Biomarker assisted improvement in the assessment of coronary artery disease with special attention to high-sensitivity troponin T

Description

Introduction
Coronary artery disease (CAD) is a major global cause of morbidity and mortality. Many patients with CAD are asymptomatic and could if identified benefit from prophylactic measures. The acute manifestation of CAD is acute coronary syndrome (ACS) where a timely diagnosis is important and patients with ACS often present with chest pain.

Aims
The aims of this thesis were 1) to evaluate the capability of different biomarker strategies to rule out non-ST elevation ACS (NSTE-ACS) in chest pain patients. 2) To investigate if dynamic high-sensitivity troponin T (hsTnT) elevations in patients with acute atrial fibrillation/flutter (AF/AFL) and rapid ventricular response (RVR) indicates need for further investigation of significant CAD.

Methods
The biomarker strategies were tested in a prospective observational study with consecutive chest pain patients (Paper I-II). Dynamic hsTnT elevations in AF/AFL patients were studied in two different cohorts. 1) AF/AFL patients with RVR and hsTnT data were retrospectively included and follow-up data were retrieved from registers (Paper III). 2) AF/AFL patients with RVR were prospectively included and performed a bicycle exercise stress test within a 30 day follow-up period (Paper IV).

Results
Paper I-II: Both undetectable hsTnT and the combination of copeptin and hsTnT ruled out NSTE-ACS with higher sensitivity compared to a single hsTnT test with the 99th percentile as cut-off or serial hsTnT testing. Paper III: AF/AFL patients with dynamic hsTnT elevations did not have any major increased risk of acute CAD related events or death during follow-up, but they had increased all-cause mortality. Paper IV: AF/AFL patients with elevated hsTnT did not have an increased incidence of pathological stress test compared to patients with hsTnT below the 99th percentile.

Conclusion
A single undetectable hsTnT test at presentation is an excellent diagnostic and prognostic tool in patients with chest pain, but alone not sufficient to rule out all NSTE-ACS. HsTnT elevations in AF/AFL patients with RVR are associated with an increased all-cause mortality but our results suggest that further investigation for possible significant CAD with stress tests may not be worthwhile.

Period	2013 Dec 1 → 2019 May 17
Examinee/Supervised person	Johan Thelin
Examination/Supervision held at	Cardiovascular Research - Hypertension
Degree of Recognition	International