Incidence, Predictors, and Outcomes of Acquired Thrombocytopenia After Percutaneous Coronary Intervention: A Pooled, Patient-Level Analysis of the CHAMPION Trials (Cangrelor Versus Standard Therapy to Achieve Optimal Management of Platelet Inhibition).

BACKGROUND: The influence of cangrelor on the incidence and outcomes of post-percutaneous coronary intervention (PCI) thrombocytopenia is not defined. We aimed to explore the incidence, predictors, and clinical impact of thrombocytopenia after PCI in cangrelor-treated patients. METHODS AND RESULTS: This was a pooled, patient-level analysis of the CHAMPION trials (Cangrelor Versus Standard Therapy to Achieve Optimal Management of Platelet Inhibition), which compared cangrelor with clopidogrel for prevention of thrombotic complications during and after PCI. Acquired thrombocytopenia was defined as either a drop in platelet count to <100 000 after PCI or a drop of >50% between baseline and a follow-up. The main efficacy outcome was major adverse cardiac events. The primary safety outcome was noncoronary artery bypass grafting-related Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries-defined severe bleeding at 48 hours. Patients (23 783) were enrolled, and 3009 (12.7%) received a GPI (glycoprotein IIb/IIIa inhibitor). Acquired thrombocytopenia occurred in 200 patients (0.8%). The adjusted rate of major adverse cardiovascular events at 48 hours was significantly higher in patients who developed thrombocytopenia compared with those who did not (odds ratio, 3.00; 95% confidence interval, 1.89-4.69; P<0.001), as was major bleeding (odds ratio, 14.71; 95% confidence interval, 5.96-36.30; P<0.001). GPI use was the strongest independent predictor of acquired thrombocytopenia (odds ratio, 2.93; 95% confidence interval, 2.15-3.97; P<0.0001). There was no difference in the rate of acquired thrombocytopenia in patients randomized to cangrelor or clopidogrel. CONCLUSIONS: Acquired thrombocytopenia after PCI is strongly associated with substantial early morbidity and mortality, as well as major bleeding. GPI use is a significant predictor of thrombocytopenia. Cangrelor is not associated with acquired thrombocytopenia, and its clinical efficacy and safety is consistent irrespective of thrombocytopenia occurrence. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifiers: NCT00305162, NCT00385138, and NCT01156571.

Comprehensive Assessment of Coronary Artery Disease by Using First-Pass Analysis Dynamic CT Perfusion: Validation in a Swine Model.

Purpose To retrospectively validate a first-pass analysis (FPA) technique that combines computed tomographic (CT) angiography and dynamic CT perfusion measurement into one low-dose examination. Materials and Methods The study was approved by the animal care committee. The FPA technique was retrospectively validated in six swine (mean weight, 37.3 kg ± 7.5 [standard deviation]) between April 2015 and October 2016. Four to five intermediate-severity stenoses were generated in the left anterior descending artery (LAD), and 20 contrast material-enhanced volume scans were acquired per stenosis. All volume scans were used for maximum slope model (MSM) perfusion measurement, but only two volume scans were used for FPA perfusion measurement. Perfusion measurements in the LAD, left circumflex artery (LCx), right coronary artery, and all three coronary arteries combined were compared with microsphere perfusion measurements by using regression, root-mean-square error, root-mean-square deviation, Lin concordance correlation, and diagnostic outcomes analysis. The CT dose index and size-specific dose estimate per two-volume FPA perfusion measurement were also determined. Results FPA and MSM perfusion measurements (PFPA and PMSM) in all three coronary arteries combined were related to reference standard microsphere perfusion measurements (PMICRO), as follows: PFPA_COMBINED = 1.02 PMICRO_COMBINED + 0.11 (r = 0.96) and PMSM_COMBINED = 0.28 PMICRO_COMBINED + 0.23 (r = 0.89). The CT dose index and size-specific dose estimate per two-volume FPA perfusion measurement were 10.8 and 17.8 mGy, respectively. Conclusion The FPA technique was retrospectively validated in a swine model and has the potential to be used for accurate, low-dose vessel-specific morphologic and physiologic assessment of coronary artery disease. © RSNA, 2017.

Functional Assessment of Coronary Artery Disease Using Whole-Heart Dynamic Computed Tomographic Perfusion.

BACKGROUND: Computed tomographic (CT) angiography is an important tool for the evaluation of coronary artery disease but often correlates poorly with myocardial ischemia. Current dynamic CT perfusion techniques can assess ischemia but have limited accuracy and deliver high radiation dose. Therefore, an accurate, low-dose, dynamic CT perfusion technique is needed. METHODS AND RESULTS: A total of 20 contrast-enhanced CT volume scans were acquired in 5 swine (40±10 kg) to generate CT angiography and perfusion images. Varying degrees of stenosis were induced using a balloon catheter in the proximal left anterior descending coronary artery, and a pressure wire was used for reference fractional flow reserve (FFR) measurement. Perfusion measurements were made with only 2 volume scans using a new first-pass analysis (FPA) technique and with 20 volume scans using an existing maximum slope model (MSM) technique. Perfusion (P) and FFR measurements were related by PFPA=1.01 FFR-0.03 (R2=0.85) and PMSM=1.03 FFR-0.03 (R2=0.80) for FPA and MSM techniques, respectively. Additionally, the effective radiation doses were calculated to be 2.64 and 26.4 mSv for FPA and MSM techniques, respectively. CONCLUSIONS: A new FPA-based dynamic CT perfusion technique was validated in a swine animal model. The results indicate that the FPA technique can potentially be used for improved anatomical and functional assessment of coronary artery disease at a relatively low radiation dose.

Effects of weekend admission on the outcomes and management of ruptured aortic aneurysms.

OBJECTIVE: Ruptured aortic aneurysm is a condition with a high rate of mortality that requires prompt surgical intervention. It has been noted that in some conditions requiring such prompt intervention, in-hospital mortality is increased in patients admitted on the weekends compared with patients admitted on weekdays. We sought to determine if this was indeed the case for both ruptured thoracic aortic aneurysms (TAA) and abdominal aortic aneurysms (AAA) and to elucidate the possible reasons. METHODS: Using the Nationwide Inpatient Sample, a publicly available database of inpatient care, we analyzed the incidence of mortality among 7200 patients admitted on the weekends compared with weekdays for ruptured aortic aneurysm. Among these patients, 19% had a TAA and 81% had an AAA, and each group was analyzed for differences in mortality during the hospitalization. We adjusted for demographics, comorbid conditions, hospital characteristics, rates of surgical intervention, timing of surgical intervention, and use of additional therapeutic measures. RESULTS: Patients admitted on the weekend for both ruptured TAA and AAA had a statistically significant increase in mortality compared with those admitted on the weekdays (TAA: odds ratio, 2.55; 95% confidence interval, 1.77-3.68; P = .03; AAA: odds ratio, 1.32; 95% confidence interval, 1.13-1.55; P = .0004). Among those with TAA, a surgical intervention was performed on day of admission in 62.1% of weekday admissions vs 34.9% of weekend admissions (P < .0001). This difference was much smaller among those with an aortic aneurysm; 79.6% had a surgical intervention on day of admission on a weekday vs 77.2% on the weekend (P < .0001). CONCLUSIONS: Weekend admission for ruptured aortic aneurysm is associated with an increased mortality compared with admission on a weekday, and this is likely due to several factors including a delay in prompt surgical intervention.