mairtin

I have persistent afib. i have good rate control with bisoprolol, also on warfarin. Left atrium dilated.
Mostly asymptomatic. Age 55. The question is, if I stick with rate control do I also control my cumulative risk of stroke? ie is it the same risk in 10 years, 20 years?

[va_tony]

Hi Mairtin

I also replied to your other thread. I noticed here that you mention an enlarged left atrium too. That's also another risk factor for eventual stroke.  At your present age and taking coumadin, your risk of stroke is really minimal--- just about zero.  As you get older, the odds go up. I would guess your (and my) chances are as high as 25% of eventually having a stroke during our lifetime (I'm not happy with those odds either).

Here's what one source says:

"Who is at high risk of stroke and thromboembolism without treatment?
The important independent prognostic factors for an increased risk of stroke among individuals with AF are increasing age, a history of previous TIA or stroke, hypertension, diabetes mellitus, and transthoracic echocardiographic evidence of moderate to severe left ventricular systolic dysfunction (E1).7,26,35-37 Echocardiographic evidence of left atrial enlargement (E2) and left atrial spontaneous echo densities ("smoke"), possibly indicative of stasis of blood, are also significant risk factors for stroke36-39 (E33).
These risk factors are cumulative: for people younger than 65 years with no risk factors the untreated annual risk of stroke is about 1%, whereas with one or more risk factors it is about 5%; for people aged 65-75 years with no risk factors the annual risk of stroke is about 4%, and with one or more risk factors it is about 6% per year; and for people older than 75 years with no risk factors the risk of stroke is about 3%-4%, whereas with one or more risk factors it is about 8% (see Box 2) (E1).7,26

from  http://www.mja.com.au/public/issues/174_05_050301/hankey/hankey.html

So taking coumadin lowers the stated risks by about 1/3rd.

My case is very similar to yours except I'm 65 and you are 55.  I'm also in persistent afib, am rate-controlled, asymptomatic and take coumadin.  Like you, I also have a dilated left atrium (that's often caused by the continuous afib) and have had high blood pressure in the past that's now well controlled with meds. I've done some research on your question because it obviously concerns me too.  I have asked my cardiologist about this but he dodges the answer.  It might be instructive to post this to the cardiologist on the heart rhythm expert board and see what he says.

I guess the bottom line is that you are following the medically recommended course of action.  The large AFFIRM clinical study showed that patients like you and me had a better outlook than those who took strong antiarrhythmic meds to keep their heart in normal sinus rhythym. I suppose the only thing that might reduce the risk of stroke further is to have a mini-Maze procedure involving pulmonary vein isolation and the removal of the left atrial appendage, where most clots form in afib patients.

Good luck

Tony

[va_tony]

Here's an interesting excel spreadsheet (from the AFFIRM study) where you can input your own particulars and calculate your 5-year cumulative risk of stroke (for the case of NO anticoagulation therapy).

http://www.nhlbi.nih.gov/about/framingham/strokecalc.xls

For example, I assumed you are a non-smoker, have a systolic BP of 120 and are 55 years old.  Your risk of a stroke even without coumadin is only 4% over 5 years.  With coumadin it's 3 times lower.

You can play around with the spreadsheet and see how the odds change as you get older.