Changes in Loop Diuretic Dose and Outcome After Cardiac Resynchronization Therapy in Patients With Heart Failure and
Pieter Martens1, Frederik H Verbrugge2, Petra Nijst1
1Department of Cardiology, Ziekenhuis Oost-Limburg, Genk, Belgium; Doctoral School for Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium.
Insights
Cardiac resynchronization therapy (CRT) allows for reduced loop diuretic doses in many heart failure patients. Down-titrating diuretics after CRT is feasible, linked to better outcomes and preserved kidney function.
Area of Science:
- Cardiology
- Nephrology
Background:
- Cardiac resynchronization therapy (CRT) is known to improve cardiac hemodynamics.
- This improvement may allow for a reduction in maintenance loop diuretic therapy doses.
Purpose of the Study:
- To evaluate the feasibility and clinical outcomes of reducing loop diuretic doses in patients undergoing CRT.
- To identify predictors of successful loop diuretic dose reduction post-CRT.
Main Methods:
- A retrospective analysis of 648 patients who underwent CRT.
- Patients' loop diuretic doses were recorded at baseline and 6 months post-implantation, categorized into no diuretic, down-titration, unchanged dose, or up-titration.
- Renal function (serum creatinine) and clinical outcomes (heart failure readmissions, all-cause mortality) were assessed.
Main Results:
- 46% of patients were diuretic-free at follow-up; 19% had their dose down-titrated.
- Renal function declined faster in patients with stable or increased diuretic doses compared to those down-titrated or diuretic-free.
- Down-titration was associated with a significantly lower risk of heart failure readmissions and all-cause mortality (aHR 0.43).
- Predictors for successful down-titration included nonischemic cardiomyopathy, higher baseline diuretic dose, and favorable hemodynamic parameters at 6 weeks post-CRT.
Conclusions:
- Down-titration of loop diuretics is often feasible after CRT and is associated with improved clinical outcomes.
- Reducing diuretic doses post-CRT may help preserve kidney function.
- Patients with nonischemic cardiomyopathy and high baseline diuretic needs are prime candidates for diuretic dose reduction after CRT.
Abstract:
Cardiac resynchronization therapy (CRT) improves cardiac hemodynamics. Therefore, the maintenance dose of loop diuretic therapy might be reduced. Consecutive patients who underwent CRT (n = 648) were retrospectively evaluated. Loop diuretic dose was recorded at baseline before implantation and 6 months later with patients classified into 4 groups: (1) no loop diuretic, (2) down-titration, (3) unchanged dose, and (4) up-titration. Afterward total loop diuretic exposure was calculated. Renal function trajectories were evaluated as the difference between implantation and censoring serum creatinine (Cr) value. Clinical outcome was evaluated as the combined end point of heart failure readmissions and all-cause mortality. Independent predictors of successful loop diuretic down-titration were identified. Two hundred ninety-six patients (46%) received no loop diuretic at follow-up, 126 (19%) underwent down-titration, 137 (21%) remained on a stable dose, and 89 (14%) underwent up-titration. In comparison with the group that was free from loop diuretics (Cr = +0.06 mg/dl), renal function deteriorated faster during follow-up in patients on stable doses (Cr = +0.29 mg/dl; p = 0.045) and those underwent up-titration (Cr = +0.44 mg/dl; p = 0.009) but not in patients who were down-titrated (Cr = +0.13 mg/dl; p = 1.00). Patients receiving down-titration had a lower risk for the combined clinical end point (adjusted hazards ratio 0.43; confidence interval 0.22 to 0.83; p = 0.012). Factors associated with successful down-titration after 6 months of CRT included nonischemic cardiomyopathy, higher baseline dose of diuretics, higher ejection fraction at 6 weeks, and lower right ventricular systolic pressure at 6 weeks. In conclusion, after CRT, down-titration of loop diuretics is often feasible and associated with improved outcome and a slower rate of kidney function decline. Patients with nonischemic cardiomyopathy, treated with high doses of loop diuretics before implantation and beneficial left ventricular remodeling with CRT, are most likely to tolerate loop diuretic down-titration.
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