Characteristics and outcome of patients with acute coronary syndrome and normal or near-normal coronary angiography

Abstract

The incidence of normal or near-normal coronary angiography (NONCA) in patients undergoing coronary angiography, who have in patients with acute coronary syndrome (ACS) is reported between 1 and 12%. Earlier studies reported conflicting results regarding the nature and outcome of these patients. We used Acute Coronary Syndrome Israeli Survey (ACSIS), a biannually, nationwide ACS survey, as a source of unselected population representative of general clinical practice for the analysis and characterization of this group along the full spectrum of ACS. This study uses patient data collected from ACSISs conducted in 2004, 2006, and 2008 in all the cardiology departments and coronary care units in Israel. Of the 5937 patients included in these surveys, 4060 (68.5%) had no earlier coronary interventions. Of these, complete angiographic data were available for 2903 patients who defines the study group. The rest of the patients were managed conservatively during the index hospitalization. On the basis of coronary angiography, 142 (4.9%) of the 2903 patients had no obstructive coronary artery disease (OCAD), 1895 (65.3%) had 1-2-vessel OCAD, 752 (25.9%) had 3-vessel OCAD, and 114 (3.9%) had left main disease. A comparison was made between the NONCA group and the OCAD group. When compared with the patients with OCAD, the NONCA patients were younger, more likely to be females, and had similar risk factors for OCAD. On admission, a higher incidence of chronic anticoagulants usage was noted in the NONCA group (5.6 vs. 2.0% in OCAD, P=0.04). One-quarter of the NONCA patients presented with ST-elevation on ECG as opposed to nearly half in the OCAD group (27.5 vs. 52.3% P<0.001). Most of the NONCA patients presented with normal or preserved left ventricular function on echocardiography, as compared with the significantly lower incidence of normal function in OCAD patients (77 vs. 45.5%, P<0.001). The NONCA patients were less likely to be treated with the recommended therapy for ACS, and this trend continued upon discharge. By stratifying the OCAD patients according to the number of diseased vessels, the NONCA patients had a similar mortality rate after 1 year, as the patients with 1-2-vessel OCAD (3.0 vs. 3.8, P=0.920). To our knowledge, this is the first study that explores the NONCA entity and its outcome along the full spectrum of ACS by using three nationwide, unbiased ACS surveys. These data indicate that, in discordance with common belief, NONCA patients share similar risk factors and outcome with the 1-2-vessels OCAD patients, but tend to be undertreated compared with the relevant ACS guidelines during, and more importantly, after the acute episode. Further follow-up is needed to establish their true long-term outcome.