In Hypercholesterolemia, Disparities Impact ACS Risk & LDL-C Severity

Photo Credit: Nemes Laszlo

Severe hypercholesterolemia affects nearly 10% of patients with acute coronary syndrome, with notable sex differences impacting risk and disease onset.

The National Lipid Association Scientific Sessions featured a focus on severe hypercholesterolemia, with an entire session devoted to the topic. The session featured three presentations, with clinicians highlighting familial hypercholesterolemia and diet-induced hypercholesterolemia.

In a separate study that was not presented at the meeting, researchers examined acute coronary syndrome in patients with hypercholesterolemia, including severe hypercholesterolemia and familial hypercholesterolemia.

“Atherosclerotic cardiovascular disease is one of the most common causes of death and disability around the world,” they wrote in Medicina. “Hypercholesterolemia is an established and widely prevalent risk factor; however, the prevalence of severe hypercholesterolemia (which is characteristic for familial hypercholesterolemia) has been studied far less.”

To assess the prevalence of severe hypercholesterolemia among patients with acute coronary syndrome (ACS), investigators conducted a single-center retrospective study of patients hospitalized due to ACS. The study team utilized an electronic medical history database to obtain information on patient characteristics, including sex, age, cardiovascular risk factors (such as hypertension and diabetes), and low-density lipoprotein cholesterol. They defined severe hypercholesterolemia as low-density lipoprotein cholesterol levels of 4.9 mmol/L or greater.

Overall Patient Characteristics

 The analysis included 34,669 patients, with a significantly higher proportion of men (65.1%) than women (34.9%; P<0.001). The median age of the study population overall was 67 years, and the researchers reported that the median age for women was significantly higher (73 years) than for men (64 years; P<0.001).

In all categories, the differences between sexes were statistically significant, according to the study results. This included higher LDL-C (both ≥4.9 mmol/L and ≥6.5 mmol/L) levels, higher rates of both diabetes and arterial hypertension, and median age all among women versus men. The P value for all was <0.001.

Severe Hypercholesterolemia & Familial Hypercholesterolemia

In total, 3,434 patients (9.9%) had severe hypercholesterolemia, 371 patients (1.1%) met the criteria for phenotypically probable familial hypercholesterolemia, and 36 patients (0.1%) presented with phenotypically definite familial hypercholesterolemia. The researchers identified arterial hypertension as the most common concomitant risk factor in the study, seen in 48% of patients.

Among patients with severe hypercholesterolemia, the median age was 66 years, indicating a statistically significant difference compared with patients without severe hypercholesterolemia (median age, 68 years). While the prevalence of hypertension did not differ significantly between those with and without severe hypercholesterolemia, the differences in the prevalence of diabetes (9.0% vs 12.0%) and the combination of diabetes with hypertension (7.0% vs 10.0%) between patients with and without severe hypercholesterolemia were statistically significant.

Researchers observed few statistically significant differences in patients who did versus did not meet the criteria for phenotypically probable familial hypercholesterolemia, except for the prevalence of diabetes among men. Only 5.1% of men with phenotypically probable familial hypercholesterolemia had diabetes compared with men who did not have phenotypically probable familial hypercholesterolemia (10.0%; P<0.005).

Overall, the most common cardiovascular risk factor across all groups was arterial hypertension, which was found in 48.0% of patients.

Hypercholesterolemia & ACS

The researchers noted the sex differences observed, with women having a higher prevalence of cardiovascular risk factors and the timing of ACS diagnosis. The study found that women with phenotypically definite familial hypercholesterolemia were diagnosed with ACS 6 years earlier, and men 10 years earlier, than the overall study population.

“Based on the results of this study, severe hypercholesterolemia is prevalent among patients with acute coronary syndrome, with as many as 9.9% of patients presenting with severe hypercholesterolemia at the time of hospitalization,” the researchers wrote. “The definite familial hypercholesterolemia phenotype is scarcer, with prevalence reaching 0.1% of patients with acute coronary syndrome.”