PURPOSE: On clinical practice, acute coronary syndrome (ACS) with normal coronariography (ACS-NC) remains an issue of strong controversy, mainly its prognosis on higher risk patients. We sought to analyze the prevalence, predictors and prognostic implications of ACS-NC patients.
METHODS: A total of 978 patients admitted to an intensive coronary care unit with ACS, submitted to coronariography, were divided in 2 groups, regarding coronary artery status on angiogram: A –with significant (> 50%) lesions (n=833); B –without significant lesions (n=145).
RESULTS: ACS-NC patients were younger (60.7 vs 64.0 years;p=0.003), more frequently women (odds-ratio [OR] 2.37;p<0.001) and non-smokers (OR 1.76;p=0.023). Admission glicemia was higher on group A patients (152.7 vs 143.3 mg/dL;p=0.03), as creatinine (1.2 vs 1.1 mg/dL;p=0.008) and peak troponin I (TNI) (44.0 vs 9.0 ug/dL;p<0.001). Nevertheless, >50% of ACS-NC patients had positive TNI tests. Lower TIMI scores (<2) were associated with NC, whereas higher scores (>=3) lowered its probability (score  OR 0.59;  OR 0.54;  OR 0.16). Group B patients had more atrial fibrillation (OR 2.18;p=0.014) and less sinus rhythm (OR 0.52;p=0.014) or ST segment elevation (OR 0.12;p<0.001). They received fewer drugs at admission, as clopidogrel (OR 0.59;p=0.009) or GPIIb/IIIa inhibitors (OR 0.55;p=0.001). On discharge, they received less statins, beta-blockers, ACEi or anti-platelet drugs (p<0.05). No differences were found among groups regarding intra-hospital or 1-year complications or mortality rates. On a 3-year follow-up group B had a better prognosis regarding major adverse cardiac events-free survival (89.9% vs 78.6%; Log-Rank p=0.017). On multivariate analysis, prior history of smoking or diabetes carried a lower probability of having NC, whereas age < 65 years and female sex were associated with NC.
CONCLUSION: The disruption of a slightly stenotic vulnerable plaque can result in a ACS-NC, which can in part explain why there are no differences among intra-hospitalar and 1-year follow-up.
CLINICAL IMPLICATIONS: As the clinical consequences of this entity remain obscure, severity scores, like TIMI, and readily available data from prior history can help physicians stratify each patient risk.
DISCLOSURE: Rui Baptista, No Financial Disclosure Information; No Product/Research Disclosure Information