Quantitative Analysis of Left Ventricular Dyssynchrony using Cardiac Computed Tomography versus Three-Dimensional Echocardiography

OBJECTIVES: We investigated whether cardiac computed tomography (CCT) can determine intraventricular dyssynchrony in comparison to real-time three-dimensional echocardiography (RT3DE) in patients who are considered for cardiac resynchronisation therapy (CRT).

METHODS: 35 patients considered for CRT were examined. Left ventricular (LV) dyssynchrony was quantified by calculating the standard deviation index (SDI) of 17 myocardial LV segments by RT3DE and ECG-gated contrast-enhanced 64-slice dual-source CCT. For both analyses the same software algorithm (4D LV-Analysis) was used.

RESULTS: Close correlations were observed for end-systolic volume, end-diastolic volume and LV ejection fraction between the two techniques (r = 0.94, r = 0.92 and r = 0.95, respectively, P < 0.001 for all). For the global dyssynchrony index SDI, a high correlation was found between RT3DE and CCT (r = 0.84, P < 0.001), which further increased after exclusion of segments with poor image quality by echocardiography (r = 0.90, P < 0.001). The required time for quantitative analysis was significantly shorter (162 ± 22 s vs. 608 ± 112 s per patient, P < 0.001) and reproducibility was significantly higher for CCT compared with RT3DE (interobserver variability of 4.5 ± 3.1% vs. 7.9 ± 6.1%, P < 0.05).

CONCLUSIONS: Quantitative assessment of LV dyssynchrony is feasible by CCT. Owing to its higher reproducibility and faster analysis time compared with RT3DE, this technique may represent a valuable alternative for dyssynchrony assessment. Key Points : • Quantitative assessment of left ventricular dyssynchrony is feasible by cardiac computed tomography (CCT). • This technique has been compared with real-timethree-dimensional echocardiography (RT3DE). • Reproducibility is significantly higher for CCT compared with RT3DE. • Time spent for analysis is significantly shorter for CCT. • Computed tomography may represent a valuable alternative to ultrasound for dyssynchrony assessment.

PMID: 22270144

The Year in Cardiac Imaging

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PMID:

Head-to-Head Comparison of Left Ventricular Function Assessment with 64-Row Computed Tomography, Biplane Left Cineventriculography, and Both 2- and 3-Dimensional Transthoracic Echocardiography – Comparison With Magnetic Resonance Imaging as the Reference Standard

OBJECTIVES: This study was designed to compare the accuracy of 64-row contrast computed tomography (CT), invasive cineventriculography (CVG), 2-dimensional echocardiography (2D Echo), and 3-dimensional echocardiography (3D Echo) for left ventricular (LV) function assessment with magnetic resonance imaging (MRI). Cardiac function is an important determinant of therapy and is a major predictor for long-term survival in patients with coronary artery disease. A number of methods are available for assessment of function, but there are limited data on the comparison between these multiple methods in the same patients.

METHODS: A total of 36 patients prospectively underwent 64-row CT, CVG, 2D Echo, 3D Echo, and MRI (as the reference standard). Global and regional LV wall motion and ejection fraction (EF) were measured. In addition, assessment of interobserver agreement was performed.

RESULTS: For the global EF, Bland-Altman analysis showed significantly higher agreement between CT and MRI (p < 0.005, 95% confidence interval: ±14.2%) than for CVG (±20.2%) and 3D Echo (±21.2%). Only CVG (59.5 ± 13.9%, p = 0.03) significantly overestimated EF in comparison with MRI (55.6 ± 16.0%). CT showed significantly better agreement for stroke volume than 2D Echo, 3D Echo, and CVG. In comparison with MRI, CVG—but not CT—significantly overestimated the end-diastolic volume (p < 0.001), whereas 2D Echo and 3D Echo significantly underestimated the EDV (p < 0.05). There was no significant difference in diagnostic accuracy (range: 76% to 88%) for regional LV function assessment between the 4 methods when compared with MRI. Interobserver agreement for EF showed high intraclass correlation for 64-row CT, MRI, 2D Echo, and 3D Echo (intraclass correlation coefficient >0.8), whereas agreement was lower for CVG (intraclass correlation coefficient = 0.58).

CONCLUSIONS: 64-row CT may be more accurate than CVG, 2D Echo, and 3D Echo in comparison with MRI as the reference standard for assessment of global LV function.

PMID:

Prediction of Arrhythmic Events in Ischemic and Dilated Cardiomyopathy Patients Referred for Implantable Cardiac Defibrillator: Evaluation of Multiple Scar Quantification Measures for Late Gadolinium Enhancement Magnetic Resonance Imaging

OBJECTIVES: Scar signal quantification using Late Gadolinium Enhancement Cardiac Magnetic Resonance (LGE-CMR) identifies patients at higher risk of future events, both in ischemic cardiomyopathy (ICM) and non-ischemic dilated cardiomyopathy (DCM). However, the ability of scar signal burden to predict events in such patient groups at the time of referral for implantable cardioverter-defibrillator (ICD) has not been well explored. This study evaluates the predictive utility of multiple scar quantification measures in ICM and DCM patients being referred for ICD.

METHODS: 124 consecutive patients referred for ICD therapy (59 with ICM and 65 with DCM) underwent a standardized LGE-CMR protocol with blinded, multi-threshold scar signal quantification and, for those with ICM, peri-infarct signal quantification. Patients were prospectively followed for the primary combined outcome of appropriate ICD therapy, survived cardiac arrest or sudden cardiac death.

RESULTS: At a mean follow-up of 632 ± 262 days, 18 patients (15%) had suffered the primary outcome. Total scar was significantly higher among those suffering a primary outcome, a relationship maintained within each cardiomyopathy cohorts (p<0.01 for all comparisons). Total scar was the strongest independent predictor of the primary outcome and demonstrated a negative predictive value of 86%. In the ICM sub-cohort peri-infarct signal showed only a non-significant trend towards elevation among those having a primary endpoint.

CONCLUSIONS: Myocardial scar quantification by LGE-CMR predicts arrhythmic events in patients being evaluated for ICD eligibility irrespective of cardiomyopathy etiology.

PMID:

Performance of 3-Dimensional Echocardiography in Measuring Left Ventricular Volumes and Ejection Fraction: A Systematic Review and Meta-Analysis

OBJECTIVES: The primary aim of this systematic review is to objectively evaluate the test performance characteristics of three-dimensional echocardiography (3DE) in measuring left ventricular (LV) volumes and ejection fraction (EF). Despite its growing use in clinical laboratories, the accuracy of 3DE has not been studied on a large scale. It is unclear if this technology offers an advantage over traditional two-dimensional (2D) methods.

METHODS: We searched for studies that compared LV volumes and EF measured by 3DE and cardiac magnetic resonance (CMR) imaging. A subset of those also compared standard 2D methods with CMR. We used meta-analyses to determine the overall bias and limits of agreement of LV end-diastolic volume (EDV), end-systolic volume (ESV), and EF measured by 3DE and 2D echocardiography (2DE).

RESULTS: Twenty-three studies (1,638 echocardiograms) were included. The pooled biases ± 2 SDs for 3DE were –19.1 ± 34.2 ml, –10.1 ± 29.7 ml, and – 0.6 ± 11.8% for EDV, ESV, and EF, respectively. Nine studies also included data from 2DE, where the pooled biases were –48.2 ± 55.9 ml, –27.7 ± 45.7 ml, and 0.1 ± 13.9% for EDV, ESV, and EF, respectively. In this subset, the difference in bias between 3DE and 2D volumes was statistically significant (p = 0.01 for both EDV and ESV). The difference in variance was statistically significant (p < 0.001) for all 3 measurements.

CONCLUSIONS: Three-dimensional echocardiography underestimates volumes and has wide limits of agreement, but compared with traditional 2D methods in these carefully performed studies, 3DE is more accurate for volumes and more precise in all 3 measurements.

PMID:

Diagnostic Performance of Noninvasive Myocardial Perfusion Imaging Using Single-Photon Emission Computed Tomography, Cardiac Magnetic Resonance, and Positron Emission Tomography Imaging for the Detection of Obstructive Coronary Artery Disease

OBJECTIVES: This study aimed to determine the diagnostic accuracy of the 3 most commonly used noninvasive myocardial perfusion imaging modalities, single-photon emission computed tomography (SPECT), cardiac magnetic resonance (CMR), and positron emission tomography (PET) perfusion imaging for the diagnosis of obstructive coronary artery disease (CAD). Additionally, the effect of test and study characteristics was explored. Accurate detection of obstructive CAD is important for effective therapy. Noninvasive myocardial perfusion imaging is increasingly being applied to gauge the severity of CAD.

METHODS: Studies published between 1990 and 2010 identified by PubMed search and citation tracking were examined. A study was included if a perfusion imaging modality was used as a diagnostic test for the detection of obstructive CAD and coronary angiography as the reference standard (50% diameter stenosis).

RESULTS: Of the 3,635 citations, 166 articles (n = 17,901) met the inclusion criteria: 114 SPECT, 37 CMR, and 15 PET articles. There were not enough publications on other perfusion techniques such as perfusion echocardiography and computed tomography to include these modalities into the study. The patient-based analysis per imaging modality demonstrated a pooled sensitivity of 88% (95% confidence interval [CI]: 88% to 89%), 89% (95% CI: 88% to 91%), and 84% (95% CI: 81% to 87%) for SPECT, CMR, and PET, respectively; with a pooled specificity of 61% (95% CI: 59% to 62%), 76% (95% CI: 73% to 78%), and 81% (95% CI: 74% to 87%). This resulted in a pooled diagnostic odds ratio (DOR) of 15.31 (95% CI: 12.66 to 18.52; I ² 63.6%), 26.42 (95% CI: 17.69 to 39.47; I ² 58.3%), and 36.47 (95% CI: 21.48 to 61.92; I ² 0%). Most of the evaluated test and study characteristics did not affect the ranking of diagnostic performances.

CONCLUSIONS: SPECT, CMR, and PET all yielded a high sensitivity, while a broad range of specificity was observed. SPECT is widely available and most extensively validated; PET achieved the highest diagnostic performance; CMR may provide an alternative without ionizing radiation and a similar diagnostic accuracy as PET. We suggest that referring physicians consider these findings in the context of local expertise and infrastructure.

PMID:

Metabolic Syndrome, Diabetes, and Incidence and Progression of Coronary Calcium

OBJECTIVES: This study sought to examine and compare the incidence and progression of coronary artery calcium (CAC) among persons with metabolic syndrome (MetS) and diabetes mellitus (DM) versus those with neither condition. MetS and DM are associated with subclinical atherosclerosis as evidenced by CAC.

METHODS: The MESA (Multiethnic Study of Atherosclerosis) included 6,814 African American, Asian, Caucasian, and Hispanic adults 45 to 84 years of age, who were free of cardiovascular disease at baseline. Of these, 5,662 subjects (51% women, mean age 61.0 ± 10.3 years) received baseline and follow-up (mean 2.4 years) cardiac computed tomography scans. We compared the incidence of CAC in 2,927 subjects without CAC at baseline and progression of CAC in 2,735 subjects with CAC at baseline in those with MetS without DM (25.2%), DM without MetS (3.5%), or both DM and MetS (9.0%) to incidence and progression in subjects with neither MetS nor DM (58%). Progression of CAC was also examined in relation to coronary heart disease events over an additional 4.9 years.

RESULTS: Relative to those with neither MetS nor DM, adjusted relative risks (95% confidence intervals [CI]) for incident CAC were 1.7 (95% CI: 1.4 to 2.0), 1.9 (95% CI: 1.4 to 2.4), and 1.8 (95% CI: 1.4 to 2.2) (all p < 0.01), and absolute differences in mean progression (volume score) were 7.8 (95% CI: 4.0 to 11.6; p < 0.01), 11.6 (95% CI: 2.7 to 20.5; p < 0.05), and 22.6 (95% CI: 17.2 to 27.9; p < 0.01) for those with MetS without DM, DM without MetS, and both DM and MetS, respectively. Similar findings were seen in analysis using Agatston calcium score. In addition, progression predicted coronary heart disease events in those with MetS without DM (adjusted hazard ratio: 4.1, 95% CI: 2.0 to 8.5, p < 0.01) and DM (adjusted hazard ratio: 4.9 [95% CI: 1.3 to 18.4], p < 0.05) among those in the highest tertile of CAC increase versus no increase.

CONCLUSIONS: Individuals with MetS and DM have a greater incidence and absolute progression of CAC compared with individuals without these conditions, with progression also predicting coronary heart disease events in those with MetS and DM.

PMID:

Prognostic Value of Late Gadolinium Enhancement in Clinical Outcomes for Hypertrophic Cardiomyopathy

OBJECTIVES: The objective of this study was to perform a systematic review and meta-analysis of the predictive value of late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) for future cardiovascular events and death in hypertrophic cardiomyopathy (HCM). The utility of LGE for detecting myocardial fibrosis is well established. The prognostic value of LGE in HCM has been described in several studies, but controversy exists given the limited power of these studies to predict future events.

METHODS: We searched multiple databases including PubMed for studies of LGE in HCM that reported selected clinical outcomes (cardiovascular mortality, sudden cardiac death [SCD], aborted SCD, and heart failure death). We performed a systematic review of the literature and meta-analysis to determine pooled odds ratios for these clinical events.

RESULTS: Four studies evaluated 1,063 patients over an average follow-up of 3.1 years. The pooled prevalence of LGE was 60%. The pooled odds ratios (OR) demonstrate that LGE by CMR correlated with cardiac death (pooled OR: 2.92, 95% confidence interval [CI]: 1.01 to 8.42; p = 0.047), heart failure death (pooled OR: 5.68, 95% CI: 1.04 to 31.07; p = 0.045), and all-cause mortality (pooled OR: 4.46, 95% CI: 1.53 to 13.01; p = 0.006), and showed a trend toward significance for predicting sudden death/aborted sudden death (pooled OR: 2.39, 95% CI: 0.87 to 6.58; p = 0.091).

CONCLUSIONS: Late gadolinium enhancement by CMR has prognostic value in predicting adverse cardiovascular events among HCM patients. There are significant relationships between LGE and cardiovascular mortality, heart failure death, and all-cause mortality in HCM. Additionally, LGE and SCD/aborted SCD displayed a trend toward significance. The assessment of LGE by CMR has the potential to provide important information to improve risk stratification in HCM in clinical practice.

PMID:

RV Dysfunction In Pulmonary Hypertension Is Independently Related To Pulmonary Artery Stiffness

OBJECTIVES: This study investigated whether right ventricular (RV) adaptation to chronic pressure overload is associated with pulmonary artery (PA) stiffness beyond the degree of severity of pulmonary hypertension (PH). Increased PA stiffness has been associated with reduced survival in PH. The mechanisms for this association remain unclear.

METHODS: Right heart catheterization and cardiac magnetic resonance were performed within 1 week in 124 patients with known or suspected chronic PH. Pulmonary vascular resistance index (PVRI) and PA pressures were quantified from right heart catheterization. Cardiac magnetic resonance included standard biventricular cine sequences and main PA flow quantification with phase-contrast imaging. Indexes of PA stiffness (elasticity, distensibility, capacitance, stiffness index beta, and pulse pressure) were quantified combining right heart catheterization and cardiac magnetic resonance data. RV performance and adaptation were measured by RV ejection fraction, right ventricular mass index (RVMI), RV end-systolic volume index, and right ventricular stroke work index (RVSWI).

RESULTS: All indexes of PA stiffness were significantly correlated with measures of RV performance (Spearman rho coefficients ranging from –0.20 to 0.61, p < 0.05). Using multivariate regression analysis, PA elasticity, distensibility, and index beta were independently associated with all measures of RV performance after adjusting PVRI (p  0.024). PA capacitance was independently associated with RV ejection fraction, RVMI, and RVSWI (p < 0.05), whereas PA pulse pressure was associated with RVMI and RVSWI (p  0.027). Compared with PVRI, PA elasticity, distensibility, capacitance, and index beta explained 15% to 68% of the variability in RV ejection fraction, RVMI, and RV end-systolic volume index. Relative contributions of PA stiffness for RVSWI were 1.2x to 18.0x higher than those of PVRI.

CONCLUSIONS: PA stiffness is independently associated with the degree of RV dysfunction, dilation, and hypertrophy in PH. RV adaptation to chronic pressure overload is related not only to the levels of vascular resistance (steady afterload), but also to PA stiffness (pulsatile load).

PMID:

Exposure to Ionizing Radiation and Estimate of Secondary Cancers in the Era of High-Speed CT Scanning: Projections From the Medicare Population

PMID:

Prevalence and Signal Characteristics of Late Gadolinium Enhancement on Contrast-Enhanced Magnetic Resonance Imaging in Patients With Takotsubo Cardiomyopathy

OBJECTIVES: To determine the prevalence and signal intensity (SI) characteristics of late gadolinium enhancement (LGE) on magnetic resonance imaging (MRI) in takotsubo cardiomyopathy (TC).

METHODS: Cine, black-blood T2-weighted and LGE MR images were acquired in 23 patients with TC within 72h of onset. Wall motion abnormality (WMA), edema and LGE were evaluated with a 16-segment model. The SI characteristics of LGE were analyzed using SI distribution in remote normal segments as reference. Follow-up MRI was performed 3 months later. Retrospective analysis of LGE MRI was also performed in 10 patients with acute myocardial infarction (AMI) to compare the SI characteristics between TC and AMI.

RESULTS: In acute phase, WMA and edema were observed in 236 (64%) and 205 (56%) of 368 segments. LGE was observed in 10 (2.7%) of 368 segments and in 5 (22%) of 23 patients. All LGE lesions in TC exhibited transmural enhancement. The contrast-to-noise ratio (CNR) in TC was significantly lower than that of AMI (3.1±0.3 standard deviations (SD) vs. 6.1±1.2 SD, P<0.01), and CNR value of 4 was useful for distinguishing TC from AMI. Both LGE and WMA disappeared within 12 months.

CONCLUSIONS: Grey myocardial signal on LGE MRI may be observed in patients with TC. However, the extent of LGE is substantially less than that of WMA and edema, and disappears within 12 months.

PMID: 22293447

Late Gadolinium Enhancement Cardiovascular Magnetic Resonance Predicts Clinical Worsening in Patients with Pulmonary Hypertension

OBJECTIVES: Late gadolinium enhancement (LGE) occurs at the right ventricular (RV) insertion point (RVIP) in patients withpulmonary hypertension (PH) and has been shown to correlate with cardiovascular magnetic resonance (CMR) derived RV indices. However, the prognostic role of RVIP-LGE and other CMR-derived parameters of RV function are not well established. Our aim was to evaluate the predictive value of contrast-enhanced CMR in patients with PH.

METHODS: RV size, ejection fraction (RVEF), and the presence of RVIP-LGE were determined in 58 patients with PH referred for CMR. All patients underwent right heart catheterization, exercise testing, and N-terminal pro-brain natriuretic peptide (NT-proBNP) evaluation; results of which were included in the final analysis if performed within 4 months of the CMR study. Patients were followed for the primary endpoint of time to clinical worsening (death, decompensated right ventricular heart failure, initiation of prostacyclin, or lung transplantation).

RESULTS: Overall, 40/58 (69%) of patients had RVIP-LGE. Patients with RVIP- LGE had larger right ventricular volume index, lower RVEF, and higher mean pulmonary artery pressure (mPAP), all p<0.05. During the follow-up period of 10.2 +/- 6.3 months, 19 patients reached the primary endpoint. In a univariate analysis, RVIP-LGE was a predictor for adverse outcomes (p=0.026). In a multivariate analysis, CMR-derived RVEF was an independent predictor of clinical worsening (p=0.036) along with well-established prognostic parameters such as exercise capacity (p=0.010) and mPAP (p=0.001).

CONCLUSIONS: The presence of RVIP-LGE in patients with PH is a marker for more advanced disease and poor prognosis. In addition, this study reveals for the first time that CMR-derived RVEF is an independent non-invasive imaging predictor of adverse outcomes in this patient population.

PMID: 22296860

Low-Grade Inflammation and the Phenotypic Expression of Myocardial Fibrosis in Hypertrophic Cardiomyopathy

OBJECTIVES: To investigate the role of inflammation in the phenotypic expression of myocardial fibrosis in hypertrophic cardiomyopathy (HCM).

METHODS: This was a clinical study at Kuopio University Hospital and University of Eastern Finland, Kuopio, Finland. Twenty-four patients with a single HCM-causing mutation D175N in the α-tropomyosin gene and 17 control subjects. Endomyocardial biopsy samples taken from the patients with HCM were compared with matched myocardial autopsy specimens. Levels of high-sensitivity C-reactive protein (hsCRP) and proinflammatory cytokines were measured in patients and controls. Myocardial late gadolinium enhancement (LGE) in cardiac MRI (CMRI) was detected.

RESULTS: Endomyocardial samples in patients with HCM showed variable myocyte hypertrophy and size heterogeneity, myofibre disarray, fibrosis, inflammatory cell infiltration and nuclear factor kappa B (NF-κB) activation. Levels of hsCRP and interleukins (IL-1β, IL-1RA, IL-6, IL-10) were significantly higher in patients with HCM than in control subjects. In patients with HCM, there was a significant association between the degree of myocardial inflammatory cell infiltration, fibrosis in histopathological samples and myocardial LGE in CMRI. Levels of hsCRP were significantly associated with histopathological myocardial fibrosis. hsCRP, tumour necrosis factor α and IL-1RA levels had significant correlations with LGE in CMRI.

CONCLUSIONS: A variable myocardial and systemic inflammatory response was demonstrated in patients with HCM attributable to an identified sarcometric mutation. Inflammatory response was associated with myocardial fibrosis, suggesting that myocardial fibrosis in HCM is an active process modified by an inflammatory response.

PMID:

MR Imaging of Pulmonary Embolism: Diagnostic Accuracy of Contrast-enhanced 3D MR Pulmonary Angiography, Contrast-enhanced Low–Flip Angle 3D GRE, and Nonenhanced Free-Induction FISP Sequences

OBJECTIVES: To evaluate relative detection of pulmonary embolism (PE) with standard bolus-triggered contrast-enhanced breath-hold magnetic resonance (MR) pulmonary angiography, contrast-enhanced recirculation-phase breath-hold low–flip angle three-dimensional (3D) gradient-echo (GRE), and nonenhanced free-induction cardiac- and respiratory-triggered true fast imaging with steady-state precession (FISP) MR sequences.

METHODS: The study was HIPAA compliant and institutional review board approved. Twenty-two patients with a computed tomographic (CT) angiography diagnosis of PE underwent MR imaging within 48 hours of CT. MR included three complementary techniques: MR pulmonary angiography, 3D GRE, and triggered true FISP. Each sequence was analyzed separately by two independent reviewers who recorded presence of emboli in categorized pulmonary artery anatomic territories. CT angiography results were analyzed by a third independent reviewer, who retrospectively recorded presence of emboli using the same format; these results served as the reference standard. Sensitivity, specificity, and positive and negative predictive values for PE detection were calculated for each MR technique on a per-embolus basis, and 95% confidence intervals were calculated according to the efficient-score method. A two-sample t test was used to compare values among MR techniques.

RESULTS: Sensitivities for PE detection were 55% for MR pulmonary angiography, 67% for triggered true FISP, and 73% for 3D GRE MR imaging. Combining all three MR sequences improved overall sensitivity to 84%. Specificity was 100% for all detection methods except for MR pulmonary angiography (one false-positive). Agreement between readers was high (κ = 0.87). Embolus detection rates were lowest in the lingula branch for all MR sequences compared with remainder of the vascular territories (P = .07).

CONCLUSIONS: There are complementary benefits to combining standard MR pulmonary angiography, 3D GRE, and triggered true FISP MR examinations for evaluation of PE.

PMID: 22438448

Computed Tomography Myocardial Perfusion Imaging with 320-Row Detector CT Accurately Detects Myocardial Ischemia in Patients with Obstructive Coronary Artery Disease.

Background—Computed tomography coronary angiography (CTA) has been shown to be accurate in detecting anatomic coronary arterial obstruction, but is limited for the detection of myocardial ischemia. The primary aim of this study was to assess the accuracy of 320-row CT perfusion imaging (CTP) to detect atherosclerosis causing myocardial ischemia.

Methods and Results—Fifty symptomatic patients with recent single photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) underwent a comprehensive cardiac CT protocol that included 320-CTA followed by adenosine stress CTP. CTP images were analyzed quantitatively for the presence of subendocardial perfusion deficits. All analyses were blinded to imaging and clinical results. CTA alone was a limited predictor of myocardial ischemia compared with SPECT with a sensitivity, specificity, positive (PPV) and negative predictive value (NPV) of 56%, 75%, 56%, 75%, and the AUC was 0.65 (95%CI: 0.51-0.78, p=0.07). CTP was a better predictor of myocardial ischemia with a sensitivity, specificity, PPV, and NPV of 72%, 91%, 81%, 85%, with an AUC of 0.81 (95%CI: 0.68-0.91, p<0.001) and was an excellent predictor of myocardial ischemia on SPECT-MPI in the presence of stenosis (≥50% on CTA) with a sensitivity, specificity, PPV, and NPV of 100%, 81%, 50%, 100%, with an AUC of 0.92 (95%CI: 0.80-0.97, p<0.001). The radiation dose for the comprehensive cardiac CT protocol and SPECT were 13.8±2.9 and 13.1±1.7; respectively (p=0.15).

Conclusions—CTP imaging with rest and adenosine stress 320-row CT is accurate in detecting obstructive atherosclerosis causing myocardial ischemia.

PMID: 22447807