Lipoprotein(a) and Pulmonary Embolism Severity-A Retrospective Data Analysis

Lipoprotein (a) is not associated with thrombus burden derived from CT pulmonary angiography in patients with acute pulmonary embolism

Lipoprotein (a) [Lp(a)] is suspected to have antifibrinolytic effects, however, its relevance for the severity of venous thromboembolic events remains unclear. We studied the association of Lp(a) levels with thrombus load in pulmonary embolism (PE). 90 patients (40% female, median age 70 [56-79] years) at our tertiary care hospital with a diagnosis of acute PE, available Lp(a) levels and CT pulmonary angiography (CT-PA) performed between April 2017 and December 2019 were included. All CT-PA scans were reanalyzed and thrombus load was determined via Qanadli CT obstruction index (CTOI) and most proximal thrombus location. Median Lp(a) levels were 11.4 [9.3-29.1] mg/dL, median D-dimer levels were 4.6 [2.1-9.8] mg/L, median CTOI was 23 [8-50], central PE was present in 27 (30%) patients. Lp(a) did not correlate with CTOI (r = 0.02, p = 0.922) and was not associated with thrombus location (p = 0.369). CTOI significantly correlated with D-dimer (r = 0.43, p < 0.001) and right to left ventricular diameter ratio (r=-0.49, p = < 0.001). Our findings showed that Lp(a) is not associated with thrombus burden in PE, which suggests that a relevant effect of Lp(a) on the extent of venous thromboembolism is unlikely.

The relationship between lipoprotein(a) and risk of cardiovascular disease: a Mendelian randomization analysis

BACKGROUND

Lipoprotein(a) [Lp(a)] is one of the residual risk factors for cardiovascular disease (CVD) in the setting of optimal low-density lipoprotein cholesterol (LDL-C). The association between Lp(a) and CVD is still in the exploratory phase, with few studies indicating a causal connection between Lp(a) and various CVD.

METHODS

Lp(a) (n = 377,590) was a genome-wide association study (GWAS) based on European populations from Neale Lab. Large GWAS datasets for CVD, including aortic aneurysm(AA) (n = 209,366), atrial fibrillation(AF) (n = 1,030,836), coronary heart disease(CHD) (n = 361,194), secondary hypertension(HBP) (n = 164,147), heart failure(HF) (n = 208,178), ischemic stroke (IS) (n = 218,792), large artery atherosclerosis stroke(ISL) (n = 150, 765), small vessel stroke(ISS) (n = 198,048), lacunar stroke(LIS) (n = 225,419), and pulmonary embolism(PE) (n = 218,413) were also based on European populations. We performed separate univariate two-sample Mendelian randomization (MR) analysis for Lp(a) and CVD as described above. We evaluated this connection mainly using the random-effects inverse variance weighted technique(IVW1) with a 95% confidence interval (CI) for the odds ratio (OR). This was supplemented by MR-Egger, weighted median, maximum likelihood, penalized weighted median, and fixed-effects inverse variance weighted methods. MR-PRESSO offers another means of statistical detection.

RESULTS

Our two-sample MR, which was predominately based on IVW1, revealed a causal relationship between Lp(a) and AA (OR = 1.005, 95%CI: 1.001-1.010, P = 0.009), CHD (OR = 1.003, 95%CI 1.001-1.004, P = 0.010), and ISL (OR = 1.003, 9 5%CI 1.002-1.004, P = 9.50E-11), in addition, there is no causal association with AF, HBP, HF, IS, ISS, LIS, or PE. Similar conclusions were reached by the MR-PRESSO method.

CONCLUSION

This MR study suggested a causal relationship between Lp(a) and CHD, AA, and ISL, but not associated with AF, HF, IS, LIS, ISS, HBP, or PE. Our work further verifies the association between Lp(a) and various CVD, resulting in improved Lp(a) management and a reduction in the prevalence of CVD.