Although there are one or two studies published in China (and in Chinese!) which have shown promising results, there is no hard evidence that acupuncture has been proven to have a strengthening effect on the heart. For conditions such as this acupuncture may well have a general supporting function, insofar as the basic premise of Chinese medicine is to treat the person, not the disease, but it would be alongside conventional treatment, complementary and not alternative.
What we can say with a good degree of certainty is that as long as someone continues with their conventional treatment there is very little likelihood of acupuncture causing any harm. The safety statistics for acupuncture in the UK are exemplary, and even across the globe and taking in all forms of sub-optimal practice the incidence of serious adverse events is very low.
Both acupuncture and Chinese herbal medicine work from an entirely different knowledge base which looks at the overall functioning of the system rather than simply repairing the bits that go wrong. The symptoms which form the basis of a diagnosis in the West are used in Chinese medicine to underpin a diagnosis in entirely different terms, and the practitioner will aim to correct the imbalances and blockages which manifest as these symptoms. In that general sense there is a possibility of making everything function better.
This is not quite the same as claiming to help specific organs, and practitioners are cautioned at the beginning of their training to remember that an organ understood in Chinese medicine terms is not the same as the physical organ described in the West. It often embraces it, but includes a wide variety of other functions, not always physical. This is why Chinese medicine textbooks use the capital letter (Heart) to differentiate from the physical organ (heart).