Supplemental Material for: Transient Ischemic Attack as a Marker of Coronary Heart Disease: A Population-Based Study

Methods

Prospective longitudinal cohort study design within the Framingham Heart Study. TIA- and CHD- free participants were matched on age and sex (ratio 3:1) to CHD-free participants with first incident TIA. The main outcomes were: 10-year risk of CHD, major CHD, CHF, and stroke comparing TIA cases with matched controls; and time trends of cardiac outcomes and stroke risk assessed in 3 epochs: 1948-1985, 1986-1999 and 2000-2019.

Results: 286 participants with TIA (116 (41%) men, mean age 73.1±10.8 years) were matched to 858 controls without TIA. 54 (19%) participants had CHD, 35 (12%) major CHD, 37 (13%) CHF, 83 (29%) stroke. Participants with TIA had significantly higher risk of CHD (adjusted Hazard Ratio 1.55, 95% CI (1.06-2.28 p=0.03) and stroke (adjusted HR 4.01 (2.73-5.87), p<0.0001), but not of major CHD or CHF. 35 strokes (42%) occurred within 3 months; 44 (81.5%) CHD events occurred >12 months.

CHD (HR 0.64, 95% CI (0.52-0.80), p<0.0001) incidence showed a significant decline over time between 1948-2019 driven by controls; it did not decline significantly among TIA cases (HR 0.80 (0.56-1.15), p=0.22. Conclusions: We found that among patients with TIA CHD events are concentrated beyond the first year, a temporal pattern distinct from the early clustering of post-TIA stroke risk and not well captured in current post-TIA management frameworks.

These findings support the need for sustained cardiovascular prevention strategies after TIA that extend beyond current pathways focused on short-term stroke risk reduction.</p>