Renal dysfunction and outcome in left ventricular non-compaction

Abstract

Background: While renal function has been observed to inversely correlate with clinical outcome in other cardiomyopathies, its prognostic significance in patients with left ventricular non-compaction cardiomyopathy (LVNC) has not been investigated. The aim of this study was to determine the prognostic value of renal function in LVNC patients.

Methods: Patients with isolated LVNC as diagnosed by echocardiography and/or magnetic resonance imaging in 4 Swiss centers were retrospectively analyzed for this study. Values for creatinine, urea, and estimated glomerular filtration rate (eGFR) as assessed by the CKD-EPI 2009 formula were collected and analyzed by a Cox regression model for the occurrence of a composite endpoint (death or heart transplantation).

Results: During the median observation period of 7.4 years 23 patients reached the endpoint. The ageand gender-corrected hazard ratios (HR) for death or heart transplantation were: 1.9 (95% confidence interval [CI] 1.4-2.6) for each increase over baseline creatinine level of 30 μmol/L (p < 0.001), 1.6 (95% CI 1.2-2.2) for each increase over baseline urea level of 5 mmol/L (p = 0.004), and 3.6 (95% CI 1.9-6.9) for each decrease below baseline eGFR level of 30 mL/min (p ≤ 0.001). The HR (log2) for every doubling of creatinine was 7.7 (95% CI 3-19.8; p < 0.001), for every doubling of urea 2.5 (95% CI 1.5-4.3; p < 0.001), and for every bisection of eGFR 5.3 (95% CI 2.4-11.6; p < 0.001).

Conclusions: This study provides evidence that in patients with LVNC impairment in renal function is associated with an increased risk of death and heart transplantation suggesting that kidney function assessment should be standard in risk assessment of LVNC patients.

Keywords: creatinine; estimated glomerular filtration rate; heart failure; kidney; prognosis; renal function; urea.

Figure 1

A. Creatinine over time and before an event (death or heart transplantation). Dot plot charts representing values of creatinine measurements over time except event-preceding measurements in all patients, and event-preceding measurements in patients reaching the endpoint. The horizontal line indicates the median value. The y-axis is depicted in a log10-scale; B. Estimated glomerular filtration rate (eGFR) over time and before an event (death or heart transplantation). Dot plot charts representing values of eGFR over time except event-preceding measurements in all patients, and event-preceding measurements in patients reaching the endpoint. The horizontal line indicates the median value; C. Urea over time and before an event (death or heart transplantation). Dot plot charts representing values of urea measurements over time except event-preceding measurements in all patients, and event-preceding measurements in patients reaching the endpoint. The horizontal line indicates the median value.

Figure 2

A. Change in creatinine over time. Paired dot plot charts representing baseline creatinine measurements (red dots) and last available creatinine measurements (blue dots) in patients without an event (left) and in patients reaching the endpoint (death or heart transplantation, right). Values for the same patient are connected via a dashed line. The y-axis is depicted in a log10-scale; B. Change in estimated glomerular filtration rate (eGFR) over time. Paired dot plot charts representing baseline eGFR measurements (red dots) and the last available eGFR measurements (blue dots) in patients without an event (left) and in patients reaching the endpoint (death or heart transplantation, right). Values from the same patient are connected via a dashed line; C. Change in urea over time. Paired dot plot charts representing baseline urea measurements (red dots) and last available urea measurements (blue dots) in patients without an event (left) and in patients reaching the endpoint (death or heart transplantation, right). Values from the same patient are connected via a dashed line.

Figure 3

A. Hazard ratios (HR) of creatinine, estimated glomerular filtration rate (eGFR) and urea per interval increase in terms of death or heart transplantation. HR, unadjusted (unadj.) and adjusted (adj.) for age and gender, with 95% confidence intervals (CI) per 30 μmol/L increase in creatinine, 15 mL/min decrease in eGFR and 5 mmol/L increase in urea; B. Hazard ratios of creatinine, eGFR and urea per log2 change in terms of death or heart transplantation. HR, unadjusted and adjusted for age and gender, with 95% CI on a log10-scale per doubling of creatinine, bisection of eGFR and doubling of urea; C. Hazard ratios of different eGFR in terms of death or heart transplantation. HR, unadjusted and adjusted for age and gender, with 95% CI for eGFR < 60 mL/min and eGFR < 30 mL/min; *significant values (p < 0.05).