Real-world analysis questions very low LDL targets

By Eleanor McDermid

Patients treated for hypercholesterolaemia in clinical practice may not derive additional benefit from very intensive statin treatment, say researchers.

In their retrospective analysis, patients who achieved a low-density-lipoprotein (LDL) cholesterol level of 70 mg/dL or lower had no better cardiovascular outcomes than those who achieved levels between 70 and 100 mg/dL.

"Our results do not provide support for a blanket principle that lower [LDL cholesterol] is better for all patients in secondary prevention", writes the team.

The findings, which appear in JAMA Internal Medicine, are based on the LDL cholesterol levels achieved after 1 year of statin treatment by 31,619 Israeli patients with ischaemic heart disease and at least 80% medication adherence.

During an average 1.6 years of follow-up, the major adverse cardiovascular event (MACE) rate was 78.1 per 1000 person-years among the 29% of patients who achieved LDL cholesterol levels of 70 mg/dL or below. And the rate among the 53% of patients who achieved levels between 70 and 100 mg/dL was 71.0 per 1000 person-years, with no significant difference between the two groups after accounting for confounders.

However, people who achieved these moderate LDL cholesterol levels were a significant 11% less likely to have a MACE than patients who failed to achieve even that target. The rate among the 18% of patients whose LDL cholesterol levels remained above 100 mg/dL was 81.3 per 1000 person-years.

Indeed, the lowest MACE risk was observed in patients with achieved levels of around 90 mg/dL, with the risk rising steeply from 100 mg/dL.

The average age of the patients was around 67 years, which researcher Morton Leibowitz (Clalit Health Services, Tel Aviv, Israel) and colleagues say is generally older than the age of patients in randomised clinical trials.

In addition, they say that the trials from which the low LDL cholesterol targets emerged did not address "the extent of comorbidities or polypharmacy" among their patients, "which are factors that increasingly affect therapeutic decisions facing physicians."

When the researchers repeated their analysis in 54,884 patients with at least 50% statin adherence, the findings were broadly similar except that the group with the lowest achieved LDL cholesterol levels had a slightly but significantly increased risk of MACE, relative to the moderate levels group.

They therefore conclude that clinical trial evidence in support of very low LDL cholesterol targets "is not yet definitive for everyday community-based practice."

Source: JAMA Intern Med 2016; Advance online publication

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