Myocardial Viability and Revascularization: Rethinking the Threshold-Insights from a Real-World Cardiac MRI Cohort

Presenting Author(s)

• 

  Amro Alsaid, MD, FSCMR

  Cardiologist
  Baylor Scott & White - The Heart Hospital Plano
  Plano, Texas, United States

Co-Author(s)

• MA

  Mohamad Bader Abo Hajar, MD

  Cardiology Research Fellow
  Baylor Scott and White The Heart Hospital Plano
  Plano, Texas, United States
• CD

  Cody Dorton, DO

  Research Fellow
  Baylor Scott & White Research Institute
  Plano, Texas, United States
• KM

  Kyle McCullough, MD

  Research Fellow
  Baylor Scott & White Research Institute
  Plano, Texas, United States
• JH

  Jennie Hocking, MSc

  Research Intern
  Baylor Scott & White Research Institute
  Plano, Texas, United States
• RG

  Rahul Gunukula, BSc

  Research Intern
  Baylor Scott & White Research Institute
  Plano, Texas, United States
• PP

  Prajakta Phatak, MD

  cardiologist
  Baylor Scott and White The Heart Hospital Plano
  Plano, Texas, United States
• JM

  Janaki Manne, MD

  cardiologist
  Baylor Scott and White The Heart Hospital Plano
  Plano, Texas, United States
• JD

  J. Michael DiMaio, MD

  cardiothoracic surgeon
  Baylor Scott and White The Heart Hospital Plano
  Plano, Texas, United States

Primary Author(s)

• 

  Amro Alsaid, MD, FSCMR

  Cardiologist
  Baylor Scott & White - The Heart Hospital Plano
  Plano, Texas, United States

Co-Author(s)

• 

  Amro Alsaid, MD, FSCMR

  Cardiologist
  Baylor Scott & White - The Heart Hospital Plano
  Plano, Texas, United States

Background: Conventional thresholds for myocardial viability, particularly a 50% scar transmurality cutoff, have long guided decisions for revascularization in ischemic cardiomyopathy. However, emerging real-world data challenges whether this cutoff remains clinically optimal in the current revascularization landscape. We therefore aimed to describe our institutional experience and outcomes following cardiac MRI in the setting of ischemic heart disease.

Methods: We retrospectively analyzed 128 patients undergoing cardiac MRI with late gadolinium enhancement (LGE) for viability assessment at a single institution. Data, including follow-up imaging and treatment modalities, was obtained via review of the electronic health record. Follow-up LVEF was available in 77 patients (60.2%), forming the analysis cohort. Scar burden was stratified by coronary territory and maximum transmurality (< 50%, 50–70%, >70%). Outcomes included LVEF improvement ≥5% and final LVEF >35%. Treatment strategies were categorized as optimal medical therapy (OMT), percutaneous coronary intervention (PCI), or coronary artery bypass grafting (CABG). Outcomes were compared against STICH and REVIVED trial benchmarks.

Results: Among 77 patients with follow-up EF, mean EF improvement was 5.3% ± 21.5%. EF improved ≥5% in 49.4% and final EF exceeded 35% in 59.7%. Patients with >70% scar in any territory (n=11) had lower success rates (EF ≥5% in 36.4%; EF >35% in 63.6%) compared with those with ≤70% scar (EF ≥5% in 50.9%; EF >35% in 56.4%). Treatment-stratified findings showed that PCI provided moderate benefit in patients with >70% scar (EF ≥5% in 50%), while CABG offered limited benefit in patients with high scar burden. Patients with < 50% scar treated with OMT alone (n=11) experienced a mean EF improvement of only 1.5%. Notably, patients with LAD scar >70% still demonstrated EF improvement ≥5% in 42.9% and final EF >35% in 57.1%.

Conclusion: This real-world analysis supports the conventional use of a 50% scar transmurality threshold for viability assessment. Patients with >70% scar had lower EF improvement and reduced clinical success rates; however, a meaningful subset still derived benefit, particularly with PCI. These findings suggest the need for individualized assessment strategies rather than utilization of rigid cutoff values in decision-making for patients with ischemic heart disease.

Distribution of change in left ventricular ejection fraction (EF) across the complete cohort (n=77) with both baseline and follow-up EF data. Nearly half (49.4%) of patients experienced ≥5% EF improvement. Range of EF change spanned from -40% to +52.5%. The mean EF change in the study cohort compared to outcomes from the STICH (~5%) and REVIVED (~2.5%) trials. The study cohort had a mean EF improvement of 5.3%, placing it between STICH and REVIVED benchmarks.
Success rates for achieving ≥5% EF improvement by treatment modality (OMT, PCI, CABG) across three scar categories ( <50%, 50–70%, >70%). Notably, PCI demonstrated benefit even in the >70% scar group, while CABG had diminishing returns beyond the 70% threshold.
Heatmap showing distribution of patients by treatment modality and scar burden. Most patients undergoing CABG had 50–70% scar, while PCI and OMT spanned a broader range. The graphic underscores the real-world treatment decision variance despite viability thresholds.