Faculty Bibliography

BACKGROUND: Myocardial systolic strain patterns in dilated cardiomyopathy are considered non-homogeneous but have not been investigated with magnetic resonance imaging (MRI)-based multiparametric systolic strain analysis. Left ventricular (LV) 3-dimensional (3D) multiparametric systolic strain analysis is sensitive to regional contractility and is generated from sequential MRI of tissue-tagging gridline-point displacements. METHODS: Sixty normal human volunteers underwent MRI-based 3D systolic strain analysis to supply normal average and standard deviation values for each of three strain parameters at each of 15,300 individual LV grid-points. Patient-specific multiparametric systolic strain data from each dilated cardiomyopathy patient (n = 10) were then subjected to a point-by-point comparison (n = 15,300 LV points) to the normal strain database for three individual strain components (45,900 database comparisons per patient). The resulting composite multiparametric Z-score values (standard deviation from normal average) were color contour mapped over patient-specific 3D LV geometry to detect the normalized regional contractile patterns associated with dilated cardiomyopathy. RESULTS: Average multiparametric strain Z-score values varied significantly according to ventricular level (p = 0.001) and region (p = 0.003). Apical Z-scores were significantly less than those in both the base (p = 0.037) and mid-ventricle (p = 0.002), whereas anterolateral wall Z-scores were less than those in the anteroseptal (p = 0.023) and posteroseptal walls (p = 0.028). CONCLUSIONS: MRI-based multiparametric systolic strain analysis suggests that myocardial systolic strain in patients with dilated cardiomyopathy has a heterogeneous regional distribution and, on average, falls almost 2 standard deviations from normal.

OBJECTIVE: The purpose of this investigation was to examine the impact of prosthesis-patient mismatch after bioprosthetic aortic valve replacement on long-term survival in patients greater than 70 years of age compared with those less than or equal to 70 years of age. METHODS: Between 1992 and 2007, 1399 patients underwent bioprosthetic aortic valve replacement, including 881 (63%) patients older than 70 years of age. Prosthesis-patient mismatch was defined as severe (prosthetic effective orifice area/body surface area < 0.65 cm(2)/m(2)), moderate (0.65-0.85 cm(2)/m(2)), or absent (>0.85 cm(2)/m(2)). For patients less than or equal to 70 years of age, mismatch was severe in 62 (12%), moderate in 251 (48%), and absent in 205 (40%). For patients greater than 70 years of age, mismatch was severe in 109 (12%), moderate in 451 (51%), and absent in 321 (37%). There was no difference in the distribution of prosthesis-patient mismatch between age groups (P = .50). RESULTS: For patients less than or equal to 70 years, prosthesis-patient mismatch was associated with impaired long-term survival (P = .02). Survival at 5 and 10 years was 61% +/- 7% and 28% +/- 12% for severe mismatch, 65% +/- 3% and 40% +/- 5% for moderate mismatch, and 73% +/- 5% and 46% +/- 9% for no mismatch. For patients greater than 70 years, prosthesis-patient mismatch did not affect long-term survival (P = .25). Survival at 5 and 10 years was 62% +/- 5% and 42% +/- 6% for severe mismatch, 62% +/- 2% and 30% +/- 5% for moderate mismatch, and 53% +/- 4% and 29% +/- 5% for absent mismatch. CONCLUSIONS: After bioprosthetic aortic valve replacement, prosthesis-patient mismatch had a negative impact on late survival for patients less than or equal to 70 years of age, but for patients greater than 70 years of age, prosthesis-patient mismatch did not influence late survival.