Impact of worsening renal function on resource utilization and medications after diuretic dose escalation in a chronic heart failure ambulatory population

Purpose: Heart failure (HF) patients often require diuretic (D) escalation to treat volume overload. Worsening renal function (WRF) is associated with increased length of stay, morbidity, mortality and costs in the inpatient setting. We sought to evaluate the impact of WRF after D escalation in the ambulatory setting.

Methods: Retrospective chart review of ambulatory HF patients whose oral D was increased between 07/01/2007 and 06/30/2010. WRF was defined as a rise in serum creatinine > 0.3 mg/dL after D therapy escalation. Unplanned visits included any phone contact, visit to the clinic, or lab for evaluation of renal function that was not scheduled at the index visit. Hospitalizations or ED visits related to HF or renal failure were also categorized as unplanned. Medications orders including orders to decrease or hold D or RAAS inhibitor were assessed. All visits and medication changes were totaled during a 3 month follow-up and analyzed using un-paired student's t test.

Results: Eighty-six patients accounted for 121 D dose increases of which there were 48 episodes of WRF. Using only the first encounter, demographics, vitals, PMH, HF medications, diuretic regimen, ejection fraction, and BNP were similar between groups.

	WRF n = 48		SRF n =73		P value
	Number	Avg/SD	Number	Avg/SD
Creatinine  change		0.71 ± 0.52		-0.034 ± 0.18	< 0.001
Planned visits	68	1.41 ± 0.87	100	1.37 ± 0.77	0.76
Unplanned visits	102	2.12 ± 1.83	46	0.63 ± 1.01	<0.001
Lab	121	2.52 ± 1.52	76	1.04 ± 0.98	< 0.001
Medications
↓ or hold D	54	1.12 ± 0.89	22	0.30 ± 0.52	<0.001
↓ or hold RAAS	20	0.42 ± 0.77	3	0.04 ± 0.2	0.002

Conclusion: WRF occurs commonly in patients with D dose escalation in the ambulatory setting, leading to increased resource utilization and subsequent reductions in D and RAAS inhibitors.