title: High prevalence of raised lipoprotein(a) in patients with refractory angina.
abstract: BACKGROUND
  Angina that is refractory to conventional medical therapy and revascularisation, remains challenging to manage and poses significant burden to patients. Elevated lipoprotein(a) [Lp(a)] has emerged as an important independent cardiovascular risk factor and predictor of adverse outcomes in atherosclerotic disease. The prevalence of raised Lp(a) amongst patients with refractory angina has not yet been defined.
  
  
  OBJECTIVE
  To establish the prevalence of raised [Lp(a)] >500 mg/L in patients with refractory angina.
  
  
  METHODS
  We conducted an epidemiological screening pilot study in 75 patients with refractory angina from a UK tertiary cardiac centre. We determined the proportion of the cohort with raised Lp(a) >500 mg/L using an isoform-insensitive method. In addition, a full fasting lipid profile (including: LDL cholesterol, HDL cholesterol, total cholesterol to HDL ratio and triglycerides) was obtained. Patients were also asked about the presence of conventional cardiovascular risk factors.
  
  
  RESULTS
  Our study demonstrated that 60% of the 75 patients with refractory angina had raised Lp(a) levels of >500 mg/L. The median and inter-quartile range of Lp(a) values were 771 mg/L (162 mg/L,1260 mg/L) respectively.
  
  
  CONCLUSIONS
  This high prevalence of raised Lp(a) detected in our cohort with refractory angina may suggest a causal role. Further research is necessary to confirm this association and prospective studies are needed to explore the potential therapeutic benefit of Lp(a) reduction in patients with refractory angina.
authors.affiliation: Harefield Hospital, London, United Kingdom.
authors.forename: Tina Z
authors.initials: TZ
authors.lastname: Khan
authors.affiliation: Harefield Hospital, London, United Kingdom.
authors.forename: Samantha
authors.initials: S
authors.lastname: Rhodes
authors.affiliation: Harefield Hospital, London, United Kingdom.
authors.forename: Alison
authors.initials: A
authors.lastname: Pottle
authors.affiliation: Royal Brompton Hospital, London, United Kingdom.
authors.forename: Winston
authors.initials: W
authors.lastname: Banya
authors.affiliation: Harefield Hospital, London, United Kingdom.
authors.forename: Robert
authors.initials: R
authors.lastname: Smith
authors.affiliation: Harefield Hospital, London, United Kingdom.
authors.forename: Tito
authors.initials: T
authors.lastname: Kabir
authors.affiliation: Harefield Hospital, London, United Kingdom.
authors.forename: Charles
authors.initials: C
authors.lastname: Ilsley
authors.affiliation: Royal Brompton Hospital, London, United Kingdom.
authors.forename: Dudley J
authors.initials: DJ
authors.lastname: Pennell
authors.affiliation: Harefield Hospital, London, United Kingdom.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Barbir
keywords: Coronary artery disease; Lipoprotein (a); Refractory angina; Risk factors