Introduction: Individuals with a family history of premature coronary artery disease (CAD) have an increased cardiovascular risk. Since current risk algorithms poorly predict risk, especially in younger individuals, novel methods are needed to assess cardiovascular risk in these families. Recently, microvascular function (using imaging of the sublingual microvasculature with videomicroscopy) was put forward as an indicator of vascular vulnerability in CAD. We set out to evaluate if microvascular dysfunction was present in premature CAD families.
Methods: In 50 patients with premature CAD (men <41 years, women <46 years), 50 healthy first degree relatives (FDRs) and 50 age and gender-matched controls, sublingual microvascular function was assessed. Using sidestream darkfield imaging, the erythrocyte perfused boundary region (PBR) was assessed as an indicator for increased penetration of the erythrocyte column towards the endothelium, indicative of microvascular dysfunction.
Results: Participants had a mean age of 45.7±6.3 years, 54.3% were men. Both in patients with premature CAD as well as their FDRs an increased PBR was observed (2.2±0.3μm and 2.2±0.3μm, respectively) compared to controls (2.0±0.2μm; p<0.05 vs. patients and FDRs). In the FDRs, the PBR was highest in those characterized by increased coronary artery calcification. Significance was retained after adjustment for traditional cardiovascular risk factors.
Conclusion: Patients with premature CAD and their FDRs are characterized by microvascular dysfunction, independent of other cardiovascular risk factors. Further studies are needed to address the predictive value of PBR changes for cardiovascular risk as well as the potential reversibility of these changes by risk-lowering interventions.