Microvascular angina. The heart problem?

I am a 49 year old male went through coronary angiography last year ( december 2024) after getting my tmt reoprt positive. Cag reports was : all normal coronary arteries without any blockage but 'slow dye clearance' microvascular angina. My calcicum score was 0 in CT cag report done on 2023. Now my hdl: 64, ldl: 52, Tg:46, total cholesterol: 122, Haemoglobin: 12.5, hs-crp: 0.48, troponin I : 1.7 pg/l( ref range shoud be below 6 for men), cpk mb: 19u/l( ref range should be below 25), cpk: 165( ref should be kess than 190). Echo was normal (EF: 65%) & Ecg is normal sinus rhythm. Every day i do a brisk walk for 30 mins. Non smoker, non alcoholic. Bp 112/70, pulse rate ( 52 to  110bpm)non diabetic. Problem facing : chest heaviness, pain some time especially at rest state. Dizziness some time. My Question:   Where lies the problem? Is it anything serious about the heart problem?