Cardiac Calcium Scoring Test

Is a score of 308 on a calcium cardiac scoring test an indication of coronary artery disease?  And should this score prompt a CTA?

[Cleveland Clinic]

No this score should prompt a left heart catheterization as this much calcium will almost always obscure the severity of the lesions and hence make the CTA a non diagnostic test. It should also prompt immediate treatment of hypertension, dyslipidemia and initiation of daily aspirin if tolerated.

[Flutterby111]

Can you please tell me what Hypertensive Cardiovascular Disease means in Layman's terms?  This is the cause of death on my father's death certficate.  He was only 51 and I found him on his exercise bike in his basement on March 19th.  I knew it was a heart attack or something and I plan on seeing his doctor to better educate my sister and I on what we're up against for ourselves and our children, but I'm anxious to know now.  I'm also waiting (im)patiently for the detailed autopsy report.  

Thank you so much, it means alot to know.

P.S. he suffered pericarditis when he was 21 and his father died at age 56