Saima Mushtaq

Diagnostic accuracy of coronary computed tomography angiography: a comparison between prospective and retrospective electrocardiogram triggering.

OBJECTIVES The aim of this study was to compare the diagnostic performance of multidetector computed tomography (MDCT) with prospective electrocardiogram (ECG) triggering versus retrospective ECG triggering. BACKGROUND MDCT allows the noninvasive visualization of the coronary arteries. However, radiation exposure is a reason for concern. METHODS One hundred eighty consecutive patients scheduled for invasive coronary angiography were enrolled in this study. Twenty patients were excluded due to contraindications to sustain MDCT. Of the 160 remaining patients, 80 were studied with MDCT with prospective ECG triggering (Group 1) and 80 with a retrospective ECG triggering (Group 2). The individual radiation dose exposure was estimated. RESULTS In nonstented segments, the evaluability of Groups 1 and 2 was 96% versus 97%, respectively (p = 0.05), the accuracy in segment-based model was 93% versus 96%, respectively (p < 0.05) including diagnostic segments and 91% versus 94%, respectively (p < 0.01) including all segments, whereas the accuracy in a patient-based model was 98% in both groups. In stented segments the evaluability in Groups 1 and 2 was 92% versus 94%, respectively, and the accuracy was 93% versus 92%, respectively, including diagnostic stented segments and 90% versus 89%, respectively, including all stented segments. Group 1 presented lower radiation dose compared with Group 2 (5.7 +/- 1.5 mSv vs. 20.5 +/- 4.3 mSv, p < 0.01). CONCLUSIONS Prospective ECG-triggering computed tomography allows an accurate detection of coronary stenosis, despite a slight reduction of diagnostic performance, with a low radiation dose.

A Long-Term Prognostic Value of Coronary CT Angiography in Suspected Coronary Artery Disease

OBJECTIVES The aim of this study was to assess the long-term prognostic role of multidetector computed tomography coronary angiography (CTA) in patients with suspected coronary artery disease (CAD). BACKGROUND Use of CTA is increasing in patients with suspected CAD. Although there is a large body of data supporting the prognostic role of CTA for major adverse cardiac events in the intermediate term, its long-term prognostic role in patients with suspected CAD is not well studied. METHODS Between February 2005 and March 2008, 1,304 consecutive patients were prospectively studied with CTA for detecting the presence and assessing extent of CAD (disease extension and coronary plaque scores). Patients were classified according to the presence of normal coronaries and nonobstructive (<50%) and obstructive (>50%) coronary lesions. The composite rates of hard cardiac events (cardiac deaths and nonfatal myocardial infarctions) and all cardiac events (including late revascularization) were the endpoints of the study. RESULTS Seventy patients were excluded because their CTA data were uninterpretable. Of the remaining 1,234 patients, clinical follow-up (mean 52 ± 22 months) was obtained for 1,196 (97%). A total of 475 events were recorded, with 136 hard events (18 cardiac deaths and 118 nonfatal myocardial infarctions) and 123 late revascularizations. A total of 216 patients with early elective revascularizations were excluded from the survival analysis. Significant independent predictors of events in multivariate analysis were multivessel disease and left main CAD. Cumulative event-free survival was 100% for hard and all events in patients with normal coronary arteries, 88% for hard events and 72% for all events in patients with nonobstructive CAD, and 54% for hard events and 31% for all events in patients with obstructive CAD. Multivessel CAD was associated with a higher rate of hard cardiac events. CONCLUSIONS CTA provides prognostic information in patients with suspected CAD and unknown cardiac disease, showing excellent long-term prognosis when there is no evidence of atherosclerosis and allowing risk stratification when CAD is present.

Feasibility and accuracy of a comprehensive multidetector computed tomography acquisition for patients referred for balloon-expandable transcatheter aortic valve implantation

BACKGROUND The aim of this study was to assess the accuracy of a comprehensive multidetector computed tomography (MDCT) evaluation of the aortic annulus (AoA), coronary artery disease (CAD), and peripheral vessels in patients referred for transcatheter aortic valve implantation (TAVI). METHODS In 60 patients referred for TAVI, the following parameters were assessed with 64-slices MDCT and compared with transesophageal echocardiography (TEE), invasive coronary angiography (ICA), and peripheral angiography: AoA maximum diameter (Max-AoA-D(MDCT)), minimum diameter (Min-AoA-D(MDCT)), and area; lumen morphology index ([Max-AoA-D(MDCT)/Min-AoA-D(MDCT)]); length of the left, right, and non-coronary aortic leaflets; degree (grades 1-4) of aortic leaflet calcifications; distance between AoA and left main coronary ostium and between AoA and right coronary ostium CAD and peripheral vessel disease. RESULTS The Max-AoA-D(MDCT) and Min-AoA-D(MDCT) were 25.1 ± 2.8 and 21.2 ± 2.2 mm, respectively, with high correlation versus AoA diameter measured with TEE (r = 0.82 and 0.86, respectively). The area of AoA, systolic and diastolic lumen morphology index were 410 ± 81.5 mm(2), 1.19 ± 0.1 and 1.22 ± 0.11, respectively. Aortic leaflet calcification score was 3.3 ± 0.5. The lengths of left, right, and non-coronary aortic leaflets were 14.2 ± 2.4, 13.7.1 ± 2.1, and 14.5 ± 2.6 mm, whereas distances between AoA and the left main coronary ostium and between AoA, and the right coronary ostium were 13.7 ± 2.9 and 15.8 ± 3.5 mm, respectively. Feasibility, negative predictive value, and accuracy for CAD detection versus ICA were 87%, 100% (CI 100-100), and 96% (95% CI 94-100), respectively. All patients (N = 17) who were ineligible for TAVI were correctly detected by MDCT. CONCLUSIONS A comprehensive MDCT evaluation of patients referred for TAVI is feasible, provides more accurate assessment than TEE of AoA morphology, and may replace peripheral angiography in all patients and ICA in patients without significant CAD.

Incremental Prognostic Value of Myocardial Fibrosis in Patients With Non–Ischemic Cardiomyopathy Without Congestive Heart Failure

Background—We conducted a prospective longitudinal study to investigate the yet unknown clinical significance of myocardial fibrosis in patients with non–ischemic cardiomyopathy without history of congestive heart failure (CHF). Methods and Results—At 3 tertiary referral centers, 228 patients with non–ischemic cardiomyopathy without history of CHF were studied with cardiovascular magnetic resonance for late gadolinium enhancement (LGE) detection and quantification and prospectively followed up for a median of 23 months. The end point was a composite of cardiac death, onset of CHF, and aborted sudden cardiac death. LGE was detected in 61 (27%) patients. Thirty-one of 61 (51%) patients with LGE reached combined end point when compared with 18 of 167 (11%) patients without LGE (hazard ratio, 5.10 [2.78–9.36]; P<0.001). Patients with LGE had greater risk of developing CHF than patients without LGE (hazard ratio, 5.23 [2.61–10.50]; P<0.001) and higher rate of aborted sudden cardiac death (hazard ratio, 8.31 [1.66–41.55]; P=0.010). Multivariate analysis showed that LGE was associated with high likelihood of composite end point independent of other prognostic determinants, including age; duration of cardiomyopathy; and left ventricular volumes, mass, and ejection fraction (hazard ratio, 4.02 [2.08–7.76]; P<0.001). Improvement &khgr;2 analysis disclosed that LGE addition to models, including clinical data alone or in combination with parameters of left ventricular remodeling and function, yielded an improvement in outcome prediction (P<0.001). Addition of LGE to age and left ventricular ejection fraction improved risk stratification for composite end point (net reclassification improvement, 29.6%) and onset of CHF (net reclassification improvement, 25.4%; both P<0.001). Conclusions—In patients with non–ischemic cardiomyopathy without history of CHF, myocardial fibrosis is a strong and independent predictor of outcome, providing incremental prognostic information and improvement in risk stratification beyond clinical data and degree of left ventricular dysfunction.

Coronary in-stent restenosis: Assessment with CT coronary angiography

PURPOSE To compare accuracy and radiation exposure of a new computed tomographic (CT) scanner with improved spatial resolution (scanner A) with those of a CT scanner with standard spatial resolution (scanner B) for evaluation of coronary in-stent restenosis (ISR) by using invasive coronary angiography (ICA) and intravascular ultrasonography (US) as reference methods. MATERIALS AND METHODS Written informed consent was obtained and study protocol was approved by institutional ethics committee. A total of 180 consecutive patients (154 men [mean age ± standard deviation, 66 years±12; range, 51-79 years] and 36 women [mean age, 70 years±12; range, 55-83 years]) scheduled to undergo ICA for suspected ISR were enrolled. Ninety patients were studied with scanner A (group 1: 72 men [mean age, 65 years±11; range, 52-79], 18 women [mean age, 68 years±12; range, 55-83 years]) and 90 with scanner B (group 2: 74 men [mean age, 64 years±10; range, 51-77 years], 16 women [mean age, 68 years±11; range, 55-82 years). Examination with the two scanners was compared with ICA and intravascular US. Radiation dose exposure was estimated. To compare stent evaluability between the two groups, χ2 test was used. RESULTS Stent evaluability was higher in group 1 than in group 2 (99% vs 92%, P=.0021). A significantly lower rate of beam-hardening artifact was observed in group 1 (two cases) than group 2 (12 cases, P<.05). For stent-based analysis, sensitivity, specificity, and accuracy of multidetector CT for ISR identification were 96%, 95%, and 96% in group 1 and 90%, 91%, and 91% in group 2, respectively, without statistically significant differences. The correlation between percent ISR evaluated at multidetector CT versus intravascular US was higher in group 1 than in group 2 (r=0.89 vs r=0.58; P=.019). The correlations of diameter and area measurements at reference site and stent maximal lumen narrowing site between multidetector CT and intravascular US were higher in group 1 than in group 2. Radiation dose was low in both multidetector CT groups (1.9 mSv±0.2). CONCLUSION Scanner A, with improved spatial resolution, allowed reliable detection and quantification of coronary ISR with low radiation exposure.

Long-term prognostic effect of coronary atherosclerotic burden validation of the computed tomography-leaman score

Background— Computed tomography–adapted Leaman score (CT-LeSc) was developed to quantify coronary CT angiography information about atherosclerotic burden (lesion localization, stenosis degree, and plaque composition). The objective of the study is to evaluate CT-LeSc long-term prognostic value in patients with suspected coronary artery disease (CAD). Methods and Results— Single-center prospective registry including 1304 consecutive patients undergoing coronary CT angiography for suspected CAD. High CT-LeSc was defined by upper tertile (score, >5) cutoff. Segment involvement score and segment stenosis score were also evaluated. Hard cardiac events (cardiac death and nonfatal acute coronary syndromes) were considered for analysis. Different Cox regression models were used to identify independent event predictors. Kaplan–Meier event-free survival was evaluated in 4 patient subgroups stratified by obstructive (≥50% stenosis) versus nonobstructive CAD and a high (>5) versus a low (≤5) CT-LeSc. Of 1196 patients included in the final analysis (mean follow-up of 52±22 months), 125 patients experienced 136 hard events (18 cardiac deaths and 118 nonfatal myocardial infarction). All atherosclerotic burden scores were independent predictors of cardiac events (hazard ratios of 3.09 for segment involvement score, 4.42 for segment stenosis score, and 5.39 for CT-LeSc). Cumulative event-free survival was 76.8% with a high CT-LeSc and 96.0% with a low CT-LeSc. Event-free survival in nonobstructive CAD with high CT-LeSc (78.6%) was similar to obstructive CAD with high CT-LeSc (76.5%) but lower than obstructive CAD with low CT-LeSc (80.7%). Conclusions— CT-LeSc is an independent long-term predictor of hard cardiac events. Patients with nonobstructive CAD and high CT-LeSc had hard event-free survival similar to patients with obstructive CAD.Background—Computed tomography–adapted Leaman score (CT-LeSc) was developed to quantify coronary CT angiography information about atherosclerotic burden (lesion localization, stenosis degree, and plaque composition). The objective of the study is to evaluate CT-LeSc long-term prognostic value in patients with suspected coronary artery disease (CAD). Methods and Results—Single-center prospective registry including 1304 consecutive patients undergoing coronary CT angiography for suspected CAD. High CT-LeSc was defined by upper tertile (score, >5) cutoff. Segment involvement score and segment stenosis score were also evaluated. Hard cardiac events (cardiac death and nonfatal acute coronary syndromes) were considered for analysis. Different Cox regression models were used to identify independent event predictors. Kaplan–Meier event-free survival was evaluated in 4 patient subgroups stratified by obstructive (≥50% stenosis) versus nonobstructive CAD and a high (>5) versus a low (⩽5) CT-LeSc. Of 1196 patients included in the final analysis (mean follow-up of 52±22 months), 125 patients experienced 136 hard events (18 cardiac deaths and 118 nonfatal myocardial infarction). All atherosclerotic burden scores were independent predictors of cardiac events (hazard ratios of 3.09 for segment involvement score, 4.42 for segment stenosis score, and 5.39 for CT-LeSc). Cumulative event-free survival was 76.8% with a high CT-LeSc and 96.0% with a low CT-LeSc. Event-free survival in nonobstructive CAD with high CT-LeSc (78.6%) was similar to obstructive CAD with high CT-LeSc (76.5%) but lower than obstructive CAD with low CT-LeSc (80.7%). Conclusions—CT-LeSc is an independent long-term predictor of hard cardiac events. Patients with nonobstructive CAD and high CT-LeSc had hard event-free survival similar to patients with obstructive CAD.

Three-dimensional dynamic assessment of tricuspid and mitral annuli using cardiovascular magnetic resonance

AIMS To explore the potentiality of cardiovascular magnetic resonance (CMR) in the quantitative evaluation of mitral valve annulus (MVA) and tricuspid valve annulus (TVA) morphology and dynamics. METHODS AND RESULTS CMR was performed in 13 normal subjects and 9 patients with mitral (n = 7) or tricuspid regurgitation (n = 2), acquiring cine-images in 18 radial long-axis planes passing through the middle of MVA or TVA. A novel algorithm was used to obtain dynamic three-dimensional (3D) reconstruction of MVA and TVA. Analysis was feasible in all cases, allowing accurate 3D annular reconstruction and tracking. The 3D area increased from systole [MVA, median = 10.0 cm(2) (first quartile = 8.6, third quartile = 11.4); TVA, 11.2 cm(2) (8.8-13.2)] to diastole [MVA, 10.6 cm(2) (9.4, 11.7); TVA, 11.9 cm(2) (9.2-13.5)], with TVA larger than MVA. While the longest diameter showed similar systolic and diastolic values, the shortest diameter elongated from systole [MVA, 30 mm (29-33); TVA, 33 mm (31-36)] to diastole [MVA, 31 mm (29-32); TVA, 36 mm (33-39)]. Also, TVA became more circular than MVA. TVA showed lower peak systolic excursion in the septal [15.9 mm (13.0-18.5)] and anterior regions [17.9 mm (12.2-20.7)] compared with the posterior [21.9 mm (18.6-24.0)] segment. Values in MVA were smaller than in TVA, slightly higher in anterior [11.2 mm (9.5-13.0)] than in posterior [12.4 mm (10.2-14.6)] segments. Valvular regurgitation was associated with enlarged, flattened, and more circular annuli. CONCLUSION The applied method was feasible and accurate in normal and regurgitant valves, and may potentially have an impact on diagnosis, improvement of surgical techniques and design of annular prostheses.

Sixty-four-slice Multidetector Computed Tomography: An Accurate Imaging Modality for the Evaluation of Coronary Arteries in Dilated Cardiomyopathy of Unknown Etiology

Background—The goal of this study was to assess the safety, feasibility, and diagnostic accuracy of 64-slice multidetector computed tomography (MDCT) for the evaluation of coronary arteries in dilated cardiomyopathy (DCM) of unknown etiology. Sixteen-slice MDCT is useful in patients affected by DCM. However, technical limitations, such as cardiac arrhythmias, an inability of patients to sustain a long breath-hold, and the need of a high dose of contrast agent may limit its accuracy and widespread use. Methods and Results—Invasive coronary angiography (ICA) and MDCT coronary angiography were performed on 132 consecutive patients (82 men; age 63±11 years) affected by DCM (ejection fraction, 34±10%) of unknown etiology. In 2 patients (1.5%), MDCT was not feasible because of atrial fibrillation. Of the remaining 130 patients, 88 exhibited normal and 42 exhibited diseased coronary arteries in both MDCT and ICA. All patients with coronary artery disease except for 1 were correctly classified by MDCT as 1-vessel (11 cases), 2-vessel (13 cases), and 3-vessel (18 cases) disease. In the segment-based analyses, the overall feasibility for MDCT was 98.5% (1902 of 1930 segments). Segment-based and patient-based analyses for the detection of luminal stenosis of >50% and >70% were performed. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MDCT for the detection of >50% stenosis were 98.1%, 99.9%, 98.7%, 99.8%, and 99.7%, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MDCT for the detection of >70% stenosis were 99.5%, 98.6%, 94.1%, 99.9%, and 99.4%, respectively. Conclusions—Excellent feasibility and diagnostic accuracy, combined with low invasiveness, make 64-slice MDCT an ideal imaging modality for the anatomic evaluation of coronary circulation in patients with DCM of unknown etiology.

Coronary Artery Disease: Diagnostic Accuracy of CT Coronary Angiography—A Comparison of High and Standard Spatial Resolution Scanning

PURPOSE To compare the image quality, evaluability, diagnostic accuracy, and radiation exposure of high-spatial-resolution (HR, 0.23-mm) computed tomographic (CT) coronary angiography with standard spatial resolution (SR, 0.625-mm) 64-section imaging in patients at high risk for coronary artery disease (CAD) by using invasive coronary angiography (ICA) as the reference method. MATERIALS AND METHODS Written informed consent was obtained from all patients, and the study protocol was approved by the institutional ethical committee. Patients at high risk for CAD (n = 184) who were scheduled for ICA were randomly assigned for study with SR (n = 91) or HR (n = 93) coronary CT angiography before they underwent ICA. To compare the two groups, the Student t test or Wilcoxon test were used to evaluate differences in continuous variables. The χ(2) test or Fisher exact test were used, as appropriate, for categorical data. The McNemar test was used to compare the diagnostic performance of coronary CT angiography versus that of ICA in each group. RESULTS HR coronary CT angiography showed a higher image quality score (3.7 vs 3.4, P < .001) and evaluability (97% vs 92%, P < .002). In a segment-based analysis, HR coronary CT angiography showed a higher specificity, positive predictive value, and accuracy in comparison with SR coronary CT angiography (98%, 91%, and 99% vs 95%, 80%, and 95%, respectively; P < .001). Moreover, HR coronary CT angiography showed a better agreement with ICA for calcified plaques compared with SR coronary CT angiography and ICA (83% vs 53%, P < .001). In a patient-based analysis, HR coronary CT angiography showed higher specificity and accuracy compared with SR coronary CT angiography (91% and 98% vs 46% and 92%, respectively; P < .01). No differences in radiation exposure were found between the two groups. CONCLUSION Improved evaluability and accuracy were seen with HR compared with SR coronary CT angiography of calcified coronary artery lesions, suggesting a potential use for this technology in patients at high risk for CAD.

Multidetector Computed Tomography Coronary Angiography for the Assessment of Coronary In-Stent Restenosis

The investigators conducted a review to evaluate the diagnostic performance of multidetector computed tomography (MDCT) for coronary stent evaluation. The prespecified inclusion criteria selected prospective or retrospective human studies published in English. Studies that did not report raw numbers of diagnostic accuracy for the detection of in-stent restenosis were excluded. The data from 24 studies are reported, 6 performed with old-generation scanners (4-, 16-, and 40-slice MDCT) and 18 performed with 64-slice MDCT or dual-source MDCT. With old-generation MDCT, up to 18% of coronary stents were missed, the rate of nonevaluable stents ranged from 2.6% to 23.5%, and the overall feasibility and diagnostic accuracy were 90.4% and 90%, respectively. With 64-slice MDCT, no stent was missed, and the overall feasibility and diagnostic accuracy were 90.4% and 91.9%, respectively. Advancements in MDCT and stent technologies may further reduce the number of nonassessable stents and improve diagnostic performance.