Thank you for your query at DoctorSpring.com
From your case history ,it seems she has been suffering from heart failure , a condition best described as when the heart is unable to pump sufficiently to maintain blood flow to meet the body's needs further aggravated by age, atrial fibrillation ,risk factors like age , diabetes etc.
In her case both heart failure and chronic kidney disease are interlinked as in heart failure the blood supply is reduced to all organs including kidney ,drugs like fursemide which is commonly used diuretic in heart failure to remove excess fluid ,if she has diabetes it can effect both heart and kidney .
Having Atrial Fibrillation can also effect the heart failure and also reduced the cardiac output , so it has to controlled .If it is present for a short duration it can be cardioverted to sinus rhythm so as to improve cardiac function and if it is present for longer duration then the rate has to controlled and anticoagulants has to be given to prevent embolic episodes.
Looking to her age and others like high BNP and nephropathy , there usually have bad prognosis with recurrent admissions for heart failure or due to embolic episodes. She requires close monitoring with cardiologist , nephrologist and general physicians