Abstract
Background
Elevated lipoprotein (a) [LP (a)] levels are an independent risk factor for coronary heart disease (CHD) and associated with myocardial infarction (MI). CHD took a devastating toll in Europe and in the United States in the 20th century, killing more people than any other disease. It remains the leading cause of death in most countries worldwide. CHD shares risk factors with atherosclerosis. It has been shown that elevated LP (a) levels are associated with an increased risk for CHD across various ethnic groups. LP (a) is genetically determined, stable throughout life and yet refractory to drug therapy. While 30 mg/dl is considered the upper normal value for LP (a) in central Europe, extremely high LP (a) levels (>150mg/dl) are rare in the general population.
The aim of our study was to analyse the correlation between lipoprotein (a) [LP (a)] levels and an incidence of coronary heart disease (CHD) in high-risk patients.
Patients and methods
We reviewed the LP (a) concentrations of 52.898 consecutive patients admitted to our cardiovascular center between January 2004 and December 2014. Of these, 579 patients had LP (a) levels above 150 mg/dl (mean 181.45±33.1mg/dl). In the control collective LP (a) was <30mg/dl (n=350). Other atherogenic risk factors in this group were HbA1c 6.58±1.65%, low density lipoprotein (LDL) 141.99±43.76 mg/dl, and body mass index 27.81±5.61. 54.40% were male, 26.07% were smokers, 93.2% had hypertension, and 24% had a family history of cardiovascular diseases. More than 82.6% were under statins. The mean glomerular filtration rate (GFR) was 69.13±24.8 ml/min [MDRD (Modification of Diet in Renal Disease)].
Results
64.98% (n=373) of the patients with LP (a) >150mg/dl had CHD. The prevalence of CHD in patients with LP (a) <30mg/dl in our control collective was 37.14%. (P- Value 0.0001). Patients with LP (a) >150mg/dl had a significantly increased risk for CHD (Odds ratio 5.98). 12.72% (n=73) of these patients suffered from CHD with single-vessel disease (VD), 14.63% (n=84) from CHD with 2VD and 37.63% (n=216) from CHD with 3VD. 47.92% of patients were re-vascularized by percutaneous coronary angioplasty (PTCA) and 37.06% of patients had to undergo coronary artery bypass grafting (CABG). 19.13% of patients had both, PTCA and CABG. Mean LP (a) level in patients with 1-vessel CHD was 181.5±29.98, in patients with 2-vessel CHD 178.94±34.26 and in patients with 3-vessel CHD 180.97±32.38 mg/dl.
Conclusion
Elevated LP (a) levels above 150 mg/dl are associated with a significantly increased risk of CHD in our collective and it confirms our hypothesis. Most of these patients had severe CHD with 3-vessel disease (VD) requiring coronary revascularization therapy. We need more prospective studies to confirm our findings.
Effect of ageing on plasma lipoprotein(a) levels
