Resumen

PUENTE B, Adriana et al. Non-Invasive evaluation of coronary atherosclerotic disease in patients with silent ischemia: Usefulness of myocardial perfusion SPECT, electrical, angiographic, and imaging correlation. Arch. Cardiol. Méx. [online]. 2005, vol.75, n.1, pp.29-34. ISSN 1665-1731.

The objective of the study was to evaluate the usefulness of SPECT myocardial perfusion imaging in the detection of silent ischemia. Methods: Myocardial perfusion SPECT was performed in 184 asymptomatic patients with diagnosis of stable coronary disease. The protocol consisted of Tc-99m tetrofosmin rest/stress in one day. Coronary angiography was performed in patients with moderate to severe ischemia. The agreement among myocardial perfusion defects, ST depression, and coronary lesions was established. Results: 80% of the patients were men and 20% were women, aged 60.5 ±10 years. The predominant risk factors were hypertension (57%), tabaquism (57%) and Diabetes Mellitus (43%). Clinical diagnoses were myocardial infarction in 77% and stable angina in 23%. The stress protocol was performed with dipyridamole in 40%, dipyridamole plus exercise in 40%, and only exercise in 20%. During the stress test all patients were asymptomatic and no evidence of ST segment changes was found in 74%. Myocardial SPECT showed necrosis in 85% of the patients, localized in the anterior descending territory (30%) and ischemia (15%) in the circumflex territory. Coronary artery disease affected the anterior descending (35%), circumflex (27%) and right coronary artery (23%). The SPECT myocardial perfusion imaging sensitivity for the detection of silent ischemia was 97%, with specificity of 97%, and predictive positive and negative value of 90% and 2%. Conclusions: The absence of chest pain and ST depression during the stress protocol were not good markers for the diagnosis of silent ischemia. Asymptomatic patients with ischemia detected in the myocardial perfusion SPECT have 3.8 more risks to have significant coronary obstructions (p < 0.0001).

Palabras llave : Silent ischemia; Myocardial perfusion; SPECT; Imaging techniques.