title: Quantitative assessment of paravalvular regurgitation following transcatheter aortic valve replacement.
abstract: BACKGROUND
  Paravalvular aortic regurgitation (PAR) following transcatheter aortic valve implantation (TAVI) is well acknowledged. Despite improvements, echocardiographic measurement of PAR largely remains qualitative. Cardiovascular magnetic resonance (CMR) directly quantifies AR with accuracy and reproducibility. We compared CMR and transthoracic echocardiography (TTE) analysis of pre-operative and post-operative aortic regurgitation in patients undergoing both TAVI and surgical aortic valve replacement (AVR).
  
  
  METHODS
  Eighty-seven patients with severe aortic stenosis undergoing TAVI (56 patients) or AVR were recruited. CMR (1.5 T) and transthoracic echocardiography (TTE) were carried out pre-operatively and a median of 6 days post-operatively. The CMR protocol included regurgitant aortic flows using through-plane phase-contrast velocity. None/trivial, mild, moderate and severe AR by CMR was defined as ≤8%, 9-20%, 21-39%, >40% regurgitant fractions respectively.
  
  
  RESULTS
  Pre- and post-operative left ventricular ejection fraction (LVEF) was similar. Post-procedure aortic regurgitant fraction using CMR was higher in the TAVI group (TAVI 16 ± 13% vs. AVR 4 ± 4%, p < 0.01). Comparing CMR to TTE, 27 of 56 (48%) TAVI patients had PAR which was at least one grade more severe on CMR than TTE (Z = -4.56, p <0.001). Sensitivity analysis confirmed the difference in PAR grade between TTE and CMR in the TAVI group (Z = -4.49, p < 0.001).
  
  
  CONCLUSIONS
  When compared to CMR based quantitative analysis, TTE underestimated the degree of paravalvular aortic regurgitation. This underestimation may in part explain the findings of increased mortality associated with mild or greater AR by TTE in the PARTNER trial. Paravalvular aortic regurgitation post TAVI assessed as mild by TTE may in fact be more severe.
authors.affiliation: South Australian Health and Medical Research Institute, Adelaide, Australia. gareth.crouch@gmail.com.|Department of Cardiothoracic Surgery, Flinders Medical Centre, Adelaide, Australia. gareth.crouch@gmail.com.|Flinders University of South Australia, Adelaide, SA, Australia. gareth.crouch@gmail.com.
authors.forename: Gareth
authors.initials: G
authors.lastname: Crouch
authors.affiliation: Department of Cardiothoracic Surgery, Flinders Medical Centre, Adelaide, Australia. phillip.tully@adelaide.edu.au.
authors.forename: Phillip J
authors.initials: PJ
authors.lastname: Tully
authors.affiliation: Department of Cardiothoracic Surgery, Flinders Medical Centre, Adelaide, Australia. jayme.bennetts@health.sa.gov.au.
authors.forename: Jayme
authors.initials: J
authors.lastname: Bennetts
authors.affiliation: Department of Cardiology, Flinders Medical Centre, Flinders Drive, Bedford Park, Adelaide, SA, 5042, Australia. ajay.sinhal@health.sa.gov.au.
authors.forename: Ajay
authors.initials: A
authors.lastname: Sinhal
authors.affiliation: South Australian Health and Medical Research Institute, Adelaide, Australia. craig.bradbrook@health.sa.gov.au.
authors.forename: Craig
authors.initials: C
authors.lastname: Bradbrook
authors.affiliation: Department of Cardiology, Flinders Medical Centre, Flinders Drive, Bedford Park, Adelaide, SA, 5042, Australia. amy.penhall@health.sa.gov.au.
authors.forename: Amy L
authors.initials: AL
authors.lastname: Penhall
authors.affiliation: South Australian Health and Medical Research Institute, Adelaide, Australia. carmine.depasquale@health.sa.gov.au.|Department of Cardiology, Flinders Medical Centre, Flinders Drive, Bedford Park, Adelaide, SA, 5042, Australia. carmine.depasquale@health.sa.gov.au.
authors.forename: Carmine G
authors.initials: CG
authors.lastname: De Pasquale
authors.affiliation: Department of Cardiothoracic Surgery, Flinders Medical Centre, Adelaide, Australia. rob.baker@health.sa.gov.au.|Flinders University of South Australia, Adelaide, SA, Australia. rob.baker@health.sa.gov.au.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Baker
authors.affiliation: South Australian Health and Medical Research Institute, Adelaide, Australia. joseph.selva@health.sa.gov.au.|Department of Cardiology, Flinders Medical Centre, Flinders Drive, Bedford Park, Adelaide, SA, 5042, Australia. joseph.selva@health.sa.gov.au.|Flinders University of South Australia, Adelaide, SA, Australia. joseph.selva@health.sa.gov.au.
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Selvanayagam
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000503:physiopathology; D001022:Aortic Valve Insufficiency / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D001024:Aortic Valve Stenosis / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D006328:Cardiac Catheterization / Q000009:adverse effects*; D005260:Female; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects* / Q000379:methods; D006439:Hemodynamics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D013318:Stroke Volume; D013997:Time Factors; D016896:Treatment Outcome; D014463:Ultrasonography; D016277:Ventricular Function, Left