The long-term survival rate of patients with acute myocardial infarction (AMI) has increased rapidly since stent revascularization became common.
However, many patients still experience coronary microvascular dysfunction (CMD) after the procedure, and CMD is related to long-term survival.
Local researchers found that CMD was closely associated with a patient’s thrombogenicity, or tendency to generate blood clotting, for the first time in the world.
The research team of professor Jeong Young-hoon at the Cardiovascular Center of Gyeongsang National University Changwon and Professor Kang Min-gyu of pulmonary medicine at Eulji University Hospital published their study results in the JACC Basic to Translational Science.
The study was titled, “Association Between Thrombogenicity Indices and Coronary Microvascular Dysfunction in Patients With Acute Myocardial Infarction.”
The research team said restoring perfusion in AMI causes reperfusion injury inevitably because of complex and diverse mechanisms such as myocyte swelling, occluding of capillaries, platelet-neutrophil recruitment, and fibrin deposition these events were related to CMD.
Although many studies have been conducted to reduce these events, the research team said no method had been established to prevent or treat them.
The research team said various testing methods could confirm thrombogenicity, but currently available methods can only confirm some causes of thrombosis.
Thromboelastography (TEG) is a test reflecting the whole process of blood coagulation and shows various indices. Among them, platelet-fibrin clot strength (P-FCS) is a representative indicator of the risk of thromboembolic events.
The research team performed TEG after collecting blood from patients with AMI immediately after the hospital visit and measured the index of microcirculatory resistance (IMR) after revascularization. Then, they analyzed how the two were associated.
The results showed that 22.4 percent of 116 patients had CMD (IMR>40U) and high P-FCS in TEG testing.
In particular, patients with high P-FCS (P-FCS ≥ 68mm) had a 4.4 times higher risk of CMD.
The three-year follow-up showed that patients with high P-FCS among CMD patients had 5.6 times higher risk of major adverse cardiovascular events (death, relapse of MI, revascularization, and hospitalization for heart failure).
“AMI patients with high thrombogenicity have an increased CMD risk after revascularization, and thrombogenicity has an important role in the long-term prognosis,” Jeong said.
“To reduce this risk, physicians should identify the patient’s thrombogenicity accurately, and additionally use anticoagulants for the peri-procedural and long-term control of hypercoagulability in high-risk patients.”