Differences in plaque composition and distribution in stable coronary artery disease versus acute coronary syndromes; non‐invasive evaluation with multi‐slice computed tomography

Objectives: to determine the diagnostic performance of non-invasive FFR derived from standard acquired coronary computed tomography angiography (CTA) datasets (FFRCT) for the diagnosis of myocardial ischemia in patients with suspected stable coronary artery disease (CAD).Methods.Prospective study included 16 patients ((m/f – 13/3 mean age 47.8 ± 2.3 years) with CAD and coronary stenosis 40–75% lumen reduction. Coronary CTA was performed prior to ICA with invasive FFR measurement. FFRCT was calculated and interpreted in a blinded fashion by an independent Core Laboratory (HeartFlow, USA). Results were compared to invasively measured FFR, with ischemia defined as FFRCT or FFR ≤ 0.80.Results. The area under the receiver operating characteristic curve (95% CI) for FFCT was 0.90. Per-vessel sensitivity and specificity to identify myocardial ischemia were 91% and 89% for FFRCT.Conclusion.FFRCT provides high diagnostic accuracy, and discrimination for the diagnosis of hemodynamically significant CAD with invasive FFR as the reference standard.

Download Full-text

Abstract 1521: Platelet RNA Content is Increased in Patients with Acute Coronary Syndromes Compared to Patients with stable Coronary Artery Disease and Healthy Individuals

Circulation ◽

10.1161/circ.116.suppl_16.ii_315-b ◽

2007 ◽

Vol 116 (suppl_16) ◽

Author(s):

Erik L Grove ◽

Anne-Mette Hvas ◽

Steen D Kristensen

Keyword(s):

Coronary Artery Disease ◽

Coronary Artery ◽

Acute Coronary Syndromes ◽

Thrombus Formation ◽

Stable Coronary Artery Disease ◽

Healthy Individuals ◽

Coronary Thrombus ◽

Coronary Syndromes ◽

Immature Platelets ◽

Artery Disease

Background: Platelets newly released from the bone marrow are characterized by large cell volumes and, contrary to mature platelets, contain RNA, which might reflect an increased capacity of producing proaggregatory proteins. We hypothesized that the fraction of RNA-containing, immature platelets (Immature Platelet Fraction = IPF) is a marker for acute coronary thrombus formation. Methods: Flow cytometric determination of immature platelets was conducted using a RNA fluorescent dye and an automated analyzer (Sysmex XE-2100). Measurements were performed in a total of 426 individuals (365 patients with acute coronary syndromes (ACS), 39 patients with stable coronary artery disease (CAD) and 22 healthy individuals). Results: Geometric mean IPF was 2.5 (CV = 0.37) in the control group, 2.9 (0.43) in patients with stable CAD, 3.0 (0.55) in the non-STEMI/Unstable Angina group and 3.7 (0.56) in patients with STEMI. IPF was significantly increased in STEMI patients compared to all other groups (t-test for log-transformed data: p < 0.004), and the overall difference between groups was significant (ANOVA: p < 0.0001). IPF was increased in active smokers among patients with ACS (3.2 vs 3.6, p=0.02), whereas no relation with age, sex, body mass index or CRP levels was observed. Conclusion: The fraction of RNA-containing platelets is increased in ACS, especially in the acute phase of STEMI. Immature platelets with an increased haemostatic potential may contribute to coronary thrombus formation and may partly explain previous findings of temporary resistance to anti-platelet therapy.

Download Full-text