# Quantitative Methods for Optimizing IMR Repair

> **NIH NIH R01** · UNIVERSITY OF PENNSYLVANIA · 2020 · $764,407

## Abstract

Ischemic mitral regurgitation (IMR) occurs when a mitral valve (MV) is rendered incompetent by
left ventricular (LV) remodeling induced by a myocardial infarction (MI). IMR is present in over
50% of patients with reduced LV function undergoing coronary artery bypass grafting (CABG)
and affects at least 300,000 Americans. The magnitude of the problem is significant and is
expected to grow substantially during the next 20 years as the population ages. MV repair with
undersized ring annuloplasty is currently the preferred treatment for IMR. However, 1/3 of all
patients treated this way develop significant recurrent IMR within 12 months. Using our real time
3D echocardiography (rt-3DE) image software we have demonstrated that IMR in humans is
heterogeneous. In some patients the cause of IMR is annular dilatation and flattening. While in
others leaflet tethering is the major pathology. In recent work we have demonstrated that it is in
the latter group that undersized ring annuloplasty does not provide durable IMR repair. There is
now agreement that adjunctive procedures are required to treat IMR caused by leaflet tethering.
But there is no consensus regarding the best procedure. Despite significant interest in
developing these procedures the reported data are from small, single center retrospective
studies. Multi-center registries and randomized trials would be necessary to prove which
procedure is superior. Given the number of proposed procedures and the complexity and
duration of such studies it is highly unlikely that IMR procedure optimization could be effectively
carried out this way. It is thus becoming clear that novel computational approaches directed
towards optimized annuloplasty ring design and leaflet augmentation procedures can
substantially reduce wasted time by minimizing trial-and-error approaches. We thus
hypothesize that our state-of-the-art MV computational models, which can directly utilize
rt-3DE imaging data coupled to novel effective MV leaflet and chordae tendonae (MVCT)
structures, can be used in conjunction with clinically applicable large animal models to
develop quantitatively optimize devices and procedures to treat IMR secondary to leaflet
tethering. To prove this hypothesis the following specific aims will be achieved by leveraging
our group's expertise in: 1) the pathogenesis of IMR, 2) IMR animal models, 3) rt-3DE MV
imaging, 4) annuloplasty ring design, 4) MV cell-tissue coupled models, and 5) micro- and
macro-anatomically accurate MV finite element models.

## Key facts

- **NIH application ID:** 9844952
- **Project number:** 5R01HL073021-11
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** Robert C Gorman
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $764,407
- **Award type:** 5
- **Project period:** 2019-01-04 → 2022-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9844952

## Citation

> US National Institutes of Health, RePORTER application 9844952, Quantitative Methods for Optimizing IMR Repair (5R01HL073021-11). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9844952. Licensed CC0.

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