Increase in plasma plasminogen activators inhibitor type 1 concentration after fibrinolytic treatment in patients with acute myocardial infarction is associated with 4G/5G polymorphism of PAI-1 gene

Quantile-specific heritability of plasminogen activator inhibitor type-1 (PAI-1, aka SERPINE1) and other hemostatic factors

BACKGROUND

Plasminogen activator inhibitor type-1 (PAI-1, aka SERPINE1) is a moderately heritable glycoprotein that regulates fibrin clot dissolution (fibrinolysis).

OBJECTIVES

Test whether the heritabilities (h2 ) of PAI-1 and other hemostatic factors are constant throughout their distribution or whether they are quantile-specific (i.e., a larger or smaller h2 depending on whether their concentrations are high or low).

METHODS

Quantile regression was applied to 5606 parent-offspring pairs and 5310 full siblings of the Framingham Heart Study. Quantile-specific heritability was estimated from the parent-offspring regression slope (βPO , h2  = 2βPO /(1+rspouse )) and the full-sib regression slope (βFS , h2  = {(1+8rspouse βFS )0.5 -1}/(2rspouse )).

RESULTS

Heritability (h2  ± SE) increased significantly with increasing percentiles of the offspring's age- and sex-adjusted PAI-1 distribution when estimated from βPO (plinear trend  = 0.0001): 0.09 ± 0.02 at the 10th, 0.09 ± 0.02 at the 25th, 0.16 ± 0.02 at the 50th, 0.29 ± 0.04 at the 75th, and 0.26 ± 0.08 at the 90th percentile of the PAI-1 distribution, and when estimated from βFS (plinear trend  = 6.5x10-7 ). There was no significant evidence for quantile-specific heritability for factor VII (plinear trend  = 0.35), D-dimer (plinear trend  = 0.08), tPA (plinear trend  = 0.74), or von Willebrand factor (plinear trend  = 0.79).

CONCLUSION

Higher mean plasma PAI-1 antigen concentrations tend to accentuate genetic effects (quantile-dependent expressivity), which is consistent with the greater reported differences in PAI-1 concentrations between rs1799889 SERPINE1 (4G/5G) genotypes in patients with osteonecrosis, meningococcal sepsis, obesity, prior myocardial infarction, deep vein thrombosis, and polycystic ovarian syndrome than in healthy controls. It is also consistent with the greater increases in PAI-1 concentrations in 4G-allele carriers than 5G/5G homozygotes following fibrinolytic treatment, low-salt intake, and high saturated fat intake.

Myocardial infarction and arterial thrombosis in identical newborn twins with homozygosity for the PAI-1 4 G/5 G polymorphism

Myocardial infarction in the perinatal period, in the absence of congenital heart disease or coronary artery lesions, is rare. The most common etiology described are the thromboembolism and perinatal asphyxia. We report a case of monozygotic twins who developed, after birth, acute vascular events and both had PAI-1 4G/4G homozygosity.

The influence of acute-phase levels of haemostatic factors on reperfusion and mortality in patients with acute myocardial infarction treated with streptokinase

BACKGROUND

The fibrinolytic system and von Willebrand factor (vWF) have been shown to play a role as risk factors for myocardial infarction. We performed this prospective cohort study to determine if components in the fibrinolytic system or vWF before or during treatment of AMI with streptokinase (SK) could predict reperfusion, recurrent ischaemia, reinfarction or mortality at one year, or mortality at five years. Reperfusion and recurrent ischaemia were assessed by continuous vectorcardiography. The setting was Umeå university hospital and Skellefteå county hospital, Sweden.

RESULTS

139 patients were included; successful reperfusion was obtained in 53%. tPA activity, PAI-activity, PAI-mass concentration and vWF were analysed immediately on arrival and after 4 and 10 h. High fibrinolytic activity, measured as tPA activity > 25 U/L after the start of treatment, was associated with reperfusion. No significant associations between pre-treatment levels of the fibrinolytic variables or vWF and reperfusion or recurrent ischaemia were found. Elevated levels of PAI-1 mass concentration and PAI-1 activity after the start of SK treatment were associated with a higher risk for death at one year, but not at five years. High levels of vWF were associated with worse prognosis but not when corrected for age.

CONCLUSION

Pre-treatment levels of PAI-1, vWF and tPA activity showed no association with reperfusion or recurrent ischaemia. Elevated levels of PAI-1 activity after the start of treatment were associated with worse prognosis.