Zero Calcium Score as a Filter for Further Testing in Patients Admitted to the Coronary Care Unit with Chest Pain

Abstract

BackgroundThe accuracy of zero coronary calcium score as a filter in patients with chest pain has been demonstrated at the emergency room and outpatient clinics, populations with low prevalence of coronary artery disease (CAD).ObjectiveTo test the gatekeeping role of zero calcium score in patients with chest pain admitted to the coronary care unit (CCU), where the pretest probability of CAD is higher than that of other populations.MethodsPatients underwent computed tomography for calcium scoring, and obstructive CAD was defined by a minimum 70% stenosis on invasive angiography.ResultsIn 146 patients studied, the prevalence of CAD was 41%. A zero calcium score was present in 35% of the patients. The sensitivity and specificity of zero calcium score yielded a negative likelihood ratio of 0.16. After logistic regression adjustment for pretest probability, zero calcium score was independently associated with lower odds of CAD (OR = 0.12, 95%CI = 0.04-0.36), increasing the area under the ROC curve of the clinical model from 0.76 to 0.82 (p = 0.006). Zero calcium score provided a net reclassification improvement of 0.20 (p = 0.0018) over the clinical model when using a pretest probability threshold of 10% for discharging without further testing. In patients with pretest probability < 50%, zero calcium score had a negative predictive value of 95% (95%CI = 83%-99%), with a number needed to test of 2.1 for obtaining one additional discharge.ConclusionZero calcium score substantially reduces the pretest probability of obstructive CAD in patients admitted to the CCU with acute chest pain. (Arq Bras Cardiol. 2017; [online].ahead print, PP.0-0)

Relationship between Coronary Artery Calcium Score and Coronary Stenosis

“…A CACS � 0 does not defnitively rule out the presence of coronary stenosis of ≥50% or ≥70%, especially in younger patients. Previous studies have shown that among patients with CACS � 0, a range of 1.5% to 8.3% displayed coronary stenosis of ≥50%, and 1.4% presented with coronary stenosis of ≥70% [13][14][15][16][17]. Feuchtner et al found that 12.5% of young adults aged 35-49 years with CACS � 0 had coronary stenosis ≥50% [18].…”

Calcium Score Use in Isolation in Acute Chest Pain Setting - Is it Sufficient?

“…In the present edition of Arquivos Brasileiros de Cardiologia , Correia et al 9 have assessed the possibility of extending this controversial indication of CCS use for patients admitted to a coronary unit of a Brazilian tertiary hospital with higher pretest probability of obstructive CAD. Those authors have concluded that despite the limited PPV associated with a CCS over zero, CCS had a NPV of 90% for obstructive CAD.…”

“…Correia et al. 9 should be congratulated for using a local sample to derive a pretest probability score for acute CAD in patients admitted to a coronary unit. However, although the pretest probability used is adequate for the present study, it has important limitations.…”