Prognostic Performance of Prospective versus Retrospective Electrocardiographic Gating in Coronary Computed Tomographic Angiography.

Coronary computed tomographic angiography (CCTA) with prospective electrocardiographic gating reduces radiation exposure, but its prognostic power for predicting cardiovascular risk in patients with suspected CAD has not been fully validated. To determine whether prospective gating performs as well as retrospective gating in this population, we compared these scan modes in patients undergoing 64-slice CCTA. From January 2009 through September 2011, 1,407 patients underwent CCTA; of these, 915 (mean age, 57.8 ± 13.5 yr; 54% male) had suspected coronary artery disease at the time of CCTA and were included in the study. Prospective gating was used in 195 (21%) and retrospective gating in 720 (79%). The mean follow-up duration was 2.4 ± 0.9 years. Overall, 390 patients (42.6%) had normal results on CCTA, 382 (41.7%) had nonobstructive coronary artery disease, and 143 (15.6%) had obstructive disease. Major adverse cardiac events occurred in 32 patients (3.5%): 11 cardiac deaths, 15 late revascularizations, and 6 nonfatal myocardial infarctions. Total event occurrences were similar in both groups (retrospective, 3.8%; prospective, 2.6%; P=0.42), as were the occurrences of each type of event. On adjusted multivariate analysis, nonobstructive (P=0.015) and obstructive (P <0.001) coronary artery disease were independently associated with major adverse cardiac events. Scan mode was not a predictor of outcome. The mean effective radiation dose was 4 ± 2 mSv for prospective compared with 12 ± 4 mSv for retrospective gating (P <0.01). The prognostic value of CCTA with prospective electrocardiographic gating compares favorably with that of retrospective gating, and it involves significantly less radiation exposure.

Prevalence and Implications of Subclinical Coronary Artery Disease in Patients With Atrial Fibrillation.

The objective of this study was to examine prevalence and clinical implications of subclinical coronary artery disease (CAD) detected by coronary artery calcium score (CACS) testing in patients with atrial fibrillation (AF). CACS was assessed in patients without history of CAD undergoing catheter ablation of AF. Age- and gender-matched patients with normal sinus rhythm (NSR) presenting with chest pain served as controls. Predicted arterial age using the Multi-Ethnic Study of Atherosclerosis registry was also compared to the chronologic age. A total of 860 patients (430 AF and 430 NSR, age 63 ± 10 years, 65% men) were included. Subclinical CAD prevalence (CACS >0) was 74% (319 of 430) in the AF group. Compared to the patients with NSR, patients with AF had higher prevalence of Subclinical CAD (74% vs 63%; p <0.001). In multivariate analysis, AF was independently associated with Subclinical CAD (hazard ratio 1.60; p = 0.002) but only with persistent AF (hazard ratio 2.28; p <0.001). Predicted arterial age was greater than chronologic age in patients with AF (69 ± 12 vs 64 ± 9 years). CACS-diagnosed subclinical CAD identified new potential candidates for statin therapy (12%; 33 of 267) and for oral anticoagulation (19%; 40 of 206) by addition of subclinical CAD to the CHA2DS2-VASc scores. In conclusion, in patients without known history of CAD, prevalence of subclinical CAD was significantly higher in those with persistent AF than those with NSR. AF was associated with subclinical CAD independently and complimentarily to clinical risk factors. Identifying subclinical CAD has potential clinical indications for prevention of CAD progression and stroke.

Additive prognostic value of coronary artery calcium score over coronary computed tomographic angiography stenosis assessment in symptomatic patients without known coronary artery disease.

The objective of this study was to examine the additive prognostic performance of coronary artery calcium score (CACS) over coronary computed tomography angiography (CCTA) stenosis assessment in symptomatic patients suspected for coronary artery disease (CAD) undergoing CCTA. A total of 805 symptomatic patients without known history of CAD who underwent coronary evaluation by multidetector cardiac CT were analyzed. Mean age of the cohort was 58 ± 13 years. A total of 44% (354 of 805) of the patients had a 0 CACS, 27% (215 of 805) had CACS 1 to 100, 14% (111 of 805) had CACS 101 to 400, and 15% (125 of 805) had CACS >400. CCTA showed normal coronary arteries in 43% (349 of 805) of patients, ≤50% stenosis in 42% (333 of 805), and >50% stenosis in 15% (123 of 805). Patients were followed for 2.3 ± 0.9 years. Major adverse cardiac event (MACE) was defined as cardiac death, nonfatal myocardial infarction, and late coronary revascularization. Overall incidence of MACE was 1.4% per year. Both CACS and CCTA stenosis were independently associated with increased MACE (p <0.05 for both). Addition of CACS into the model with clinical risk factors and CCTA stenosis significantly improved predictive performance for MACE from the model with clinical risk factors and CCTA stenosis only (global chi-square score 108 vs 70; p = 0.019). In conclusion; in symptomatic patients without known CAD, both CACS and CCTA stenosis were independently associated with increased cardiac events, and performing non-contrast-enhanced CACS evaluation in addition to contrast-enhanced CCTA improved predictive ability for future cardiac events compared to CCTA stenosis assessment alone.

Association Between Hematological Indices and Coronary Calcification in Symptomatic Patients without History of Coronary Artery Disease.

BACKGROUND: Atherosclerotic coronary artery disease (CAD) has long been shown to involve chronic low-grade subclinical inflammation. However, whether there is association between hematological indices assessed by complete blood count (CBC) and coronary atherosclerotic burden has not been well studied. MATERIALS AND METHODS: Consecutive 868 patients without known CAD who presented with acute chest pain to emergency department and underwent coronary artery calcium (CAC) scoring evaluation by multi-detector cardiac computed tomography were included in our study. Clinical characteristics and CBC indices were compared among different CAC groups. RESULTS: The cohort comprised 60% male with a mean age of 61 (SD = 14) years. Median Framingham risk of CAD was 4% (range 1-16%). Median CAC score was 0 (IQR 0-43). Higher CAC groups had significantly higher Framingham risk of CAD than lower CAC groups (P < 0.001). Among different CAC categories, there was no statistically significant difference in hemoglobin level (p 0.45), mean corpuscular volume (p 0.43), mean corpuscular hemoglobin (p 0.28), mean corpuscular hemoglobin volume (p 0.36), red cell distribution width (0.42), total white blood cell counts (p 0.291), neutrophil counts (p 0.352), lymphocyte counts (p 0.92), neutrophil to lymphocyte ratio (p 0.68), monocyte count (p 0.48), and platelet counts (p 0.25). CONCLUSION: Our study did not detect significant association between hematological indices assessed with CBC and coronary calcification in symptomatic patients without known CAD.