Author + information
Background: Raised lipoprotein(a) is a strong independent cardiovascular risk factor, which may be prevalent in refractory angina; and can be reduced by lipoprotein apheresis (LA). Lipoprotein(a) [Lp(a)] promotes thrombosis via numerous mechanisms including via structural homology of its apolipoprotein(a) component to plasminogen, thereby reducing fibrinolysis.
Methods: We conducted a randomised controlled trial in 20 patients with refractory angina and raised Lp(a) >500mg/L, with three months of blinded weekly LA or sham, followed by crossover. The Global Thrombosis Test (GTT), which assesses both thrombus formation and lysis activity under physiological conditions, was used to assess the impact of LA on occlusion time (OT, seconds) and lysis time (LT, seconds).
Results: OT (s) increased significantly by a mean value of 147 (95% CI 98, 196) following apheresis from 576 ± 116 to 723 ± 142, indicating an improvement in thrombotic risk. In response to sham, OT (s) did not change significantly with a mean change of −13 (95% CI −63, 38) from 585 ± 142 to 573 ± 113 (P=0.0002 between treatment arms). LT (s) decreased significantly by a median value of −355 (IQR −738, −89) in response to apheresis from 1340 (IQR 1128, 1682) to 847 (IQR 685, 1302), representing an improvement in fibrinolytic activity. In response to sham, LT (s) increased slightly with a median change of 36 (IQR −56, 204) from 1098 (IQR 983, 1573) to 1248 (IQR 987, 1592) (P=0.005 between treatment arms).
Conclusions: In patients with refractory angina and raised Lp(a), LA leads to improvements in thrombotic and fibrinolytic parameters. Further studies are needed to assess whether LA may reduce thrombotic events in these patients with refractory angina.
Poster Hall, Hall C
Saturday, March 18, 2017, 3:45 p.m.-4:30 p.m.
Session Title: Antithrombotic Therapy in Ischemic Heart Disease
Abstract Category: 3. Acute and Stable Ischemic Heart Disease: Therapy
Presentation Number: 1252-309
- 2017 American College of Cardiology Foundation