Low- vs. High-Dose Loop Diuretics and Mortality Risk in HF Patients
WASHINGTON, DC—An increased risk of mortality was seen with doses of loop diuretics ≥80 Furo mgEq per day among patients with heart failure, according to data presented by researchers at the ACC.17 Scientific Session.
Kirkwood F. Adams, from the University of North Carolina Chapel Hill, NC, and coauthors aimed to study the relationship patterns of dose-related increases in mortality associated with loop diuretics in this patient population. The UNITE-HF Registry is a prospective, observational outpatient HF study that enrolled most patients from 2000–2002 to study the link between low and high doses of loop diuretics and mortality.
"The baseline daily doses of loop diuretic were converted to milligram equivalents of furosemide (Furo mgEq)," Adams said. Study authors also assessed the relative risk of death at specific doses vs. no loop diuretic use and among specific loop diuretic doses.
The patient sample included in the analysis (n=1,262) had a mean age of 58 years with creatinine 1.43 and left ventricular ejection fraction (LVEF) of 31%. Loop diuretics were taken at baseline in most (75%) patients at a median dose of 40mgEq/day; the lower quartile was taking <20mgEq/day and the upper quartile was taking >80mgEq/day.
The study reported 661 deaths during the 6.6 years of follow-up. "Mortality was not increased at low doses," Adams noted. Mortality was significantly lower in the 20 Furo mgEq/day vs. 40 Furo mgEq/day groups (hazard ratio [0.64, 95% CI: 0.44–0.92; P<0.016). Similarly, mortality was significantly lower in the 40 Furo mgEq/day vs. 80 Furo mgEq/day groups (HR 0.73, 95% CI: 0.57–0.93; P<0.012).
Although mortality was higher at high doses, the relative risk did not vary among doses ≥120 Furo mgEq/day (for all P>0.176).
Findings from this retrospective observational analysis showed loop diuretic use was associated with higher mortality at doses ≥80 Furo mgEq/day in patients with heart failure, study authors concluded.