A plasma test to determine the maximum density of a blood clot and how long it takes to break down could help identify heart attack patients at increased risk for cardiovascular death or another myocardial infarction (MI), according to a study published Jan. 29 in the European Heart Journal.
This finding might also drive the creation of novel therapies to improve clot lysis time with the goal of reducing subsequent adverse events, senior author Robert F. Storey, MD, and colleagues wrote.
After adjusting for cardiovascular risk factors, each 50 percent increase in lysis time was associated with 36 percent increased risk of cardiovascular death within one year and 17 percent increased risk of cardiovascular death or spontaneous MI. Patients in the highest quartile of lysis time had a 92 percent increased chance of cardiovascular death compared to the lowest quartile.
Higher maximum turbidity—a measurement of clot density—was also associated with increased odds of cardiovascular death and MI, but those associations weren’t significant after further adjustment for other prognostic biomarkers such as high-sensitivity troponin T and N-terminal pro B-type natriuretic peptide. However, lysis time remained significantly predictive of events even after accounting for these biomarkers.
“We have shown, in a large population of ACS (acute coronary syndrome) patients treated with contemporary therapies and followed up for up to one year, that fibrin clot properties independently predict the risk of spontaneous MI and CV death following initial in-hospital management,” Storey et al. wrote. “Importantly, lysis time predicted worse outcome after adjusting for other established or new prognostic biomarkers, thus indicating the potential for a further biomarker that provides insight into prognosis following ACS.”
The researchers drew their conclusions from a substudy of 4,354 patients with ACS from the PLATO trial who were randomized to treatment with either clopidogrel or ticagrelor. In the substudy, the use of one drug versus another didn’t have a significant impact on cardiovascular mortality.
Storey and colleagues said patients with “adverse fibrin clot properties” may benefit from treatment outside of antiplatelets.
“Our data support the hypothesis that at least a subgroup of patients might benefit from additional therapy that aims at improving lysis potential,” they wrote. “For example, further work could explore whether anticoagulant therapy, in combination with a platelet P2Y12receptor antagonist, offers an advantage over dual antiplatelet therapy in those with adverse fibrin clot properties. Other novel therapies that specifically target proteins implicated in impaired lysis, such as complement C3 or plasmin inhibitor, is another approach that might have less impact on hemostasis, particularly if the aim was to normalize lysis potential.”
The authors noted the plasma analysis requires laboratory personnel, so it can’t be used as a bedside test.