Surgical Application of a Novel Biomaterial Attenuates Post-MI Remodeling and Heart Failure: Impact of Intervention Timing Relative to Infarct Stage on Functional Recovery

BACKGROUND: Epicardial infarct repair (EIR) using a bio-inductive extracellular matrix (ECM) biomaterial is a novel surgical approach that targets the infarcted myocardium to enhance myocardial repair. We previously... [ view full abstract ]

BACKGROUND: Epicardial infarct repair (EIR) using a bio-inductive extracellular matrix (ECM) biomaterial is a novel surgical approach that targets the infarcted myocardium to enhance myocardial repair. We previously demonstrated that EIR prevents maladaptive LV remodeling and improves post-MI functional recovery. In this study we determine the effect of timing of biomaterial implant relative to infarct stage on the magnitude of functional benefit.
METHODS AND RESULTS: Permanent coronary artery ligation was performed in a rat model. Animals were randomized to receive EIR, the surgical application of ECM-biomaterial (CorMatrix-ECM, CorMatrix Cardiovascular Inc., GA, USA) to the infarcted myocardium, immediately following ischemic injury (early; N=8) or 3-weeks following ischemic injury (late; N=8). Indices of LV myocardial performance were evaluated by echocardiography and pressure volume loop analysis 14-weeks post-treatment. All animals treated with EIR demonstrated functional improvement when compared to infarcted animals that received a sham surgery (N=8). EIR resulted in an increased ejection fraction (EIR vs. sham: 42.43±13.09% vs. 25.15±6.99%; P=0.035), and contractility (0.7973±0.2245mmHg/uL vs. 0.4120±0.2415mmHg/uL; P=0.023). No significant differences in the degree of functional recovery were observed when EIR was performed early after ischemic injury as compared to late (ejection fraction: 41.45±14.49% vs. 39.17±15.20%, respectively; P=0.83; contractility: 0.7302±0.2846mmHg/uL vs. 0.7183±0.3261mmHg/uL, respectively; P=0.96).
CONCLUSION: These data demonstrate that EIR improves cardiac performance following MI regardless of whether EIR is applied during an evolving MI or after the infarct is complete. This has important implications for the clinical application of EIR as an adjunct to coronary artery bypass surgery.