Hello,
Since you had the stent surgery just 4 weeks prior, it is important to avoid any strenuous physical activity like altitude climbing at such a short time span. This may cause further complications.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
You will have to ask your cardiologist. It isn't about the stents, but about the condition of your heart.