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Electrocardiogram-gated multidetector computed tomography in the evaluation of mechanical prosthetic valves
124
Abstracts / Cardiovascular Revascularization Medicine 9 (2008) 101–129
Four-year outcome of moderate left main disease: intravascular ultrasound predictor of events T Okabe a, GS Mintz b, SY Lee a, B Lee a, P Roy a, DH Steinberg a, TL Pinto Slottow a, KA Smith a, R Torguson a, Z Xue a, LF Satler a, KM Kent a, AD Pichard a, NJ Weissman a, J Lindsay a, R Waksman a a Washington Hospital Center, Washington, DC, USA b Cardiovascular Research Foundation, New York, NY, USA Background: The long-term outcome of moderate diseased left main coronary artery (LMCA) remains unknown. Methods and results: One hundred fourteen patients who underwent angiographic and intravascular ultrasound (IVUS) evaluation for moderate LMCA disease without intervention were followed up for 4 years. Three patients died of noncardiac diseases. Of the remaining 111 patients, 19 had events (9 died of cardiac or unknown causes and 13 had coronary artery bypass surgery). There were no percutaneous coronary interventions for LMCA and myocardial infarctions. Univariate predictors for events were age, diabetes, untreated non-LMCA coronary artery with angiographic diameter stenosis (DS) above 50%; mean plaque and media (P&M) area; plaque burden over the entire length of LMCA lesion; and minimum luminal area (MLA), external elastic membrane, P&M area, plaque burden, and calcium arc above 90° at MLA site. By multiple logistic regression analysis, plaque burden at MLA (odds ratio [OR] 1.313, 95% confidence interval [CI] 1.100-1.566, P=.003), MLA (OR 1.471, 95% CI 1.038-2.083, P=.03) and untreated non-LMCA coronary artery with DS above 50% (OR 7.982, 95% CI 1.127-56.517, P=.038) were independent predictors. Conclusion: Moderate diseased LMCA had a 4-year event rate of 17.1%. Plaque burden and MLA of moderate diseased LMCA with other untreated diseased coronary ought to be checked by IVUS for future LMCA event.
n Diabetes (%) An untreated vessel with DS N50% (%) Angiographic data Reference diameter (mm) Minimum luminal diameter (mm) DS (%) IVUS data Lesion length (mm) External elastic membrane area at MLA site (mm 2) MLA (mm 2) P&M area at MLA site (mm 2) Plaque burden at MLA site (mm 2) Calcium arc N90° at MLA site (%)
All
Any event
No event
111 27 (24) 55 (50)
19 10 (53) 16 (84)
92 17 (18) 39 (42)
.002 .001
4.0±1.0 2.7±0.7
3.8±1.0 2.5±0.6
4.0±1.1 2.7±0.7
.4 .3
32±9
33±10
32±9
.7
5.4±3.7 19.7±5.6
3.8±2.4 22.7±5.3
5.7±3.9 19.1±5.5
.052 .013
10.3±3.4 9.4±3.8
8.9±2.8 13.9±4.1
10.6±3.4 8.5±3.0
.035 b.001
47±11
61±10
44±9
b.001
20 (18)
11 (58)
9 (10)
b.001
with these techniques. The purpose of this study was to evaluate electrocardiogram (ECG)–gated multidetector computed tomography (MDCT) in the functional evaluation of mechanical prosthetic aortic and mitral valves. Patients and methods: Twenty sequential patients with 23 mechanical prosthetic valves (18 bileaflet, 5 single-leaflet) were retrospectively studied. Patients were evaluated with a 40- or 64-slice MDCT scanner. Indications for scans were coronary artery evaluation in 14 patients and valvular function evaluation in 6 patients. Using retrospective electrocardiogram gating, reconstructions were obtained into 10 cardiac phases of the R-R interval. A variety of reformations generated perpendicular to leaflet axis were used for the visualization of the valve leaflets. Opening and closing angles of the mechanical valve leaflets were measured. Visibility of each mechanical valve was evaluated using a subjective 5-point scale. MDCT findings were correlated with fluoroscopic angle measurements in 11 bileaflet valves. Results: Visibility score at MDCT for the bileaflet mechanical valves was excellent (4/4) in all 18 cases. However, visibility scores of the single-leaflet valves were lower (mean, 2.8) with 2 of 5 cases in which the valve leaflet could not be clearly imaged. In 4 patients a stuck mitral valve was demonstrated on MDCT and by fluoroscopy. In all remaining cases, MDCT demonstrated free movement of mechanical leaflets: opening and closing angles were in concordance with manufacturer's data. Bland-Altman analysis of opening and closing angle measurements showed good agreement between MDCT and fluoroscopy. Conclusion: Multidetector computed tomography is a helpful technique for functional evaluation of bileaflet mechanical valves, allowing reliable measurements of opening and closing leaflet angles. However, the role of MDCT in the evaluation of single leaflet valves might be limited. doi:10.1016/j.carrev.2008.02.075
P Growth factors are increased in bone marrow–derived stem cell hypoxia conditioned media S Rastogi, VG Sharov, HN Sabbah Henry Ford Hospital, Detroit, MI, USA Background: Transplantation of bone marrow–derived stem cells (BMSC) into infarcted and/or failing myocardium can stimulate angiogenesis and improve left ventricular function. BMSCs likely induce angiogenesis through release of growth factors rather than cell incorporation into new vessels, suggesting that mechanisms other than BMSC incorporation contribute to left ventricular functional improvements seen after BMSC therapy. Objective: This study examined the expression of growth factors in media of cultured BMSCs exposed to hypoxia. Methods: Bone marrow–derived stem cells were obtained from adult mongrel dogs and cultured using Iscoves modified Dulbecco media. Cultured BMSCs were exposed to hypoxia in an airtight incubator for 72 hours where room air was replaced by 95% nitrogen and 5% carbon dioxide or to normoxia (95% room air and 5% carbon dioxide). RNA was extracted from normoxia and hypoxia conditioned BMSC media. mRNA expression of angiopoetin, vascular endothelial growth factor, fibroblast growth factor, placental growth factor, and Glyceraldehyde-3-phosphate dehydrogenase was measured using real time polymerase chain reaction.
doi:10.1016/j.carrev.2008.02.074
Electrocardiogram-gated multidetector computed tomography in the evaluation of mechanical prosthetic valves E Konen, O Goitein, E Di Segni Sheba Medical Center, Tel Hashomer, Israel Background: Prosthetic valve malfunction is a serious complication of heart valve replacement. Evaluation of mechanical prosthetic valves is currently obtained by echocardiography and cinefluoroscopy, but optimal visualization of valve leaflets and their motion may occasionally be difficult
Table 1 Expression of growth factors Growth factor
Fold Increase with hypoxia
Angiopoetin VEGF FGF PGF
8.73 13.47 33.31 5.81
VEGF, vascular endothelial growth factor; FGF, fibroblast growth factor; PGF, placental growth factor.
Abstracts / Cardiovascular Revascularization Medicine 9 (2008) 101–129
Four-year outcome of moderate left main disease: intravascular ultrasound predictor of events T Okabe a, GS Mintz b, SY Lee a, B Lee a, P Roy a, DH Steinberg a, TL Pinto Slottow a, KA Smith a, R Torguson a, Z Xue a, LF Satler a, KM Kent a, AD Pichard a, NJ Weissman a, J Lindsay a, R Waksman a a Washington Hospital Center, Washington, DC, USA b Cardiovascular Research Foundation, New York, NY, USA Background: The long-term outcome of moderate diseased left main coronary artery (LMCA) remains unknown. Methods and results: One hundred fourteen patients who underwent angiographic and intravascular ultrasound (IVUS) evaluation for moderate LMCA disease without intervention were followed up for 4 years. Three patients died of noncardiac diseases. Of the remaining 111 patients, 19 had events (9 died of cardiac or unknown causes and 13 had coronary artery bypass surgery). There were no percutaneous coronary interventions for LMCA and myocardial infarctions. Univariate predictors for events were age, diabetes, untreated non-LMCA coronary artery with angiographic diameter stenosis (DS) above 50%; mean plaque and media (P&M) area; plaque burden over the entire length of LMCA lesion; and minimum luminal area (MLA), external elastic membrane, P&M area, plaque burden, and calcium arc above 90° at MLA site. By multiple logistic regression analysis, plaque burden at MLA (odds ratio [OR] 1.313, 95% confidence interval [CI] 1.100-1.566, P=.003), MLA (OR 1.471, 95% CI 1.038-2.083, P=.03) and untreated non-LMCA coronary artery with DS above 50% (OR 7.982, 95% CI 1.127-56.517, P=.038) were independent predictors. Conclusion: Moderate diseased LMCA had a 4-year event rate of 17.1%. Plaque burden and MLA of moderate diseased LMCA with other untreated diseased coronary ought to be checked by IVUS for future LMCA event.
n Diabetes (%) An untreated vessel with DS N50% (%) Angiographic data Reference diameter (mm) Minimum luminal diameter (mm) DS (%) IVUS data Lesion length (mm) External elastic membrane area at MLA site (mm 2) MLA (mm 2) P&M area at MLA site (mm 2) Plaque burden at MLA site (mm 2) Calcium arc N90° at MLA site (%)
All
Any event
No event
111 27 (24) 55 (50)
19 10 (53) 16 (84)
92 17 (18) 39 (42)
.002 .001
4.0±1.0 2.7±0.7
3.8±1.0 2.5±0.6
4.0±1.1 2.7±0.7
.4 .3
32±9
33±10
32±9
.7
5.4±3.7 19.7±5.6
3.8±2.4 22.7±5.3
5.7±3.9 19.1±5.5
.052 .013
10.3±3.4 9.4±3.8
8.9±2.8 13.9±4.1
10.6±3.4 8.5±3.0
.035 b.001
47±11
61±10
44±9
b.001
20 (18)
11 (58)
9 (10)
b.001
with these techniques. The purpose of this study was to evaluate electrocardiogram (ECG)–gated multidetector computed tomography (MDCT) in the functional evaluation of mechanical prosthetic aortic and mitral valves. Patients and methods: Twenty sequential patients with 23 mechanical prosthetic valves (18 bileaflet, 5 single-leaflet) were retrospectively studied. Patients were evaluated with a 40- or 64-slice MDCT scanner. Indications for scans were coronary artery evaluation in 14 patients and valvular function evaluation in 6 patients. Using retrospective electrocardiogram gating, reconstructions were obtained into 10 cardiac phases of the R-R interval. A variety of reformations generated perpendicular to leaflet axis were used for the visualization of the valve leaflets. Opening and closing angles of the mechanical valve leaflets were measured. Visibility of each mechanical valve was evaluated using a subjective 5-point scale. MDCT findings were correlated with fluoroscopic angle measurements in 11 bileaflet valves. Results: Visibility score at MDCT for the bileaflet mechanical valves was excellent (4/4) in all 18 cases. However, visibility scores of the single-leaflet valves were lower (mean, 2.8) with 2 of 5 cases in which the valve leaflet could not be clearly imaged. In 4 patients a stuck mitral valve was demonstrated on MDCT and by fluoroscopy. In all remaining cases, MDCT demonstrated free movement of mechanical leaflets: opening and closing angles were in concordance with manufacturer's data. Bland-Altman analysis of opening and closing angle measurements showed good agreement between MDCT and fluoroscopy. Conclusion: Multidetector computed tomography is a helpful technique for functional evaluation of bileaflet mechanical valves, allowing reliable measurements of opening and closing leaflet angles. However, the role of MDCT in the evaluation of single leaflet valves might be limited. doi:10.1016/j.carrev.2008.02.075
P Growth factors are increased in bone marrow–derived stem cell hypoxia conditioned media S Rastogi, VG Sharov, HN Sabbah Henry Ford Hospital, Detroit, MI, USA Background: Transplantation of bone marrow–derived stem cells (BMSC) into infarcted and/or failing myocardium can stimulate angiogenesis and improve left ventricular function. BMSCs likely induce angiogenesis through release of growth factors rather than cell incorporation into new vessels, suggesting that mechanisms other than BMSC incorporation contribute to left ventricular functional improvements seen after BMSC therapy. Objective: This study examined the expression of growth factors in media of cultured BMSCs exposed to hypoxia. Methods: Bone marrow–derived stem cells were obtained from adult mongrel dogs and cultured using Iscoves modified Dulbecco media. Cultured BMSCs were exposed to hypoxia in an airtight incubator for 72 hours where room air was replaced by 95% nitrogen and 5% carbon dioxide or to normoxia (95% room air and 5% carbon dioxide). RNA was extracted from normoxia and hypoxia conditioned BMSC media. mRNA expression of angiopoetin, vascular endothelial growth factor, fibroblast growth factor, placental growth factor, and Glyceraldehyde-3-phosphate dehydrogenase was measured using real time polymerase chain reaction.
doi:10.1016/j.carrev.2008.02.074
Electrocardiogram-gated multidetector computed tomography in the evaluation of mechanical prosthetic valves E Konen, O Goitein, E Di Segni Sheba Medical Center, Tel Hashomer, Israel Background: Prosthetic valve malfunction is a serious complication of heart valve replacement. Evaluation of mechanical prosthetic valves is currently obtained by echocardiography and cinefluoroscopy, but optimal visualization of valve leaflets and their motion may occasionally be difficult
Table 1 Expression of growth factors Growth factor
Fold Increase with hypoxia
Angiopoetin VEGF FGF PGF
8.73 13.47 33.31 5.81
VEGF, vascular endothelial growth factor; FGF, fibroblast growth factor; PGF, placental growth factor.