Elevated NT proBNP

I am a 44yo Female with a history of a MI in October of 2012 and when looking through my lab-work I came across a lab test showing my NT proBNP was 364 when ref was <125 (on 10/8) and since I have a history of mild LVH (12mm) I was startled to see this since I was not informed about it being elevated.

I am having a hard time finding any reference online to see just how "high" this is and how serious I should take these findings.

My cardiac enzymes were -
Triponin I- 0.94 on 10/7
Triponin T- 0.22 on 10/7

I know that my EF was 65% during the angiogram done a day before and I will be having a echo done asap but since I cannot find anything about the NT proBNP levels online, only that mine are elevated I was wondering if I am getting alarmed over nothing and this is normal after a MI or if I should have been informed of a possible worsening of my LVH?

[CCF HeartMD6]

The NT proBNP is not a direct reflection of any structural abnormalities of the heart (i.e. LVH, etc) but rather an indication of volume (and/or pressure) that is being transmitted to the ventricle which can be due to a variety of reasons including some diastolic dysfunction (stiffening of the ventricle) due to injury such as an MI.  The "normal ranges" of the NT proBNP may vary from institution from institution but a general range would be from 400-2000 pg/mL (47-236 pmol/litre). I am unsure what units you are using to report your value.