ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the diagnostic accuracy of 320-slice CT coronary angiography (CTA) in the evaluation of in-stent restenosis (ISR, ≥50% luminal narrowing) in comparison with quantitative coronary angiography (CAG).</p><p><b>METHODS</b>A total of 69 patients with previous stent implantation who underwent both CTA and CAG were prospectively included. We assessed diagnostic valve for ISR with CTA in comparison with CAG.</p><p><b>RESULTS</b>A total of 110 stents were implanted in these patients.CAG identified 14 ISR. CTA correctly identified 13 ISR and misdiagnosed 5 ISR in stents without ISR. Besides, 6 stents could not be evaluated by CTA due to unsatisfied image quality. Accordingly, sensitivity, specificity, positive and negative predictive value of CTA for diagnosing ISR were 93%, 89%, 54% and 99%, respectively. The image quality of CTA was significantly better in larger stents (percentages of good and moderate stent image of ≥3.0 mm and <3.0 mm: 56% vs. 27%, 25% vs. 49%) and which was linked with better diagnostic coincidence rate (95% vs. 78%) for larger stents. The image quality of CTA was significantly better in stents with thinner stent strut thickness (percentages of poor CTA stent image quality of stent strut thickness<140 µm and ≥140 µm: 12% vs. 45%, P<0.01) and which was associated with better diagnostic coincidence rate for stents with thinner stent strut thickness (94% vs. 76%, P<0.05). The image quality of CTA was also significantly better in single stent (percentages of poor CTA stent image quality of single stent vs. overlap and dedicated stent: 17% vs. 36%, P<0.05). However, heart rate (≥65 beats/min vs. <65 beats/min) during CTA acquisition was not associated with image quality and the diagnostic coincidence rate (all P>0.05).</p><p><b>CONCLUSIONS</b>Our results indicate that 320-slice CTA allows accurate noninvasive assessment of significant in-stent restenosis in selected patients. Stents with a large diameter and thin struts are associated with better image quality and higher diagnostic accuracy.</p>
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Coronary Angiography , Coronary Restenosis , Diagnostic Imaging , Predictive Value of Tests , Prospective Studies , Sensitivity and Specificity , Stents , Tomography, X-Ray Computed , MethodsABSTRACT
<p><b>OBJECTIVE</b>To evaluate the platelet inhibition efficacy in patients under regular maintenance dose of clopidogrel by VerifyNow-P2Y12 assay and explore the clinical characteristics of clopidogrel non-responders and related predicting factors.</p><p><b>METHODS</b>A total of 99 patients underwent percutaneous coronary intervention procedure and receiving clopidogrel in regular maintenance dose for at least 1 week were enrolled. Platelet reactivity, including baseline, P2Y12 reaction unit (PRU), and platelet inhibition rate were measured with VeifyNow-P2Y12 assay. The dosage of anti-platelet drugs, combination with any other drugs, clinical characters in baseline of all enrolled patients were analyzed. PRU ≤ 240 was used as cut-off to identify clopidogrel responder and clopidogrel non-responder. In the non-responder group, patients were further separated into 3 sub-groups (types) according to the baseline and platelet inhibition rate: type I with high baseline, high inhibition rate, representing false non-responder; type II with low inhibition rate, representing true non-responder and type III mixed type.</p><p><b>RESULTS</b>In this study, 48 of 99 patients were found to be clopidogrel non-responder (48.5%). The ratio of type I, type II and type III in the non-responder group was 9.1% (n = 9), 27.3% (n = 27), and 12.1% (n = 12), respectively. Baseline platelet value in female patients was significantly higher than in males (P < 0.01), number of females with high PRU also is higher than males (P < 0.01), female gender was a predict factor for type I non-responder (OR = 6.5, 95%CI 2.295 - 18.407, P < 0.01). BMI > 24 kg/m(2) was a risk factor for clopidogrel non-responder (P < 0.05), and may be regarded as a predict factor for type II non-responder (OR = 3.207, 95%CI 1.375 - 7.485, P < 0.01). Age, hypertension, diabetics, smoking, hyperlipidemia, CRP and pantoprazole use do not show significant correlation with baseline and platelet inhibition rate.</p><p><b>CONCLUSIONS</b>Clopidogrel responses could be reliably detected by VerifyNow-P2Y12 assay. Female gender and high body weight are independent risk factors for clopidogrel non-responses.</p>