Until the introduction of the high-level structure in 2015, ISO 9001:2008 and ISO 13485:2003 were very similar standards.
Unfortunately, corrections on the ISO 13485:2003 took too long. The new version of ISO 13485 has been decided to be released in 2016 although it relies on ISO 9001: 2008. So when ISO 9001:2015 was finally released with the new structure, 13485: 2016 was also already ready for release with the ISO 9001: 2008 structure. Then the ISO organization decided to release 13485 with the old structure.
For more information on similarities between ISO 9001 and ISO 13485, see the following article: