Association between hypercoagulability and microvascular dysfunction in patients with acute myocardial infarction

Abstract Background Microvascular dysfunction (MVD) following percutaneous coronary intervention (PCI) can increase the risk of adverse clinical outcomes, which partly may be related with thromboembolic microvascular obstruction. This study was sought to determine whether hypercoagulability is linked with MVD post-PCI in patients with acute myocardial infarction (AMI). Methods Hypercoagulability was determined with thrombin-induced platelet-fibrin clot strength (maximal amplitude [MAthrombin] ≥68 mm evaluated by thromboelastography). Microvascular function was assessed by invasive physiological index after PCI (MVD: index of microcirculatory resistance [IMR] ≥40 U). Major adverse cardiovascular events (MACE) was defined as the incidence of death or rehospitalization for heart failure post-PCI. Results Among AMI patients (n=116), 46 patients (39.7%) met the criteria of hypercoagulability and 27 patients (23.3%) had a MVD. Level of IMR showed a significant correlation with MAthrombin value (r=0.313; p=0.001). Prevalence of MVD was increased proportionally according to the quartile scale of MAthrombin (3.6% vs. 21.9% vs. 25.9% vs. 41.4%; p for trend = 0.009). Hypercoagulability significantly increased the predictive value for MVD occurrence (odds ratio: 4.35; 95% confidence interval: 1.74 to 10.89; p=0.001). During the follow-up post-PCI of 40.9 months (IQR: 19.8 to 59.4 months), MVD and hypercoagulability were both associated with MACE (hazard ratio: 5.86 and 2.28 respectively). Patients with both MVD and hypercoagulability showed an increased risk for MACE compared with the others (18.2% vs. 5.3%; adjusted hazard ratio: 4.50; 95% confidence interval: 1.26 to 16.12; Log rank p=0.011) (Figure). Conclusion This is the first analysis to demonstrate that baseline hypercoagulability is an independent determinant of post-PCI MVD in AMI patients. Combining the measurements of hypercoagulability and MVD may enhance risk stratification and deserves further study. Long-term outcomes Funding Acknowledgement Type of funding source: None