Lipoprotein (a): A link between thrombogenesis and atherogenesis

Predictive value of lipoprotein(a) for left atrial thrombus or spontaneous echo contrast in non-valvular atrial fibrillation patients with low CHA2DS2-VASc scores: a cross-sectional study

OBJECTIVE

Current guidelines are debated when it comes to starting anticoagulant therapy in patients with non-valvular atrial fibrillation (NVAF) and low CHA2DS2-VASc scores (1-2 in women and 0-1 in men). However, these individuals still have a high likelihood of developing left atrial thrombus/spontaneous echo contrast (LAT/SEC) and experiencing subsequent thromboembolism. Recent research has demonstrated that lipoprotein(a) [Lp(a)] may increase the risk of thrombosis, but the relationship between Lp(a) and LAT/SEC in NVAF patients is not clearly established. Therefore, this study sought to evaluate the predictive ability of Lp(a) for LAT/SEC among NVAF patients with low CHA2DS2-VASc scores.

METHODS

NVAF patients with available transesophageal echocardiography (TEE) data were evaluated. Based on the TEE results, the subjects were classified into non-LAT/SEC and LAT/SEC groups. The risk factors for LAT/SEC were examined using binary logistic regression analyses and were validated by using 1:1 propensity score matching (PSM). Subsequently, novel predictive models for LAT/SEC were developed by integrating the CHA2DS2-VASc score with the identified factors, and the accuracy of these models was tested using receiver operating characteristic (ROC) analysis.

RESULTS

In total, 481 NVAF patients were enrolled. The LAT/SEC group displayed higher Lp(a) concentrations. It was found that enlarged left atrial diameter (LAD), high concentrations of Lp(a), and a history of coronary heart disease (CHD) were independent predictors of LAT/SEC. Lp(a) and LAD still had predictive values for LAT/SEC after adjusting for PSM. In both the highest quartile groups of Lp(a) (>266 mg/L) and LAD (>39.5 mm), the occurrence of LAT/SEC was higher than that in the corresponding lowest quartile. By incorporating Lp(a) and the LAD, the predictive value of the CHA2DS2-VASc score for LAT/SEC was significantly improved.

CONCLUSION

Elevated Lp(a) and enlarged LAD were independent risk factors for LAT/SEC among NVAF patients with low CHA2DS2-VASc scores. The prediction accuracy of the CHA2DS2-VASc score for LAT/SEC was significantly improved by the addition of Lp(a) and LAD. When evaluating the stroke risk in patients with NVAF, Lp(a) and LAD should be taken into account together with the CHA2DS2-VASc score.

TRIAL REGISTRATION

Retrospectively registered.

Ischemic stroke in a young adult with extremely elevated lipoprotein(a): A case report and review of literature

Lipoprotein(a) [Lp(a)] is an apolipoprotein(a) molecule bound to 1 apolipoprotein B-100. Elevated levels of Lp(a) are thought to be an independent risk factor for atherosclerosis and to promote thrombosis through incompletely understood mechanisms. We report a 34-year-old man with an ischemic stroke in the setting of an extremely high Lp(a) level-212 mg/dL. He developed severe carotid artery stenosis over a 6-year period and had thrombus formation post-carotid endarterectomy. To our knowledge, this case is unique because the Lp(a) is the highest reported level in a patient without renal disease. Moreover, this is the first reported case of the youngest individual with a stroke presumably related to development of carotid plaque over a 6-year period. The thrombotic complication after endarterectomy may have been related to the prothrombotic properties of Lp(a). Of note, the Lp(a) level did not respond to atorvastatin but did decrease 15% after aspirin 325 mg was added although his Lp(a) levels were variable, and it is not clear that this was cause and effect. This case highlights the need to better understand the relation between Lp(a) and vascular disease and the need to screen family members for elevated Lp(a). We also review treatment options to lower Lp(a) and ongoing clinical trials of newer lipid-lowering drugs that can also lower Lp(a).

Lipoprotein apheresis: present and future uses

PURPOSE OF REVIEW

For the past 40 years, apheresis, in particular, lipoprotein apheresis, has been the therapy of choice to lower LDL-C for familial hypercholesterolemia patients with uncontrolled dyslipidemia and cardiovascular disease. With the advent of recent and future lipid-modifying agents and their ability to lower LDL-C, the question arises on what will be the future of lipoprotein apheresis.

RECENT FINDINGS

Lipoprotein apheresis lowers not only plasma levels of apolipoprotein B lipoproteins but also markers of vascular inflammation and blood rheology. Other vascular diseases, not necessarily associated with familial hypercholesterolemia, such as nephrotic syndrome and peripheral arterial disease have profited from lipoprotein apheresis therapy. In 2013, the Food and Drug Administration approved lipoprotein apheresis therapy for patients with focal segmental glomerulosclerosis. Since 2010, the German healthcare ministry has approved lipoprotein apheresis therapy for patients with an elevated lipoprotein(a) and ongoing cardiovascular disease irrespective of LDL-C levels.

SUMMARY

Recent and future lipid-modifying therapies will most likely reduce the practice of lipoprotein apheresis therapy for familial hypercholesterolemia patients. Future implications for lipoprotein apheresis will involve vascular diseases that are at present lacking clinically effective therapy, whereas acute and chronic reductions of lipids, vascular inflammation, and/or rheology may improve the clinical outcome.