Background: The implementation and accuracy of the modalities for differential diagnosis of chest pain, such as CT coronary angiography (CCA), myocardial perfusion scan (SPECT), and exercise electrocardiography (ExECG) has never been investigated in the real world. In this study, we investigated the clinical effectiveness of noninvasive tests for the diagnosis of ischemic heart disease.
Methods: Total 4354 consecutive patients who presented to outpatient clinic with chest pain were analyzed retrospectively. Patients with previous history of coronary disese were excluded. Patients who underwent noninvasive tests were classified into 5 groups according to the pretest probability by Diamond & Forrester's scoring system (group A: <10, B:10-29, C:30-60, D:61-90, E: >90). The Likelihood ratio(LR) of positive and negative predictive value (PPV and NPV) of each modalities (CCA, SPECT, ExECG) were analyzed. The end points were defined as myocardial infarction or cardiovascular death within 1 year as well as significant stenosis (more than 50%) in coronary angiography(CAG).
Results: Among 4354 patients CCA was performed on 635 patients, SPECT on 998 patients, and ExECG on 853 patients as their initial test for differential diagnosis for chest pain. 722 patients were directly performed CAG, and 1146 patients were followed up medically without noninvasive test. 182(28.6%) of 635 patients performed CCA, 357(35.8%) of 998 performed SPECT, and 142(16.6%) of 853 performed ExECG have done CAG as their confirmatory test. The LR of each tests are descripted in Table 1. Among the patients who directly performed CAG, 5 (17.24%) patients in group A, 105 (54.69%) patients in group B, 33 (38.37%) patients in group C, 151 (58.98%) patients in group D, and 121 (76.10%) patients in group E had significant stenosis in CAG.
Conclusions: CCA is recommended for intermediate-to-high risk patients (group B to D) to rule out non-coronary originated chest pain. SPECT could be selectively used for very high risk patients (group E).