You really should not. 60 beats per minute means that in ten years the leads of a pacemaker will be bent *315 million* times. That's an order of magnitude higher than we typically test fatigue resistance, and even if we were that confident about being able to produce flawless materials, there are
millions of different enzymes and acids and temperature fluctuations in the body. Any one of those could impact the fatigue resistance.
Additionally, any kind of implanted device is significantly prone to a wide range of problems that range from inconvenient to devastating. The human body is very hostile to foreign objects, often with few warning signs. Clots and fibrous capsules (and eventually, calcified capsules) form around ANY implant, and that's the best case problem.
Titanium is extremely biocompatible. It forms a thinner capsule than most materials. It integrates with bones beautifully, due to surface treatments that allow bone to grow into microscopic surface cavities, with strong molecular bonds. But also sometimes, for no apparent reason, all the bone around a titanium implant will just start dying and resorbing. It's rare, but if you get a hip replacement you absolutely need to check on it regularly because if you don't you'll lose use of the leg completely (and quickly, and permanently).
In and around the heart is one of the most challenging places to implant things, aside from maybe the brain. Any moving part of the body will constantly stress any mechanical part, and build up scar tissue around and rubbing spots. The only reason the brain is worse is because its fragile and changes size significantly when you sleep.
Recently we started using leadless pacemakers. Even before that pacemakers were continually getting smaller, and smaller pacemakers are less irritating and experience less stress and movement. Even if that weren't true, it would still be worth checking in on pacemakers, because they're doing incredibly hard jobs and if they fail people can die faster than they can get to a hospital.
EDIT: oh, and heart disease is the #1 cause of death in the US, while heart surgery is one of the most difficult specialties to get in to. They are absolutely never short on patients, lol.