Role of lipoprotein (a) and LPA KIV2 repeat polymorphism in bicuspid aortic valve stenosis and calcification: a proof of concept study

Lipoprotein(a; Lp[a]) and its associated oxidized phospholipids are causal, genetic risk factors for calcific aortic valve stenosis (CAVS). We determined the prevalence of Lp(a) measurement among 2710 patients with CAVS and 1369 control patients (∼50% of study group) without CAVS with an echocardiogram between January 2010 and February 2016 in an academic echocardiography laboratory. Lipoprotein(a) measurements were performed at a referral laboratory using an isoform-independent assay. The prevalence of any Lp(a) measurement was 4.6% (124 of the 2710) in patients with CAVS and 3.1% (42 of the 1369) in the control group ( P = .021). In patients with CAVS, mean (standard deviation) Lp(a) levels were 38 (54) mg/dL and median (interquartile range) Lp(a) levels were 14 (6-48) mg/dL. Of the 124 patients with CAVS having Lp(a) measurements, 83 (66.9%) had Lp(a) <30 mg/dL and 41 (33.1%) had Lp(a) ≥30 mg/dL. This study reflects low physician testing of Lp(a) levels in CAVS. Given the role of Lp(a) as a causal risk factor for CAVS, and the ongoing development of therapies to normalize Lp(a) levels, our results suggest that Lp(a) measurements in CAVS should be more widely obtained in clinical practice.

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P2748Lipoprotein(a) and autotaxin in patients with stenotic atherosclerosis of coronary arteries and aortic valve stenosis

European Heart Journal ◽

10.1093/eurheartj/ehz748.1065 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Author(s):

O Afanasieva ◽

N Tmoyan ◽

O Razova ◽

E Klesareva ◽

M Afanasieva ◽

...

Keyword(s):

Aortic Valve ◽

Aortic Valve Stenosis ◽

Odds Ratio ◽

Control Group ◽

Elevated Concentration ◽

Oxidized Phospholipids ◽

Lipoprotein A ◽

Group I ◽

Group Ii

Abstract Background Lipoprotein(a) [Lp(a)] is an independent risk factor of coronary heart disease (CHD) and calcific aortic valve stenosis (CAVS). It has been recently shown that autotaxin (ATX), which breaks down lysophosphatidylcholine, derived from oxidized phospholipids, to lysophosphatidic acid, was strongly associated with CAVS. Purpose The aim of the study was to investigate the role of Lp(a) and ATX in CHD patients with and without CAVS. Methods The study included 438 patients (average age 66±11 years, men 310), 332 had CHD with ≥50% stenosis in at least one coronary artery according to angiography. CAVS was diagnosed with ultrasound. The control group consisted of 106 patients without CHD and CAVS. The concentrations of Lp(a), ATX, lipids and blood cells were measured for all the patients. Results CHD without CAVS (group I) was diagnosed in 287 patients, 45 patients had CHD and CAVS (group II). Patients in both groups were older than patients in the control group (75±8, 66±10 and 61±13 years respectively). ATX level was lower in group I (median [25; 75%]: 493 [406; 583] ng/ml) than in control group (544 [412; 655] ng/ml, p=0.02) or group II (553 [475; 609] ng/ml, p=0.003). Lp(a) was lower in control group (14.5 [5.5; 36.0] mg/dl) than in group I (25.6 [9.7; 58.5] mg/dl, p=0.0004) and group II (23.8 [9.9; 79.1] mg/dl, p=0.02). Elevated level of ATX was positively associated with CAVS in CHD patients, but negatively with CHD in patients without CAVS. We have shown that age, glucose level and neutrophil-lymphocytes index (NLI) could be predictors of CAVS in patients with CHD according to results of logistic regression analysis. Odds ratio of high (QIV) vs. low (QI) Odds ratio (95% confidence interval) Groups Autotaxin Lipoprotein(a) Neutrophil-lymphocytes index I vs. control 0.5 (0.3–0.9)* 2.7 (1.3–5.2)** 2.4 (1.3–4.6)* II vs. control 8.6 (1.1–70.1)* 3.4 (1.2–9.4)* 6.2 (2.2–16.9)** II vs. I 16.6 (2.1–131.1)** 1.3 (0.5–3.2) 2.5 (1.0–6.37)* *p<0.05, **p<0.005. Conclusion Elevated Lp(a) level is a predictor of CHD regardless of calcific aortic valve stenosis, whereas elevated concentration of autotoxin in CHD patients was associated with calcific aortic valve stenosis.

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