Ankylosing spondylitis has a mortality rate of 14.5 percent, according to a 2011 abstract released by the National Institutes of Health. Circulatory disease is the most common cause of death.
The Spondylitis Association of America describes ankylosing spondylitis as a type of arthritis that causes pain and stiffness of the spine from the neck down to the lower back. In advanced cases, AS may cause the bones of the spine to fuse, resulting in stooped posture, notes WebMD. AS has no known cure, but treatment of symptoms can include a combination of physical and occupational therapy, exercise, and non-steroidal anti-inflammatory drugs. The Spondylitis Association of America recommends that AS patients receive close monitoring for cardiac issues due to the higher risk of vascular disease.