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Research

Researchers Find Low Response Rate by Clinicians to Elevated Levels of Lp(a)

Elevated Lipoprotein(a) [Lp(a)] is an independent, genetically determined risk factor for atherosclerotic cardiovascular disease (ASCVD), with levels >50 mg/dL affecting 20–30% of the global population. Despite therapeutic limitations, interest in Lp(a) has increased, driven by its prognostic value and the emergence of targeted therapies. However, with increasing guideline-directed Lp(a) testing, clinician response to elevated concentrations, especially in the absence of guideline-based treatment indications, remains unclear.

In a new study and presentation at the American College of Cardiology, researchers found that elevated Lp(a) was associated with earlier and more frequent initiation of preventive pharmacotherapy.  These response rates were modest in a low-risk, primary prevention study population.

While not currently a standard indication for statin therapy alone, elevated Lp(a) is increasingly used by clinicians as a “risk enhancer” to guide more aggressive, albeit often unstandardized, preventive measures.

Sheilah A. Bernard, MD, associate professor of medicine

Specifically, nearly 80% of patients with elevated Lp(a) >50 mg/dL did not initiate lipid-lowering therapy in the absence of other ASCVD risk factors. Drugs that drastically lower “bad” LDL cholesterol (PCSK9 inhibitors) and aspirin initiation was even less common, suggesting selective rather than systematic responses to elevated Lp(a). Together, these findings suggest that elevated Lp(a) appears to only occasionally influence prescribing behavior – behavior consistent with previous reports.

“While not currently a standard indication for statin therapy alone, elevated Lp(a) is increasingly used by clinicians as a “risk enhancer” to guide more aggressive, albeit often unstandardized, preventive measures,” says corresponding author Sheilah A. Bernard, MD, associate professor of medicine at Boston University Chobanian & Avedisian School of Medicine.

The researchers conducted a multicenter retrospective observational cohort study evaluating initiation of preventive pharmacotherapy following Lp(a) measurement among nearly 15,000 patients at low risk for ASCVD. Within 90 days of Lp(a) measurement, lipid-lowering therapy initiation was uncommon but more frequent among patients with elevated Lp(a) compared to those with non-elevated Lp(a). PCSK9 inhibitor initiation was rare but more frequent among patients with elevated Lp(a). Similarly, aspirin initiation was uncommon but more frequent among patients with elevated Lp(a).

According to the researchers, these findings should not be interpreted as indicating that such prescribing is guideline-directed. “Current recommendations recognize Lp(a) as a risk-enhancing factor rather than as a treatment target, and no therapy is approved solely for Lp(a) elevation. Our analysis describes contemporary practice rather than appropriate management,” adds Bernard who also is a cardiologist at Boston Medical Center.

The findings also appear online in the American Journal of Preventive Cardiology.