Regional and ethnic influences on the response to empagliflozin in patients with heart failure and a reduced ejection fraction: the EMPEROR-Reduced trial

Aims The aim of this article is to explore the influence of region and race/ethnicity on the effects of empagliflozin in the Empagliflozin Outcome Trial in Patients with Chronic Heart Failure and a Reduced Ejection Fraction (EMPEROR-Reduced) trial. Methods and results Of 3730 patients, 1353 (36.3%) were enrolled in Europe, 1286 (34.5%) in Latin America, 425 (11.4%) in North America, and 493 (13.2%) in Asia; 2629 (70.5%) were White, 257 (6.9%) Black, and 672 (18.0%) Asian. Placebo event rates (per 100 patient-years) for cardiovascular death or heart failure (HF) hospitalization varied by region (Asia 27.7, North America 26.4, Latin America 21.4, and Europe 17.5) and race/ethnicity (Black 34.4, Asian 24.3, and White 18.7); driven by differences in HF hospitalization. The ratio of total HF hospitalization to cardiovascular death varied from 5.4 in Asia and 4.8 in North America to 2.1 in Europe; and from 4.8 in Black and 4.2 in Asian to 2.2 in White patients. Groups with the highest ratio had the greatest reduction in the primary outcome with empagliflozin. Inclusion of outpatient worsening HF episodes added more events in Europe vs. other regions; enhanced the placebo event rates in Europe vs. other regions; and increased the relative risk reduction with empagliflozin in Europe from 6% to 26%. Conclusions There were notable differences in the placebo event rates for major HF events across diverse regions and race/ethnic groups. The benefit of empagliflozin was most pronounced in groups with the highest ratio of HF hospitalization to cardiovascular death. Regional differences were attenuated when the definition of HF events was expanded to include outpatient worsening HF events.