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Published on: March 27, 2018
Impact of Myocardial Viability on Long-term Outcomes after Surgical Revascularization
Suk Ho Sohn1, Yoonjin Kang1, Ji Seong Kim1
1Department of Thoracic and Cardiovascular Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea.
Insights
Cardiac MRI
Area of Science:
- Cardiology
- Medical Imaging
- Cardiovascular Surgery
Background:
- Ischemic cardiomyopathy (ICMP) impacts long-term outcomes after coronary artery bypass grafting (CABG).
- Assessing myocardial viability pre-CABG is crucial for predicting patient prognosis.
- Cardiac magnetic resonance (CMR) offers detailed myocardial assessment.
Purpose of the Study:
- To determine if myocardial viability, assessed by CMR, influences long-term clinical outcomes in ICMP patients undergoing CABG.
- To identify specific CMR-derived parameters that predict adverse events post-CABG.
Main Methods:
- 103 ICMP patients with 3-vessel disease and LVEF ≤ 0.35 underwent preoperative CMR with late gadolinium enhancement (LGE).
- Transmural extent of LGE was quantified using a 16-segment model and a 5-point scale (0-100%).
- Primary endpoint: composite of all-cause mortality or heart failure hospitalization; median follow-up: 65.5 months.
Main Results:
- Operative mortality was 1.9%.
- The number of myocardial segments with transmural LGE (grade 4, >75%) was a significant predictor of the primary endpoint (HR 1.42, p=0.007).
- Other risk factors included age, dialysis, COPD, and EuroSCORE II.
Conclusions:
- Myocardial scar burden, specifically transmural LGE extent, is a significant prognostic factor after CABG in ICMP patients.
- CMR-derived myocardial viability assessment can refine risk stratification for these patients.
- This finding aids in optimizing surgical decision-making and patient management.
Background:
This study was conducted to evaluate whether myocardial viability assessed with cardiac magnetic resonance (CMR) affected long-term clinical outcomes after coronary artery bypass grafting (CABG) in patients with ischemic cardiomyopathy (ICMP).
Methods:
Preoperative CMR with late gadolinium enhancement (LGE) was performed in 103 patients (64.9 ± 10.1 years, male:female = 82:21) with 3-vessel disease and left ventricular dysfunction (ejection fraction ≤ 0.35). Transmural extent of LGE was evaluated on a 16-segment model, and transmurality was graded on a 5-point scale: grades-0, absence; 1, 1 to 25%; 2, 26 to 50%; 3, 51 to 75%; 4, 76 to 100%. Median follow-up duration was 65.5 months (interquartile range = 27.5-95.3 months). Primary endpoint was the composite of all-cause mortality or hospitalization for congestive heart failure.
Results:
Operative mortality was 1.9%. During the follow-up, all-cause mortality and readmission for congestive heart failure occurred in 29 and 8 patients, respectively. The cumulative incidence of the primary endpoint was 31.3 and 46.8% at 5 and 10 years, respectively. Multivariable analysis demonstrated that the number of segments with LGE grade 4 was a significant risk factor (hazard ratio 1.42, 95% confidence interval 1.10-1.83, p = 0.007) for the primary endpoint among the variables assessed by CMR. Other risk factors included age, dialysis, chronic obstructive pulmonary disease, and EuroSCORE II.
Conclusion:
The number of myocardial segments with transmurality of LGE >75% might be a prognostic factor associated with the composite of all-cause mortality or hospitalization for congestive heart failure after CABG in patients with 3-vessel disease and ICMP.
