Among US Medicare beneficiaries, colder ambient temperatures were associated with increased heart failure hospitalizations while warmer temperatures were not, and the U-shaped temperature–cardiovascular risk association seen for cardiovascular mortality did not apply to heart failure hospitalizations, according to a time-stratified case-crossover study of 1,517,756 hospitalizations from 996,312 patients (mean age, 78.0 years; 60.3% female) hospitalized between January 1, 2007, and December 31, 2022, with daily mean ambient temperature linked by residential zip code and analyzed nationally and across 9 climate regions using conditional logit distributed lag nonlinear models with a reference of 75 °F; at the regional fifth percentile temperature compared with 75 °F, the largest associations were observed in the West North Central (OR, 1.62), West (OR, 1.40), Southwest (OR, 1.34), and Northwest (OR, 1.34) regions, whereas temperatures above 75 °F showed no association, suggesting that ongoing region-specific surveillance of heat- and cold-related heart failure hospitalization risk will be essential, particularly in areas with limited adaptive capacity. Source: https://jamanetwork.com/
