Familial hypercholesterolaemia (FH) has a relatively high prevalence in a regional population of patients presenting with ACS, a Victorian study has found.
The findings from a Geelong study reinforce the importance of considering FH as a possibility, particularly in patients with significantly elevated or difficult to control lipids.
The study enrolled 180 consecutive patients presenting to the CCU at the University Hospital Geelong during six months in 2017-2018. Most were male, aged 61 years and presenting with NSTEMI (46%) and STEMI (44%).
A total of 11 patients (6.1%) were classified as having phenotypic FH according to the Dutch Lipid Clinic Network Criteria (DLCNC).
“When considering patients aged 60 and younger, a subgroup that selects for premature coronary disease, this figure rises to 11.0%,” the study authors said.
Patients with the phenotypic FH cohort were younger (53.1 v 62.0 years, p=0.011); and more likely to have documented ischaemic heart disease (63.6% v 20.7%, p=0.001) compared to the non-phenotypic FH patients.
“Phenotypic FH patients also had higher levels of total cholesterol, corrected LDL and triglycerides, but no statistically significant difference in HDL levels compared with non-FH counterparts.”
FH patients had a higher rate of statin (91% v 33%) and ezetimibe (18% v 2%) use but fibrate use was not significantly different than the non-FH patients.
There was no significant difference in rates of hypertension, hyperlipidaemia, diabetes, peripheral vascular disease, stroke or current smoking between the two groups.
The investigators said in Heart, Lung and Circulation that the prevalence of FH in their under-60 year-olds was consistent with other data from WA (14.3%) and a European study (15.4%).
“Given these findings, cascade screening takes on a greater significance for early detection and management of FH cases,” they said. “This is the most cost effective approach for the identification of new FH cases.”
They said current Australian recommendations suggest patients with phenotypic FH should be referred to a specialist clinic.
“This may have specific implications for regional, rural and remote populations of Australian given the difficulties in accessing these services.”
“The findings from this study support the ongoing need for primary and secondary preventive cardiac care in regional areas; and potentially for delivery of more specialised services such as genetic counselling given the prevalence of FH.”
Lead author Dr Rohit Samuel, now at Vancouver General Hospital, Canada, told the limbic that while it was pleasing only a single patient with FH was not on a statin on admission, the lack of uptitration was definitely a concern.
“This does reflect the wider evidence base that there is significant room for improvement in escalating therapies for CV risk factors such as hypertension and hyperlipidaemia. In my opinion monitoring is done relatively well in primary care settings, but sometimes there is a degree of therapeutic inertia, particularly when a specialist is also involved in a patient’s care.”
“Earlier this year the PBS has allowed the use of PCSK9 inhibitors for broader indications, including in high risk patients requiring secondary prevention. It is important that patients in regional and rural areas are considered for these, particularly in light of our study showing the prevalence of FH within a regional community.”
The study authors said none of the patients underwent genetic testing.
“The use of the Dutch Lipid Clinic Network Criteria in the study means a diagnosis of FH can be presumed in patients who score highly. There is no real added benefit from the genetic testing in this population of patients, given it would not change their management.”
Meanwhile in a letter to the journal editor, a WA team including Professor Gerald Watts said risk factors including family history were underreported in an audit of 280 discharge summaries from CCU.
“246 patients (88%) had no documentation of family history of CAD in their discharge summary,” the authors said.
Yet when followed up, 53% were found to have premature CAD (before age 60), 48% had a family history of CAD, and 33% had a diagnosis of at least possible FH using DLCNC.
“This might have reduced or delayed identification of FH in these high-risk patients. There is clearly a need to improve the detection of FH in both hospital clinics and the community, noting the population prevalence of FH of close to 1 in 250.”