NEW ORLEANS — The number of acute myocardial infarctions in 90- to 99-year-olds is rising sharply in tandem with rapid growth in the nonagenarian population, Dr. William J. Kostis reported at the annual meeting of the American College of Cardiology.
Percutaneous or surgical revascularization is performed much less frequently in nonagenarians with a first myocardial infarction than in younger myocardial infarction patients but is associated with a 66% reduction in 1-year all-cause mortality, compared with that in nonagenarians who don't get revascularized, added Dr. Kostis of the Robert Wood Johnson Medical School, New Brunswick, N.J.
He presented a study of all 10,213 nonagenarians hospitalized with a first myocardial infarction in New Jersey in 1986–2002. The data came from the Myocardial Infarction Data Acquisition System (MIDAS), a unique registry that captures all admissions for myocardial infarction statewide.
The annual number of nonagenarians with a first MI nearly doubled from 828 women and 426 men in 1986 to 1,598 women and 840 men in 2002. The incidence was relatively stable, however: 1.4% in 1986 and 1.5% in 2002 for women, and 1.8% in 1986 and 1.9% in 2002 for men.
In-hospital mortality following both Q wave and non-Q wave MI remained stable at about 35% and 15%, respectively, during 1986–2002. Yet overall in-hospital mortality in nonagenarian MI patients dropped over time, largely because the proportion of less deadly non-Q wave MIs rose. Dr. Kostis cited two possible explanations for this trend in an interview: increased use of sensitive serum markers of myocardial infarction such as troponin I allows earlier identification of infarcts before Q waves develop, and public education efforts aimed at getting patients to present to the hospital sooner after symptom onset.
Overall 1-year mortality was 52% in both men and women. This rate dropped by two-thirds in those who underwent coronary revascularization.
But while utilization of revascularization in nonagenarians increased over the study years, rates remained far lower than in younger MI patients.
For example, percutaneous revascularization was performed in about 5% of nonagenarian MI patients in 2002, compared with 30% of younger patients statewide. Dr. Kostis speculated that the low rates might be due to physician reluctance to intervene in the very elderly because of extensive comorbidities, or perhaps to less willingness of nonagenarians to provide informed consent, although there are no data addressing these possibilities.