Advantages and disadvantages of a pacemaker over a heart transplant?

A heart-valve replacement is a much simpler operation than a heart transplant. With a transplant, there are more risks and they are far greater; rejection, infection and blood clots, not to mention the short and long-term side-effects of immunosuppressive medication (organ failure, blood disorders, cancer etc...). A transplanted heart is not guaranteed to function any better than what the patient already has - it only becomes a viable option when a patient is certain to die without one.