Randomized trial supports early surgery once AS is severe vs waiting for symptoms

[Chuck C]

Interesting outcomes for this recently published randomized trial. It suggests better outcomes for asymptomatic patients, when their aortic stenosis becomes severe, vs waiting for symptoms to develop.

"Conclusion

In asymptomatic patients with severe AS, early surgery reduced a primary composite of all-cause death, acute myocardial infarction, stroke, or unplanned hospitalization for heart failure compared with conservative treatment. This randomized trial provides preliminary support for early SAVR once AS becomes severe, regardless of symptoms."

https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.121.057639

 

[Astro]

Thanks Chuck C,

This is the second randomised controlled trial (RCT) looking at the timing of surgery for severe aortic stenosis. The other one was by Kang:

Early Surgery or Conservative Care for Asymptomatic Aortic Stenosis - PubMed

Both are small trials so we won't know the definitive answers until the large trials are completed (several trials are underway). Both suggest clear benefit to having surgery when your aortic stenosis is severe, before symptoms develop rather waiting for symptoms to develop. This makes sense to me - why risk irreversible heart scaring? Replacing the valve won't fix irreversible heart scarring. If such scarring is present, this may effect life expectancy.

We'll see what subsequent trials show.

 

[pellicle]

Hi

Early Surgery or Conservative Care for Asymptomatic Aortic Stenosis - PubMed

Both are small trials so we won't know the definitive answers until the large trials are completed (several trials are underway). Both suggest clear benefit to having surgery when your aortic stenosis is severe, before symptoms develop rather waiting for symptoms to develop. This makes sense to me - why risk irreversible heart scaring? Replacing the valve won't fix irreversible heart scarring. If such scarring is present, this may effect life expectancy.

I'm more recently interested in this from the perspective of specifically arrhythmias (having recently developed my own), which are of course also associated with life expectancy. Some of these can be well managed with simple drugs (such as beta blockers) but some seem to necessitate interventions (such as ablations).

Recently (regrettably I can't find this) I read something about the damage to neural pathways resulting in these being 'reformed' around the site and taking on new (not necessarily the correct) pathways and I suspected that this may be the basis for the presentation of atrial complexes which can then lead to other things such as tachycardia, bradycardia and AF.

I understood that the association between these developments and structural heart disease (like valve stenosis, leading to pumping problems leading to adaptations like enlargement) is well associated with arrhythmias.

https://www.hindawi.com/journals/crp/2014/615987/

(ii) Structural Heart Disease. Postoperative dysrhythmias are most likely to occur in patients with structural heart disease. Patients undergoing cardiac surgery often have the substrate of atrial enlargement or elevation in atrial pressures. These changes predispose to atrial tachyarrhythmias. The propagation of reentrant circuits during atrial fibrillation (AFib) can be promoted by larger atrial sizes that can support multiple circuits. Similarly, in patients with cardiomegaly, underlying structural heart disease can play as a ventricular arrhythmogenic substrate.​

I'm of the view that if a more holistic approach to intervention is desirable that we should move away from the mid 20th Century view of risk analysis (where we defer surgery until the risk of death from not having surgery exceeds that of having surgery) to a model where we know the risks are actually quite low and we should act early to prevent sutrctural damage to not just the musculature of the heart but to what we can see (building on evidence) turning inevitably into an electro-cardiology issue too (which brings increases in mortality).

https://pubmed.ncbi.nlm.nih.gov/28076963/

Conclusions New-onset atrial fibrillation after first-time isolated aortic valve replacement correlated significantly with late morbidity and mortality. Advanced age and absence of a postoperative β-blocker may increase the incidence of atrial fibrillation.​

I'd be interested to hear your thoughts on this line of thinking.

PS: I was going to mention you to Chuck in relation to this as its been a topic we've been discussing a bit lately, so I'm glad you've dropped by (as it were).

 

[Astro]

Hi pellicle,

Best wishes with your arrhythmia. The scarring from heart surgery can certainly change conduction in the heart leading to arrhythmias. However, arrhythmias are also common in people with structurally normal hearts who have had no heart interventions.
The association between AF after AVR and late morbidity and mortality, does make sense. A less happy myocardium is more likely to develop both arrhythmias and longer term heart failure. The study you mentioned looked at AF within 6 months of surgery. This wouldn't apply to you unless I missed that you had surgery again recently. Even if this line of thought applies to you, you are still likely to have a good outcome despite the increased risk.

How do I view balancing risks for heart surgery? Now that surgery mortality is so low (<1% in good institutions), I think that it makes sense to think about long term mortality (at least 10 year survival). Once a valve problem becomes severe, perhaps it is best to plan surgery rather than waiting for symptoms (and heart scarring) to occur. This is a hotly debated topic in the literature. Future studies will give us the answers. Not everyone has a chance of having earlier surgery - many people don't know they have a valve problem until symptoms develop.

 

[pellicle]

Hi

Best wishes with your arrhythmia. The scarring from heart surgery can certainly change conduction in the heart leading to arrhythmias.

indeed, but I was interested more in the sorts of damage that will occur to nerves when they are first stretched (not in a growth phase) and then later the surrounding tissue returns to normal size and there must have be some damage to the endoneurium sheath of the nerve at this time (as many nerves are not adapted to be stretched.

The association between AF after AVR and late morbidity and mortality, does make sense.

naturally, as AF will cause problems as will other forms arrhythmias ...

The study you mentioned looked at AF within 6 months of surgery. This wouldn't apply to you unless I missed that you had surgery again recently. Even if this line of thought applies to you, you are still likely to have a good outcome despite the increased risk.

exactly, and no I've not had any cardiac surgeries since 2011, but there is a paucity of studies on late development

How do I view balancing risks for heart surgery? .... This is a hotly debated topic in the literature. Future studies will give us the answers.

indeed

Not everyone has a chance of having earlier surgery - many people don't know they have a valve problem until symptoms develop.

indeed, but those who are diagnosed may be better off having surgery earlier for the reason I'm conjecturing now (as well as the currently established ones).

That was what I was asking about

 

[AZATADINE]

I had my surgery 1 year ago tomorrow. I went for my routine annual check up (always knew I had BAV and had an annual Echo etc.) but the valve area had significantly reduced from previous year and gradient increased. I was asymptomatic still though. The cardiologist asked if I wanted to increase the monitoring until it was "time" or proceed with AVR electively (or at least semi-electively.....). I opted to get it replaced rather than wait for symptoms. I really couldn't understand why somebody would throw the dice and wait for symptoms when a surgery would rectify the situation. I didn't want to become symptomatic. Surgery and recovery went very well.

That said, it's not like I had the surgery years ahead of when I needed it though. I was probably on the cusp of getting symptoms as my valve area was 1cm^2 (down from 1.5 cm^2 over a year).