The old spontaneously hypertensive rat as a model for transmyocardial laser revascularisation research

Animal models used in transmyocardial laser revascularisation (TMLR) research lack the increased fibrosis observed in patients with chronic myocardial ischaemia. This pathology has also been described in patients with chronic elevated afterload, and therefore we evaluated the spontaneously hypertensive rat (SHR) as a model for TMLR research. We compared (1) the myocardial pathology of SHR with the pathology of three TMLR patients, (2) the reaction to TMLR in SHR and human myocardium using three different lasers, and (3) myocardial hypoxia in SHR myocardium and (healthy) Wistar rat myocardium. SHR and human myocardium both showed increased fibrosis and a similar myocardial reaction to TMLR (comparable morphology of fibrotic TMLR channel scars). More hypoxic cells were observed in SHR than in Wistar control rat myocardium. The similarities between SHR and human chronic ischaemic myocardium make the SHR a suitable model for TMLR research.