Impaired fibrin clot lysis is associated with increased mortality in patients after coronary artery bypass grafting: A long-term follow-up study

Abstract

Background: Mortality after coronary artery bypass grafting (CABG) is primarily thromboembolic by nature. We investigated whether impaired fibrinolysis observed in cardiovascular diseases is associated with long-term mortality following CABG.

Methods: The study population comprised 292 consecutive patients (aged 64.6 ± 8.1 years) who underwent scheduled CABG. We measured plasma clot lysis time (CLT) preoperatively as a measure of fibrinolysis capacity. Cardiovascular and all-cause deaths were recorded during a median follow-up of 13.8 years.

Result: CLT positively correlated with age (r = .56, p < .001), fibrinogen (r = .25, p = .002) and EuroSCORE I (r = .32, p < .001). The cardiovascular and overall mortality rates were 3.0 and 4.9 per 100 patient-years (32.4% vs 52.8%) respectively. In patients who died from cardiovascular and all causes, CLT was prolonged compared with survivors (both p < .050). Multivariable Cox regression analysis adjusted for potential confounders showed that long-term cardiovascular and all-cause deaths were associated with CLT (HR per 10 min 1.206; 95% CI 1.037-1.402, p = .015 and HR 1.164; 96% CI 1.032-1.309, p = .012), low-density lipoprotein cholesterol (HR per 1 mmol/L 1.556; 95% CI 1.205-2.010, p < .001 and HR 1.388; 96% CI 1.125-1.703, p = .002), C-reactive protein (HR per 10 mg/L 1.171; 95% CI 1.046-1.312, p = .006 and HR 1.127; 95% CI 1.005-1.237, p = .022) and EuroSCORE I (HR 1.173; 95% CI 1.016-1.355, p = .030 and HR 1.183; 95% CI 1.059-1.317, p = .003 respectively). Type 2 diabetes was solely associated with overall mortality (HR 1.594; 96% CI 1.088-2.334, p = .017).

Conclusions: In this study, we showed that reduced fibrin clot susceptibility to fibrinolysis is weekly associated with long-term mortality in advanced CAD.

Keywords: clot lysis time; coronary artery bypass grafting; fibrinolysis; follow-up; mortality.