Hulya Yalcin1, Ines Valenta2, Min Zhao2,3, Abdel Tahari2, Dai-Yin Lu1,4,5, Takahiro Higuchi6, Fatih Yalcin1, Nagehan Kucukler1, Yalda Soleimanifard1, Yun Zhou2, Martin G Pomper2, Theodore P Abraham1,7, Ben Tsui2, Martin A Lodge2, Thomas H Schindler2, M Roselle Abraham8,9. 1. Hypertrophic Cardiomyopathy Center of Excellence, Johns Hopkins School of Medicine, Baltimore, MD, USA. 2. Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins School of Medicine, Baltimore, MD, USA. 3. Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, China. 4. Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan. 5. Institute of Public Health, National Yang-Ming University, Taipei, Taiwan. 6. National Cerebral and Cardiovascular Center, Osaka, Japan. 7. Hypertrophic Cardiomyopathy Center, UCSF Division of Cardiology, 555 Mission Bay Blvd South, Smith Cardiovascular Research Building, 252G, San Francisco, CA, USA. 8. Hypertrophic Cardiomyopathy Center of Excellence, Johns Hopkins School of Medicine, Baltimore, MD, USA. Roselle.Abraham@ucsf.edu. 9. Hypertrophic Cardiomyopathy Center, UCSF Division of Cardiology, 555 Mission Bay Blvd South, Smith Cardiovascular Research Building, 252G, San Francisco, CA, USA. Roselle.Abraham@ucsf.edu.
Abstract
BACKGORUND: Quantification of myocardial blood flow (MBF) by positron emission tomography (PET) is important for investigation of angina in hypertrophic cardiomyopathy (HCM). Several software programs exist for MBF quantification, but they have been mostly evaluated in patients (with normal cardiac geometry), referred for evaluation of coronary artery disease (CAD). Software performance has not been evaluated in HCM patients who frequently have hyperdynamic LV function, LV outflow tract (LVOT) obstruction, small LV cavity size, and variation in the degree/location of LV hypertrophy. AIM: We compared results of MBF obtained using PMod, which permits manual segmentation, to those obtained by FDA-approved QPET software which has an automated segmentation algorithm. METHODS: 13N-ammonia PET perfusion data were acquired in list mode at rest and during pharmacologic vasodilation, in 76 HCM patients and 10 non-HCM patients referred for evaluation of CAD (CAD group.) Data were resampled to create static, ECG-gated and 36-frame-dynamic images. Myocardial flow reserve (MFR) and MBF (in ml/min/g) were calculated using QPET and PMod softwares. RESULTS: All HCM patients had asymmetric septal hypertrophy, and 50% had evidence of LVOT obstruction, whereas non-HCM patients (CAD group) had normal wall thickness and ejection fraction. PMod yielded significantly higher values for global and regional stress-MBF and MFR than for QPET in HCM. Reasonably fair correlation was observed for global rest-MBF, stress-MBF, and MFR using these two softwares (rest-MBF: r = 0.78; stress-MBF: r = 0.66.; MFR: r = 0.7) in HCM patients. Agreement between global MBF and MFR values improved when HCM patients with high spillover fractions (> 0.65) were excluded from the analysis (rest-MBF: r = 0.84; stress-MBF: r = 0.72; MFR: r = 0.8.) Regionally, the highest agreement between PMod and QPET was observed in the LAD territory (rest-MBF: r = 0.82, Stress-MBF: r = 0.68) where spillover fraction was the lowest. Unlike HCM patients, the non-HCM patients (CAD group) demonstrated excellent agreement in MBF/MFR values, obtained by the two softwares, when patients with high spillover fractions were excluded (rest-MBF: r = 0.95; stress-MBF: r = 0.92; MFR: r = 0.95). CONCLUSIONS: Anatomic characteristics specific to HCM hearts contribute to lower correlations between MBF/MFR values obtained by PMod and QPET, compared with non-HCM patients. These differences indicate that PMod and QPET cannot be used interchangeably for MBF/MFR analyses in HCM patients.
BACKGORUND: Quantification of myocardial blood flow (MBF) by positron emission tomography (PET) is important for investigation of angina in hypertrophic cardiomyopathy (HCM). Several software programs exist for MBF quantification, but they have been mostly evaluated in patients (with normal cardiac geometry), referred for evaluation of coronary artery disease (CAD). Software performance has not been evaluated in HCM patients who frequently have hyperdynamic LV function, LV outflow tract (LVOT) obstruction, small LV cavity size, and variation in the degree/location of LV hypertrophy. AIM: We compared results of MBF obtained using PMod, which permits manual segmentation, to those obtained by FDA-approved QPET software which has an automated segmentation algorithm. METHODS:13N-ammonia PET perfusion data were acquired in list mode at rest and during pharmacologic vasodilation, in 76 HCM patients and 10 non-HCM patients referred for evaluation of CAD (CAD group.) Data were resampled to create static, ECG-gated and 36-frame-dynamic images. Myocardial flow reserve (MFR) and MBF (in ml/min/g) were calculated using QPET and PMod softwares. RESULTS: All HCM patients had asymmetric septal hypertrophy, and 50% had evidence of LVOT obstruction, whereas non-HCM patients (CAD group) had normal wall thickness and ejection fraction. PMod yielded significantly higher values for global and regional stress-MBF and MFR than for QPET in HCM. Reasonably fair correlation was observed for global rest-MBF, stress-MBF, and MFR using these two softwares (rest-MBF: r = 0.78; stress-MBF: r = 0.66.; MFR: r = 0.7) in HCM patients. Agreement between global MBF and MFR values improved when HCM patients with high spillover fractions (> 0.65) were excluded from the analysis (rest-MBF: r = 0.84; stress-MBF: r = 0.72; MFR: r = 0.8.) Regionally, the highest agreement between PMod and QPET was observed in the LAD territory (rest-MBF: r = 0.82, Stress-MBF: r = 0.68) where spillover fraction was the lowest. Unlike HCM patients, the non-HCM patients (CAD group) demonstrated excellent agreement in MBF/MFR values, obtained by the two softwares, when patients with high spillover fractions were excluded (rest-MBF: r = 0.95; stress-MBF: r = 0.92; MFR: r = 0.95). CONCLUSIONS: Anatomic characteristics specific to HCM hearts contribute to lower correlations between MBF/MFR values obtained by PMod and QPET, compared with non-HCM patients. These differences indicate that PMod and QPET cannot be used interchangeably for MBF/MFR analyses in HCM patients.
Authors: Barry J Maron; William J McKenna; Gordon K Danielson; Lukas J Kappenberger; Horst J Kuhn; Christine E Seidman; Pravin M Shah; William H Spencer; Paolo Spirito; Folkert J Ten Cate; E Douglas Wigle Journal: J Am Coll Cardiol Date: 2003-11-05 Impact factor: 24.094
Authors: Ran Klein; Jennifer M Renaud; Maria C Ziadi; Stephanie L Thorn; Andy Adler; Rob S Beanlands; Robert A deKemp Journal: J Nucl Cardiol Date: 2010-04-13 Impact factor: 5.952
Authors: P Camici; G Chiriatti; R Lorenzoni; R C Bellina; R Gistri; G Italiani; O Parodi; P A Salvadori; N Nista; L Papi Journal: J Am Coll Cardiol Date: 1991-03-15 Impact factor: 24.094
Authors: R O Cannon; V Dilsizian; P T O'Gara; J E Udelson; E Tucker; J A Panza; L Fananapazir; C L McIntosh; R B Wallace; R O Bonow Journal: Circulation Date: 1992-03 Impact factor: 29.690