- Email: [email protected]
Pressure-wire guided balloon angioplasty in allograft coronary vasculopathy
CASE REPORT
Pressure-Wire Guided Balloon Angioplasty in Allograft Coronary Vasculopathy Gianni Casella, MD, Johannes Rieber, MD, Harald Mudra, MD, Volker Klauss, MD We report a case of successful percutaneous transluminal coronary angioplasty guided from pressure-wire measurements in a transplanted patient. Fractional flow reserve, a lesion-specific, pressure-independent index of functional stenosis severity, was used to guide the intervention. J Heart Lung Transplant 1999;18:1143–1146.
C
ardiac allograft vasculopathy (CAV) mainly consists of diffuse, concentric intimal proliferation, but focal lesions are also observed.1 To decrease ischemia-related morbidity and mortality, palliative coronary revascularizations of these lesions is currently performed.2 However, the high incidence of procedural complications and the high long-term restenosis rate suggests careful patient selection with limitation of revascularization to significant stenosis with a high likelihood of procedural success.2 Among the several invasive approaches proposed to assess the physiological significance of epicardial coronary stenosis, pressure-derived fractional flow reserve (FFR)3–5 seems promising. Fractional flow reserve is a lesion-specific, pressureindependent index of functional stenosis severity that can be obtained during catheterization by means of steerable, sensor-tipped angioplasty guide wires. Fractional flow reserve relates maximum myocarFrom the Department of Medicine, Division of Cardiology, Klinikum Innenstadt, Ludwig-Maximilians University, Munich, Germany Submitted December 22, 1998; accepted August 4, 1999. Reprint requests: Volker Klauss, MD, Medizinische Klinik, Klinikum Innenstadt, Ludwig-Maximilians University, Ziemssenstrasse, 1 D-80336 Munich Germany; telephone, 49-8951602177; fax, 49-89-51602152; e-mail, klauss@medinn. med.uni-muenchen.de. Copyright © 1999 by the International Society for Heart and Lung Transplantation. 1053-2498/99/$–see front matter PII S1053-2498(99)00074-1
dial blood flow in the presence of an epicardial stenosis to the theoretic maximum hyperemic flow in the same artery without stenosis. Thus, FFR represents that fraction of normal maximum flow that is still achievable despite the presence of an epicardial coronary lesion.3,4 Fractional flow reserve has a very high diagnostic accuracy for stenosis responsible for reversible ischemia3–5 as well as a promising rationale for the assessment of the success of interventions.6 Recently, it has been shown that restenosis and cardiac events were low in patients with both good morphologic and functional success after percutaneous transluminal coronary angioplasty (PTCA), as defined by angiographic and FFR criteria.7 Therefore, we used FFR to guide the following intervention in a patient with focal CAV, attempting to avoid stent implantation because of inadequate vessel diameter. A 59-year-old man, who underwent orthotopic heart transplantation in 1987, was referred to our institution in February 1998 for yearly, routine angiographic and intravascular ultrasound evaluation. His medical history revealed non-insulin dependent diabetes mellitus, arterial hypertension, and significant renal insufficiency. The baseline catheterization showed normal right and left chamber pressures. The left ventricle ejection fraction was 54%. The coronary angiogram showed a longitudinal narrowing of the left anterior descending artery and of the right coronary artery along with a tight stenosis of the first diagonal branch (75% to 1143
1144
Casella et al.
The Journal of Heart and Lung Transplantation November 1999
FIGURE 1 Coronary angiograms (left anterior oblique projection) showing (1) the pre-
intervention stenosis of the first diagonal branch of the left anterior descending artery (top left panel, small arrows), and the final result after pressure-guided balloon angioplasty (bottom left panel); and (2) the simultaneous pressure recordings of distal coronary pressure (Pd) and aortic pressure (Pa) before intervention. At baseline (top right panel), after injection of an intracoronary bolus of 18 g adenosine, fractional flow reserve (FFR) is calculated by the Pd/Pa ratio (78/128), which equals 0.61. This value is well below the cutoff point of 0.75 for reversible ischemia; therefore, it indicates a functionally significant stenosis. After percutaneous transluminal coronary angioplasty (PTCA) (bottom right panel), a significant decrease of the pre-intervention gradient is observed. After adenosine, FFR myo is calculated as 131/143 ⫽ 0.91. Thus, FFR returned to the normal range.
90% diameter stenosis by visual estimate) and of a small first marginal branch (Figure 1, top left panel). Angiographically these findings were representative of diffuse CAV associated with focal lesions. The intravascular ultrasound imaging of the left anterior descending and of the circumflex artery confirmed a diffuse allograft vasculopathy. Although the stenosis of the first diagonal branch could be already judged suitable for revascularization on an anatomical basis, decision for PTCA was additionally based on physiologic parameters, because stress echocardiography was insufficient due to poor image quality. Furthermore, we were concerned with the small caliber of the vessel (2.5 mm), not optimal for stenting, and with the high restenosis rate of transplanted patients. Therefore, we decided to confirm the functional significance of the stenosis by pressure measurements and then to guide the intervention by use of the pressure wire to reduce the risk of restenosis. Therefore, 2 weeks later an 8F Judkins leftguiding catheter without side-holes was engaged in the left coronary ostium. Intracoronary nitroglycerin and 10,000 U of heparin were administered accord-
ing to standard practice. Instead of a regular angioplasty guide wire, a 0.014-inch high-fidelity pressuremonitoring wire (PressureWire™, Radi Medical Systems, Uppsala, Sweden) that allowed measurement of Pd (mean distal coronary pressure) was used. After calibration, this wire was introduced into the guiding catheter and advanced to its tip. At that point, equality of pressures registered by the guiding catheter and the wire was verified. The wire was then advanced into the coronary artery and positioned across the stenosis, in the first diagonal branch, without difficulty. Mean arterial and mean post-stenotic coronary pressure were measured. After the pressures had stabilized, maximum coronary hyperemia was obtained with an intracoronary bolus of 18 g adenosine. From simultaneous recording of aortic pressure (Pa) and Pd at steady maximum hyperemia, FFR before PTCA was calculated. The value obtained was 0.61, thus suggestive of a functionally significant lesion (Figure 1, top right panel). Afterward, the PTCA was performed with a 2.5 mm balloon (Passage™, Cordis Corp., Miami FL, USA) and a single inflation with 6 atmospheres for 120 seconds. A satisfactory angiographic result was im-
The Journal of Heart and Lung Transplantation Volume 18, Number 11
mediately obtained (Figure 1, bottom left panel), and FFR was again determined, indicating an optimal physiological result of 0.91 (Figure 1, bottom right panel). The subsequent clinical course was uneventful, and the following day the patient could be discharged from the hospital on aspirin, as usual. However, 4 months later, the patient underwent a new angiogram for shortness of breath. No angiographic evidence of restenosis of the lesion treated was detected, but there was a severe, diffuse progression of the disease of the left anterior descending and of the circumflex arteries. Thus, due to the diffuse disease, no further intervention was performed. Accelerated CAV represents the most important cause of morbidity and mortality in cardiac transplant recipients beyond the first year after transplantation. Allograft arteriopathy consists mainly of diffuse arterial narrowings and, less frequently, of discrete focal stenoses, as confirmed by intravascular ultrasound.1 However, coronary artery revascularization in heart transplant recipients, utilizing PTCA, stenting, or bypass surgery, have been performed in selected patients as palliative therapy to decrease ischemia-related morbidity and mortality.2 In selected transplanted patients the immediate success rate of PTCA is comparable to that of routine angioplasty, but the incidence of complications as well as the long-term restenosis rate is higher.2 In particular, most of the studies report a restenosis rate of up to 62%.2 Therefore, the availability of an handleable tool, which could help with the revascularization decision and with conducting interventions, is urged from interventional cardiologists treating CAV. Recently, the development of maneuverable Doppler-tipped and pressure-monitoring guide wires has revived the interest in invasive evaluation of the physiological significance of epicardial coronary stenosis as a complement to coronary angiography. These methods, mainly coronary flow reserve8 and pressurederived fractional flow reserve,3 have demonstrated a strong relation not only with the presence of significant coronary lesions3,4 but also with the results of interventions.8,9 In fact, despite a successful angiographic appearance, standard PTCA may not achieve a satisfactory physiologic result. Combined intracoronary ultrasound (ICUS) imaging and flowvelocity studies6 –9 demonstrated that increases in coronary vasodilatory reserve after PTCA or stenting are often related to residual lumen area .6,10 Furthermore, in the DEBATE Trial (Doppler Endpoints Balloon Angioplasty Trial Europe)11 the
Casella et al.
1145
combination of optimal angiographic results (residual stenosis ⱕ35%) and high coronary flow reserve (CFR ⬎2.5) allowed the identification of a subgroup of patients with favorable outcome without stenting. Fractional flow reserve3 is a lesion-specific, pressure-independent index relating maximum myocardial blood flow in the presence of an epicardial stenosis to normal maximum flow. In another way, FFR represents that fraction of normal maximum flow that remains despite the presence of an epicardial lesion. Theoretically, FFR should be 1.0 for normal coronary arteries along which no significant decrease of pressure occurs. Contrary to absolute coronary flow reserve, FFR is independent of changes in systemic blood pressure and heart rate, and is not affected by conditions known to increase baseline myocardial blood flow.5 In addition, FFR takes into account collateral blood flow to the dependent myocardium. Several studies, mainly from the group of de Bruyne3–5 have demonstrated that a FFR value below 0.75 reliably indicates a significant stenosis, associated with inducible ischemia. In patients with coronary artery disease, the diagnostic accuracy of FFR for this purpose is 93% and exceeds the diagnostic accuracy of thallium exercise testing and dobutamine stress echocardiography when performed as single tests.3 In addition, strictly speaking microvascular disease as CAV may influence FFR to some degree, because in such cases epicardial blood flow may not be as high as it could be without the microvascular disease and FFR might be overestimated.4,8 Furthermore, FFR measurements have not been validated in patients with microvascular disease. From a practical viewpoint, however, coronary pressure measurements indicate to what extent the epicardial lesion contributes to the ischemia and to what extent myocardial perfusion will be improved by intervention. Thus, we decided to apply FFR to assess the lesion and to guide the following intervention. In patients with optimal angiographic, Bech et al.,7 recently reported a post-angioplasty FFR ⬎0.90; event-free survival rates at 6, 12, and 24 months follow-up of 92%, 92%, and 88%, respectively, compared with 72%, 69%, and 59% in patients with a similar angiographic result but an FFR ⬍0.90. Furthermore, FFR is effective also when used to assess the results of stenting. Hanekamp et al.6 evaluated 30 patients with angiographically successful stent implantation with ICUS and FFR. The study demonstrated that after optimal stent deployment by ICUS, the FFR returns to the normal range. Thus, if FFR is not completely normalized
1146
Casella et al.
after stent implantation, stent deployment has been inadequate even if the angiogram is apparently normal. Therefore, there is a complementary value of FFR and angiography in evaluating angioplasty results. In summary, we report a case of successful PTCA guided by intracoronary pressure measurements in a transplant recipient. Fractional flow reserve is a highly lesion-specific, pressure-independent index of functional stenosis severity. Moreover FFR can be easily obtained just before and during PTCA by using a pressure guide wire as primary guide wire. Fractional flow reserve can facilitate the clinical decision-making with respect to the appropriateness of PTCA, as well as the assessment of the results of interventions or the real need of stenting in the challenging setting of CAV.
REFERENCES 1. Klauss V, Mudra H, Uberfuhr P, Theisen K. Intraindividual variability of cardiac allograft vasculopathy as assessed by intravascular ultrasound. Am J Cardiol 1995;76:436 – 66. 2. Halle III AA, DiSciascio G, Massin EK, et al. Coronary angioplasty, atherectomy and bypass surgery in cardiac transplant recipients. J Am Coll Cardiol 1995;26:120 – 8. 3. Pijls NHJ, de Bruyne B, Peels K, et al. Measurement of fractional flow reserve to assess the functional severity of coronary-artery stenoses. N Engl J Med 1996;334:1703– 8. 4. Pijls NHJ, Van Gelder B, Van der Voort P, et al. Fractional flow reserve: a useful index to evaluate the influence of an
The Journal of Heart and Lung Transplantation November 1999
5.
6.
7.
8.
9.
10.
11.
epicardial coronary stenosis on myocardial blood flow. Circulation 1995;92:3183–93. de Bruyne B, Bartunek J, Sys SU, Pijls NHJ, Heyndrickx GR, Wijns W. Simultaneous coronary pressure and flow velocity measurements in humans. Feasibility, reproducibility, and hemodynamic dependence of coronary flow velocity reserve, hyperemic flow versus pressure slope index, and fractional flow reserve. Circulation 1996;94:1842–9. Hanekamp CEE, Koolen JJ, Pijls NHJ, Herzfeld I, Michels HR, Bonnier HJRM. Comparison of quantitative coronary angiography, intravascular ultrasound, and coronary pressure measurement to assess optimum stent deployment. Circulation 1999;99:1015–21. Bech GJW, Pijls NHJ, de Bruyne B, et al. Usefulness of fractional flow reserve to predict clinical outcome after balloon angioplasty. Circulation 1999;99:883– 8. Kern MJ, de Bruyne B, Pijls N. From research to clinical practice: current role of intracoronary physiologically based decision making in the cardiac catheterisation laboratory. J Am Coll Cardiol 1997;30:613–20. Ge J, Erbel R, Zamorano J, et al. Improvement of coronary morphology and blood flow after stenting. Int J Cardiovasc Imaging 1995;11:81–7. Kern MJ, Dupoy P, Denry JH, et al. Role of coronary artery lumen enlargement in improving coronary blood flow after balloon angioplasty and stenting: a combined intravascular ultrasound Doppler flow and imaging study. J Am Coll Cardiol 1997;29:1520 –7. Serruys PW, Di Mario C, Piek J, et al. Prognostic value of intracoronary flow velocity and diameter stenosis in assessing the short- and long-term outcome of coronary balloon angioplasty. The DEBATE Study (Doppler Endpoints Balloon Angioplasty Trial Europe). Circulation 1997;96:3369 –77
Pressure-Wire Guided Balloon Angioplasty in Allograft Coronary Vasculopathy Gianni Casella, MD, Johannes Rieber, MD, Harald Mudra, MD, Volker Klauss, MD We report a case of successful percutaneous transluminal coronary angioplasty guided from pressure-wire measurements in a transplanted patient. Fractional flow reserve, a lesion-specific, pressure-independent index of functional stenosis severity, was used to guide the intervention. J Heart Lung Transplant 1999;18:1143–1146.
C
ardiac allograft vasculopathy (CAV) mainly consists of diffuse, concentric intimal proliferation, but focal lesions are also observed.1 To decrease ischemia-related morbidity and mortality, palliative coronary revascularizations of these lesions is currently performed.2 However, the high incidence of procedural complications and the high long-term restenosis rate suggests careful patient selection with limitation of revascularization to significant stenosis with a high likelihood of procedural success.2 Among the several invasive approaches proposed to assess the physiological significance of epicardial coronary stenosis, pressure-derived fractional flow reserve (FFR)3–5 seems promising. Fractional flow reserve is a lesion-specific, pressureindependent index of functional stenosis severity that can be obtained during catheterization by means of steerable, sensor-tipped angioplasty guide wires. Fractional flow reserve relates maximum myocarFrom the Department of Medicine, Division of Cardiology, Klinikum Innenstadt, Ludwig-Maximilians University, Munich, Germany Submitted December 22, 1998; accepted August 4, 1999. Reprint requests: Volker Klauss, MD, Medizinische Klinik, Klinikum Innenstadt, Ludwig-Maximilians University, Ziemssenstrasse, 1 D-80336 Munich Germany; telephone, 49-8951602177; fax, 49-89-51602152; e-mail, klauss@medinn. med.uni-muenchen.de. Copyright © 1999 by the International Society for Heart and Lung Transplantation. 1053-2498/99/$–see front matter PII S1053-2498(99)00074-1
dial blood flow in the presence of an epicardial stenosis to the theoretic maximum hyperemic flow in the same artery without stenosis. Thus, FFR represents that fraction of normal maximum flow that is still achievable despite the presence of an epicardial coronary lesion.3,4 Fractional flow reserve has a very high diagnostic accuracy for stenosis responsible for reversible ischemia3–5 as well as a promising rationale for the assessment of the success of interventions.6 Recently, it has been shown that restenosis and cardiac events were low in patients with both good morphologic and functional success after percutaneous transluminal coronary angioplasty (PTCA), as defined by angiographic and FFR criteria.7 Therefore, we used FFR to guide the following intervention in a patient with focal CAV, attempting to avoid stent implantation because of inadequate vessel diameter. A 59-year-old man, who underwent orthotopic heart transplantation in 1987, was referred to our institution in February 1998 for yearly, routine angiographic and intravascular ultrasound evaluation. His medical history revealed non-insulin dependent diabetes mellitus, arterial hypertension, and significant renal insufficiency. The baseline catheterization showed normal right and left chamber pressures. The left ventricle ejection fraction was 54%. The coronary angiogram showed a longitudinal narrowing of the left anterior descending artery and of the right coronary artery along with a tight stenosis of the first diagonal branch (75% to 1143
1144
Casella et al.
The Journal of Heart and Lung Transplantation November 1999
FIGURE 1 Coronary angiograms (left anterior oblique projection) showing (1) the pre-
intervention stenosis of the first diagonal branch of the left anterior descending artery (top left panel, small arrows), and the final result after pressure-guided balloon angioplasty (bottom left panel); and (2) the simultaneous pressure recordings of distal coronary pressure (Pd) and aortic pressure (Pa) before intervention. At baseline (top right panel), after injection of an intracoronary bolus of 18 g adenosine, fractional flow reserve (FFR) is calculated by the Pd/Pa ratio (78/128), which equals 0.61. This value is well below the cutoff point of 0.75 for reversible ischemia; therefore, it indicates a functionally significant stenosis. After percutaneous transluminal coronary angioplasty (PTCA) (bottom right panel), a significant decrease of the pre-intervention gradient is observed. After adenosine, FFR myo is calculated as 131/143 ⫽ 0.91. Thus, FFR returned to the normal range.
90% diameter stenosis by visual estimate) and of a small first marginal branch (Figure 1, top left panel). Angiographically these findings were representative of diffuse CAV associated with focal lesions. The intravascular ultrasound imaging of the left anterior descending and of the circumflex artery confirmed a diffuse allograft vasculopathy. Although the stenosis of the first diagonal branch could be already judged suitable for revascularization on an anatomical basis, decision for PTCA was additionally based on physiologic parameters, because stress echocardiography was insufficient due to poor image quality. Furthermore, we were concerned with the small caliber of the vessel (2.5 mm), not optimal for stenting, and with the high restenosis rate of transplanted patients. Therefore, we decided to confirm the functional significance of the stenosis by pressure measurements and then to guide the intervention by use of the pressure wire to reduce the risk of restenosis. Therefore, 2 weeks later an 8F Judkins leftguiding catheter without side-holes was engaged in the left coronary ostium. Intracoronary nitroglycerin and 10,000 U of heparin were administered accord-
ing to standard practice. Instead of a regular angioplasty guide wire, a 0.014-inch high-fidelity pressuremonitoring wire (PressureWire™, Radi Medical Systems, Uppsala, Sweden) that allowed measurement of Pd (mean distal coronary pressure) was used. After calibration, this wire was introduced into the guiding catheter and advanced to its tip. At that point, equality of pressures registered by the guiding catheter and the wire was verified. The wire was then advanced into the coronary artery and positioned across the stenosis, in the first diagonal branch, without difficulty. Mean arterial and mean post-stenotic coronary pressure were measured. After the pressures had stabilized, maximum coronary hyperemia was obtained with an intracoronary bolus of 18 g adenosine. From simultaneous recording of aortic pressure (Pa) and Pd at steady maximum hyperemia, FFR before PTCA was calculated. The value obtained was 0.61, thus suggestive of a functionally significant lesion (Figure 1, top right panel). Afterward, the PTCA was performed with a 2.5 mm balloon (Passage™, Cordis Corp., Miami FL, USA) and a single inflation with 6 atmospheres for 120 seconds. A satisfactory angiographic result was im-
The Journal of Heart and Lung Transplantation Volume 18, Number 11
mediately obtained (Figure 1, bottom left panel), and FFR was again determined, indicating an optimal physiological result of 0.91 (Figure 1, bottom right panel). The subsequent clinical course was uneventful, and the following day the patient could be discharged from the hospital on aspirin, as usual. However, 4 months later, the patient underwent a new angiogram for shortness of breath. No angiographic evidence of restenosis of the lesion treated was detected, but there was a severe, diffuse progression of the disease of the left anterior descending and of the circumflex arteries. Thus, due to the diffuse disease, no further intervention was performed. Accelerated CAV represents the most important cause of morbidity and mortality in cardiac transplant recipients beyond the first year after transplantation. Allograft arteriopathy consists mainly of diffuse arterial narrowings and, less frequently, of discrete focal stenoses, as confirmed by intravascular ultrasound.1 However, coronary artery revascularization in heart transplant recipients, utilizing PTCA, stenting, or bypass surgery, have been performed in selected patients as palliative therapy to decrease ischemia-related morbidity and mortality.2 In selected transplanted patients the immediate success rate of PTCA is comparable to that of routine angioplasty, but the incidence of complications as well as the long-term restenosis rate is higher.2 In particular, most of the studies report a restenosis rate of up to 62%.2 Therefore, the availability of an handleable tool, which could help with the revascularization decision and with conducting interventions, is urged from interventional cardiologists treating CAV. Recently, the development of maneuverable Doppler-tipped and pressure-monitoring guide wires has revived the interest in invasive evaluation of the physiological significance of epicardial coronary stenosis as a complement to coronary angiography. These methods, mainly coronary flow reserve8 and pressurederived fractional flow reserve,3 have demonstrated a strong relation not only with the presence of significant coronary lesions3,4 but also with the results of interventions.8,9 In fact, despite a successful angiographic appearance, standard PTCA may not achieve a satisfactory physiologic result. Combined intracoronary ultrasound (ICUS) imaging and flowvelocity studies6 –9 demonstrated that increases in coronary vasodilatory reserve after PTCA or stenting are often related to residual lumen area .6,10 Furthermore, in the DEBATE Trial (Doppler Endpoints Balloon Angioplasty Trial Europe)11 the
Casella et al.
1145
combination of optimal angiographic results (residual stenosis ⱕ35%) and high coronary flow reserve (CFR ⬎2.5) allowed the identification of a subgroup of patients with favorable outcome without stenting. Fractional flow reserve3 is a lesion-specific, pressure-independent index relating maximum myocardial blood flow in the presence of an epicardial stenosis to normal maximum flow. In another way, FFR represents that fraction of normal maximum flow that remains despite the presence of an epicardial lesion. Theoretically, FFR should be 1.0 for normal coronary arteries along which no significant decrease of pressure occurs. Contrary to absolute coronary flow reserve, FFR is independent of changes in systemic blood pressure and heart rate, and is not affected by conditions known to increase baseline myocardial blood flow.5 In addition, FFR takes into account collateral blood flow to the dependent myocardium. Several studies, mainly from the group of de Bruyne3–5 have demonstrated that a FFR value below 0.75 reliably indicates a significant stenosis, associated with inducible ischemia. In patients with coronary artery disease, the diagnostic accuracy of FFR for this purpose is 93% and exceeds the diagnostic accuracy of thallium exercise testing and dobutamine stress echocardiography when performed as single tests.3 In addition, strictly speaking microvascular disease as CAV may influence FFR to some degree, because in such cases epicardial blood flow may not be as high as it could be without the microvascular disease and FFR might be overestimated.4,8 Furthermore, FFR measurements have not been validated in patients with microvascular disease. From a practical viewpoint, however, coronary pressure measurements indicate to what extent the epicardial lesion contributes to the ischemia and to what extent myocardial perfusion will be improved by intervention. Thus, we decided to apply FFR to assess the lesion and to guide the following intervention. In patients with optimal angiographic, Bech et al.,7 recently reported a post-angioplasty FFR ⬎0.90; event-free survival rates at 6, 12, and 24 months follow-up of 92%, 92%, and 88%, respectively, compared with 72%, 69%, and 59% in patients with a similar angiographic result but an FFR ⬍0.90. Furthermore, FFR is effective also when used to assess the results of stenting. Hanekamp et al.6 evaluated 30 patients with angiographically successful stent implantation with ICUS and FFR. The study demonstrated that after optimal stent deployment by ICUS, the FFR returns to the normal range. Thus, if FFR is not completely normalized
1146
Casella et al.
after stent implantation, stent deployment has been inadequate even if the angiogram is apparently normal. Therefore, there is a complementary value of FFR and angiography in evaluating angioplasty results. In summary, we report a case of successful PTCA guided by intracoronary pressure measurements in a transplant recipient. Fractional flow reserve is a highly lesion-specific, pressure-independent index of functional stenosis severity. Moreover FFR can be easily obtained just before and during PTCA by using a pressure guide wire as primary guide wire. Fractional flow reserve can facilitate the clinical decision-making with respect to the appropriateness of PTCA, as well as the assessment of the results of interventions or the real need of stenting in the challenging setting of CAV.
REFERENCES 1. Klauss V, Mudra H, Uberfuhr P, Theisen K. Intraindividual variability of cardiac allograft vasculopathy as assessed by intravascular ultrasound. Am J Cardiol 1995;76:436 – 66. 2. Halle III AA, DiSciascio G, Massin EK, et al. Coronary angioplasty, atherectomy and bypass surgery in cardiac transplant recipients. J Am Coll Cardiol 1995;26:120 – 8. 3. Pijls NHJ, de Bruyne B, Peels K, et al. Measurement of fractional flow reserve to assess the functional severity of coronary-artery stenoses. N Engl J Med 1996;334:1703– 8. 4. Pijls NHJ, Van Gelder B, Van der Voort P, et al. Fractional flow reserve: a useful index to evaluate the influence of an
The Journal of Heart and Lung Transplantation November 1999
5.
6.
7.
8.
9.
10.
11.
epicardial coronary stenosis on myocardial blood flow. Circulation 1995;92:3183–93. de Bruyne B, Bartunek J, Sys SU, Pijls NHJ, Heyndrickx GR, Wijns W. Simultaneous coronary pressure and flow velocity measurements in humans. Feasibility, reproducibility, and hemodynamic dependence of coronary flow velocity reserve, hyperemic flow versus pressure slope index, and fractional flow reserve. Circulation 1996;94:1842–9. Hanekamp CEE, Koolen JJ, Pijls NHJ, Herzfeld I, Michels HR, Bonnier HJRM. Comparison of quantitative coronary angiography, intravascular ultrasound, and coronary pressure measurement to assess optimum stent deployment. Circulation 1999;99:1015–21. Bech GJW, Pijls NHJ, de Bruyne B, et al. Usefulness of fractional flow reserve to predict clinical outcome after balloon angioplasty. Circulation 1999;99:883– 8. Kern MJ, de Bruyne B, Pijls N. From research to clinical practice: current role of intracoronary physiologically based decision making in the cardiac catheterisation laboratory. J Am Coll Cardiol 1997;30:613–20. Ge J, Erbel R, Zamorano J, et al. Improvement of coronary morphology and blood flow after stenting. Int J Cardiovasc Imaging 1995;11:81–7. Kern MJ, Dupoy P, Denry JH, et al. Role of coronary artery lumen enlargement in improving coronary blood flow after balloon angioplasty and stenting: a combined intravascular ultrasound Doppler flow and imaging study. J Am Coll Cardiol 1997;29:1520 –7. Serruys PW, Di Mario C, Piek J, et al. Prognostic value of intracoronary flow velocity and diameter stenosis in assessing the short- and long-term outcome of coronary balloon angioplasty. The DEBATE Study (Doppler Endpoints Balloon Angioplasty Trial Europe). Circulation 1997;96:3369 –77