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ABSTRACT: A decision to perform coronary angioplasty on a constricted coronary artery should always be preceded by objective evidence of myocardial ischaemia in the flow region concerned. However, for patients with multi-vessel coronary disease it can be difficult to determine which of the several coronary stenoses present is responsible for the anginal complaints. Recently, special miniaturized sensor-equipped guide wires are introduced in the cardiac catheterisation laboratory. Therefore it is now possible to selectively evaluate coronary stenoses by means of haemodynamic parameters: fractional flow reserve (FFR, based on intracoronary derived pressure measurements) and coronary flow velocity reserve (CFVR, based on intracoronary derived Doppler flow velocity measurements). The diagnosis of coronary artery disease in the cardiac catheterisation laboratory has improved considerably due to the use of these intracoronary derived haemodynamic parameters. Several clinical studies have shown that it is safe to defer a coronary angioplasty based on an FFR > or = 0.75 or a CFVR > or = 2.0. In the case of an abnormal FFR or CFVR result, the appropriate treatment strategy can be implemented. Furthermore, these parameters can be used to evaluate the result of the therapy.
Nederlands tijdschrift voor geneeskunde 09/2001; 145(37):1782-8.
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ABSTRACT: This study was performed to evaluate the relationship between plaque inflammation of the initial culprit lesion and the incidence of recurrent angina for one year after directional coronary atherectomy (DCA).
A positive correlation between coronary plaque inflammation and angiographic restenosis has been reported.
A total of 110 patients underwent DCA. Cryostat sections were immunohistochemically stained with monoclonal antibodies CD68 (macrophages), CD-3 (T lymphocytes) and alpha-actin (smooth muscle cells [SMCs]). The SMC and macrophage contents were planimetrically quantified as a percentage of the total tissue area. T lymphocytes were counted as the number of cells/mm2. The patients were followed for one year to document recurrent unstable angina pectoris (UAP) or stable angina pectoris (SAP).
Recurrent UAP developed in 16 patients, whereas recurrent SAP developed in 17 patients. The percent macrophage areas were larger in patients with recurrent UAP (27 +/- 12%) than in patients with recurrent SAP (8 +/- 4%; p = 0.0001) and those without recurrent angina (18 +/- 14%; p = 0.03). The number of T lymphocytes was also greater in patients with recurrent UAP (25 +/- 14 cells/mm2) than in patients with recurrent SAP (14 +/- 8 cells/mm2; p = 0.02) and those without recurrent angina (14 +/- 12 cells/mm2; p = 0.002). Multiple stepwise logistic regression analysis identified macrophage areas and T lymphocytes as independent predictors for recurrent UAP.
There is a positive association between the extent of initial coronary plaque inflammation and the recurrence of unstable angina during long-term follow-up after DCA. These results underline the role of ongoing smoldering plaque inflammation in the recurrence of unstable angina after coronary interventions.
Journal of the American College of Cardiology 05/2001; 37(5):1271-6. · 14.16 Impact Factor
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S A Chamuleau,
M Meuwissen,
B L van Eck-Smit,
K T Koch,
A de Jong,
R J de Winter,
C E Schotborgh,
M Bax,
H J Verberne,
J G Tijssen,
J J Piek
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ABSTRACT: We sought to perform a direct comparison between perfusion scintigraphic results and intracoronary-derived hemodynamic variables (fractional flow reserve [FFR]; absolute and relative coronary flow velocity reserve [CFVR and rCFVR, respectively]) in patients with two-vessel disease.
There is limited information on the diagnostic accuracy of intracoronary-derived variables (CFVR, FFR and rCFVR) in patients with multivessel disease.
Dipyridamole technetium-99m sestamibi (MIBI) single-photon emission computed tomography (SPECT) was performed in 127 patients. The presence of reversible perfusion defects in the region of interest was determined. Within one week, angiography was performed; CFVR, rCFVR and FFR were determined in 161 coronary lesions after intracoronary administration of adenosine. The predictive value for the presence of reversible perfusion defects on MIBI SPECT of CFVR, rCFVR and FFR was evaluated by the area under the curve (AUC) of the receiver operating characteristics curves.
The mean percentage diameter stenosis was 57% (range 35% to 85%), as measured by quantitative coronary angiography. Using per-patient analysis, the AUCs for CFVR (0.70 +/- 0.052), rCFVR (0.72 +/- 0.051) and FFR (0.76 +/- 0.050) were not significantly different (p = NS). The percentages of agreement with the results of MIBI SPECT were 76%, 78% and 77% for CFVR, rCFVR and FFR, respectively. Per-lesion analysis, using all 161 measured lesions, yielded similar results.
The diagnostic accuracy of three intracoronary-derived hemodynamic variables, as compared with the results of perfusion scintigraphy, is similar in patients with two-vessel coronary artery disease. Cut-offvalues of 2.0 for CFVR, 0.65 for rCFVR and 0.75 for FFR can be used for clinical decision-making in this patient cohort. Discordant results were obtained in 23% of the cases that require prospective evaluation for appropriate patient management.
Journal of the American College of Cardiology 05/2001; 37(5):1316-22. · 14.16 Impact Factor
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ABSTRACT: Fractional flow reserve (FFR) and coronary blood flow velocity reserve (CFR) represent physiological quantities used to evaluate coronary lesion severity and to make clinical decisions. A comparison between the outcomes of both diagnostic techniques has not been performed in a large cohort of patients with intermediate coronary lesions.
FFR and CFR were assessed in 126 consecutive patients with 150 intermediate coronary lesions (between 40% and 70% diameter stenosis by visual assessment). Agreement between outcomes of FFR and CFR, categorized at cut-off values of 0.75 and 2.0, respectively, was observed in 109 coronary lesions (73%), whereas discordant outcomes were present in 41 lesions (27%). In 26 of these 41 lesions, FFR was <0.75 and CFR>or=2.0 (group A); in the remaining 15 lesions, FFR was >or=0.75 and CFR<2.0 (group B). Minimum microvascular resistance, defined as the ratio of mean distal pressure to average peak blood flow velocity during maximum hyperemia, showed a large variability (overall range, 0.65 to 4.64 mm Hg x cm(-1) x s(-1)) and was significantly higher in group B than in group A (2.42+/-0.77 versus 1.91+/-0.70 mm Hg x cm(-1) x s(-1); P:=0.034).
Our findings demonstrate the prominent role of microvascular resistance in modulating the relationship between FFR and CFR and emphasize the importance of combined pressure and flow velocity measurements to evaluate coronary lesion severity and microvascular involvement.
Circulation 01/2001; 103(2):184-7. · 14.74 Impact Factor
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ABSTRACT: To evaluate immunohistochemically various parameters of inflammation in coronary atherectomy specimens obtained from restenotic culprit lesions of patients presenting with either stable or unstable angina (UA).
There is no information regarding the relationship between atherosclerotic plaque inflammation and the severity of the coronary syndromes in patients with restenotic coronary lesions.
A total of 37 patients with either stable angina or UA underwent directional coronary atherectomy for restenotic coronary lesions. Cryostat sections of atherectomy specimen were immunohistochemically stained with monoclonal antibodies CD68 (macrophages [MACs]), CD3 (T-lymphocytes) and alpha-actin (smooth muscle cells [SMCs]). Smooth muscle cell contents and MAC contents were planimetrically quantified as the percentage immunopositive tissue area of the total tissue area. T-lymphocytes were counted at 100-X magnification throughout the entire section and expressed as number of cells per mm2.
Restenotic coronary lesions of patients with UA or stable angina showed no significant difference in SMC areas (31.9%+/-16.3% vs. 38.5%+/-18.8%, respectively; p = NS). However, restenotic coronary lesions of patients presenting with unstable angina contained significantly more MACs (24.4%+/-15.1% vs. 10.5%+/-5.8%, p = 0.001) and T-lymphocytes (18.8 cells/mm2+/-15.1 cells/mm2 vs. 8.6 cells/mm2+/-9.8 cells/mm2; p = 0.034) than patients with stable angina.
These results suggested that inflammation appears to affect plaque instability in restenotic coronary lesions resulting in unstable coronary syndromes.
Journal of the American College of Cardiology 04/2000; 35(4):963-7. · 14.16 Impact Factor
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ABSTRACT: In patients with acute myocardial infarction (AMI) receiving thrombolytic therapy and i.v. unfractionated heparin, anticoagulant levels are frequently outside the target range. We evaluated the effects on anticoagulant levels before (group A) and after (group B) the introduction of a heparin nomogram in consecutive AMI-patients, receiving thrombolytic therapy and adjunctive heparin treatment. The target activated partial thromboplastin time (aPTT) was defined as 60-90 s. During the first 72 h after admission, the total number of aPTTs within the target range and the time taken to achieve the range were compared. The incidence of bleeding complications was assessed. Group A consisted of 56 and group B of 55 patients. The number of patients within the target range at 72 h (44 versus 51; chi2=4.51; P=0.034) was significantly higher in group B. No difference was found between total aPTTs within the target range (26% in group A versus 30% in group B; P=ns). Bleeding complications were slightly less in group B (7 versus in group A versus 2 patients in group B; P=ns). We concluded that the introduction of a nomogram resulted in significantly more patients with aPTTs within the target range. However, a substantial number of aPTTs before and after introduction of the nomogram were outside the target range. Moreover, this retrospective study shows that previously acquired prospective data (which showed a marked improvement of anticoagulation using a heparin nomogram) are not necessarily reproduced in the real life clinical setting.
International Journal of Cardiology 01/1999; 67(3):241-6. · 7.08 Impact Factor
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ABSTRACT: To investigate the feasibility of fixed dose, weight adjusted subcutaneous low molecular weight heparin (LMWH), with monitoring of anti-Xa levels and assessment of coronary patency rates after three to five days, thereby giving an initial indication of its safety and efficacy.
In 30 patients with acute myocardial infarction, LMWH (nadroparine) was given as a body weight adjusted intravenous bolus with thrombolysis (rt-PA infusion) and in weight adjusted subcutaneous doses at six hours, and every 12 hours thereafter for 72 hours. The target range was defined prospectively as 0.35-0.70 anti-factor Xa activity (aXa) units. The aXa level was measured every six hours. Coronary angiography was performed in all patients within five days after the start of thrombolytic treatment to determine patency (TIMI 2 and 3 flow) of the infarct related artery.
The mean (SEM) aXa level over 72 hours was 0.52 (0.08) U/ml; from 12 hours onwards 88% of all aXa measurements were within the target range. At angiography, a patent infarct related artery was present in 24 of the 30 patients. No major bleeding complications occurred, though minor bleeding complications were observed in two patients.
This small study indicates that LMWH is feasible as an adjunct to thrombolysis in patients with acute myocardial infarction. The aXa levels were within the target range and patency rates at three to five days were around 80%, with no major bleeding complications.
Heart (British Cardiac Society) 08/1998; 80(1):35-9. · 4.22 Impact Factor
