How imminent is Heart Failure?

My father-in-law is 55 years old. He has suffered 3 heart attacks, the first when he was just 38. He has 17 stints in his heart, they put in at least 2 more in about every four months. He is also a smoker. This year they put in a pacemaker/defibulator. Two nights ago, he awoke when his defibulator shocked him. He hadn't had any pain or symptoms. When he went to the doctor, they said that his heart had completely stopped. If he hadn't had the defibulator, he would have died in his sleep. I was wondering how many times the defibulator would work before the heart could not come back from failure?

You ask the question, "How imminent is Heart failure?"... Your father-in-law has heart failure already. The heart attacks he has experienced have weakened his heart to the point that he became a candidate for placement of the defibrillator which he now has.
What can be done at this point? He needs to be on optimal medical management including beta blockers (Coreg/carvedilol most successful in heart failure), ace inhibitors, and diuretics for the treatment of his heart failure. These medicines can help to improve the ejection fraction (how strong his heart muscle is) which will help improve his chances.He should also be on a statin preferably for cholesterol management to reduce risk of another heart attack (myocardial infarction/MI).
He does need to stop smoking and he can do this "cold-turkey". He will NOT go into DT's as stated by another respondent. If unable to stop on his own there are programs designed to assist in smoking cessation, some that involve meds and some that do not.
Finally, regarding his device. It needs to be evaluated by the doctor 4 times per year to make sure it is set at optimal settings. Also, needs to be checked when he receives shock therapy. The device will continue to provide therapy for rhythms that require it indefinitely but it will depend on your father-in-laws heart muscle as to how long he will respond to this therapy.

It depends how much damage is done to the heart muscle. If too damaged the defib can no longer help. Heart transplant would be an option before it gets to that point.

That depends on his genes, how much damage was done and how much he can take. My mother didn't make it to 37. Not to sound mean, but we all eventually die. Pick your battles and live the best you can. It might help if he stopped smoking, but he needs the doctors help with that, considering his condition. His body may go into DTs if he stops cold-turkey and that could be harder than continuing smoking.

There is no timeline. Sadly, the heart muscle will eventually have had enough and it will not be able to be restarted. It can be 30 hours or 30 years.

JUSTMEHERE; IF THE FOOL WANTS TO DIE TELL HIM TO KEEP SMOKING, BUT IF HE WANTS TO GET BETTER AND LIVE A FEW MORE YEARS YOU SEARCH FOR " DR.JOHANNA BUDWIGS CANCER DIET" THE DIET WILL HELP THE HEART RESTORE ITS STRENGTH AND PREVENT CANCER AS WELL AS CURE IT AND ITS A VERY SIMPLE AND INEXPENSIVE THING TO DO

One problem with an ICD is that it sometimes delivers shocks when you do not need them. Even though a shock lasts a very short time, you can usually feel it. Every shock you feel should be notified to your doctor. The settings of the ICD may need to be adjusted or your medications may need to be changed. ICD problems can sometimes be prevented by programming the device to sound an alert when there is a problem. This can be done by your electrophysiologist. If you heart your ICD alert, you should immediately call your doctor.
Please see the web pages for more details on Implantable cardioverter-defibrillators (ICDs)