Association of E/E' and NT-proBNP with renal function in patients with essential hypertension

Fatigue in Nondialysis Chronic Kidney Disease: Correlates and Association with Kidney Outcomes

BACKGROUND

Fatigue, although common and associated with outcomes in dialysis-dependent chronic kidney disease (CKD), has not been studied in nondialysis chronic kidney disease (CKD-ND) patients.

METHODS

In this longitudinal cohort of 266 outpatients with CKD-ND stages 2-5, we measured self-reported fatigue on 3 scales-Quick Inventory of Depression Symptomatology-Self Report (QIDS-SR16), Beck Depression Inventory-I (BDI-I), and short form 12 health survey (SF-12) questionnaires and evaluated the prespecified composite of progression to dialysis initiation, death, or hospitalization after 12 months. Logistic and linear regression assessed characteristics associated with fatigue. Survival analysis measured associations of fatigue with outcomes.

RESULTS

Mean age was 64.4 ± 12.0 years, and mean estimated glomerular filtration rate (eGFR) was 31.6 ± 16.7 mL/min/1.73 m2. Fatigue was common, with 69.2% reporting fatigue on QIDS-SR16 and 77.7% on BDI-I. Unemployment, comorbidities, use of antidepressant medications, and lower hemoglobin correlated with fatigue. There were 126 outcome events. Participants that reported any versus no fatigue on QIDS-SR16 were more likely to reach the composite, hazard ratio (HR) 1.70 (95% CI 1.11-2.59), which persisted after adjusting for demographics, comorbidities, substance abuse, hemoglobin, albumin, eGFR, and calcium-phosphorus product, HR 1.63 (1.05-2.55). Fatigue severity by the SF-12 was also associated with outcomes independent of demographics, comorbidities, and substance abuse, HR per unit increase 1.18 (1.03-1.35). No association was observed with fatigue on the BDI-I.

CONCLUSION

Fatigue affected about 2/3 of CKD-ND patients and associated with unemployment, comorbidities, antidepressant medication use, and anemia. Fatigue measured by the QIDS-SR16 and SF-12 independently predicted outcomes in CKD patients. Eliciting the presence of fatigue may be a clinically significant prognostic assessment in CKD patients.

Association Between Elevated Echocardiographic Index of Left Ventricular Filling Pressure and Acute Kidney Injury After Off-Pump Coronary Artery Surgery

BACKGROUND

The ratio of the early transmitral flow velocity to early diastolic velocity of the mitral annulus (E/e') is an echocardiographic index of mean left ventricular (LV) filling pressure. We investigated the association between the preoperative E/e' ratio and postoperative acute kidney injury (AKI) during off-pump coronary artery bypass surgery (OPCAB).

METHODS AND RESULTS

We reviewed 585 patients who underwent OPCAB and with preserved LV ejection fraction determined by preoperative echocardiography. AKI was determined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria. Multivariable logistic regression analysis was performed. E/e' was also analyzed as 3 categories (E/e' <8, 8≤E/e'≤15, and E/e' >15) and as a continuous variable. A propensity score analysis was used to match the patients with E/e' >15 and E/e' ≤15. A preoperative E/e' >15 was an independent predictor for AKI (odds ratio 3.01, 95% confidence interval 1.40-6.17). E/e' >15 was also an independent predictor for AKI when E/e' was analyzed with 3 categories or as a continuous variable. In the matched sample, the incidence of AKI and 1-year mortality was significantly higher in patients with E/e' >15.

CONCLUSIONS

Among patients undergoing OPCAB with preserved LV systolic function, a preoperative E/e' ratio >15 was an independent predictor of postoperative AKI. Measurement of the preoperative E/e' ratio may help to assess the risk of postoperative AKI.

Diastolic Dysfunction and Hypertension

Left ventricular (LV) diastolic dysfunction (LVDD) is characterized by alterations in LV diastolic filling, and is a strong predictor of cardiovascular events and heart failure. Hypertension is the most important risk factor for LVDD in the community and promotes LVDD through several mechanisms, including hemodynamic overload and myocardial ischemia. Associated factors such as age, ethnicity, dietary sodium, obesity, diabetes mellitus, and chronic kidney disease also contribute to LVDD in hypertensive individuals. Blood pressure lowering using antihypertensive medications can improve LVDD; however, it remains unclear whether this improvement in LV diastolic function can improve cardiovascular outcomes.

Effects of multielectrode renal denervation on cardiac and neurohumoral adaptations in resistant hypertension with cardiac hypertrophy: an EnligHTN I substudy

OBJECTIVE

This EnligHTN I nonrandomized substudy investigated the effect of multielectrode renal denervation (RDN) on cardiac and neurohumoral adaptations.

METHODS

Eighteen patients with true drug-resistant hypertension [age: 56 ± 10 years, 12 men, BMI: 33.6 ± 5.4 kg/m, office blood pressure (BP) by automatic device (Omron): 182 ± 19/97 ± 18 mmHg and ambulatory BP (Spacelabs): 153 ± 16/87 ± 15 mmHg receiving 4.5 antihypertensive drugs/day] and left ventricular hypertrophy underwent multielectrode RDN (EnligHTN system; St. Jude Medical), whereas 10 patients served as controls. Both groups were followed-up for 6 months.

RESULTS

Demographic data were homogenous between both patient groups. In addition to reduction of office (-42/-17 mmHg, P < 0.001) and ambulatory (-19/-9 mmHg, P < 0.001) BP, RDN contributed to attenuation of left ventricular mass index from 140.0 ± 17.0 g/m (57.9 ± 7.9 g/m) to 126.7 ± 19.2 g/m (52.6 ± 8.4 g/m) (P < 0.01 for both) and left atrial diameter from 42.4 ± 4.3 to 40.6 ± 3.6 mm (P = 0.004) at 6 months. Up to 56% of the RDN-group patients achieved a target of less than 140/90 mmHg in the office BP; proportion of RDN-group patients with concentric left ventricular hypertrophy had decreased by 39%; mitral lateral E/E' ratio decreased from 14.8 ± 6.1 to 12.0 ± 3.2 (P = 0.016); isovolumic relaxation time shortened from 109.8 ± 16.2 to 100.8 ± 17.1 ms (P = 0.003); and N-terminal pro B-type natriuretic peptide levels reduced from 84.9 ± 35.9 to 57.2 ± 38.8 pg/ml (P < 0.001) significantly at 6 months post-RDN. Control patients exhibited no significant changes in all the above parameters (P > 0.05) at 6 months.

CONCLUSION

Multielectrode RDN contributes to improvement of diastolic dysfunction, reduction of left ventricular mass and attenuation of NT-proBNP, suggesting additional cardiovascular benefits in drug-resistant hypertension associated with left ventricular hypertrophy.

Utility of traditional circulating and imaging-based cardiac biomarkers in patients with predialysis CKD

Cardiac biomarkers, such as cardiac troponin T (cTnT), brain natriuretic peptide (BNP), and N-terminal-pro-BNP (NT-pro-BNP), are commonly used to diagnose acute coronary syndrome and congestive heart failure exacerbation in symptomatic patients. Levels of these biomarkers are frequently chronically elevated in asymptomatic patients with ESRD who are receiving maintenance dialysis. Other imaging biomarkers commonly encountered in nephrologists' clinical practice, such as coronary artery calcium measured by computed tomography, left ventricular hypertrophy, and carotid intima-media thickness, are also frequently abnormal in asymptomatic patients with ESRD. This article critically reviews the limited observational data on associations between cTnT, BNP, NT-pro-BNP, coronary artery calcium, left ventricular hypertrophy, and carotid intima-media thickness with cardiovascular events and death in non-dialysis-dependent patients with CKD. Although sufficient evidence suggests that these biomarkers may be used for prognostication, the diagnostic utility of cTnT, BNP, and NT-pro-BNP remain challenging in patients with CKD. Decreased renal clearance may affect the plasma levels of these biomarkers, and upper reference limits were originally derived in patients without CKD. Until better data are available, higher cutoffs, or a rise in level compared with previous values, have been proposed to help distinguish acute myocardial infarction from chronic elevations of cTnT in symptomatic patients with CKD. Additionally, it is not known whether these biomarkers are modifiable and amenable to interventions that could change hard clinical outcomes in patients with CKD not yet undergoing long-term dialysis.