title: Association of chronic kidney disease with abnormal cardiac mechanics and adverse outcomes in patients with heart failure and preserved ejection fraction.
abstract: OBJECTIVE
  Chronic kidney disease (CKD) is associated with worse outcomes in heart failure with preserved ejection fraction (HFpEF). Whether this association is due the effect of CKD on intrinsic abnormalities in cardiac function is unknown. We hypothesized that CKD is independently associated with worse cardiac mechanics in HFpEF.
  
  
  RESULTS
  We prospectively studied 299 patients enrolled in the Northwestern University HFpEF Program. Using the creatinine-based CKD-Epi equation to calculate estimated glomerular filtration rate (eGFR), study participants were analysed by CKD status (using eGFR <60 mL/min/1.73 m(2) to denote CKD). Indices of cardiac mechanics (longitudinal strain parameters) were measured using speckle-tracking echocardiography. Using multivariable-adjusted linear and Cox regression analyses, we determined the association between CKD and echocardiographic parameters and clinical outcomes (cardiovascular hospitalization or death). Of 299 study participants, 48% had CKD. CKD (dichotomous variable) and reduced eGFR (continuous variable) were both associated with worse cardiac mechanics indices including left atrial (LA) reservoir strain, LV longitudinal strain, and right ventricular free wall strain even after adjusting for potential confounders, including co-morbidities, EF, and volume status. For example, for each 1-SD decrease in eGFR, LA reservoir strain was 3.52% units lower (P < 0.0001) after multivariable adjustment. Reduced eGFR was also associated with worse outcomes [adjusted hazard ratio (HR) 1.28, 95% confidence interval (CI) 1.01-1.61 per 1-SD decrease in eGFR; P = 0.039]. The association was attenuated after adjustment for indices of cardiac mechanics (P = 0.064).
  
  
  CONCLUSIONS
  In HFpEF, CKD is independently associated with worse cardiac mechanics, which may explain why HFpEF patients with CKD have worse outcomes.
  
  
  BACKGROUND
  NCT01030991.
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Erin D
authors.initials: ED
authors.lastname: Unger
authors.affiliation: Division of Nephrology, Department of Medicine, University of California, San Francisco, CA, USA.
authors.forename: Ruth F
authors.initials: RF
authors.lastname: Dubin
authors.affiliation: Division of Cardiology, Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Rajat
authors.initials: R
authors.lastname: Deo
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Vistasp
authors.initials: V
authors.lastname: Daruwalla
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Julie L
authors.initials: JL
authors.lastname: Friedman
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Crystal
authors.initials: C
authors.lastname: Medina
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Lauren
authors.initials: L
authors.lastname: Beussink
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Benjamin H
authors.initials: BH
authors.lastname: Freed
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Sanjiv J
authors.initials: SJ
authors.lastname: Shah
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D004452:Echocardiography / Q000379:methods; D005260:Female; D005919:Glomerular Filtration Rate; D006333:Heart Failure / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D013318:Stroke Volume; D014481:United States / Q000453:epidemiology
keywords: Cardiac mechanics; Chronic kidney disease; Diastolic heart failure; Outcomes