Cardiovascular magnetic resonance evaluation of symptomatic severe aortic stenosis: association of circumferential myocardial strain and mortality.
BACKGROUND
It is unknown whether circumferential strain is associated with prognosis after treatment of aortic stenosis (AS). We aimed to characterise strain in severe AS, using myocardial tagging cardiovascular magnetic resonance (CMR), prior to and following Transcatheter Aortic Valve Implantation (TAVI) and Surgical Aortic Valve Replacement (SAVR), and determine whether abnormalities in strain were associated with outcome.


METHODS
CMR was performed pre- and 6 m post-intervention in 98 patients (52 TAVI, 46 SAVR; 77 ± 8 years) with severe AS. TAVI patients were older (80.9 ± 6.4 vs. 73.0 ± 7.0 years, p < 0.01) with a higher STS score (2.06 ± 0.6 vs. 6.03 ± 3.4, p < 0.001). Tagged cine images were acquired at the basal, mid and apical LV levels with a complementary spatial modulation of magnetization (CSPAMM) pulse sequence. Circumferential strain, strain rate and rotation were calculated using inTag© software.


RESULTS
No significant change in basal or mid LV circumferential strain, or of diastolic strain rate, was seen following either intervention. However, a significant and comparable decline in LV torsion and twist was observed (SAVR: torsion 14.08 ± 8.40 vs. 7.81 ± 4.51, p < 0.001, twist 16.17 ± 7.01 vs.12.45 ± 4.78, p < 0.01; TAVI: torsion 14.43 ± 4.66 vs. 11.20 ± 4.62, p < 0.001, twist 16.08 ± 5.36 vs. 12.36 ± 5.21, p < 0.001) which likely reflects an improvement towards normal physiology following relief of AS. Over a maximum 6.0y follow up, there were 23 (16%) deaths following valve intervention. On multivariable Cox analysis, baseline mid LV circumferential strain was significantly associated with all-cause mortality (hazard ratio, 1.03; 1.01-1.05; p = 0.009) independent of age, LV ejection fraction and STS mortality risk score. ROC analysis indicated a mid LV circumferential strain > -18.7% was associated with significantly reduced survival.


CONCLUSIONS
TAVI and SAVR procedures are associated with comparable declines in rotational LV mechanics at 6 m, with largely unchanged strain and strain rates. Pre-operative peak mid LV circumferential strain is associated with post-operative mortality.
Multidisciplinary Cardiovascular Research Centre & The Division of Cardiovascular and Diabetes Research, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, LS2 9JT, UK.
Tarique Al
TA
Musa
Multidisciplinary Cardiovascular Research Centre & The Division of Cardiovascular and Diabetes Research, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, LS2 9JT, UK.
Akhlaque
A
Uddin
Multidisciplinary Cardiovascular Research Centre & The Division of Cardiovascular and Diabetes Research, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, LS2 9JT, UK.
Peter P
PP
Swoboda
Multidisciplinary Cardiovascular Research Centre & The Division of Cardiovascular and Diabetes Research, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, LS2 9JT, UK.
Timothy A
TA
Fairbairn
Multidisciplinary Cardiovascular Research Centre & The Division of Cardiovascular and Diabetes Research, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, LS2 9JT, UK.
Laura E
LE
Dobson
Department of Cardiovascular Sciences, and the National Institute of Health Research (NIHR), Cardiovascular Biomedical Research Unit, Glenfield General Hospital, University of Leicester, Leicester, UK.
Anvesha
A
Singh
Multidisciplinary Cardiovascular Research Centre & The Division of Cardiovascular and Diabetes Research, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, LS2 9JT, UK.
Pankaj
P
Garg
Department of Cardiovascular Sciences, and the National Institute of Health Research (NIHR), Cardiovascular Biomedical Research Unit, Glenfield General Hospital, University of Leicester, Leicester, UK.
Christopher D
CD
Steadman
Multidisciplinary Cardiovascular Research Centre & The Division of Cardiovascular and Diabetes Research, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, LS2 9JT, UK.
Bara
B
Erhayiem
Multidisciplinary Cardiovascular Research Centre & The Division of Cardiovascular and Diabetes Research, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, LS2 9JT, UK.
Ananth
A
Kidambi
Multidisciplinary Cardiovascular Research Centre & The Division of Cardiovascular and Diabetes Research, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, LS2 9JT, UK.
David P
DP
Ripley
Multidisciplinary Cardiovascular Research Centre & The Division of Cardiovascular and Diabetes Research, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, LS2 9JT, UK.
Adam K
AK
McDiarmid
Multidisciplinary Cardiovascular Research Centre & The Division of Cardiovascular and Diabetes Research, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, LS2 9JT, UK.
Philip
P
Haaf
Leeds Teaching Hospitals NHS Trust, Leeds General Infirmary, Leeds, UK.
Daniel J
DJ
Blackman
Multidisciplinary Cardiovascular Research Centre & The Division of Cardiovascular and Diabetes Research, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, LS2 9JT, UK.|Leeds Teaching Hospitals NHS Trust, Leeds General Infirmary, Leeds, UK.
Sven
S
Plein
Department of Cardiovascular Sciences, and the National Institute of Health Research (NIHR), Cardiovascular Biomedical Research Unit, Glenfield General Hospital, University of Leicester, Leicester, UK.
Gerald P
GP
McCann
Multidisciplinary Cardiovascular Research Centre & The Division of Cardiovascular and Diabetes Research, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, LS2 9JT, UK. j.greenwood@leeds.ac.uk.|Leeds Teaching Hospitals NHS Trust, Leeds General Infirmary, Leeds, UK. j.greenwood@leeds.ac.uk.
John P
JP
Greenwood
D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging* / Q000401:mortality / Q000503:physiopathology / Q000601:surgery; D019540:Area Under Curve; D001696:Biomechanical Phenomena; D016009:Chi-Square Distribution; D004739:England; D005260:Female; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D053208:Kaplan-Meier Estimate; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D015999:Multivariate Analysis; D009200:Myocardial Contraction; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012372:ROC Curve; D020127:Recovery of Function; D012307:Risk Factors; D012720:Severity of Illness Index; D012984:Software; D013314:Stress, Mechanical; D013318:Stroke Volume; D054159:Torsion, Mechanical; D065467:Transcatheter Aortic Valve Replacement; D016896:Treatment Outcome; D016277:Ventricular Function, Left
Aortic stenosis; Aortic valve replacement; Myocardial tissue tagging; Transcatheter aortic valve implantation