Global Burden of Ischemic Heart Disease and Ischemic Stroke, 1990-2023: Spatial Heterogeneity, SDI Inequalities, Pandemic-Era Inflections, and Scenario Forecasts to 2035 Using GBD 2023.

BACKGROUND: Ischemic heart disease (IHD) and ischemic stroke (IS) remain leading causes of death and disability, with substantial geographic and sociodemographic inequalities. We assessed long-term trends, sociodemographic index (SDI) disparities, COVID-19-period inflections, risk-factor profiles, and scenario forecasts using Global Burden of Disease (GBD) 2023 estimates. METHODS: Using GBD 2023 data (1990-2023), we analyzed age-standardized incidence (ASIR), death (ASDR), and DALY rates (ASDALY) globally and across SDI quintiles. COVID-19 impacts were evaluated using segmented log-linear models (2010-2019 vs. 2020-2023), estimating the average annual percent change (AAPC) and counterfactual deviations extrapolating pre-COVID trends. Risk attribution used the GBD comparative risk assessment framework. ARIMA-based forecasts projected global ASDR/ASDALY to 2035, with S1 fitted to 2010-2019 and S2 to 2010-2023; 1990-start forecasts were assessed as sensitivity analyses. RESULTS: In 2023, ASDRs varied widely across countries (IHD 24.9-441.0; IS 6.0-182.5 per 100,000). From 1990 to 2023, global ASDR declined for both diseases (IHD -38.2%; IS -53.1%), with an IHD SDI reversal (high SDI -52.8% vs. low SDI +13.4%). During 2020-2023, IHD mortality plateaued (AAPC 0.06%/year), whereas IS continued to decline but slowed (AAPC -1.48%/year). Forecasts to 2035 indicated a higher projected burden under S2 than S1. CONCLUSIONS: Progress in IHD and IS burden has been uneven, with widening SDI disparities and pandemic-era attenuation, underscoring the need for equitable and resilient prevention and care.