Jan-Willem Sels

Fractional Flow Reserve for the Assessment of Nonculprit Coronary Artery Stenoses in Patients With Acute Myocardial Infarction

OBJECTIVES We investigated the reliability of fractional flow reserve (FFR) of nonculprit coronary stenoses during percutaneous coronary intervention (PCI) in acute myocardial infarction. BACKGROUND Assessing the hemodynamic severity of the nonculprit coronary artery stenoses at the acute phase of a myocardial infarction could improve risk stratification and shorten the diagnostic work-up. METHODS One hundred one patients undergoing PCI for an acute myocardial infarction (n = 75 with ST-segment elevation myocardial infarction [STEMI], and n = 26 with non-ST-segment elevation myocardial infarction) were prospectively recruited. The FFR measurements in 112 nonculprit stenoses were obtained immediately after PCI of the culprit stenosis and were repeated 35 ± 4 days later. In addition, left ventricular ejection fraction, quantitative coronary angiographic measurements of the nonculprit stenoses, Thrombolysis In Myocardial Infarction (TIMI) flow, corrected TIMI frame count (cTFC), and the index of microcirculatory resistance (n = 14) of the nonculprit vessels were assessed in the acute phase and at control angiogram. RESULTS The FFR value of the nonculprit stenoses did not change between the acute and follow-up (0.77 ± 0.13 vs. 0.77 ± 0.13, respectively, p = NS). In only 2 patients, the FFR value was higher than 0.8 at the acute phase and lower than 0.75 at follow-up. The TIMI flow, cTFC, percentage diameter stenosis, minimum lumen diameter, and index of microcirculatory resistance did not change. Left ventricular ejection fraction increased significantly in patients with STEMI (from 54 ± 13% to 57 ± 13%, p = 0.03). CONCLUSIONS During the acute phase of acute coronary syndromes, the severity of nonculprit coronary artery stenoses can reliably be assessed by FFR. This allows a decision about the need for additional revascularization and might contribute to a better risk stratification.

Fractional flow reserve in unstable angina and non-ST-segment elevation myocardial infarction experience from the FAME (Fractional flow reserve versus Angiography for Multivessel Evaluation) study.

OBJECTIVES The aim of this study was to study whether there is a difference in benefit of fractional flow reserve (FFR) guidance for percutaneous coronary intervention (PCI) in multivessel coronary disease in patients with unstable angina (UA) or non-ST-segment elevation myocardial infarction (NSTEMI), compared with stable angina (SA). BACKGROUND The use of FFR to guide PCI has been well established for patients with SA. Its use in patients with UA or NSTEMI has not been investigated prospectively. METHODS In the FAME (Fractional flow reserve versus Angiography for Multivessel Evaluation) study 1,005 patients with multivessel disease amenable to PCI were included and randomized to either angiography-guided PCI of all lesions ≥50% or FFR-guided PCI of lesions with an FFR ≤0.80. Patients admitted for UA or NSTEMI with positive troponin but total creatine kinase <1,000 U/l were eligible for inclusion. We determined 2-year major adverse cardiac event rates of these patients and compared it with stable patients. RESULTS Of 1,005 patients, 328 had UA or NSTEMI. There was no evidence for heterogeneity among the subgroups for any of the outcome variables (all p values >0.05). Using FFR to guide PCI resulted in similar risk reductions of major adverse cardiac events and its components in patients with UA or NSTEMI, compared with patients with SA (absolute risk reduction of 5.1% vs. 3.7%, respectively, p = 0.92). In patients with UA or NSTEMI, the number of stents was reduced without increase in hospital stay or procedure time and with less contrast use, in similarity to stable patients. CONCLUSIONS The benefit of using FFR to guide PCI in multivessel disease does not differ between patients with UA or NSTEMI, compared with patients with SA.

Deep Proteome Profiling of Circulating Granulocytes Reveals Bactericidal/Permeability-Increasing Protein as a Biomarker for Severe Atherosclerotic Coronary Stenosis

Coronary atherosclerosis represents the major cause of death in Western societies. As atherosclerosis typically progresses over years without giving rise to clinical symptoms, biomarkers are urgently needed to identify patients at risk. Over the past decade, evidence has accumulated suggesting cross-talk between the diseased vasculature and cells of the innate immune system. We therefore employed proteomics to search for biomarkers associated with severe atherosclerotic coronary lumen stenosis in circulating leukocytes. In a two-phase approach, we first performed in-depth quantitative profiling of the granulocyte proteome on a small pooled cohort of patients suffering from chronic (sub)total coronary occlusion and matched control patients using stable isotope peptide labeling, two-dimensional LC-MS/MS and data-dependent decision tree fragmentation. Over 3000 proteins were quantified, among which 57 candidate biomarker proteins remained after stringent filtering. The most promising biomarker candidates were subsequently verified in the individual samples of the discovery cohort using label-free, single-run LC-MS/MS analysis, as well as in an independent verification cohort of 25 patients with total coronary occlusion (CTO) and 19 matched controls. Our data reveal bactericidal/permeability-increasing protein (BPI) as a promising biomarker for severe atherosclerotic coronary stenosis, being down-regulated in circulating granulocytes of CTO patients.

Fractional flow reserve is not associated with inflammatory markers in patients with stable coronary artery disease

Background Atherosclerosis is an inflammatory condition and increased blood levels of inflammatory biomarkers have been observed in acute coronary syndromes. In addition, high expression of inflammatory markers is associated with worse prognosis of coronary artery disease. The presence and extent of inducible ischemia in patients with stable angina has previously been shown to have strong prognostic value. We hypothesized that evidence of inducible myocardial ischemia by local lesions, as measured by fractional flow reserve (FFR), is associated with increased levels of blood based inflammatory biomarkers. Methods Whole blood samples of 89 patients with stable angina pectoris and 16 healthy controls were analyzed. The patients with stable angina pectoris underwent coronary angiography and FFR of all coronary lesions. We analyzed plasma levels of cytokines IL-6, IL-8 and TNF-α and membrane expression of Toll-like receptor 2 and 4, CD11b, CD62L and CD14 on monocytes and granulocytes as markers of inflammation. Furthermore, we quantified the severity of hemodynamically significant coronary artery disease by calculating Functional Syntax Score (FSS), an extension of the Syntax Score. Results For the majority of biomarkers, we observed lower levels in the healthy control group compared with patients with stable angina who underwent coronary catheterization. We found no difference for any of the selected biomarkers between patients with a positive FFR (≤0.75) and negative FFR (>0.80). We observed no relationship between the investigated biomarkers and FSS. Conclusion The presence of local atherosclerotic lesions that result in inducible myocardial ischemia as measured by FFR in patients with stable coronary artery disease is not associated with increased plasma levels of IL-6, IL-8 and TNF-α or increased expression of TLR2 and TLR4, CD11b, CD62L and CD14 on circulating leukocytes.

Temporal changes of soluble ST2 after cardiovascular interventions

Soluble ST2 (sST2), a member of the IL‐1 receptor family, has been proposed as a novel biomarker with predictive value for heart failure and mortality in patients suffering from cardiovascular diseases. The influence of clinical characteristics on variability of sST2 levels is relatively unexplored. Here, we studied the effect of cardiovascular interventions and clinical characteristics on plasma sST2 expression levels.

Increased cytokine response after toll-like receptor stimulation in patients with stable coronary artery disease

OBJECTIVE Atherosclerosis is associated with increased levels of plasma cytokines and expression of Toll-like receptors (TLRs). Yet, little is known about the potential use of TLR ligand induced cytokine release as a biomarker of coronary artery disease (CAD). In this study, we investigated whether TLR ligand induced cytokine release is associated with atherosclerotic disease severity and its predictive value for future cardiovascular events. METHODS Blood samples were obtained from 260 patients with stable angina and 15 healthy controls. Cytokine levels of TNFα, IL-8 and IL-6 were measured after 2 h of whole blood stimulation with 10 ng/ml lipopolysaccharide (LPS, TLR4 ligand) and P3C 500 ng/ml (TLR2 ligand). In a subgroup, dose-response curves were created using additional LPS concentrations. RESULTS LPS induced whole blood release of TNFα and IL-6, but not IL-8, was significantly higher in patients compared to healthy controls. Among CAD patients, TLR responses did hardly differ when associated with the presence of traditional risk factors and atherosclerotic disease severity (number of diseased vessels and coronary stenosis degree). Patients with secondary events during follow-up showed a trend towards an increased TLR response. Furthermore, positive associations were found between CRP levels and TLR-induced TNFα (CRP<2: 2055 pg/ml; CRP>2: 2364 pg/ml) and IL-6 production (CRP<2: 1742 pg/ml; CRP>2: 2250 pg/ml). CONCLUSION In conclusion, TLR-induced whole blood cytokine release in patients with stable angina indicates the presence of coronary atherosclerosis but does not reflect its severity.

The relationship between fractional flow reserve, platelet reactivity and platelet leukocyte complexes in stable coronary artery disease.

Background The presence of stenoses that significantly impair blood flow and cause myocardial ischemia negatively affects prognosis of patients with stable coronary artery disease. Altered platelet reactivity has been associated with impaired prognosis of stable coronary artery disease. Platelets are activated and form complexes with leukocytes in response to microshear gradients caused by friction forces on the arterial wall or flow separation. We hypothesized that the presence of significantly flow-limiting stenoses is associated with altered platelet reactivity and formation of platelet-leukocyte complexes. Methods One hundred patients with stable angina were studied. Hemodynamic significance of all coronary stenoses was assessed with Fractional Flow Reserve (FFR). Patients were classified FFR-positive (at least one lesion with FFR≤0.75) or FFR-negative (all lesions FFR>0.80). Whole blood samples were stimulated with increasing concentrations of ADP, TRAP, CRP and Iloprost with substimulatory ADP. Expression of P-selectin as platelet activation marker and platelet–leukocyte complexes were measured by flowcytometry. Patients were stratified on clopidogrel use. FFR positive and negative patient groups were compared on platelet reactivity and platelet-leukocyte complexes. Results Platelet reactivity between FFR-positive patients and FFR-negative patients did not differ. A significantly lower percentage of circulating platelet-neutrophil complexes in FFR-positive patients and a similar non-significant decrease in percentage of circulating platelet-monocyte complexes in FFR-positive patients was observed. Conclusion The presence of hemodynamically significant coronary stenoses does not alter platelet reactivity but is associated with reduced platelet-neutrophil complexes in peripheral blood of patients with stable coronary artery disease.

Inducible cardiac ischaemia is related to a decrease in the whole-blood Toll-like receptor 2 and 4 response

TLR (Toll-like receptor) activation-induced inflammatory responses are important in the progression of atherosclerosis. We previously showed that TLR-dependent leucocyte responsiveness is acutely attenuated following percutaneous coronary intervention or vascular surgery. Furthermore, cytokine release following whole-blood TLR-2 and TLR-4 stimulation is negatively correlated with fractional flow reserve, suggesting that chronic ischaemia can elicit an enhanced inflammatory response. In the present study, we assessed the association between leucocyte TLR-2 and TLR-4 responsiveness and pre-existent and inducible ischaemia in patients undergoing SPECT (single-photon emission computed tomography)-MPI (myocardial perfusion imaging). TLR-2, TLR-4 and CD11b expression on monocytes were measured in blood samples that were obtained from 100 patients with suspected coronary artery disease before and after myocardial stress testing for SPECT-MPI. IL-8 (interleukin-8) levels were determined after whole-blood stimulation with Pam3Cys (TLR-2) and LPS (lipopolysaccharide; TLR-4). On the basis of SPECT-MPI, patients were categorized into three groups: reversible defect, irreversible defect and no defect. Myocardial stress induced a reduction in TLR-4 expression (2.46±0.21 compared with 2.17±0.16 arbitrary units, P=0.001) and CD11b expression (83.2±1.73 compared with 76.0±1.89 arbitrary units, P<0.001). TLR-induced IL-8 production before myocardial stress induction was not associated with the results of SPECT-MPI. However, a significant decrease in IL-8 production following TLR stimulation was observed after stress, which was more pronounced in patients with a reversible defect. In conclusion, inducible ischaemia is associated with a decrease in whole-blood TLR-2 and TLR-4 response. These results point to a regulating role of TLRs in order to prevent excessive inflammatory events known to occur during acute ischaemia.

Toll-Like Receptor Induced CD11b and L-Selectin Response in Patients with Coronary Artery Disease

Toll-Like Receptor (TLR) -2 and -4 expression and TLR-induced cytokine response of inflammatory cells are related to atherogenesis and atherosclerotic plaque progression. We examined whether immediate TLR induced changes in CD11b and L-selectin (CD62L) expression are able to discriminate the presence and severity of atherosclerotic disease by exploring single dose whole blood TLR stimulation and detailed dose-response curves. Blood samples were obtained from 125 coronary artery disease (CAD) patients and 28 controls. CD11b and L-selectin expression on CD14+ monocytes was measured after whole blood stimulation with multiple concentrations of the TLR4 ligand LPS (0.01–10 ng/ml) and the TLR2 ligand P3C (0.5–500 ng/ml). Subsequently, dose-response curves were created and the following parameters were calculated: hillslope, EC50, area under the curve (AUC) and delta. These parameters provide information about the maximum response following activation, as well as the minimum trigger required to induce activation and the intensity of the response. CAD patients showed a significantly higher L-selectin, but not CD11b response to TLR ligation than controls after single dose stimulations as well as significant differences in the hillslope and EC50 of the dose-response curves. Within the CAD patient group, dose-response curves of L-selectin showed significant differences in the presence of hypertension, dyslipidemia, coronary occlusion and degree of stenosis, whereas CD11b expression had the strongest discriminating power after single dose stimulation. In conclusion, single dose stimulations and dose-response curves of CD11b and L-selectin expression after TLR stimulation provide diverse but limited information about atherosclerotic disease severity in stable angina patients. However, both single dose stimulation and dose-response curves of LPS-induced L-selectin expression can discriminate between controls and CAD patients.