Younger patients presenting to coronary care units should be routinely screened for lipoprotein (a) as well as LDL-cholesterol, WA cardiologists say.
They made the recommendation after their study showed elevated lipoprotein (a) and LDL-C consistent with familial hypercholesterolemia are significant and independent predictors of the severity and complexity of premature coronary artery disease.
The findings support ESC/EAS recommendations to check Lp(a) levels in selected cases at high risk and in people with a family history of premature cardiovascular disease.
The WA study of 147 patients under 60 years of age presenting with an acute coronary syndrome found 30% of patients had an elevated Lp(a) greater than 0.5 g/L.
Elevated Lp(a) and pretreatment LDL were both significantly associated with angiographic severity and complexity as measured by SYNTAX and Gensini scores.
“Lp(a) and pretreatment LDL- cholesterol, as continuous or dichotomous variables, remained significant after adjusting for age, previous coronary event, diabetes and hypertension,” the study said.
Most patients with neither elevated Lp(a) nor LDL were in the first tertile of SYNTAX scores, most with one elevated finding were in the second or third SYNTAX tertiles and most patients with both elevated Lp(a) and LDL were in the third tertile.
“Accordingly, elevated Lp(a) and LDL cholesterol appeared to have an additive effect on the severity and complexity of angiographic-defined CAD.”
The researchers said the only effective therapies for lowering Lp(a) were lipoprotein apheresis and possibly nicotinic acid.
However testing for elevated Lp(a) ensured “patients at the highest risk of recurrence are identified, treated with high doses of potent statins, and additional therapy such as ezetimibe and their noncholesterol CVD risk factors optimally managed”.
Professor Carl Schultz, from the Royal Perth Hospital’s cardiology department told the limbic screening for Lp(a) was probably underdone because, until recently, it was not widely appreciated just how common it was.
“And part of the reason is that there are no specific treatments at the moment that can reduce this Lp(a).”
He said new treatments were on the horizon however.
“And while there is no guarantee of that yet, it’s very exciting and suggests that we should be screening routinely in this relatively young group of people that have premature coronary disease.”
“When they have the Lp(a) factor, their disease is much more advanced and the combination with FH is extremely averse. Simply knowing that the two factors are present can help motivate for more aggressive therapy.”
More testing for elevated Lp(a) would also lead to the detection of more index cases and allow for cascade testing of at-risk family members, the study said.