Yes, solely associated with strontium ranelate.
More importantly, it was based on a population study where older, sicker women were using the strontium ranelate. Several studies tried to reproduce these results, but none were able to find the same conclusions as that one study. Denmark performed a population study for several years and never found a link from strontium ranelate to the cardio risks. see link at bottom of this reply
Saying that, I, personally, would still never take strontium ranelate; the asparatame is a concern; plus why take it when you can take strontium citrate which has never been associated with cardio side effects, and we have generations of people who have had high content in their ground water with no corresponding finding of disease.
There was one place in Iran or Iraq where the strontium ground water was so high that it resulted in very compact bones with loss of height. The "cure" was that calcium was provided to the inhabitants to off-set the large strontium intake.
Which is why we always say make sure that you are getting lots of calcium.
Here is a link to the Denmark study and conclusion:
https://pubmed.ncbi.nlm.nih.gov/24651624/