Aim: To define the prognostic impact of stress myocardial perfusion scintigraphy (MPS) in patients with angiographic exclusion of significant coronary artery disease.
Methods: Angiographic and MPS databases were matched to define patients without significant coronary artery disease by quantitative angiography (diameter stenosis <50%) who underwent stress MPS and coronary angiography within a time period of 3 months. A total of 118 patients were identified and followed for a mean of 6.3 +/- 1.2 years for death, a composite of death, myocardial infarction, bypass surgery, or percutaneous coronary intervention [MAE]) as well as occurrence of symptoms (angina or dyspnoe class CCS II to IV). Stress and rest MPS (using (99m)Tc-MIBI or tetrofosmin) were analyzed by quantitative perfusion SPECT (QPS) for summed stress and rest scores (SSS/SRS).
Results: There were 16 deaths, 29 MAE, and 76 patients with MAE or significant symptoms during follow-up. Significant differences in SSS were found between patients who died (9.5 +/- 6.9 vs. 5.4 +/- 5.6, P = 0.012), had MAE (8.7 +/- 7.2 vs. 5.2 +/- 5.0, P = 0.010), or had MAE or significant clinical symptoms (7.2 +/- 7.1 vs. 4.6 +/- 6.2, P = 0.042) compared to those without the respective event. Logistic regression analysis demonstrated SSS to be a predictor of death (OR = 1.074 [95% CI: 1.004-1.149], P = 0.026) and MAE (OR = 1.087 [95% CI: 1.004-1.181], P = 0.027).
Conclusions: In patients without significant angiographic coronary artery disease, the result of stress MPS is a predictor of long-term prognosis. Quantitative analysis of MPS allows definition of patients with a higher likelihood to develop clinical events or symptoms.