Dobutamine stress echocardiography in patients with moderate coronary artery disease detected by coronary computed tomography angiography could reduce the rate of unnecessary coronary angiography.

AIMS: To test the hypothesis that dobutamine stress echocardiography (DSE) reduces the rate of unnecessary invasive coronary angiography (CA) in patients with chronic stable coronary artery disease (CAD) and moderate to severe stenosis detected by coronary computed tomography angiography (CCTA). METHODS: This study included 49 consecutive, symptomatic CAD patients with coronary lesions greater than 50% detected by CCTA who underwent all DSE and a CA with pressure wire evaluation and FFR measurement. The DSE operators was aware of the CCTA results, but invasive physicians were blinded to DSE results. The primary endpoint was the negative predictive value of a CCTA followed by a DSE test for detecting significant coronary artery disease (CAD). This was defined by the presence of significant coronary lesions (>90% stenosis) or moderate coronary lesions (50-90%) with abnormal FFR value of less than 0.80 evaluated by invasive angiogram (CA). Secondary endpoints included major adverse cardiovascular events (MACEs). RESULTS: In patients with abnormal CCTA followed by CA, 33 patients (67.34%) had non-significant CAD lesions. In patients with both abnormal CCTA and DSE only 6 patients (12.24%) presented non-significant CAD. The negative predictive value of a CCTA followed by a DSE was significantly increased to 92.5%, when compared with CCTA alone. Thus DSE on top of abnormal CCTA could reduce unnecessary CA by 5.5 fold. During follow-up (mean 38.75 ± 12.25 months) 1 (2.1%) patient had a cardiac sudden death, 3 (6.12%) patients had an unplanned myocardial revascularization and 1 (2.1%) patient had a stroke, none of which occurred in patients with normal DSE. No patients experienced a myocardial infarction or needed un unplanned surgical revascularization. CONCLUSIONS: The addition of DSE in case of abnormal CCTA increases significantly the negative predictive value for detecting significant CAD in need for revascularisation and thus reduces markedly the number of unnecessary CA. This diagnostic strategy has a higher diagnostic accuracy and negative predictive value to the opposite approach where an abnormal CCTA mandates a CA without additional functional testing.

Mass Spectrometry for the Monitoring of Lipoprotein Oxidations by Myeloperoxidase in Cardiovascular Diseases.

Oxidative modifications of HDLs and LDLs by myeloperoxidase (MPO) are regularly mentioned in the context of atherosclerosis. The enzyme adsorbs on protein moieties and locally produces oxidizing agents to modify specific residues on apolipoproteins A-1 and B-100. Oxidation of lipoproteins by MPO (Mox) leads to dysfunctional Mox-HDLs associated with cholesterol-efflux deficiency, and Mox-LDLs that are no more recognized by the LDL receptor and become proinflammatory. Several modification sites on apoA-1 and B-100 that are specific to MPO activity are described in the literature, which seem relevant in patients with cardiovascular risk. The most appropriate analytical method to assess these modifications is based on liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). It enables the oxidized forms of apoA-1and apoB-100 to be quantified in serum, in parallel to a quantification of these apolipoproteins. Current standard methods to quantify apolipoproteins are based on immunoassays that are well standardized with good analytical performances despite the cost and the heterogeneity of the commercialized kits. Mass spectrometry can provide simultaneous measurements of quantity and quality of apolipoproteins, while being antibody-independent and directly detecting peptides carrying modifications for Mox-HDLs and Mox-LDLs. Therefore, mass spectrometry is a potential and reliable alternative for apolipoprotein quantitation.