Well only your doc can accurately assess what is really going on with you with testing and she or he has to be the one to give you the directive. Obviously the BNP blood test is one of the methods that is used to determine the level of CHF with the highest result being over 1300....but try to remember that as of last year they were still doing the clinical trials of the accuracy of the test. There are other tests that should be administered as well for confirmation of the readings....