How are hiccups and angina related?

They aren't : However, some people have dyspepsia as symptom of angina...Get evaluated.

Rare: There are rare case reports of hiccups occurring on exertion due to coronary artery disease. The diagnosis should be considered if hiccups occur predictably with exertion. In such an instance, one should be evaluated with testing to rule out coronary artery disease. It merits a visit to ones doctor or to a cardiologist.