Objective: Chronic angina prior to myocardial infarction (CAPMI) is one of the clinical expressions of ischaemic preconditioning. The implications of this physiopathological phenomenon have been of little interest in myocardial perfusion gated SPECT (Single Photon Emission Computed Tomography) studies. The objective was to analyse the influence of CAPMI in the diagnosis of post-infarction myocardial viability and left ventricular remodelling in myocardial perfusion gated SPECT, and between patients with and without diabetes mellitus.
Methods: 131 patients with history of myocardial infarction and depressed systolic function were studied consecutively, analysing the clinical, electrocardiographic and ergometric characteristics and myocardial perfusion gated SPECT in patients with (n = 27) and without (n = 104) CAPMI.
Results: Patients with CAPMI were characterised by having a lesser extent of myocardial necrosis, more myocardial viability criteria and less left ventricular remodelling (lower volumes, less apical remodelling and higher EF) on the gated SPECT. Statistical significance for viability, necrosis and ventricular remodelling was not reached between diabetic patients with and without CAPMI.
Conclusions: CAPMI seems to protect patients with ischaemic cardiopathy from having a more extensive infarction at the expense of more residual myocardial viability scintigraphic criteria.