title: Coronary flow reserve in idiopathic dilated cardiomyopathy: relation with left ventricular wall stress, natriuretic peptides, and endothelial dysfunction.
abstract: Studies have demonstrated impaired coronary blood flow reserve (CBFR) in idiopathic dilated cardiomyopathy (IDCM). It was the aim of this study to examine the potential underlying mechanisms for CBFR reduction in patients with IDCM by Doppler ultrasound techniques. Forty-eight clinically stable patients with heart failure caused by IDCM (New York Heart Association classes 1-3) were evaluated by echocardiographic and Doppler techniques with the assessments of CBFR and brachial artery flow-mediated dilation (FMD). CBFR was estimated as the hyperemic (dipyridamole: 0.84 mg/kg in 10 minutes, intravenously) to resting coronary diastolic peak velocities ratio. N-terminal pro-brain natriuretic peptide (Nt-pro-BNP) plasma levels were measured at the time of the index echocardiogram. Left ventricular (LV) ejection fraction was 30% +/- 8%, and wall motion score index was 2.0 +/- 0.25. The best correlation with CBFR was found with LV wall thickness-to-cavity radius (r = 0.77, P < .0001). A strong correlation of log-transformed Nt-pro-BNP levels was observed with CBFR (r = -0.64; P < .0001). No significant correlation was documented between CBFR and FMD. The stepwise regression model showed that LV wall thickness-to-cavity radius was the strongest independent predictor of CBFR followed by New York Heart Association class and log-transformed Nt-pro-BNP leading to a cumulative R value of 0.82 (P < .0001). The results of the study indicate that by measuring variables related to LV end-diastolic wall stress, such as LV wall thickness-to-cavity radius and plasma Nt-proBNP, it is possible to have information about CBFR in patients with heart failure secondary to IDCM.
authors.affiliation: Unità Malattie Cardiovascolari 2, Santa Chiara Hospital, Pisa, Italy. f.dini@ao-pisa.toscana.it
authors.forename: Frank Lloyd
authors.initials: FL
authors.lastname: Dini
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Ghiadoni
authors.forename: Umberto
authors.initials: U
authors.lastname: Conti
authors.forename: Francesco
authors.initials: F
authors.lastname: Stea
authors.forename: Simona
authors.initials: S
authors.lastname: Buralli
authors.forename: Stefano
authors.initials: S
authors.lastname: Taddei
authors.forename: Salvatore Mario
authors.initials: SM
authors.lastname: De Tommasi
mesh_terms: D002311:Cardiomyopathy, Dilated / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D054459:Elasticity Imaging Techniques / Q000379:methods; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging / Q000503:physiopathology; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D008297:Male; D008875:Middle Aged; D045265:Natriuretic Peptides / Q000097:blood*; D013314:Stress, Mechanical; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology*
chemical_list: D045265:Natriuretic Peptides