Myocardial infarction (MI) animal models that emulate the natural process of the disease in humans are crucial to understanding pathophysiological mechanisms and testing the safety and efficacy of new emergent therapies. Here, we describe an MI swine model created by deploying a percutaneous embolization coil.
Myocardial infarction (MI) is the leading cause of mortality worldwide. Despite the use of evidence-based treatments, including coronary revascularization and cardiovascular drugs, a significant proportion of patients develop pathological left-ventricular remodeling and progressive heart failure following MI. Therefore, new therapeutic options, such as cellular and gene therapies, among others, have been developed to repair and regenerate injured myocardium. In this context, animal models of MI are crucial in exploring the safety and efficacy of these experimental therapies before clinical translation. Large animal models such as swine are preferred over smaller ones due to the high similarity of swine and human hearts in terms of coronary artery anatomy, cardiac kinetics, and the post-MI healing process. Here, we aimed to describe an MI model in pig by permanent coil deployment. Briefly, it comprises a percutaneous selective coronary artery cannulation through retrograde femoral access. Following coronary angiography, the coil is deployed at the target branch under fluoroscopic guidance. Finally, complete occlusion is confirmed by repeated coronary angiography. This approach is feasible, highly reproducible, and emulates the pathogenesis of human non-revascularized MI, avoiding the traditional open-chest surgery and the subsequent postoperative inflammation. Depending on the time of follow-up, the technique is suitable for acute, sub-acute, or chronic MI models.
Myocardial infarction (MI) is the most prevalent cause of mortality, morbidity, and disability worldwide1. Despite current therapeutic advances, a significant proportion of patients develop adverse ventricular remodeling and progressive heart failure following MI, resulting in poor prognosis due to ventricular dysfunction and sudden death2,3,4. New therapeutic options to repair and/or regenerate injured myocardium are thus under scrutiny, and translational MI animal models are crucial in testing their safety and efficacy. Although several models have been used for cardiovascular research, including rats5,6, mice7,8, dogs9, and sheep10, pigs are one of the best choices for modeling cardiac ischemia studies because of their high similarity to humans in terms of heart size, coronary artery anatomy, cardiac kinetics, physiology, metabolism, and the post-MI healing process11,12,13,14,15.
In this context, many different open-surgical and percutaneous approaches are available to develop MI swine models. The open-chest approach involves a left lateral thoracotomy procedure and is useful in performing surgical coronary artery ligation16,17, myocardial cryo-injury, cauterization12, and coronary artery placement of a hydraulic occlude18 or an ameroid constrictor19, among others. Surgical coronary occlusion has been extensively used to test new therapeutic options such as cardiac tissue engineering and cell therapy, as it allows wide access and visual assessment of the heart; however, in contrast to human MI, it can result in surgical adhesions, adjacent scarring, and postoperative inflammation17. Myocardial cryo-injury and cauterization are easily reproducible techniques but do not reproduce the pathophysiological MI progression observed in humans12. On the other hand, several percutaneous techniques have been developed to produce temporary or permanent coronary blocking. These comprise transcoronary or intracoronary ethanol ablation20,21, occlusion by balloon angioplasty22, or delivery of thrombogenic materials such as agarose gel beads23, fibrinogen mixtures9, or coil embolization17,24. While balloon angioplasty is better suited for ischemia/reperfusion studies, coronary coil deployment is one of the best choices for modeling non-revascularized MI. This percutaneous approach is feasible, consistently reproducible, and avoids open-chest surgery. It allows precise control of the infarct location and results in pathophysiology similar to that of a human non-reperfused MI. Moreover, coil embolization is suitable for modeling acute, sub-acute, or chronic MI; chronic congestive heart failure; or valvular disease17.
The present protocol aims to describe how to develop an MI swine model by permanent coil deployment. Briefly, it comprises a percutaneous selective coronary artery cannulation through retrograde femoral access. Following coronary angiography, a coil is deployed at the target branch artery under fluoroscopic guidance. Finally, complete occlusion is confirmed by repeated coronary angiography.
A coil deployed in a coronary artery provides a reproducible and consistent pre-clinical non-reperfused MI model in swine that can be used to develop and test new cardiovascular therapeutic strategies.
In our hands, mortality at follow-up was 19% related to complications of MI, mostly within the first 24 h of the procedure. All these deaths are related to the natural history of the non-reperfused MI and were the primary outcomes of the study. One of the most critical steps in this protocol rel…
The authors have nothing to disclose.
We express our gratitude to the Center of Comparative Medicine and Bioimaging of Catalonia (CMCiB) and staff for their contribution to the animal model execution. This work was supported by the Instituto de Salud Carlos III (PI18/01227, PI18/00256, INT20/00052), the Sociedad Española de Cardiología, and the Generalitat de Catalunya [2017-SGR-483]. This work was also funded by the Red de Terapia Celular – TerCel [RD16/0011/0006] and CIBER Cardiovascular [CB16/11/00403] projects, as part of the Plan Nacional de I+D+I, and cofunded by the ISCIII-Subdirección General de Evaluación y el Fondo Europeo de Desarrollo Regional (FEDER). Dr. Fadeuilhe was supported by a grant from the Spanish Society of Cardiology (Madrid, Spain).
6-F JR4 0-71"guiding catheter | Medtronic | LA6JR40 | 6F JR4 90 cm Guiding catheter |
Adrenaline 1 mg/mL | B.Braun | National Code (NC). 602486 | Adrenaline |
Atropine 1 mg/mL | B.Braun | NC. 635649 | Atropine |
Betadine | Mylan | NC. 694109-1 | Povidone iodine solution |
Bupaq 0.3 mg/mL | Richter Pharma AG | NC. 578816.6 | Buprenorphine |
Dexdomitor 0.5 mg/mL | Orion Pharma | NC. 576303.3 | Dexmedetomidine |
Draxxin | Zoetis | NC. 576313.2 | Tulathromycin |
EMERALD Guidewire | Cordis | 502-585 | 0.035-inch J-tipped wire |
External defibrillator | DigiCare | CS81XVET | Manual external defibrillator |
Fendivia 100 µg/h | Takeda | NC. 658524.5 | Fentanyl transdermal patch |
Guidewire Introducer Needle 18 G x 7 cm | Argon | GWI1802 | Introducer needle |
Heparine 1% | ROVI | NC. 641647.1 | Heparin |
Hi-Torque VersaTurn F | Abbott | 1013317J | 0.014-inch 200 cm Guidewire |
IsoFlo | Zoetis | 50019100 | Isoflurane |
Ketamidor | Richter Pharma AG, | NC. 580393.7 | Ketamine |
Lidocaine 50 mg/mL | B.Braun | NC. 645572.2 | Lidocaine |
MD8000vet | Meditech Equipment | MD8000vet | Multi-parameter monitor |
Midazolam | Laboratorios Normon | NC. 624437.1 | Midazolam |
Prelude.6F.11 cm (4.3").0.035" (0.89 mm).50 cm (19.7").Double Ended.Stainless Steel.6F.16 | Merit | PSI-6F-11-035 | 6F Vascular sheath |
Propovet Multidosis 10 mg/mL | Zoetis | NC. 579742.7 | Propofol |
RENEGADE STC-18 150/20/STRAIGHT/1RO | Boston Scientific | M001181370 | 150 cm length with 0.017-inch inner diameter Microcatheter |
Ruschelit | Teleflex | 112482 | Endotracheal tube with balloon (#6.5) |
SPUR II | Ambu | 325 012 000 | Airway mask bag unit-ventilation (AMBU) |
Vasofix 20 G | B.Braun | 4269098 | 20 G Cannula |
Visipaque 320 mg/mL USB 10 x 200 mL | General Electrics | 1177612 | Iodinated contrast medium |
VortX-18 Diamond 3 mm/3.3 mm | Boston Scientific | M0013822030 | Coil |
WATO EX-35 | Mindray | WATO EX-35Vet | Anesthesia machine |