Objective:

To evaluate national trends in heat-related cardiovascular mortality in the United States from 1999 to 2024.

Approach:

• Data Source: Retrospective analysis using the CDC WONDER Multiple Cause-of-Death database.
• Population: Adults aged ≥25 years with heat-related conditions (ICD-10 code T67) and circulatory system diseases (ICD-10 codes I00–I99).
• Analysis Method: Age-adjusted mortality rates (AAMRs) calculated; temporal trends analyzed using Joinpoint regression.

Key Findings:

• A total of 10,731 deaths were identified from heat-related cardiovascular conditions.
• Mortality declined significantly from 1999 to 2004, followed by variable trends.
• A sharp and statistically significant increase in mortality was observed from 2015 to 2024 (APC: 17.58%; p < 0.001).
• Males demonstrated a significant overall increase in mortality (AAPC: 3.64%; p = 0.034).
• Hispanic populations exhibited the most pronounced recent increases in mortality.
• The highest burden of mortality was observed in the Western and Southern United States.

Interpretation:

Heat-related cardiovascular mortality has increased significantly in recent years, with notable demographic and geographic disparities.

Limitations:

• Analysis limited to adults aged ≥25 years.
• Data on race and ethnicity restricted to certain groups due to reliability concerns.

Conclusion:

The study highlights the increasing impact of climate-related heat exposure on cardiovascular mortality.