Background

Serum cardiac troponin T (cTnT) is associated with increased risk of heart failure and cardiovascular death in several population settings. We evaluated associations of cTnT levels with cardiac structural and functional abnormalities in a cohort of patients with chronic kidney disease (CKD) without heart failure.

Study design

Cross-sectional.

Setting & participants

Chronic Renal Insufficiency Cohort (CRIC; N=3,243).

Predictor

The primary predictor was cTnT level. Secondary predictors included demographic and clinical characteristics, hemoglobin level, high-sensitivity C-reactive protein level, and estimated glomerular filtration rate using cystatin C.

Outcomes

Echocardiography was used to determine left ventricular (LV) mass and LV systolic and diastolic function.

Measurements

Circulating cTnT was measured in stored sera using the highly sensitive assay. Logistic and linear regression models were used to examine associations of cTnT level with each echocardiographic outcome.

Results

cTnT was detectable in 2,735 (84%) persons; median level was 13.3 (IQR, 7.7-23.8) pg/mL. Compared with undetectable cTnT (<3.0 pg/mL), the highest quartile (23.9-738.7 pg/mL) was approximately 2 times as likely to have LV hypertrophy (OR, 2.43; 95% CI, 1.44-4.09) in the fully adjusted model. cTnT level had a more modest association with LV systolic dysfunction; as a log-linear variable, a significant association was present in the fully adjusted model (OR of 1.4 [95% CI, 1.2-1.7] per 1-log unit; P < 0.001). There was no significant independent association between cTnT level and LV diastolic dysfunction. When evaluated as a screening test, cTnT level functioned only modestly for LV hypertrophy and concentric hypertrophy detection (area under the curve, 0.64 for both), with weaker areas under the curve for the other outcomes.

Limitations

The presence of coronary artery disease was not formally assessed using either noninvasive or angiographic techniques in this study.

Conclusions

In this large CKD cohort without heart failure, detectable cTnT had a strong association with LV hypertrophy, a more modest association with LV systolic dysfunction, and no association with diastolic dysfunction. These findings indicate that circulating cTnT levels in patients with CKD are predominantly an indicator of pathologic LV hypertrophy.

Background

It is not clear whether the pattern of kidney function decline in patients with chronic kidney disease (CKD) may relate to outcomes after reaching end-stage renal disease (ESRD). We hypothesize that an abrupt decline in kidney function prior to ESRD predicts early death after initiating maintenance hemodialysis therapy.

Study design

Prospective cohort study.

Setting & participants

The Chronic Renal Insufficiency Cohort (CRIC) Study enrolled men and women with mild to moderate CKD. For this study, we studied 661 individuals who developed chronic kidney failure that required hemodialysis therapy initiation.

Predictors

The primary predictor was the presence of an abrupt decline in kidney function prior to ESRD. We incorporated annual estimated glomerular filtration rates (eGFRs) into a mixed-effects model to estimate patient-specific eGFRs at 3 months prior to initiation of hemodialysis therapy. Abrupt decline was defined as having an extrapolated eGFR≥30mL/min/1.73m(2) at that time point.

Outcomes

All-cause mortality within 1 year after initiating hemodialysis therapy.

Measurements

Multivariable Cox proportional hazards.

Results

Among 661 patients with CKD initiating hemodialysis therapy, 56 (8.5%) had an abrupt predialysis decline in kidney function and 69 died within 1 year after initiating hemodialysis therapy. After adjustment for demographics, cardiovascular disease, diabetes, and cancer, abrupt decline in kidney function was associated with a 3-fold higher risk for death within the first year of ESRD (adjusted HR, 3.09; 95% CI, 1.65-5.76).

Limitations

Relatively small number of outcomes; infrequent (yearly) eGFR determinations; lack of more granular clinical data.

Conclusions

Abrupt decline in kidney function prior to ESRD occurred in a significant minority of incident hemodialysis patients and predicted early death in ESRD.