The Universal Definition classifies MI by type according to the mechanism of myocardial ischemia. Type 1 MI (T1MI) result spontaneously from atherosclerotic plaque instability. Type 2 MI (T2MI) are secondary to other causes such as sepsis and cocaine-induced vasospasm resulting in oxygen demand-supply mismatch. We previously demonstrated that, in contrast to the general population, almost half of MIs among people living with HIV (PLWH) are T2MI. We conducted this study to compare MI rates by type and age among PLWH. We hypothesized that increases in rates with older age would differ by MI type, and that in contrast to the general population, T2MI would be more common in younger individuals, but there would be a measurable rate of T1MI even among 18-30 year-old PLWH.
Potential MI events were identified in the centralized data repository at 6 CNICS sites. Case identification criteria included MI diagnoses and cardiac biomarkers to optimize ascertainment sensitivity. For each potential MI, sites assembled de-identified packets with physician notes, ECGs, procedure results, and lab results. Two experts reviewed each packet followed by a 3rd if discrepancies occurred. Reviewers categorized each MI by type and identified causes for T2MI. By decade of age, we calculated T1 and T2MI rates and confidence intervals (CI) per 1000 person-years of follow-up. Rate ratios were calculated for rates of T2MI vs. T1MI per decade of age.
We included 564 T1MI (54%) and 483 T2MI (46%). T1MI rates increased with older age although T1MI occurred in all decades including young adults (Table). T2MI rates were significantly higher than T1MI rates for PLWH under 40 and increased with age among those over 40 (Table). T1MI rates were similar or higher than T2MI rates among those over 40 (significantly higher for those 61-70 years of age). Of note, there were differences in causes of T2MI among those at younger vs. older ages with cocaine-induced vasospasm more common in younger PLWH while causes such as hypertensive urgency and arrhythmia were more common in older PLWH.
We found that among PLWH rates of T2MI were higher than T1MI until age 40 differing from what is seen in the general population, but rates of both were very high among older PLWH. Causes of T2MI differed by age with substance use prominent at younger ages and cardiovascular-related risk factors common at older ages. These results highlight the importance of evaluating MI by type among PLWH.