After a Heart Attack, a New Problem May Emerge

Mayo Clinic investigators found that the chief cause of death after a heart attack has changed in recent years; originally it was a cardiovascular condition, but more recently non-cardiovascular conditions have been responsible for mortality.  Based on occasional reports of a possible link between heart attacks and fracture rates, they decided to study this further; their results appear in the online edition of Circulation.

Consecutive Minnesota residents diagnosed with a heart attack (myocardial infarction, or MI) between 1979 and 2006 were matched individually on age, gender, and year of onset with community-based non-MI subject.  There were 3,321 people in each group, who were followed until 2009.  The time to occurrence of osteoporotic fractures, the sites of fractures, and death were recorded.

Fracture occurrence rates were stable in the controls, but increased markedly in the post-MI patients.  After adjustments for confounding factors, such as medication use, an overall 32% excess of fracture risk after MI was found.  There was a big difference in when this increase in fracture risk happened; between 1979 and 1989 it was not-significantly different (19% lower) from the non-MI controls, whereas in 1990 to 1999 it was 47% higher.

On the other hand, the overall risk of death in post-MI cases did not change over time, except for a continuous decline in deaths within 30 days of MI, which fell from 12.5% in 1979 to 6.7% in 2000 to 2006.  The short-term improvement in post-MI mortality was presumably due to improvements in medical care.

These results are so clear-cut that they have immediate implications, without waiting for further studies to explore causation.  Prevention of falls in MI patients is obviously of increased importance, along with full utilization of cardiac rehabilitation, a much neglected tool.