has anyone taken the drug mavacamten for wall thickening?

Hello @donnademps, and welcome to Mayo Clinic Connect.

You have been through a rough time, haven't you? I'm so sorry this is all coming at you at once.
There is a large group of Camzyos folks here on Connect, have you had a chance to read their stories?
Here is the link to that:
https://connect.mayoclinic.org/discussion/camzyos-mavacamten-prescription/
And...let me introduce you to a fellow member who is full of wisdom and experience with Camzyos, and also a fellow Canadian, meet @boatsforlife. Click on his name, and it will take you to his posts.
I think you will benefit from his words of wisdom.

As you will see if you expand your search here on Connect, there are a lot of folks on Camzyos. I couldn't take it and had to have open heart surgery.
Although the mere thought of open heart surgery can strike fear in the hypertrophic hearts of many, I assure you it is not as bad as it seems. The thought of it is more terrifying than anything else!
How are you doing after your lung surgery?
Are you healthy otherwise?

Hi @donnademps As you will see if you look back through my posts, I'm also in Canada (Alberta). When I started Camzyos there was a REMS program (can't remember exactly what REMS stood for) which paid 100% of the cost for me, which at the time was supposedly over US$80,000 per year! Even if it's down to "only" CA$22,000, that's still inaccessibly high for most of us. I thought I heard that REMS had been stopped but I also thought I heard that there were other means to work around that financial hurdle. Most health insurance that I have heard of (in Canada anyway), probably including provincial plans, have a catastrophic drug cost clause in which you pay up to a certain amount and then the plan takes care of everything over that. All that to say, keep talking to your cardiologist about it - he will be in-the-know about how to handle it.

Regarding side effects and other people's experiences, this has been a miracle drug for some of us and has been a miserable disappointment for others. I'm one of the lucky ones. The big, black-box warning that says "may cause heart failure"? First, realize that "heart failure is not "heart attack." Heart failure is a syndrome where the heart struggles to pump or relax properly - which sounds a lot like HCM to me. And HCM itself can cause heart failure. So for me, I could live with a condition that could cause heart failure, or I could take a medication that could cause heart failure, but could also help make my debilitating symptoms go away. But even I did a whole lot of hand-wringing before I came to that conclusion, and not everyone will feel that way. As I have said several times before, listen to your doctor(s) & cardiologist, not to some idiot who posts things on the internet (i.e. "me"). My experience may be of value to you, but my advice is not. It sounds like your cardiologist is really dialled in! Feel free to send me a private message if you want to discuss in more detail. Best of luck with Camzyos or with whatever other treatment you get!

@karukgirl Thank you so much for your recommendation. "boatsforlife" certainly reassured me. I am grateful to have found Connect from the Mayo Clinic. I joined after having my lobectomy and found the information and support great. I also feel better after joining this HCM group, as I was in a quandry about what treatment I was prescribed.

@boatsforlife Thank you so very much for sharing your experince. After reading your first paragragh regarding the cost, I checked what the policy is in Ontario, and it is somewhat vague using the word "may" be eligible. We have extra insurance of our own, but I haven't checked to see if it is covered. I hadn't thought about coverage, so thanks for pointing that out. My cardiologist's receptionist told me the Camzyos would likely come in my mailbox instead of a pharmacy, which I thought was a bit weird. I was also told the application for this script would take some time before everything was set up.
Your information regarding the "may cause heart failure" was so helpful to me. I was not aware what it actually meant and the thing is, I don't have any symptoms. The condition was discovered incidentally during pre-op. I have had a heart murmer and abnormal ecg for years, and was told I had something benign. My cardiologist found the blockage thru ultrasounds after my lung surgery The ultra-sound showed the thickening and and a blockage. I have tried 3 different medications and the ultra sounds are still showing concerns for the cardiologist. I have read one of symptoms is shortness of breath. It's difficult for me to separate the healing of my lobectomy (removed 40% of my rt lung) and/or oHCM. Sorry, I'm running on. Thanks again for your response. It was very helpful.