CMR-Analysis (including machine learning)
Cole R. Latvis, BSc
PhD Student
Weill Cornell Medicine
Cortland, New York, United States
Cole R. Latvis, BSc
PhD Student
Weill Cornell Medicine
Cortland, New York, United States
Robert Y. Park, MD
Fellow
Weill Cornell Medical College, United States
Maria Chiara Palumbo, MSc
PhD Student
Politecnico di Milano
New York, New York, Italy
Jiwon Kim, MD
Associate Professor of Medicine
Weill Cornell Medicine
New York, New York, United States
Hannah Agoglia, BSc
Research Assistant
Weill Cornell Medicine, United States
Nicole Liberman, BA
Research Assistant
Weill Cornell Medicine, United States
Pablo Villar-Calle, MD
Fellow
Weill Cornell Medicine, Spain
Alexander Phan, MD
Fellow
Weill Cornell Medicine, United States
Lisa Q. Rong, MD, MSc
assistant professor
Weill Cornell Medicine
New York, New York, United States
Yadong Wang, PhD
McAdam Family Foundation Professor of Heart Assist Technology
Cornell University, United States
Alberto Redaelli, PhD
Professor
Politecnico di Milano
Milano, Italy
Mary Roman, MD
Professor of Medicine
Weill Cornell Medicine, New York, United States
Richard C. Devereux, MD
Professor of Medicine
Weill Cornell Medical College
Bronxville, New York, United States
Mario Gaudino, MD, PhD
Professor
Weill Cornell Medicine
New York, NY, United States
Leonard N. Girardi, MD
O. Wayne Isom Professor and Chairman
Weill Cornell Medicine
New York, New York, United States
Jonathan W. Weinsaft, MD
Professor of Medicine
Weill Cornell Medical College
New York, New York, United States
In patients with ascending thoracic aortic aneurysms (TAA), prosthetic graft replacement yields benefit but risk for complications in the distal aorta persists – especially in patients with genetic aortopathies such as Marfan syndrome (MFS): Mechanisms for adverse events after proximal graft implantation are uncertain and poorly predicted by aortic size. Cine cardiac magnetic resonance (cine-CMR) enables quantification of both aortic size and vessel wall dynamics but has yet to be used to study the long-term impact prosthetic grafts have on aortic biomechanics within and distal to prosthetic grafts.
Methods:
MFS pts chronically ( > 1 year) after proximal aortic graft (Dacron) implantation of ascending TAA, and non-surgical MFS pts (maximal diameter < 4.5cm) were studied. Cine-CMR (76% 3T, 24% 1.5T) employed ECG gated (temporal resolution ~30msec) steady state free precession to quantify aortic size (area, maximal diameter), and biomechanics including global circumferential strain (GCS), fractional area change (FAC), and distensibility at landmarks in the mid ascending and descending aorta. GCS was calculated [GCS = (Cs-Cd)/Cd × 100] based on aortic end-systolic and end-diastolic circumference (Cs, Cd). Fractional area change was derived from end-systolic (ESA) and end-diastolic (EDA) area [FAC= (ESA-EDA)/EDA × 100]; Distensibility [(ESA-EDA)/(EDA × PP)] incorporated brachial arterial pulse pressure; Descending aortic analyses were performed blinded to ascending analyses, and to surgical status.
Results: 45 MFS pts (18% F, 39.6±14.0 yo) underwent clinical CMR of whom 21 pts had chronic proximal grafts (10.9±7.3 years post-operatively). Pts with grafts tended to be older (43.7±13.6 vs 36.1±13.6, p=0.07), but were otherwise similar in clinical characteristics and medications. Table 1 reports cine-CMR quantified aortic size and vessel wall dynamics. As shown, despite similar ascending size, grafted territories manifested 2-4 fold decrements in GCS, FAC, and distensibility (p< 0.001), consistent with lesser vessel wall compliance. Conversely, native descending aortic size was larger in chronic graft pts (all p< 0.001), paralleled by increased GCS, FAC, and distensibility (all p< 0.05). In multivariate analysis (Table 2), proximal grafts associated with increased descending aortic strain (B=5.13, p< 0.001) after controlling for age and descending aortic size. Similarly, proximal grafts associated with decreased ascending aortic strain (B=-6.70, p< 0.001) independent of age and maximal (root, ascending) aortic size.
Conclusion: Cine-CMR enables novel insights into aortic biomechanics beyond conventional size-based indices: Prosthetic graft replacement increases stiffness of the ascending aorta and associates with chronic increments in distal (native) aortic strain, providing a potential mechanism for adverse aortic remodeling and events in pts with genetic aortopathies.