Combination diuretic therapies in heart failure: Insights from GUIDE-IT

Introduction

Diuretics are the mainstay of maintaining and restoring euvolemia in the management of heart failure. Loop diuretics are often preferred, however, combination diuretic therapy (CDT) with a thiazide diuretic is often used to overcome diuretic resistance and increase diuretic effect. We performed an analysis of the GUIDE-IT study to assess all-cause mortality and time to first hospitalizations in patients necessitating CDT.

Methods

Patients from the GUIDE-IT dataset were stratified by their requirement for CDT with a thiazide to achieve euvolemia. A total of 894 patients were analyzed, 733 of which were treated with loop diuretics alone vs 161 used either chlorothiazide or metolazone in addition to loop diuretics. Kaplan-Meir curves were derived with log-rank p-values to evaluate for differences between the groups.

Results

There was no significant difference in all-cause mortality regardless of CDT utilization status (mean survival of 612.704 days vs 603.326 days, p = 0.083). On subgroup analysis, there was no significant difference in all-cause mortality amongst those using loop diuretics compared to CDT in the BNP-guided therapy group, (mean survival time 576.385 days vs 620.585 days, p = 0.0523), nor the control group (614.1 days vs 588.9 days; p = 0.5728). Time to first hospitalization was reduced in all using CDT compared to loop diuretics alone (280.5 days vs 407.2 days, p < 0.0001). On subgroup analysis, both the BNP-guided group as well as the control group had reduced time to first hospitalization in the CDT group compared to those who did not require CDT (BNP group: 287.503 days vs 402.475 days, p ≤0.0001; control group 248.698 days vs 399.035 days, p = 0.0009).

Conclusion

Use of CDT is associated with earlier time to hospitalization, though no association was identified with increased all-cause mortality. Further prospective studies are likely needed to determine the true risk and benefits of combination diuretic therapy.