title: Haemoglobin levels do not correlate with the extent of coronary artery disease: results from a large cohort study.
abstract: OBJECTIVE
  Even though anaemia has been shown to be a risk factor for adverse cardiovascular disease, there is scarce evidence of its relationship with angiographically proven coronary artery disease (CAD). The aim of this study was to evaluate the relationship between haemoglobin (Hb) levels and the extent of CAD.
  
  
  METHODS
  We measured Hb, mean corpuscular volume and red blood cell count in 2363 consecutive patients undergoing coronary angiography. Patients were divided into four groups according to quartile values of Hb (≤12.2 g/dl, group 1; 12.3-13.5 g/dl, group 2; 13.6-14.6 g/dl, group 3; >14.6 g/dl, group 4).
  
  
  RESULTS
  Patients with lower Hb were older (P<0.001), there was a predominance of women (P<0.0001), and patients had diabetes (P<0.0001), hypertension (P=0.024), renal failure (P<0.0001), previous coronary artery bypass graft (P<0.0001), previous cerebrovascular accident (P=0.039) and platelet count (P<0.0001). In terms of angiographic features, low Hb levels were associated with a larger prevalence of calcified lesions (P<0.001), but a lower prevalence of thrombus-containing lesions (P<0.001). Hb was not associated with the prevalence of CAD [odds ratio (OR) (95% confidence interval (CI))=0.96 (0.89-1.04), P=0.35], whereas an association was observed with the severity of CAD [OR (95% CI)=0.92 (0.85-0.99), P=0.032] that was not confirmed after correction for baseline confounding factors [OR (95% CI)=0.98 (0.89-1.09), P=0.76]. Similar findings were observed for mean corpuscular volume and red blood cell count.
  
  
  CONCLUSIONS
  This study showed that Hb levels are not associated with the prevalence and extent of CAD.
authors.affiliation: aDivision of Cardiology bClinical Chemistry, Azienda Ospedaliera-Universitaria 'Maggiore della Carità', Eastern Piedmont University, Novara, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: De Luca
authors.forename: Gioel G
authors.initials: GG
authors.lastname: Secco
authors.forename: Ettore
authors.initials: E
authors.lastname: Cassetti
authors.forename: Monica
authors.initials: M
authors.lastname: Verdoia
authors.forename: Giorgio
authors.initials: G
authors.lastname: Bellomo
authors.forename: Paolo
authors.initials: P
authors.lastname: Marino
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood; D016009:Chi-Square Distribution; D015897:Comorbidity; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000097:blood* / Q000000981:diagnostic imaging / Q000453:epidemiology; D004906:Erythrocyte Count; D004909:Erythrocyte Indices; D005260:Female; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D007558:Italy; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011237:Predictive Value of Tests; D015995:Prevalence; D057216:Propensity Score; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D012737:Sex Factors
chemical_list: D015415:Biomarkers; D006454:Hemoglobins