Elevated lipoprotein(a) (Lp[a]) levels are associated with increased risk for left atrial remodeling, myocardial scar prevalence, and greater subclinical interstitial myocardial fibrosis, according to results of a study published in the Journal of the American College of Cardiology.
Myocardial fibrosis occurs when extracellular matrix proteins and collagen accumulate in the myocardium. This process is a key feature of cardiovascular disease progression.
To evaluate the role Lp(a) has in the myocardial fibrosis process, data for this study were sourced from the Multi-Ethnic Study of Atherosclerosis (MESA) study which was conducted at 6 locations in the United States and recruited participants between 2000 and 2002. Individuals (N=2040) who had Lp(a) data at baseline and cardiac magnetic resonance (CMR) T1 mapping and late gadolinium enhancement data from follow-up in 2010 were included.
The study participants had Lp(a) levels of less than 30 mg/dL (70%), 30 to less than 50 mg/dL (12%), and 50 mg/dL or higher (18%) at baseline. The 3 groups comprised 50%, 46%, and 39% women (P <.001); they had median ages of 67, 69, and 70 years; 50%, 42%, and 40% were White (P <.001); and 36%, 31%, and 47% were using lipid-lowering medications (P <.001), respectively.
In the fully-adjusted model that accounted for aortic valve calcification and moderate to severe aortic stenosis, log-transformed Lp(a) levels were associated with markers for interstitial myocardial fibrosis, extracellular volume (ECV; b, 0.2%; 95% CI, 0.06%-0.3%; P =.004) and native T1 time (b, 4; 95% CI, 2-5.5 ms; P <.001). Similarly, log-transformed Lp(a) levels were associated with risk for exceeding clinical thresholds of 30% or higher ECV (adjusted odds ratio [aOR], 1.4; 95% CI, 1.1-1.7; P =.002) and native T1 of 955 ms or longer (aOR, 1.2; 95% CI, 1.1-1.4; P =.006).
Among a subset of 1262 patients with relevant data, the presence of a myocardial scar was associated with Lp(a) levels of 30 or higher (aOR, 1.7; 95% CI, 1.1-2.8; P =.01) and 50 or higher (aOR, 1.8; 95% CI, 1.05-3; P =.03) mg/dL but not with log-transformed Lp(a) levels (aOR, 1.15; 95% CI, 0.9-1.4; P =.10).
Among patients who received cardiac magnetic resonance cine tagging, log-transformed Lp(a) was associated with left atrial emptying fraction (b, -0.5%; 95% CI, -0.8% to -0.1%; P =.01) and tended to be associated with minimal left atrial volume index to body surface area (b, 0.3; 95% CI, 0.0-0.6 mL/m2; P =.05). No relationship between log-transformed Lp(a) levels and left ventricular circumferential strain was observed (b, -0.1%; 95% CI, -0.2% to 0.1%; P =.30).
The major limitation of this study was the cross-sectional design which did not allow for causal inferences to be made.
The study authors wrote, “This population-based cohort study offers evidence demonstrating a significant association between elevated Lp(a) levels and both interstitial and replacement myocardial fibrosis.”
This article originally appeared on The Cardiology Advisor
References:
Chehab O Abdollahi A, Whelton SP, et al. Association of lipoprotein(a) levels with myocardial fibrosis in the Multi-Ethnic Study of Atherosclerosis. J Am Coll Cardiol. Published online December 4, 2023. doi:10.1016/j.jacc.2023.10.016