This discovery was to have a major effect on the treatment of heart disease.
Does was to have mean supposed or destined in this sentence?
This discovery was to have a major effect on the treatment of heart disease.
Does was to have mean supposed or destined in this sentence?
No, was to have
doesn't mean 'supposed' or 'destined' in this case, it is merely the standard way of talking about an event in the past without using past tense for the whole sentence.