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The correlation of necrotic core percentage in coronary plaques by virtual histology to patients' characteristics and clinical presentation
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Abstracts / Cardiovascular Revascularization Medicine 9 (2008) 192–216
cholesterol and cholesterol esters. Raman spectroscopy is a rapid nondestructive technique which is capable of assaying these chemicals in human artery tissues and characterizing plaques in vivo. Recent developments in Raman spectroscopy technology enable one to collect quality Raman spectra remotely via a single optical fiber, greatly simplifying the size and complexity of cardiovascular catheters and making them commercially feasible. We have conducted a study demonstrating that chemical concentrations calculated with Raman spectra agree with standard chemical assays to within a few percent. Raman spectra are acquired using a custom-built spectrometer (River Diagnostics), an Andor iDus CCD40-11 camera, and a CrystaLaser 671-nm diode laser, providing a spectral resolution of 5 cm−1. Measurements are made through a 100-μm core 0.22NA flat cleaved fiber with a typical output power of 75 mW. Human coronary artery is submerged in liquid nitrogen and homogenized in a tissue pulverizer. The homogenized tissue is then placed on a quartz slide and compressed between two 1-mm-thick quartz slides and covered with a 100μm-thick quartz cover slip. The top slides are compressed while applying downward pressure on the cover slip until the tissue is well distributed throughout the cavity and is in good contact with the cover slip. A flat cleaved fiber is lowered onto the cover slip and measurements are made throughout the volume of the sample. Each mince was then subject to standard chemical assays to provide relative concentrations of cholesterol, cholesterol esters, triglycerides, and protein. An initial set of data was used to calibrate the Raman spectra to the standard assay results. Verification studies conducted after model development yielded excellent agreement between the concentrations of components determined with the Raman assay and those of the standard assay, with quantification accuracies of ∼2% for lipids and ∼2% for protein. doi:10.1016/j.carrev.2008.03.024
Prediction of functional recovery of the left ventricular regional function after percutaneous coronary revascularization in thrombus-containing lesions AM Mahrous, S Mohamed, F Eltobgi, SI Ghareeb, MM Abdel-Ghany Kasr Elainy Hospital, Cairo, Egypt Background: It has not been established whether specific features of angiography early after percutaneous coronary intervention (PCI) for thrombus-containing lesions could provide prognostic value. Objective: To identify immediate post-interventional angiographic predictors of short-term echocardiographic improvement of left ventricular regional function in patients undergoing PCI for thrombus-containing lesions. Methods: Thirty-five consecutive patients with thrombus-containing lesions were submitted for assessment of thrombus scoring system, Thrombolysis In Myocardial Infarction (TIMI) flow grade, corrected TIMI frame count, tissue myocardial perfusion grading (TMP), and myocardial dye intensity before and after successful PCI. The X-sizer thrombectomy catheter systems were used in 10 patients. The left ventricular global wall motion index (GWMI) was determined by echocardiography before and 6 months after intervention. Improved regional left ventricular function at follow-up was defined as GWMI reduction N0.3. Results: Both groups were similar in terms of clinical and pre-interventional angiographic characteristics. On multivariate analysis, improvement of TMP grade (0.30±0.73 at baseline vs. 2.20±0.95 after PCI, P =.007) and use of a thrombectomy device (P =.02) were the only independent predictors of 6-month improvement of GWMI (r 2=0.64). GWMI at follow-up showed significant correlation with reduction of the thrombus score (4.40±0.88 at baseline vs. 0.15±0.48 after PCI, r 2=0.42, P =.012) and with enhanced myocardial dye intensity (5.86±5.95 vs. 10.55±4.72 pixel, r 2=)0.65, Pb.001). Conclusions: TMP grading and use of a thrombectomy device have a potential to predict improvement of regional left ventricular function after PCI for thrombus-containing lesions. doi:10.1016/j.carrev.2008.03.025
The correlation of necrotic core percentage in coronary plaques by virtual histology to patients' characteristics and clinical presentation K Aziz, J Frank, A Alroaini, J Torey, A Kawa, T Lalonde St. John Hospital, Detroit, MI, USA Background: Virtual histology (Volcano Therapeutics, Laguna Hills, CA, USA) intravascular ultrasound (IVUS) is a new technology with growing use; however, we have limited knowledge of the clinical significance of virtual histology findings. The presence of a large necrotic core is a sign of plaque vulnerability. Therefore we sought to correlate the percentage of the necrotic core measured by virtual histology to patients' characteristics and clinical presentation. Methods: Virtual histology coronary IVUS recordings of 43 patients (26 males, 17 males, age 64.1±10.87) performed over a period of 4 months were reviewed by two readers. The percentage of the necrotic core was measured at the frame of maximal stenosis and was correlated with patient age, gender, the presence of diabetes, clinical presentation, the degree of area stenosis, and to low-density lipoprotein (LDL) and high-density lipoprotein (HDL) levels. Results: The percentage of necrotic core at the area of the maximal stenosis did not correlate with age, gender, and degree of stenosis. The necrotic core was higher in diabetics (17.97±10.5) compared to nondiabetics (15.48±7.7, P =.19) and higher in patients who presented with acute coronary syndromes (16.49±7.23) compared to other presentations (13.52±7.64, P =.30). There was weak positive correlation between the necrotic core percentage and LDL level (r =0.30) and weak negative correlation with HDL levels (r =-0.17). Conclusion: The percentage of necrotic core in the area of maximal stenosis did not correlate with patient age, gender, and degree of stenosis. The necrotic core was higher but not statistically significant in diabetics and patients with acute coronary syndrome. It was also visually noted that necrotic core distributed around stents struts in patients with previously placed stents. Our study is limited by the small number of patients and the inability to measure necrotic core percentage in the whole plaque since manual pull up rather than automatic pull up was performed. Larger studies in different patient populations (like the currently ongoing PROSPECT trial) will be needed to better understand the clinical significance of virtual histology findings. doi:10.1016/j.carrev.2008.03.026
Very late thrombosis in acute myocardial infarction: drug-eluting vs. uncoated stents D Capodanno, N Garro, V Cammalleri, C Tamburino Ferrarotto, Catania, Italy Objectives: To evaluate clinical outcomes at 24 months in unselected population with ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI) with drug-eluting stent (DES). Background: DES in STEMI seems to decrease the incidence of both restenosis and target vessel revascularization (TVR) as compared with bare metal stents (BMS), showing no significant differences in early and late thrombosis, but few data are available about very late thrombosis. Methods: We report our series of 245 consecutive patients with STEMI undergoing PCI with DES (n=117) or BMS (n=128) from January 2003 to August 2005. The primary end point was the incidence of major adverse cardiac events assessed at 24 months. The secondary end point was the incidence of stent thrombosis according to the Academic Research Consortium classification. Propensity score was used to adjust groups for angiographic characteristics. Results: The adjusted rate of the primary end point was lower in DES as compared with BMS group (15.2% vs. 25.7%; P =.1), driven by a significant reduction of TVR (10.1% vs. 23%; P =.03), without any significant difference about death and recurrent MI. The cumulative incidence of stent thrombosis was 5.3% in DES vs. 0.8% in BMS group (P =.06).
Abstracts / Cardiovascular Revascularization Medicine 9 (2008) 192–216
cholesterol and cholesterol esters. Raman spectroscopy is a rapid nondestructive technique which is capable of assaying these chemicals in human artery tissues and characterizing plaques in vivo. Recent developments in Raman spectroscopy technology enable one to collect quality Raman spectra remotely via a single optical fiber, greatly simplifying the size and complexity of cardiovascular catheters and making them commercially feasible. We have conducted a study demonstrating that chemical concentrations calculated with Raman spectra agree with standard chemical assays to within a few percent. Raman spectra are acquired using a custom-built spectrometer (River Diagnostics), an Andor iDus CCD40-11 camera, and a CrystaLaser 671-nm diode laser, providing a spectral resolution of 5 cm−1. Measurements are made through a 100-μm core 0.22NA flat cleaved fiber with a typical output power of 75 mW. Human coronary artery is submerged in liquid nitrogen and homogenized in a tissue pulverizer. The homogenized tissue is then placed on a quartz slide and compressed between two 1-mm-thick quartz slides and covered with a 100μm-thick quartz cover slip. The top slides are compressed while applying downward pressure on the cover slip until the tissue is well distributed throughout the cavity and is in good contact with the cover slip. A flat cleaved fiber is lowered onto the cover slip and measurements are made throughout the volume of the sample. Each mince was then subject to standard chemical assays to provide relative concentrations of cholesterol, cholesterol esters, triglycerides, and protein. An initial set of data was used to calibrate the Raman spectra to the standard assay results. Verification studies conducted after model development yielded excellent agreement between the concentrations of components determined with the Raman assay and those of the standard assay, with quantification accuracies of ∼2% for lipids and ∼2% for protein. doi:10.1016/j.carrev.2008.03.024
Prediction of functional recovery of the left ventricular regional function after percutaneous coronary revascularization in thrombus-containing lesions AM Mahrous, S Mohamed, F Eltobgi, SI Ghareeb, MM Abdel-Ghany Kasr Elainy Hospital, Cairo, Egypt Background: It has not been established whether specific features of angiography early after percutaneous coronary intervention (PCI) for thrombus-containing lesions could provide prognostic value. Objective: To identify immediate post-interventional angiographic predictors of short-term echocardiographic improvement of left ventricular regional function in patients undergoing PCI for thrombus-containing lesions. Methods: Thirty-five consecutive patients with thrombus-containing lesions were submitted for assessment of thrombus scoring system, Thrombolysis In Myocardial Infarction (TIMI) flow grade, corrected TIMI frame count, tissue myocardial perfusion grading (TMP), and myocardial dye intensity before and after successful PCI. The X-sizer thrombectomy catheter systems were used in 10 patients. The left ventricular global wall motion index (GWMI) was determined by echocardiography before and 6 months after intervention. Improved regional left ventricular function at follow-up was defined as GWMI reduction N0.3. Results: Both groups were similar in terms of clinical and pre-interventional angiographic characteristics. On multivariate analysis, improvement of TMP grade (0.30±0.73 at baseline vs. 2.20±0.95 after PCI, P =.007) and use of a thrombectomy device (P =.02) were the only independent predictors of 6-month improvement of GWMI (r 2=0.64). GWMI at follow-up showed significant correlation with reduction of the thrombus score (4.40±0.88 at baseline vs. 0.15±0.48 after PCI, r 2=0.42, P =.012) and with enhanced myocardial dye intensity (5.86±5.95 vs. 10.55±4.72 pixel, r 2=)0.65, Pb.001). Conclusions: TMP grading and use of a thrombectomy device have a potential to predict improvement of regional left ventricular function after PCI for thrombus-containing lesions. doi:10.1016/j.carrev.2008.03.025
The correlation of necrotic core percentage in coronary plaques by virtual histology to patients' characteristics and clinical presentation K Aziz, J Frank, A Alroaini, J Torey, A Kawa, T Lalonde St. John Hospital, Detroit, MI, USA Background: Virtual histology (Volcano Therapeutics, Laguna Hills, CA, USA) intravascular ultrasound (IVUS) is a new technology with growing use; however, we have limited knowledge of the clinical significance of virtual histology findings. The presence of a large necrotic core is a sign of plaque vulnerability. Therefore we sought to correlate the percentage of the necrotic core measured by virtual histology to patients' characteristics and clinical presentation. Methods: Virtual histology coronary IVUS recordings of 43 patients (26 males, 17 males, age 64.1±10.87) performed over a period of 4 months were reviewed by two readers. The percentage of the necrotic core was measured at the frame of maximal stenosis and was correlated with patient age, gender, the presence of diabetes, clinical presentation, the degree of area stenosis, and to low-density lipoprotein (LDL) and high-density lipoprotein (HDL) levels. Results: The percentage of necrotic core at the area of the maximal stenosis did not correlate with age, gender, and degree of stenosis. The necrotic core was higher in diabetics (17.97±10.5) compared to nondiabetics (15.48±7.7, P =.19) and higher in patients who presented with acute coronary syndromes (16.49±7.23) compared to other presentations (13.52±7.64, P =.30). There was weak positive correlation between the necrotic core percentage and LDL level (r =0.30) and weak negative correlation with HDL levels (r =-0.17). Conclusion: The percentage of necrotic core in the area of maximal stenosis did not correlate with patient age, gender, and degree of stenosis. The necrotic core was higher but not statistically significant in diabetics and patients with acute coronary syndrome. It was also visually noted that necrotic core distributed around stents struts in patients with previously placed stents. Our study is limited by the small number of patients and the inability to measure necrotic core percentage in the whole plaque since manual pull up rather than automatic pull up was performed. Larger studies in different patient populations (like the currently ongoing PROSPECT trial) will be needed to better understand the clinical significance of virtual histology findings. doi:10.1016/j.carrev.2008.03.026
Very late thrombosis in acute myocardial infarction: drug-eluting vs. uncoated stents D Capodanno, N Garro, V Cammalleri, C Tamburino Ferrarotto, Catania, Italy Objectives: To evaluate clinical outcomes at 24 months in unselected population with ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI) with drug-eluting stent (DES). Background: DES in STEMI seems to decrease the incidence of both restenosis and target vessel revascularization (TVR) as compared with bare metal stents (BMS), showing no significant differences in early and late thrombosis, but few data are available about very late thrombosis. Methods: We report our series of 245 consecutive patients with STEMI undergoing PCI with DES (n=117) or BMS (n=128) from January 2003 to August 2005. The primary end point was the incidence of major adverse cardiac events assessed at 24 months. The secondary end point was the incidence of stent thrombosis according to the Academic Research Consortium classification. Propensity score was used to adjust groups for angiographic characteristics. Results: The adjusted rate of the primary end point was lower in DES as compared with BMS group (15.2% vs. 25.7%; P =.1), driven by a significant reduction of TVR (10.1% vs. 23%; P =.03), without any significant difference about death and recurrent MI. The cumulative incidence of stent thrombosis was 5.3% in DES vs. 0.8% in BMS group (P =.06).