to study because it's been known anecdotally for years, that if you stop tablets and some of these people, they don't get better when you restart them. There has been one rather small pilot study done a few years ago on 50 patients who had dilated cardiomyopathy. Half of them had their medication continued. Half of them had stopped, the half that had it stopped about 30% of them within six months had deteriorated and had to go back on medication again. So there is really no impetus to do a large scale study because it would probably be unethical.

Dr Patricia Ding:

Okay. All right. Thank you. So just to summarize, if someone's got dilated cardiomyopathy, they got better with their heart failure treatment with echo evidence LVEF is back into normal range. We would still recommend for them to keep on taking the medication, but how do you convince people to take tablets when they're feeling well?

Dr Warwick Jaffe:

Okay. So that is a challenge because from the patient's point of view, they just take, they feel well, they take these tablets and they wonder if some of the other things they've got in life are due to the medication. I always give them an analogy, which is like a horse running along a track. Now, if the horses muscle got a little bit weak, what you'd notice is that the horse wouldn't feel too well. So you could make that horse feel better by doing a number of things. Firstly, you could make it so it runs downhill. And that means that the muscle recovers and then the horse feels better. And that's essentially what a lot of the ACE inhibitor type drugs do. They reduce afterload. And sometimes when the horse is going along the track, the jockey will be whipping it and making it go harder. And that's really what our neuro hormones do. And so for example, beta blockers, block that whipping effect. And so the muscle fatigue can improve. And so I just tell people that imagine if the horse is running down the hill and you then made it run on the flat again and started whipping it. Well, the whole same thing might come back again. So we've got to keep taking the tablets.

Dr Patricia Ding:

Okay. I'll try to remember that analogy to tell my patients, thank you very much Warwick. It's been a pleasure.

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