Indexing left ventricular wall thickness to body surface area improves prognostic value.

BACKGROUND: Guidelines provide normal ranges of left ventricular (LV) wall thicknesses (WT) without indexing. We hypothesized that indexing WT to body surface area (BSA) improves prognostic value. METHODS: We examined the relationship between WT and BSA in 9737 patients undergoing echocardiography without risk factors for LV hypertrophy other than obesity. We compared WT to BSA and examined the relationship of WT and LV mass index (LVMI) to mortality. RESULTS: There is a linear relationship between BSA and septal and posterior WT (r = 0.38, P < 0.001 for each). Higher quartiles of BSA were associated with increased WT (P < 0.001). After adjusting for age and gender, greater mean WT (MWT) (Hazards Ratio [HR] 1.10 per mm, 95% Confidence Interval [CI] 1.04-1.16, P = 0.001, C-statistic 0.66), LVMI (HR 1.01, 95% CI 1.001-1.01, P = 0.01, C-statistic 0.66), and indexed MWT (HR 1.34 per mm/m2 , 95% CI 1.23-1.47, P < 0.001, C-statistic 0.67) are each associated with increased mortality, with indexed MWT having the highest prognostic value. Each decile of indexed MWT ≥8th decile was associated with increased mortality compared to the 1st decile (P < 0.01 for each). Individuals with indexed MWT ≥8th decile (≥5.0 mm/m2 ) had increased adjusted mortality (HR 1.67, 95% CI 1.43-1.94, P < 0.001, C-statistic 0.67); this had improved prognostic value over guideline definitions of increased MWT (C-statistic 0.66) or LVMI (P = NS). CONCLUSIONS: We observe a linear relationship between BSA and WT. Indexing WT improves mortality prediction over LVMI and nonindexed WT. These findings support indexing WT to BSA.

Acute aortic syndromes: diagnosis and management, an update.

Acute aortic syndromes (AAS) encompass a constellation of life-threatening medical conditions including classic acute aortic dissection (AAD), intramural haematoma, and penetrating atherosclerotic aortic ulcer. Given the non-specific symptoms and physical signs, a high clinical index of suspicion is necessary to detect the disease before irreversible lethal complications occur. In order to reduce the diagnostic time delay, a comprehensive flowchart for decision-making based on pre-test sensitivity of AAS has been designed by the European Society of Cardiology guidelines on aortic diseases and should be thus applied in the emergency scenario. When the definitive diagnosis is made, prompt and appropriate therapeutic interventions should be undertaken if indicated by a highly specialized aortic team. Urgent surgery for AAD involving the ascending aorta (Type A) and medical therapy alone for AAD not involving the ascending aorta (Type B) are typically recommended. In complicated Type B AAD, thoracic endovascular aortic repair (TEVAR) is generally indicated. On the other hand, in uncomplicated Type B AAD, pre-emptive TEVAR rather than medical therapy alone to prevent late complications, while intuitive, requires further study in randomized cohorts. Finally, it should be highlighted that there is an urgent need to increase awareness of AAS worldwide, including dedicated education/prevention programmes, and to improve diagnostic and therapeutic strategies, outcomes, and lifelong surveillance.

Iterative Reconstruction Results in Larger Computed Tomography Measurements of Iliofemoral Artery Diameter in Patients Referred for Transcatheter Aortic Valve Replacement.

OBJECTIVES: We hypothesized that improved iterative reconstruction increases image quality and reduces artifacts for iliofemoral artery computed tomography imaging in patients referred for transcatheter aortic valve replacement (TAVR). METHODS: We examined 56 consecutive patients undergoing computed tomography for possible TAVR and compared image quality and iliofemoral artery size between adaptive statistical iterative reconstructions (ASIRs) and improved model-based iterative reconstructions (MBIRs). RESULTS: Model-based iterative reconstruction (vs ASIR) was associated with improved (P < 0.001 for each) image quality (3.4 ± 0.8 vs 2.8 ± 1.0), beam hardening (3.5 ± 0.8 vs 3.0 ± 1.1), and wall definition (3.6 ± 0.6 vs 3.1 ± 0.8). Image signal-to-noise ratios (20.4 ± 10.1 vs 13.7 ± 6.6, P < 0.001) were also increased with MBIR as compared with ASIR. Mean iliofemoral artery size was larger using MBIR compared with ASIR (left, 7.7 ± 1.5 vs 7.4 ± 1.7 mm, P < 0.001; right, 7.8 ± 1.2 vs 7.4 ± 1.5 mm, P = 0.008). CONCLUSIONS: In patients referred for TAVR, improved MBIR resulted in higher image quality, reduced artifacts, and larger iliofemoral artery diameters compared with standard iterative reconstructions.

Left ventricular function and volume with coronary CT angiography improves risk stratification and identification of patients at risk for incident mortality: results from 7758 patients in the prospective multinational CONFIRM observational cohort study.

PURPOSE: To assess whether gradations of left ventricular (LV) ejection fraction (LVEF) and volumes measured with coronary computed tomography (CT) would augment risk stratification and discrimination for incident mortality. MATERIALS AND METHODS: This study was approved by the institutional review board, and informed consent was obtained when required. Subjects without known coronary artery disease (CAD) who underwent cardiac CT angiography with quantitative LV measurements were categorized according to LVEF (≥ 55%, 45%-54.9%, 35%-44.9%, or <35%). LV end-systolic volume (LVESV) and LV end-diastolic volume (LVEDV) were classified as normal (≥ 90 mL) or abnormal (≥ 200 mL). CAD extent and severity was categorized as none, nonobstructive, obstructive (≥ 50%), one-vessel, two-vessel, and three-vessel or left main disease. LVEF and volumes were assessed for risk prediction and discrimination of future mortality by using Cox hazards model and receiver operating characteristic curve analysis, respectively. RESULTS: During a follow-up of 2.0 years ± 0.9, 7758 patients (mean age, 58.5 years ± 13.0; 4220 male patients [54.4%]) were studied. At multivariable analysis, worsening LVEF was independently associated with mortality for moderately (hazard ratio = 3.14, P < .001) and severely (hazard ratio = 5.19, P < .001) abnormal ejection fraction. LVEF demonstrated improved discrimination for mortality (Az = 0.816) when compared with CAD risk factors alone (Az = 0.781) or CAD risk factors plus extent and severity. At multivariable analysis of a subgroup of 3706 individuals, abnormal LVEDV (hazard ratio = 4.02) and LVESV (hazard ratio = 6.46) helped predict mortality (P < .001). Similarly, LVESV and LVEDV demonstrated improved discrimination when compared with CAD risk factors or CAD extent and severity (P < .05). CONCLUSION: LV dysfunction and volumes measured with cardiac CT angiography augment risk prediction and discrimination for future mortality.

Coronary artery imaging with single-source rapid kilovolt peak-switching dual-energy CT.

PURPOSE: To evaluate beam-hardening (BH) artifact reduction in coronary computed tomography (CT) angiography with dual-energy CT, to define the optimal monochromatic-energy levels for coronary and myocardial signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in dual-energy CT, and to compare these levels with single-energy CT. MATERIALS AND METHODS: The study was approved by the institutional review board and/or ethics committee at each site. Patients provided informed consent. Thirty-nine patients were prospectively enrolled to undergo dual-energy CT, and 25 also underwent single-energy CT. Myocardial and coronary SNR, CNR, and iodine concentration were measured across multiple segments at varying monochromatic energy levels (40-140 keV). BH was defined as signal decrease in basal inferior wall versus midinferior wall, and signal increase in midseptum versus midinferior wall. Generalized estimating equation was used to identify optimal monochromatic-energy levels and compare them with single-energy CT. RESULTS: BH was noted at single-energy CT with basal inferior wall mean reduction of 19.7 HU ± 29.2 (standard deviation) and midseptum increase of 46.3 HU ± 36.3. There was reduction in this artifact at 90 keV or greater (1.7 HU ± 18.4 in basal inferior wall and 20.1 HU ± 37.5 in midseptum at 90 keV; P < .05). SNR and CNR were higher in the myocardium and coronary arteries at 60-80 keV than single-energy CT (myocardium: SNR, 3.02 vs 2.39, and CNR, 6.73 vs 5.16; coronary arteries: SNR, 10.83 vs 7.75, and CNR, 13.31 vs 9.54; P < .01). Mean iodine concentration in resting myocardium was 2.19 mg/mL ± 0.57. CONCLUSION: Rapid kilovolt peak-switching dual-energy CT resulted in significant BH reduction and improvements in SNR and CNR in the myocardium and coronary arteries.

All-cause mortality benefit of coronary revascularization vs. medical therapy in patients without known coronary artery disease undergoing coronary computed tomographic angiography: results from CONFIRM (COronary CT Angiography EvaluatioN For Clinical Outcomes: An InteRnational Multicenter Registry).

AIMS: To date, the therapeutic benefit of revascularization vs. medical therapy for stable individuals undergoing invasive coronary angiography (ICA) based upon coronary computed tomographic angiography (CCTA) findings has not been examined. METHODS AND RESULTS: We examined 15 223 patients without known coronary artery disease (CAD) undergoing CCTA from eight sites and six countries who were followed for median 2.1 years (interquartile range 1.4-3.3 years) for an endpoint of all-cause mortality. Obstructive CAD by CCTA was defined as a ≥50% luminal diameter stenosis in a major coronary artery. Patients were categorized as having high-risk CAD vs. non-high-risk CAD, with the former including patients with at least obstructive two-vessel CAD with proximal left anterior descending artery involvement, three-vessel CAD, and left main CAD. Death occurred in 185 (1.2%) patients. Patients were categorized into two treatment groups: revascularization (n = 1103; 2.2% mortality) and medical therapy (n = 14 120, 1.1% mortality). To account for non-randomized referral to revascularization, we created a propensity score developed by logistic regression to identify variables that influenced the decision to refer to revascularization. Within this model (C index 0.92, χ2 = 1248, P < 0.0001), obstructive CAD was the most influential factor for referral, followed by an interaction of obstructive CAD with pre-test likelihood of CAD (P = 0.0344). Within CCTA CAD groups, rates of revascularization increased from 3.8% for non-high-risk CAD to 51.2% high-risk CAD. In multivariable models, when compared with medical therapy, revascularization was associated with a survival advantage for patients with high-risk CAD [hazards ratio (HR) 0.38, 95% confidence interval 0.18-0.83], with no difference in survival for patients with non-high-risk CAD (HR 3.24, 95% CI 0.76-13.89) (P-value for interaction = 0.03). CONCLUSION: In an intermediate-term follow-up, coronary revascularization is associated with a survival benefit in patients with high-risk CAD by CCTA, with no apparent benefit of revascularization in patients with lesser forms of CAD.

A prospective randomized controlled trial to assess the diagnostic performance of reduced tube voltage for coronary CT angiography.

OBJECTIVE: Tube voltage reduction has been shown to be an effective method to reduce radiation dose in nonobese patients undergoing coronary CT angiography. To date, the impact of reduced tube voltage on objective measures of diagnostic accuracy, as defined by quantitative coronary angiography (QCA), has not been established. The purpose of this article was to investigate the impact of tube voltage reduction on the diagnostic performance of coronary CTA compared with QCA. SUBJECTS AND METHODS: We performed a prospective randomized trial evaluating 50 consecutive patients referred for catheter angiography with a body mass index (BMI) ≤ 35 kg/m². Patients were randomly assigned to reduced (n = 24) or standard tube voltage (n = 26). Reduced tube voltage was defined as 80 or 100 kVp for individuals with BMI < 25 kg/m² or 25-35 kg/m², respectively; whereas standard tube voltage was defined as 100 or 120 kVp for individuals with BMI < 25 kg/m² or 25-35 kg/m², respectively. Tube current was fixed by study protocol as 600 mA (BMI < 30 kg/m²) or 650 mA (BMI ≥ 30 kg/m²). Coronary CTA examinations were interpreted by two blinded experienced readers with a third reader providing consensus. QCA was performed by an independent experienced core laboratory blinded to coronary CTA findings. Coronary artery segments were graded for stenosis as < 50%, 50-69%, and ≥ 70% by coronary CTA and as percentage stenosis by QCA. In an intention-to-diagnose fashion, all segments were included for final analysis, with nonevaluable segments by coronary CTA graded as obstructive. Signal and noise; contrast (mean signal-signal in left ventricular myocardium); and signal-to-noise ratio (SNR) and contrast-to-noise (CNR) ratio were compared. RESULTS: Mean age of the study cohort was 60.2 years; 78% were men. Prospective ECG gating was used in all patients, and no differences existed in scan length between groups (p = 0.19). Standard versus reduced tube voltage was associated with a reduction in effective radiation dose (2.6 ± 0.4 vs 1.3 ± 0.5 mSv, p < 0.001). The patient prevalence of luminal stenosis ≥ 50% was 56% (28/50). For detection of ≥ 50% stenosis in the standard versus reduced kVp groups, there were no differences in per-segment sensitivity (87% vs 84%, p = 0.73), specificity (92% vs 93%, p = 0.81), or accuracy (92% vs 91%, p = 0.70). No differences were noted for reduced versus standard tube current for SNR (13 ± 4 vs 13 ± 3, p = 0.59), CNR (10 ± 3 vs 10 ± 2, p = 0.99), or graded (0-4) image quality score (3.4 ± 0.8 vs 3.5 ± 0.6, p = 0.19). CONCLUSION: Compared with standard tube voltage, coronary CTA using reduced tube voltage results in lower effective radiation dose with comparable diagnostic performance.

Coronary CT angiography of patients with a normal body mass index using 80 kVp versus 100 kVp: a prospective, multicenter, multivendor randomized trial.

OBJECTIVE: We determined the effect of reduced 80-kVp tube voltage on the radiation dose and image quality of coronary CT angiography (CTA) in patients with a normal body mass index (BMI). SUBJECTS AND METHODS: A prospective, multicenter, multivendor trial was performed of 208 consecutive patients with a normal BMI (< 25 kg/m(2)) who had been referred for coronary CTA and did not have a history of coronary revascularization. Patients were randomized to 80-kVp imaging (n = 103) or 100-kVp imaging (n = 105). Three blinded readers graded interpretability and image quality. Study signal, noise, and contrast were also compared. RESULTS: Imaging with 80 kVp instead of 100 kVp was associated with 47% lower median radiation dose (median dose-length product, 62.0 mGy · cm [interquartile range, 54.0-123.3 mGy · cm] vs 117.0 mGy · cm [110.0-225.9 mGy · cm], respectively; 0.9 mSv [0.8-1.7 mSv] vs 1.6 mSv [1.4-3.2 mSv]; p < 0.001 for each) with no significant difference in interpretability (99% vs 99%; p = 0.99) or image quality (median score, 4.0 [interquartile range, 3.6-4.0] vs 4.0 [interquartile range, 3.8-4.0]; p = 0.20). Studies obtained using 80 kVp were associated with 27% increased signal (mean ± SD, 756 ± 157 vs 594 ± 105 HU; p < 0.001), 25% higher contrast (890 ± 156 vs 709 ± 108 HU; p < 0.001), and 50% greater noise (55 ± 15 vs 37 ± 12 HU; p < 0.001) with resultant 15% and 16% decreases in signal-to-noise (mean ± SD, 15 ± 5 vs 17 ± 5; p < 0.001) and contrast-to-noise (mean ± SD, 17 ± 6 vs 21 ± 5; p < 0.001) ratios, respectively. CONCLUSION: Coronary CTA using 80 kVp instead of 100 kVp was associated with a nearly 50% reduction in radiation dose with no significant difference in interpretability and noninferior image quality despite lower signal-to-noise and contrast-to-noise ratios. The use of 80-kVp tube voltage should be considered in dose-reduction strategies for coronary CTA of individuals with a normal BMI.

Impact of diastolic dysfunction severity on global left ventricular volumetric filling - assessment by automated segmentation of routine cine cardiovascular magnetic resonance.

OBJECTIVES: To examine relationships between severity of echocardiography (echo) -evidenced diastolic dysfunction (DD) and volumetric filling by automated processing of routine cine cardiovascular magnetic resonance (CMR). BACKGROUND: Cine-CMR provides high-resolution assessment of left ventricular (LV) chamber volumes. Automated segmentation (LV-METRIC) yields LV filling curves by segmenting all short-axis images across all temporal phases. This study used cine-CMR to assess filling changes that occur with progressive DD. METHODS: 115 post-MI patients underwent CMR and echo within 1 day. LV-METRIC yielded multiple diastolic indices - E:A ratio, peak filling rate (PFR), time to peak filling rate (TPFR), and diastolic volume recovery (DVR80 - proportion of diastole required to recover 80% stroke volume). Echo was the reference for DD. RESULTS: LV-METRIC successfully generated LV filling curves in all patients. CMR indices were reproducible (< or = 1% inter-reader differences) and required minimal processing time (175 +/- 34 images/exam, 2:09 +/- 0:51 minutes). CMR E:A ratio decreased with grade 1 and increased with grades 2-3 DD. Diastolic filling intervals, measured by DVR80 or TPFR, prolonged with grade 1 and shortened with grade 3 DD, paralleling echo deceleration time (p < 0.001). PFR by CMR increased with DD grade, similar to E/e' (p < 0.001). Prolonged DVR80 identified 71% of patients with echo-evidenced grade 1 but no patients with grade 3 DD, and stroke-volume adjusted PFR identified 67% with grade 3 but none with grade 1 DD (matched specificity = 83%). The combination of DVR80 and PFR identified 53% of patients with grade 2 DD. Prolonged DVR80 was associated with grade 1 (OR 2.79, CI 1.65-4.05, p = 0.001) with a similar trend for grade 2 (OR 1.35, CI 0.98-1.74, p = 0.06), whereas high PFR was associated with grade 3 (OR 1.14, CI 1.02-1.25, p = 0.02) DD. CONCLUSIONS: Automated cine-CMR segmentation can discern LV filling changes that occur with increasing severity of echo-evidenced DD. Impaired relaxation is associated with prolonged filling intervals whereas restrictive filling is characterized by increased filling rates.

Effect of padding duration on radiation dose and image interpretation in prospectively ECG-triggered coronary CT angiography.

OBJECTIVE: Prospectively ECG-triggered coronary CT angiography images are acquired during a window in middiastole. Additional surrounding x-ray beam on time, or padding, can be variably set, and the increased padding results in additional available phases for analysis. The purpose of this study was to assess the effect of padding duration on image interpretability and its incident effect on radiation dose. SUBJECTS AND METHODS: We prospectively evaluated imaging of 886 patients undergoing consecutive prospectively ECG-triggered coronary CT angiographic examinations at three centers and compared the findings in patients stratified by padding duration. We assessed the effect of padding duration on image interpretability and radiation dose. RESULTS: The mean patient age was 56 +/- 12 years, and 58% of the patients were men. The median heart rate was 55 beats/min (interquartile range, 50-61 beats/min). Padding duration was 0, 1-99, and 100-150 milliseconds for 268, 482, and 136 patients, respectively, with no difference in image interpretability rate between groups (per patient, 98.8%, 97.3%, and 97.1%; per artery, 99.2%, 99.2%, and 99.1%). The groups differed in median radiation dose (2.3 mSv [interquartile range, 1.5-3.2 mSv]; 3.8 mSv [interquartile range, 2.3-4.7 mSv]; 5.5 mSv [interquartile range, 3.8-6.1 mSv]; p < 0.001). Independent of patient and scan parameters, increased padding was associated with greater radiation dose (45% increase per 100-millisecond increase in padding, p < 0.001). CONCLUSION: In a large multicenter study of coronary CT angiography of patients with excellent heart rate control, the use of minimal padding was associated with a substantial reduction in radiation dose with preserved image interpretability. Use of no or reduced padding should be considered in dose-reduction strategies.

Estimated radiation dose reduction using adaptive statistical iterative reconstruction in coronary CT angiography: the ERASIR study.

OBJECTIVE: The objective of our study was to assess the impact of Adaptive Statistical Iterative Reconstruction (ASIR) on radiation dose and study quality for coronary CT angiography (CTA). SUBJECTS AND METHODS: We prospectively evaluated 574 consecutive patients undergoing coronary CTA at three centers. Comparisons were performed between consecutive groups initially using filtered back projection (FBP) (n = 331) and subsequently ASIR (n = 243) with regard to patient and scan characteristics, radiation dose, and diagnostic study quality. RESULTS: There was no difference between groups in the use of prospective gating, tube voltage, or scan length. The examinations performed using ASIR had a lower median tube current than those obtained using FBP (median [interquartile range], 450 mA [350-600] vs 650 mA [531-750], respectively; p < 0.001). There was a 44% reduction in the median radiation dose between the FBP and ASIR cohorts (4.1 mSv [2.3-5.2] vs 2.3 mSv [1.9-3.5]; p < 0.001). After adjustment for scan settings, ASIR was associated with a 27% reduction in radiation dose compared with FBP (95% CI, 21-32%; p < 0.001). Despite the reduced current, ASIR was not associated with a difference in adjusted signal, noise, or signal-to-noise ratio (p = not significant). No differences existed between FBP and ASIR for interpretability per coronary artery (98.5% vs 99.3%, respectively; p = 0.12) or per patient (96.1% vs 97.1%, p = 0.65). CONCLUSION. ASIR enabled reduced tube current and lower radiation dose in comparison with FBP, with preserved signal, noise, and study interpretability, in a large multicenter cohort. ASIR represents a new technique to reduce radiation dose in coronary CTA studies.

Adaptive statistical iterative reconstruction: assessment of image noise and image quality in coronary CT angiography.

OBJECTIVE: The purpose of our study was to determine the effect of Adaptive Statistical Iterative Reconstruction (ASIR) on cardiac CT angiography (CTA) signal, noise, and image quality. MATERIALS AND METHODS: We evaluated 62 consecutive patients at three sites who underwent clinically indicated cardiac CTA using an ASIR-capable 64-MDCT scanner and a low-dose cardiac CTA technique. Studies were reconstructed using filtered back projection (FBP), ASIR-FBP composites using 20-80% ASIR, and 100% ASIR. The signal and noise were measured in the aortic root and each of the four coronary arteries. Two blinded readers graded image quality on a 5-point Likert scale and determined the proportion of interpretable segments. All segments were included for analysis regardless of size. RESULTS: In comparison with FBP (0% ASIR), the use of 20%, 40%, 60%, 80%, and 100% ASIR resulted in reduced image noise between groups (-7%, -17%, -26%, -35%, and -43%, respectively; p < 0.001) without difference in signal (p = 0.60). There were significant differences between groups (0%, 20%, 40%, 60%, 80%, and 100% ASIR) in the Likert scores (1.5, 2.1, 3.7, 3.8, 2.0, and 1.1, respectively; p < 0.001) and proportion of interpretable segments (88.7%, 89.3%, 90.5%, 90.4%, 88.0%, and 87.3%, respectively; p < 0.001). Reconstruction using 40% and 60% ASIR had the highest Likert scores and largest proportion of interpretable segments. In comparison with FBP, each was associated with higher Likert scores and increased interpretable segments (p < 0.001 for all). CONCLUSION: ASIR resulted in noise reduction and significantly impacted image quality. When using a low tube current technique, cardiac CTA reconstruction using 40% or 60% ASIR significantly improved image quality and the proportion of interpretable segments compared with FBP reconstruction.

Evaluation of mechanical heart valve size and function with ECG-gated 64-MDCT.

OBJECTIVE: The purpose of our study was to determine whether CT can accurately evaluate mechanical heart valve size and function. MATERIALS AND METHODS: Sixty-two patients with mechanical valves (37 single-disc, 27 bileaflet; 59 aortic, 5 mitral) were evaluated with ECG-gated 64-MDCT and transthoracic echocardiography; a subset of 10 patients underwent cinefluoroscopy. Two readers independently interpreted each study. RESULTS: The mean age of the patients was 46.4 +/- 14.4 years; 50 were men and 12 were women. There was excellent correlation, and differences between CT readers were absent to small in measuring the opening angle (r = 0.96, p < 0.001; 76.7 +/- 9.0 degrees vs 76.8 +/- 9.6 degrees , p = 0.73), annulus diameter (r = 0.96, p < 0.001; 25.9 +/- 3.3 vs 25.9 +/- 3.2 mm, p = 0.62), and geometric orifice area (r = 0.98, p < 0.001; 3.8 +/- 0.9 vs 3.6 +/- 0.8 cm(2), p < 0.001). There was strong correlation without difference in opening angle between CT and cinefluoroscopy (r = 0.77, p < 0.001; 79.2 degrees +/- 9.8 degrees vs 77.2 degrees +/- 15.5 degrees , p = 0.45). Compared with manufacturer specifications, CT reported opening angles that were smaller for single-disc valves (n = 36, 67.4 degrees +/- 5.7 degrees vs 75 degrees , p < 0.001) and similar for bileaflet valves (n = 42 for 21 valves, 83.8 degrees +/- 3.9 degrees vs 85 degrees , p = 0.05), valves, with small underestimation with CT versus specifications in annulus diameter (n = 41; r = 0.75, p < 0.001; 26.4 +/- 3.0 vs 27.5 +/- 3.3 mm, p = 0.003), and geometric orifice area (n = 35; r = 0.90, p < 0.001; 3.7 +/- 0.7 vs 3.8 +/- 0.8 cm(2), p = 0.04). Each disc closed fully on CT; none had more than mild regurgitation on echocardiography. CONCLUSION: CT can measure the size and function of mechanical valves with high interobserver agreement and results similar to specifications. The opening angle with CT strongly correlates with cinefluoroscopy. CT is promising for the assessment of mechanical valves.

Differences in Echocardiographic Measures of Aortic Dimensions by Race.

It is not clear whether there are differences in aortic dimensions by race. Our hypothesis was that race-specific differences in aortic size exist. We compared the relation between race and aortic dimensions among 15,295 adults without known risk factors for cardiovascular disease or aortic dilatation, who underwent clinically indicated transthoracic echocardiography. We compared inner edge-to-inner edge measurements between whites (n = 12,932), blacks (n = 958), Asians (n = 827), Hispanics (n = 366), Native Americans (n = 38), and others (n = 174). Multivariate analysis compared measurements indexed with body surface area (BSA) between races and adjusted for variables including age, gender, and mean blood pressure. Mean age was 49.9 ± 17.6 years, and 58.7% were female. On gender-specific comparisons, there were significant differences in aortic size between races (p <0.001 for each). Using whites as a baseline, multivariable analysis demonstrated that blacks had smaller BSA-indexed aortic sinus (-0.34 mm/m2, p <0.001) and ascending aorta (-0.43 mm/m2, p <0.001) dimensions; Asians had larger BSA-indexed aortic sinus (0.36 mm/m2, p <0.001), ascending aorta (0.41 mm/m2, p <0.001), and aortic arch (0.20 mm/m2, p = 0.002) dimensions; Hispanics had larger BSA-indexed aortic arch dimensions (0.15 mm/m2, p = 0.01); Native Americans had increased BSA-indexed aortic arch dimensions (0.32 mm/m2, p = 0.01); and other races had increased BSA-indexed aortic arch dimensions (0.11 mm/m2, p = 0.03). In a cohort without known risk factors for aortic dilatation, race is associated with significant differences in aortic dimensions. In conclusion, these findings suggest that reference ranges for aortic size should be established using racially diverse cohorts to prevent misdiagnosis of aortic dilatation based on race.

Effect of Race on Echocardiographic Measures of Cardiac Structure and Function.

The relations between race and cardiac structure and function are incompletely understood. We hypothesized that race-specific differences in echocardiography measurements exist. We compared the relation between echocardiography measurements and race among 12,429 nonobese adults without known cardiovascular disease who underwent echocardiography. We compared measurements between whites (n = 10,508), blacks (n = 792), Asians (n = 628), Hispanics (n = 315), Native Americans (n = 34), and multiracial/other (n = 152) cohorts. Multivariate analysis compared measurements indexed to body surface area (BSA) between races and adjusted for variables including age, gender, and mean blood pressure. Mean age was 46.9 ± 17.4 years and 60.5% were women. After multivariable adjustment and using whites as a baseline, there were significant differences (p <0.05) in left ventricular end-diastolic diameter/BSA for blacks (-0.5 mm/m2), Asians (0.4 mm/m2), Hispanics (0.2 mm/m2), and multiracial/others (0.1 mm/m2); septal wall thickness/BSA for blacks (0.4 mm/m2) and Asians (0.1 mm/m2); posterior wall thickness/BSA for blacks (0.4 mm/m2), Asians (0.1 mm/m2), Hispanics (0.04 mm/m2), and multiracial/others (0.03 mm/m2); left atrial diameter/BSA for Asians (0.2 mm/m2), Hispanics (0.3 mm/m2), and multiracial/others (0.1 mm/m2); septal and lateral e' for blacks (-0.7 cm/s; -0.9 cm/s); and peak tricuspid regurgitation gradient for blacks (4.3 mm Hg) and Asians (-0.9 mm Hg). Race is associated with significant differences in left ventricular size, left atrial size, mitral annular velocity, and tricuspid regurgitation gradient. Normal reference ranges for echocardiography measurements should utilize racially diverse cohorts to prevent misclassification of echocardiography findings based on race.

The Clinical Impact of Imaging Surveillance and Clinic Visit Frequency after Acute Aortic Dissection.

BACKGROUND: Guidelines recommend frequent follow-up after acute aortic dissection (AAD), but optimal rates of follow-up are not clear. METHODS: We examined rates of imaging and clinic visits in 267 individuals surviving AAD during recommended intervals (≤1, > 1-3, > 3-6, > 6-12 months, then annually), frequency of adverse imaging findings, and the relationship between follow-up and mortality. RESULTS: Type A and B AAD were noted in 46 and 54% of patients, respectively. Mean follow-up was 54.7 ± 13.3 months, with 52 deaths. Adverse imaging findings peaked at 6 to 12 months (5.6%), but rarely resulted in an intervention (3.4% peak at 6-12 months). Compared with those with less frequent imaging, patients with imaging for 33 to 66% of intervals (p = 0.22) or ≥66% of intervals (p = 0.77) had similar adjusted survival. In comparison to patients with fewer clinic visits, those with visits in 33 to 66% of intervals experienced lower adjusted mortality (hazards ratio: 0.47, 95% confidence interval: 0.23-0.97, p = 0.04), with no difference seen in those with ≥66% (vs. < 33%) interval visits (p = 0.47). Imaging at 6 to 12 months (vs. none) was associated with decreased adjusted mortality (hazards ratio: 0.50, 95% confidence interval: 0.27-0.91, p = 0.02), while imaging during other intervals, or clinic visits during any specific intervals, was not associated with a difference in mortality (p > 0.05 for each). CONCLUSIONS: Adverse imaging findings following AAD are common, but rarely require prompt intervention. Patients with the lowest and highest rates of clinic visits experienced increased mortality. While the overall rate of surveillance imaging did not correlate with mortality, adverse imaging findings and related interventions peaked at 6 to 12 months after AAD, and imaging during this time was associated with improved survival.

Aortic valve area on 64-MDCT correlates with transesophageal echocardiography in aortic stenosis.

OBJECTIVE: The purpose of our study was to compare aortic valve area and calcification between CT and echocardiography. MATERIALS AND METHODS: We performed retrospective evaluation of 80 consecutive patients with aortic stenosis (AS) who underwent ECG-gated 64-MDCT and transesophageal echocardiography (TEE). Valve planimetry was feasible in 80 patients with CT and in 63 patients with TEE; valve area by transthoracic echocardiography was available in 46 patients. Valve calcification grade on CT was compared with TEE. One cardiologist (echocardiography) and two radiologists (CT) independently and blindly reviewed the studies. Pearson's correlations, Spearman's rank correlations, paired Student's t tests, and weighted kappa tests were used. RESULTS: The median valve area on TEE was 0.7 +/- 0.9 cm(2). There was excellent correlation (n = 80; r = 0.91, p < 0.001) and no difference (0.06 +/- 0.26 cm(2), p = 0.06) between CT readers. There was strong correlation (n = 63; r = 0.84, p < 0.001) and no difference (-0.06 +/- 0.48 cm(2), p = 0.33) in valve area between CT and TEE, with a strong correlation (n = 46; r = 0.83, p < 0.001) and small overestimation (0.17 +/- 0.33 cm(2), p < 0.001) in valve area with CT versus transthoracic echocardiography. The sensitivity and specificity of CT to detect severe aortic stenosis compared with TEE were 92.1% (35/38) and 89.5% (17/19), respectively. Calcification grade had fair agreement between CT readers and TEE (kappa = 0.34 and 0.37, respectively). CONCLUSION: Aortic valve area on CT strongly correlates with echocardiography and has excellent sensitivity and specificity to detect severe stenosis. Valve calcification has fair agreement between studies. Valve area and calcification should be reported on CT angiography in patients with AS.

Extracorporeal Membrane Oxygenation in a 29-Year-Old Man with Pneumocystis jirovecii Respiratory Failure and AIDS.

The use of extracorporeal membrane oxygenation (ECMO) in patients who have acute respiratory distress syndrome has been generally beneficial. However, because of various concerns, ECMO has rarely been used in patients who have human immunodeficiency virus infection with or without acquired immune deficiency syndrome. We report our successful use of venovenous ECMO in a 29-year-old man who presented with severe respiratory distress secondary to Pneumocystis jirovecii pneumonia associated with undiagnosed infection with the human immunodeficiency virus and acquired immune deficiency syndrome. After highly active antiretroviral therapy was begun, acute immune reconstitution inflammatory syndrome developed. The patient's respiratory condition deteriorated rapidly; he was placed on venovenous ECMO for 19 days and remained intubated thereafter. After a 65-day hospital stay and inpatient pulmonary rehabilitation, he recovered fully. In addition to presenting this case, we review the few previous reports and note the multidisciplinary medical and surgical support necessary to treat similar patients.