Prevalence, risk factors, and outcome of myocardial infarction with angiographically normal and near-normal coronary arteries: A systematic review and meta-analysis

Context: Coronary artery diseases are mostly detected using angiographic methods demonstrating arteries status. Nevertheless, Myocardial Infarction (MI) may occur in the presence of angiographically normal coronary arteries. Therefore, this study aimed to investigate the prevalence of MI with normal angiography and its possible etiologies in a systematic review. Evidence Acquisition: In this meta-analysis, the required data were collected from PubMed, Science Direct, Google Scholar, Scopus, Magiran, Scientific Information Database, and Medlib databases using the following keywords: “coronary angiograph”, “normal coronary arteries”, “near-normal coronary arteries”, “heart diseases”, “coronary artery disease”, “coronary disease”, “cardiac troponin I”, “Myocardial infarction”, “risk factor”, “prevalence”, “outcome”, and their Persian equivalents. Then, Comprehensive Meta-Analysis software, version 2 using randomized model was employed to determine the prevalence of each complication and perform the meta-analysis. P values less than 0.05 were considered to be statistically significant. Results: Totally, 20 studies including 139957 patients were entered into the analysis. The patients’ mean age was 47.62 ± 6.63 years and 64.4% of the patients were male. The prevalence of MI with normal or near-normal coronary arteries was 3.5% (CI = 95%, min = 2.2%, and max = 5.7%). Additionally, smoking and family history of cardiovascular diseases were the most important risk factors. The results showed no significant difference between MIs with normal angiography and 1- or 2-vessel involvement regarding the frequency of major adverse cardiac events (5.4% vs. 7.3%, P = 0.32). However, a significant difference was found between the patients with normal angiography and those with 3-vessel involvement in this regard (5.4% vs. 20.2%, P < 0.001). Conclusions: Although angiographic studies are required to assess the underlying etiology of MI, physicians facing patients presenting with the clinical features of MI in presence of normal or near-normal coronary arteries should consider the prevalence and risk factors of MI with normal or near-normal coronary arteries.