Effect of Adding Nitroglycerin to Early Diuretic Therapy on the Morbidity and Mortality of Patients with Chronic Kidney Disease Presenting with Acute Decompensated Heart Failure

Abstract

Background: Loop diuretics are considered first-line therapy for patients with acute decompensated heart failure (ADHF). Adding nitroglycerin (NTG) to diuretic therapy for alleviation of acute shortness of breath has been advocated in our institution. We evaluated the benefits of adding NTG to diuretics in the emergency department for patients with ADHF and chronic kidney disease (CKD). Methods: 430 consecutive patients with ADHF who were admitted with a chief complaint of dyspnea were included in this retrospective study. Patients were divided into 3 groups. Group A patients were treated with neither diuretics nor NTG; Group B patients were treated with diuretics only; and Group C patients were treated with both diuretics and NTG. Estimated glomerular filtration rate (GFR) was calculated according to the Cockcroft-Gault formula. Follow-up was 36 ± 9 (mean ± standard deviation [SD]) months. Primary endpoints were readmission rate at 30 days and mortality at 24 months. Results: 430 patients were included in this study (42% men; age, 69 ± 14 [mean ± SD] years); mean New York Heart Association class was 2.4 ± 0.7 (mean ± SD) and mean ejection fraction was 28% ± 17% (mean ± SD). Group A included 257 (59%) patients, Group B had 127 (29%) patients, and Group C had 46 (11%) patients. Group C patients were older (mean age, 72 ± 13 years) with lower body mass index (26 ± 7 kg/m²), lower estimated GFR (55.8 ± 38 mL/min per 1.73 m²), higher B-type natriuretic peptide levels (1112 ± 876 pg/mL; P = nonsignificant [NS]), and higher systolic and diastolic blood pressures on admission (P = 0.001). The primary endpoint was assessed as a composite of all-cause mortality and ADHF readmission seen in 143 (56%) Group A patients, 68 (53%) Group B patients, and 22 (48%) Group C patients (P = NS). At 30 days there were 53 (12%) readmissions—26 in Group A, 20 in Group B, and 7 in Group C (P = NS). However, survival at 24 months was higher in Group C (87%) compared with Groups A (79%) and B (82%) (P = 0.002). Using the Cox proportional-hazards regression module, early administration of NTG and Lasix (95% confidence interval [CI], 1.06–1.62; P = 0.01) followed by CKD stage (95% CI, 1.00–1.35; P = 0.04) were the only predictors for survival. Conclusion: There is a role for early administration of NTG in addition to diuretic therapy in patients admitted to the emergency department with ADHF, with resultant decreased length of stay and a trend toward a decrease in the composite endpoint of all-cause mortality and ADHF readmission. The mortality benefit at 2 years reported in our study is thought-provoking and raises a premise to be proven in randomized clinical trials.