Impact of extreme heat on acute decompensated heart failure: Global evidence and GCC-focused insights

Abstract

Background and Purpose: Climate change has intensified global heat exposure, posing new challenges for cardiovascular health. Emerging evidence links extreme ambient temperatures to increased hospitalizations and mortality in patients with heart failure (HF). This review aimed to synthesize current global data on the association between heat exposure and acute decompensated heart failure (ADHF) and to highlight knowledge gaps and clinical implications for the Gulf Cooperation Council region, where extreme heat is endemic and under-studied.

Methods: A narrative review of English-language studies published between 2000 and 2025 was conducted. Epidemiologic studies assessing the relationship between heat exposure and HF outcomes were identified, alongside reports addressing pathophysiological mechanisms, regional climate characteristics, and public-health adaptation strategies. Reference lists were screened to include relevant observational studies, reviews, and climate reports.

Results: Evidence across more than 20 countries demonstrates a consistent association between extreme heat and higher rates of HF hospitalization and mortality. Global analyses indicate that temperatures above the 97th–99th percentile increase HF-related deaths by approximately 10–15%. Mechanistically, heat stress provokes dehydration, vasodilation, and neurohormonal activation, leading to fluid-electrolyte imbalance, hypotension, and congestion in susceptible patients. In the GCC, where summer temperatures regularly exceed 45 °C and wet-bulb values approach human survivability limits, local research remains scarce. Reliance on air-conditioning mitigates risk for some populations but leaves outdoor workers and elderly citizens particularly vulnerable. Preventive strategies—including patient education, medication review during heatwaves, and regional heat-health action plans—are seldom implemented or evaluated.

Conclusions: Extreme heat is an underrecognized precipitant of acute HF decompensation. The GCC faces unique exposure risks due to its climatic extremes and demographic profile. Regional data collection, adaptation policies, and clinician-led “heat action” protocols are urgently needed to reduce preventable morbidity and mortality. Integrating cardiovascular considerations into climate-resilience planning should be prioritized as global temperatures continue to rise.