From the Division of Cardiovascular Medicine (S.A.M.K, L.A.E., A.S.N.), University of Pennsylvania, Philadelphia.
Penn Cardiovascular Outcomes, Quality, and Evaluative Research Center (S.A.M.K., L.A.E., A.S.N., P.W.G.), University of Pennsylvania, Philadelphia.
Circulation. 2023 Nov 14;148(20):1559-1569. doi: 10.1161/CIRCULATIONAHA.123.066017. Epub 2023 Oct 30.
Climate change is causing an increase in extreme heat. Individuals with cardiovascular disease are at high risk of heat-related adverse health effects. How the burden of extreme heat-associated cardiovascular deaths in the United States will change with the projected rise in extreme heat is unknown.
We obtained data on cardiovascular deaths among adults and the number of extreme heat days (maximum heat index ≥90 °F [32.2 °C]) in each county in the contiguous United States from 2008 to 2019. Based on representative concentration pathway trajectories that model greenhouse gas emissions and shared socioeconomic pathways (SSP) that model future socioeconomic scenarios and demographic projections, we obtained county-level projected numbers of extreme heat days and populations under 2 scenarios for the midcentury period 2036 to 2065: SSP2-4.5 (representing demographic projections from a "middle-of-the-road" socioeconomic scenario and an intermediate increase in emissions) and SSP5-8.5 (demographic projections in an economy based on "fossil-fueled development" and a large increase in emissions). The association of cardiovascular mortality with extreme heat was estimated with a Poisson fixed-effects model. Using estimates from this model, the projected number of excess cardiovascular deaths associated with extreme heat was calculated.
Extreme heat was associated with 1651 (95% CI, 921-2381) excess cardiovascular deaths per year from 2008 to 2019. By midcentury, extreme heat is projected to be associated with 4320 (95% CI, 2369-6272) excess deaths annually, which is an increase of 162% (95% CI, 142-182) under SSP2-4.5, and 5491 (95% CI, 3011-7972) annual excess deaths, which is an increase of 233% (95% CI, 206-259) under SSP5-8.5. Elderly adults are projected to have a 3.5 (95% CI, 3.2-3.8) times greater increase in deaths in the SSP2-4.5 scenario compared with nonelderly adults. Non-Hispanic Black adults are projected to have a 4.6 (95% CI, 2.8-6.4) times greater increase compared with non-Hispanic White adults. The projected change in deaths was not statistically significantly different for other race and ethnicity groups or between men and women.
By midcentury, extreme heat is projected to be associated with a significantly greater burden of excess cardiovascular deaths in the contiguous United States.
气候变化导致极端高温的出现频率增加。患有心血管疾病的个体面临与热相关的不良健康影响的高风险。美国与极端高温相关的心血管死亡负担将如何随着极端高温的预计上升而变化尚不清楚。
我们获取了 2008 年至 2019 年期间美国相邻各州成年人心血管死亡人数和极端高温天数（最高热指数≥90°F[32.2°C]）的相关数据。基于代表温室气体排放的代表性浓度途径轨迹和代表未来社会经济情景和人口预测的共享社会经济途径（SSP），我们获取了 2036 年至 2065 年中期 2 个情景下的县一级预计极端高温天数和人口数据：SSP2-4.5（代表来自“中等社会经济情景”和排放中度增加的人口预测）和 SSP5-8.5（基于“以化石燃料为动力的发展”和排放大量增加的经济的人口预测）。使用泊松固定效应模型估计心血管死亡率与极端高温之间的关系。使用该模型的估计值，计算与极端高温相关的超额心血管死亡人数。
2008 年至 2019 年，极端高温与每年 1651 例（95%CI，921-2381）超额心血管死亡相关。到本世纪中叶，预计极端高温每年将与 4320 例（95%CI，2369-6272）超额死亡相关，在 SSP2-4.5 情景下增加 162%（95%CI，142-182），在 SSP5-8.5 情景下每年增加 5491 例（95%CI，3011-7972）超额死亡，与非老年成年人相比，SSP2-4.5 情景下老年成年人的死亡人数预计将增加 3.5 倍（95%CI，3.2-3.8）。与非西班牙裔白人成年人相比，预计非西班牙裔黑人成年人的死亡人数将增加 4.6 倍（95%CI，2.8-6.4）。其他种族和族裔群体或男性和女性之间的死亡人数预计变化没有统计学显著差异。
到本世纪中叶，预计美国相邻各州与极端高温相关的心血管死亡人数将大幅增加。
