title: Coronary flow reserve is impaired in hypertensive patients with subclinical renal damage.
abstract: BACKGROUND
  Renal dysfunction is relatively common in patients with primary hypertension (PH). A reduction in coronary vasodilator capacity has recently been reported in patients with renal damage undergoing coronary angiography. We investigated the relationship between coronary flow reserve (CFR) and early renal abnormalities in patients with PH and normal serum creatinine.
  
  
  METHODS
  Seventy-six untreated patients were studied. Albuminuria was measured as the albumin-to-creatinine ratio and glomerular filtration rate (eGFR) was estimated by the Cockroft-Gault formula. Chronic kidney disease (CKD) was defined as an eGFR <60 ml/min/1.73 m(2) and/or in the presence of microalbuminuria. Coronary blood flow velocities (cm/s) were measured by Doppler ultrasound at rest and after adenosine administration. CFR was defined as the ratio of hyperemic-to-resting diastolic peak velocities.
  
  
  RESULTS
  Prevalence of reduced eGFR, microalbuminuria, CKD, and left ventricular (LV) hypertrophy was 8, 10, 16, and 31%, respectively. Overall, 10% of patients showed impaired CFR (i.e., <2.0). Patients with CKD were more likely to be older (P < 0.05) and of female gender (P < 0.01) and showed higher LV mass index (LVMI) (P < 0.05), lower CFR (P < 0.05; analysis of covariance, P < 0.05), and CFR/LVMI (P < 0.05) than patients with normal renal function. Conversely, patients with impaired CFR showed a significantly higher prevalence of reduced eGFR (chi(2) 5.2, P < 0.05), microalbuminuria (chi(2) 10.2, P < 0.01), and CKD (chi(2) 9.2.1, P < 0.01). Even after adjustment for gender, the presence of CKD entailed a sevenfold higher risk of having impaired CFR (confidence interval 1.17-40.9, P < 0.05).
  
  
  CONCLUSIONS
  Early renal abnormalities are associated with reduced CFR in PH.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, University of Genoa, Azienda Ospedaliera Universitaria San Martino, Genoa, Italy.
authors.forename: Gian P
authors.initials: GP
authors.lastname: Bezante
authors.forename: Francesca
authors.initials: F
authors.lastname: Viazzi
authors.forename: Giovanna
authors.initials: G
authors.lastname: Leoncini
authors.forename: Elena
authors.initials: E
authors.lastname: Ratto
authors.forename: Novella
authors.initials: N
authors.lastname: Conti
authors.forename: Manrico
authors.initials: M
authors.lastname: Balbi
authors.forename: Sergio
authors.initials: S
authors.lastname: Agosti
authors.forename: Luca
authors.initials: L
authors.lastname: Deferrari
authors.forename: Giacomo
authors.initials: G
authors.lastname: Deferrari
authors.forename: Roberto
authors.initials: R
authors.lastname: Pontremoli
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D003326:Coronary Circulation / Q000502:physiology*; D018618:Echocardiography, Doppler, Color; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D051436:Renal Insufficiency, Chronic / Q000150:complications / Q000503:physiopathology*