Typical angina is associated with greater coronary endothelial dysfunction but not abnormal vasodilatory reserve.

Abstract

BackgroundTypical angina (TA) is defined as substernal chest pain precipitated by physical exertion or emotional stress and relieved with rest or nitroglycerin. Women and elderly patients are usually have atypical symptoms both at rest and during stress, often in the setting of nonobstructive coronary artery disease (CAD).HypothesisTo further understand this, we performed subgroup analysis comparing subjects who presented with TA vs nontypical angina (NTA) using baseline data of patients with nonobstructive CAD and coronary microvascular dysfunction (CMD) enrolled in a clinical trial.Methods155 subjects from the RWISE study were divided into 2 groups based on angina characteristics: TA (defined as above) and NTA (angina that does not meet criteria for TA). Coronary reactivity testing (responses to adenosine, acetylcholine, and nitroglycerin), cardiac magnetic resonance–determined myocardial perfusion reserve index (MPRI), baseline Seattle Angina Questionnaire (SAQ), and Duke Activity Status Index (DASI) scores were evaluated.ResultsThe mean age was 55 ± 10 years; Overall, 30% of subjects had TA. Baseline shortness of breath, invasively assessed acetylcholine‐mediated coronary endothelial function, and SAQ score were worse in the TA group (all P < 0.05), whereas adenosine‐mediated coronary flow reserve, MPRI, and DASI score were similar to the NTA group.ConclusionsAmong subjects with CMD and no obstructive CAD, those with TA had more angina pectoris, shortness of breath, and worse quality of life, as well as more severe coronary endothelial dysfunction. Typical angina in the setting of CMD is associated with worse symptom burden and coronary endothelial dysfunction. These results indicate that TA CMD subjects represent a relatively new CAD phenotype for future study and treatment trials.