Incremental Value of Biomarkers in the Diagnosis of Functionally Relevant Coronary Artery Disease and the Prognosis of Adverse Cardiovascular Outcomes

Summary
The most common of heart diseases is coronary artery disease (CAD). Atherosclerosis is the underlying cause of CAD, which leads to plaque formation through an orchestrated inflammatory process. Consequently, blood and oxygen flow to the heart become limited. This can lead to chest pain and potentially a heart attack.
CAD make up the largest portion of deaths caused by cardiovascular diseases, which are the leading cause of death world-wide. These numbers are inclining as the prevalence of cardiovascular risk factors, such as diabetes mellitus, obesity and lack of physical exercise are on the rise. However, according to the WHO, 75% of major adverse cardiac events (MACE) related to CAD can be prevented if the right interventions are incorporated. Therefore, the early and accurate detection of especially functional relevant CAD (fCAD), defined as exercise-induced myocardial ischemia, belongs to most important tasks in modern medicine.
The current gold-standard for the non-invasive detection of CAD are cardiac imaging techniques. These imaging modalities, however, are not widely available in all health care settings and carry along an array of challenges: they require specialist referral, are costly and associated with rare, but potentially serious adverse events including radiation-induced cancer. Therefore, it is of great interest and importance to find alternatives in guiding the diagnosis of CAD. Biomarkers, being intrinsically minimally-invasive, bearing less risks and comparably cheap, may combat those issues that are related to imaging techniques.
While current guidelines, however, suggest multiple biomarkers to help understanding the influence of co-morbidities on CAD and to estimate cardiovascular risk factors, to date, there is still no biomarker that can be recommended for the diagnosis of CAD. Therefore, it is important to search for and evaluate novel biomarkers that may facilitate the diagnosis of CAD, assess their incremental value and to evaluate their prognostic value on adverse cardiovascular outcomes.
In the frame of the Basel VIII study, patients with suspected fCAD referred to the University Hospital of Basel for rest/stress cardiac imaging were recruited. Biomarkers were measured in those patients and the clinical utility of those markers was assessed by evaluating the diagnostic and prognostic value of those biomarkers with the aim to facilitate detection of fCAD.
Finally, we see that the biomarkers analysed in this PhD project display a prognostic value for adverse cardiovascular outcomes, it remains a challenging task to find suitable biomarkers for the diagnosis of fCAD.