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Apolipoprotein(a) phenotypes predict the severity of coronary artery stenosis
Insights
Smaller apolipoprotein(a) phenotypes, not elevated levels, predict coronary artery stenosis severity. High-density lipoprotein cholesterol (HDL-c) independently correlated with reduced stenosis extent, offering insights into coronary artery disease risk factors.
Area of Science:
- Cardiology
- Genetics
- Lipid Metabolism
Background:
- Controversial findings exist regarding the impact of elevated lipoprotein(a) (Lp[a]) or apolipoprotein(a) (apo[a]) on coronary artery disease (CAD).
- The precise relationship between specific apo(a) phenotypes and the degree of coronary artery stenosis remains unclear.
Purpose of the Study:
- To investigate the association between apo(a) phenotypes, apo(a) levels, and coronary artery stenosis.
- To explore the correlation of lipid profiles with coronary artery stenosis severity.
Main Methods:
- Analyzed lipid profiles, apo(a) levels, and phenotypes in 225 patients undergoing coronary angiography.
- Assessed coronary artery stenosis using a minimal lesion (ML) grading system.
- Employed linear and logistic regression models to examine relationships between lipoprotein variables and stenosis.
Main Results:
- Smaller apo(a) phenotypes (S1, S1a, S2, S2a) were associated with a higher rate of coronary artery stenosis (79%-95%) compared to larger phenotypes (S3, S3a, S4 - 68%-76%).
- Odds of stenosis were significantly higher in patients with smaller apo(a) phenotypes (p < 0.001).
- Elevated high-density lipoprotein cholesterol (HDL-c) negatively correlated with the extent of stenosis (p < 0.001), while elevated apo(a) levels did not significantly predict stenosis.
Conclusions:
- Smaller apo(a) phenotypes serve as a potential predictor for coronary artery stenosis rate and severity.
- Elevated apo(a) levels were not found to be a significant predictor of coronary artery stenosis.
- High-density lipoprotein cholesterol (HDL-c) independently and negatively correlated with the extent of coronary artery stenosis.
Background:
Studies on the impact of elevated levels of lipoprotein(a) (Lp[a]) or apolipoprotein(a) (apo[a]) on the development of coronary artery disease have given controversial results. The relationship between apo(a) phenotypes and coronary artery stenosis remains unclear.
Methods:
Lipid profiles, and apo(a) levels and phenotypes were analyzed in 225 patients who underwent elective coronary angiography. Coronary artery stenosis, as indicated by angiography, was estimated by a newly devised minimal lesion (ML) grading system. Relationships between lipoprotein variables and coronary artery stenosis were examined by linear and logistic regression models.
Results:
On the basis of ML score, patients with larger apo(a) phenotypes (S3, S3a or S4) had a lower rate of coronary artery stenosis (68%-76%) than those with smaller phenotypes (S1, S1a, S2 or S2a - 79%-95%). The odds of coronary artery stenosis in patients with smaller apo(a) phenotypes were significantly different from those of patients with larger phenotypes (p < 0.001). Also, patients with a history of myocardial infarction, angina, hypertension, diabetes or hypercholesterolemia were more likely to show coronary artery stenosis on angiography. With respect to lipid levels, 20.2% of patients had an elevated serum total cholesterol (TC) level and 16.1% an elevated low-density lipoprotein cholesterol (LDL-c) level. In 21.3%, the high-density lipoprotein cholesterol (HDL-c) level was decreased. There were significant positive correlations of serum TC with those of the TC/HDL-c ratio, LDL-c, triglycerides and HDL-c (p < 0.05 and 0.001), of LDL-c with TC and apo(a) (p < 0.001) and of ML scores with the TC/HDL-c ratio and patient age (p < 0.01 and 0.001). There were significant negative correlations of TC and apo(a) levels with apo(a) phenotypes (p < 0.05 and 0.001) and of ML scores with HDL-c (p < 0.001). The odds of coronary artery stenosis in patients with abnormally high apo(a) levels (44.6%) were not significantly different from those of patients with apo(a) levels in the normal range.
Interpretation:
Smaller apo(a) phenotypes, but not elevated levels of apo(a), may help to predict the rate and severity of coronary artery stenosis. HDL-c independently and negatively correlated with the extent of the stenosis.