Plasma concentration of lipoprotein(a) [Lp(a)] may be associated with the risk for cardiovascular death in elderly patients who experienced a recent acute myocardial infarction, according to the results of a prospective cohort study published in Atherosclerosis.
A total of 1008 patients aged ≥80 years (mean age, 82.86±2.88 years; 60.2% men; 73.1% with hypertension; 39.0% with diabetes mellitus) with coronary artery disease were recruited from Fuwai Hospital in China between 2012 and 2018. Acute myocardial infarction was determined using the Third Universal Definition of Myocardial Infarction. Blood samples were collected within 24 hours of hospital admission for immunoturbidimetry and enzymatic assays.
In this cohort, 28.5% of participants experienced cardiac death after an average of 36.26 months.
Patients with vs without cardiac death differed significantly by: median age (P =.019), body mass index (P =.003), diastolic blood pressure (P =.002), heart rate (P <.001), left ventricular ejection fraction (P <.001), glucose (P =.017), estimated glomerular filtration rate (P <.001), high sensitive C-reactive protein (P <.001), rate of diabetes mellitus (P =.004), and revascularization (P <.001).
Lp(a) concentrations were higher in patients who experienced vs did not experience cardiac death (median, 24.6 mg/dL; interquartile range [IQR], 11.1-48.0 mg/dL vs median, 20.1 mg/dL; IQR, 9.3-44.4 mg/dL, respectively; P =.045).
Patients were stratified based on their baseline Lp(a) concentration: low, £10 mg/dL; intermediate, 10 to 30 mg/dL; and high, >30 mg/dL. These patient groups differed in: the rate of cardiovascular death (low Lp(a), 22.8%; intermediate Lp(a), 27.8%; high Lp(a) 31.8%; P =.026), gender (men: low Lp(a), 70.8%; intermediate Lp(a), 71.8%; high Lp(a), 65.8%; P =.039), and left ventricular ejection fraction (low Lp(a), 53.75%; intermediate Lp(a), 53.16%; high Lp(a), 51.20%; P =.009).
Patients with high vs low Lp(a) had an increased risk for cardiovascular death after correcting for demographic factors (hazard ratio [HR], 1.477; 95% CI, 1.063-2.053; P =.020). This phenomenon was still observed after correcting for all possible risk factors (HR, 1.519; 95% CI, 1.083-2.132; P =.016). No significant difference was observed between low and intermediate groups after correcting for demographics (P =.694) or other risk factors (P =.304).
Study limitations include the fact that the cohort study was Chinese and, as Lp(a) concentrations are known to vary with genetic background, the results may not be generalizable across all populations.
“Our data suggested that Lp(a) measurements may clinically be useful to identify the oldest-old at high risk for [cardiovascular death] after [acute myocardial infarction],” noted the study authors.”
Zhang M, Liu H-H, Yan X-N, et al. Lipoprotein(a) and cardiovascular death in oldest-old (≥80 years) patients with acute myocardial infarction: A prospective cohort study. [published online September 8, 2020] Atherosclerosis. doi:10.1016/j.atheroscleroisis.2020.08.033