Angina Frequency After Acute Myocardial Infarction In Patients Without Obstructive Coronary Artery Disease

Abstract

Background: Myocardial infarction (MI) patients without obstructive coronary artery disease (CAD) are at increased risk for recurrent ischemic events, but angina frequency post-MI has not been described.

Methods and results: Among MI patients who underwent angiography, we assessed angina at baseline, 1, 6, and 12 months using the Seattle Angina Questionnaire (SAQ). A hierarchical repeated measures modified Poisson model assessed the association between the absence of obstructive CAD (defined as epicardial stenoses >70% or left main >50%) and angina. Among 5539 MI patients from 31 US hospitals (mean age 60, 68% male), 6.9% had no angiographic obstructive CAD. More patients without obstructive CAD (vs. obstructive CAD) were female (57% vs 30%), non-white (51% vs 24%) and had NSTEMI (87% vs 51%). In unadjusted analyses, patients without obstructive CAD had less angina prior to MI but more angina and worse health status post-discharge. After adjustment for socio-demographic and clinical factors, the risk of post-MI angina was similar in patients without vs. with obstructive CAD (IRR=0.89, 95% CI 0.77-1.02). Among patients without obstructive CAD, depression and self-reported avoidance of care due to cost were independently associated with angina (IRR=1.28 per 5 points on PHQ, 95% CI 1.17-1.41; IRR=1.34, 95% 1.02-1.1.74).

Conclusions: Following MI, patients without obstructive CAD experience an angina burden at least as high as those with obstructive CAD, affecting 1 in 4 patients at 12 months. As these patients are not candidates for revascularization, other anti-anginal strategies are needed to improve their health status and quality of life.

Keywords: Acute myocardial infarction; Angina; Coronary artery disease.

Figures

Figure 1

Flowchart of analytical cohort in the TRIUMPH and PREMIER registries.

Figure 2

Rate of patient-reported angina in patients without vs. with obstructive coronary artery disease over the year following myocardial infarction.

Figure 3

Rates of all-cause rehospitalizations and rehospitalization due to chest pain over the year following myocardial infarction according to the presence of obstructive coronary artery disease.