According to Scientific American, many generic heart medications work just as well as their name-brand equivalents. The article cites a report by the Journal of the American Medical Association:

“The report in today’s Journal of the American Medical Association reviewed 47 head-to-head trials between generic and brand-name versions of heart drugs between 1984 and this year. It found equivalent effects among most medicines in nine drug sub-classes: beta-blockers, diuretics, calcium-channel blockers, anti-clotting drugs, statins, ACE inhibitors, alpha-blockers, anti-arrhythmic drugs (for irregular heartbeats) and warfarin. Americans spend more on those drugs on an outpatient basis than on any other prescription medicines, according to the paper.”

The Scientific American article goes on to say:

“‘Generic drugs can be a very useful part of a treatment plan — they reduce cost and improve adherence, but it’s a common view that brand-name drugs are superior to generic drugs,’ says study co-author Aaron Kesselheim, an instructor at Harvard Medical School. ‘There is no evidence that brand-name drugs are superior.'”

Here’s a link to the article:
Generic heart drugs as good as brand names