Although metabolic syndrome (MS) is associated with adverse cardiovascular outcomes, its association with the presence and extent of coronary atherosclerotic plaques is not well described. To assess ...this relation, multidetector computed tomography–based patterns of coronary plaque were assessed in 77 patients enrolled in the ROMICAT study (age 54 ± 12 years; 79% Caucasians, and 36% women) and compared betwen those who did (n = 35; 45%) and did not (n = 42; 55%) have MS. The presence of any, calcified, and noncalcified plaque was significantly higher in patients with than without MS (91%, 74%, and 77% vs 46%, 45%, and 40% segments with plaque, respectively; all p <0.01). The overall number of segments with plaques was also higher in patients with MS (5.8 ± 3.7 vs 2.1 ± 3.3; p <0.001). MS was independently associated with both the presence and extent of overall plaques after adjusting for the Framingham risk score (odds ratio 6.7, 95% confidence interval 1.6 to 28.8, p <0.01 for presence, β coefficient = 3.59 ± 0.88 SE, p = 0.009 for extent) and individual risk factors, including age, gender, smoking, body mass index, hypertension, diabetes, hyperlipidemia, and clinical coronary disease (odds ratio 8.4, 95% confidence interval 1.7 to 42.5, p = 0.008 for presence, β coefficient = 2.35 ± 0.86 SE, p = 0.007 for extent). Similarly, MS was independently associated with calcified and noncalcified plaques individually. In conclusion, MS was independently associated with the presence and extent of both calcified and noncalcified coronary atherosclerotic plaques detected using multidetector computed tomography. These data may explain the higher cardiovascular risk in these patients and may lay the foundation for studies to determine whether such information may improve risk stratification.
To identify the age- and gender-specific subpopulations of patients with acute chest pain in whom coronary computed tomographic angiography (CTA) will yield the greatest diagnostic benefit. Subjects ...with acute chest pain and an inconclusive initial evaluation (nondiagnostic electrocardiograhic findings, negative cardiac biomarkers) underwent contrast-enhanced 64-slice coronary CTA as a part of an observational cohort study. Independent investigators determined the presence of significant coronary stenosis (>50% luminal narrowing) and the occurrence of acute coronary syndrome (ACS) during the index hospitalization. We determined the diagnostic accuracy and effect on pretest probability of ACS using Bayes' theorem by age and gender. Of 368 patients (age 52.7 ± 12 years, 61% men), 8% had ACS. The presence of significant coronary stenosis on CTA and the occurrence of ACS increased with age for both men and women (p <0.001). Cardiac CTA was highly sensitive and specific in women <65 years of age (sensitivity 100% and specificity >87%) and men <55 years of age (sensitivity 100% for men <45 years and 80% for men 45 to 54 years old; specificity >88.2%). Moreover, in these patients, coronary CTA led to restratification from low to high risk (for positive findings on CTA) or from low to very low risk (for negative findings on CTA). In contrast, a negative result on CTA did not result in restratification to a low-risk category in women >65 years and men >55 years old. In conclusion, the present analysis provides initial evidence that men <55 years and women <65 years might benefit more from cardiac CTA than older patients. Thus, age and gender might serve as simple criteria to appropriately select patients who would derive the greatest diagnostic benefit from coronary CTA in the setting of acute chest pain.
Background To lower the radiation exposure associated with cardiac CT, it is essential to identify all factors that influence radiation dose. Objectives We explored the effect of heart rhythm during ...scan acquisition on radiation dose with a 64-slice dual-source cardiac CT. Methods Patient and scan data were collected prospectively in 302 consecutive patients referred for a clinical dual-source cardiac CT. Electrocardiograms recorded during acquisition were interpreted by a cardiologist and categorized as (1) normal sinus rhythm (NSR), (2) premature atrial contraction (PAC) or premature ventricular contraction (PVC), or (3) atrial fibrillation or flutter. Results Of the 302 patients, 227 (75.2%) were in NSR and had no ectopy, 55 (18.2%) had PAC/PVC, and 20 (6.6%) had atrial fibrillation or flutter during the scan. Patients with irregular rhythm (PAC/PVC and atrial fibrillation or flutter) were older than patients with regular rhythm (61.0 vs 54.8 years; P = 0.006). Patients with NSR had the lowest estimated radiation dose, followed by PAC/PVC and atrial fibrillation/flutter (9.4, 14.5, 20.9 mSv; P < 0.001). The difference remained significant after adjustments for differences in examination type, tube current and voltage, scan length, pitch, and use of tube current modulation (9.8, 14.1, 17.9 mSv; P < 0.001). No significant association was observed between heart rhythm and subjective image quality although scans with regular rhythm and no ectopy had higher signal-to-noise and contrast-to-noise ratios ( P < 0.01). Conclusion Compared to patients with NSR, patients with atrial fibrillation/flutter had the highest radiation exposure, followed by those with PAC/PVC. Even after adjustment for factors associated with radiation exposure, a significant difference in radiation dose persisted. These findings can be used to identify patients who are more likely to receive higher radiation dose when undergoing cardiac CT and to develop future more-efficient scanner algorithms for use in patients with arrhythmias.
Background Perfusion defects (PDs) detected with cardiac magnetic resonance (CMR) imaging predict the functional recovery of myocardial function after acute myocardial infarction. Objective We ...evaluated the ability of cardiac computed tomography (CCT) to predict the recovery of regional left ventricular (LV) systolic function after ST elevation myocardial infarction (STEMI). Methods Seventeen patients (mean age, 60 ± 10 years) presenting with STEMI were prospectively studied. Each patient underwent CCT and CMR at baseline and after an average of 6 months. Areas of PD were quantified. Segmental LV systolic function was semiquantitatively assessed by CMR. An improvement at 6 months by ≥1 category in the regional wall motion score was considered LV recovery. Results Coronary artery revascularization was successfully performed with postprocedural TIMI 3 flow in 16 cases. On CCT assessment, 107 of 289 segments (37%) had some degree of PD. On follow-up, segments with <25% PD at baseline had no worsening of wall motion. In segments with >75% PD, 89% (9 of 11) showed akinesis or worsening of wall motion. The odds ratio for improvement in segmental wall motion with increasing PD category was 0.63 (95% CI, 0.42–0.97; P = 0.035). The degree of PD on CT predicted LV recovery at follow-up ( P < 0.0001). Conclusions The transmural extent of myocardial infarction as detected and quantified with CCT predicts the recovery of regional systolic LV function after revascularization for acute STEMI.
Background The 2006 Cardiac CT Appropriate Use Criteria (AUC) were recently revised in 2010. In addition to rating an expanded number of indications, the new criteria adjusted the appropriateness of ...existing indications to reflect changes in clinical practice and new evidence since 2006. Objective We sought to determine how the appropriateness of cardiac CT examinations performed at a tertiary-care hospital changed under the revised criteria compared with the original AUC. Methods Data were collected from the medical records and personal interview of 267 consecutive patients referred for cardiac CT in 2008. With the use of the 2010 and 2006 AUCs, two physicians designated each examination’s indication as appropriate, inappropriate, uncertain, or “not classified” if examination indication could not be assigned. Results With the use the new 2010 AUC, a highly significant change was observed in the classification of examination appropriateness ( P < 0.001), with 40% of examinations changing appropriateness level compared with the 2006 AUC. Under the 2010 AUC, there were an increased proportion of both appropriate examinations (59% vs. 45%; P < 0.001) and inappropriate examinations (15% vs. 10%; P < 0.001), and approximately the same proportion with uncertain appropriateness (13% vs. 16%; P = 0.33). Consequently, the proportion of examinations that were not classified was significantly reduced under the 2010 AUC (29% vs. 13%; P < 0.001). Conclusion The revision of the AUC for cardiac CT had a significant effect on examination appropriateness. In comparison to the 2006 AUC, the 2010 AUC provided improved clarification of examination appropriateness. This shift was because of the inclusion of many previously unaddressed indications and the designation of more examinations as either appropriate or inappropriate.
Cardiac magnetic resonance (CMR) has been shown to predict left ventricular (LV) recovery in patients after acute ST-segment elevation myocardial infarction. The purpose of this investigation was to ...determine the relative values of infarct transmurality and microvascular obstruction (MVO) using delayed enhancement CMR to predict LV recovery. We studied 17 patients (mean age 60 ± 10 years, 14 men) presenting with first acute ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention who underwent CMR within 6 days after presentation and again at 6 months. In total 680 myocardial segments were evaluated, of which 267 (39%) demonstrated delayed hyperenhancement (DHE) and 116 (18%) demonstrated MVO. Unadjusted odds ratio (OR) for any improvement in regional LV function with increasing DHE category (<50%, 51% to 75%, >75% transmurality) was 0.20 (95% confidence interval CI 0.13 to 0.30, p <0.0001), whereas it was 0.40 (95% CO 0.28 to 0.55, p <0.0001) with increasing MVO category (0, <50th, >50th percentile). However, when coadjusted together, the relation remained robust with regard to degree of transmurality of DHE (OR 0.21, 95% CI 0.13 to 0.36, p <0.0001), but the relation was lost for MVO (OR 0.90, 95% CI 0.58 to 1.40, p = 0.64). In conclusion, when using the delayed enhancement technique for assessment of DHE and MVO, degree of infarct transmurality appears to be a more powerful predictor of LV recovery by CMR.
Infarct detection with a comprehensive cardiac CT protocol Ghoshhajra, Brian B., MD, MBA; Maurovich-Horvat, Pal, MD; Techasith, Tust, BS ...
Journal of cardiovascular computed tomography,
01/2012, Letnik:
6, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Background Cardiac CT has the potential to offer comprehensive infarct detection by assessing regional wall motion abnormalities (RWMAs), rest perfusion defects (RPDs), and delayed contrast ...enhancement (DCE). However, the diagnostic accuracy of these techniques for the detection of myocardial infarction (MI) is unknown. Methods Forty-eight patients with intermediate-to-high probability for coronary artery disease after single-photon emitting CT myocardial perfusion imaging were prospectively enrolled for a research comprehensive 64-detector row dual-source cardiac CT protocol that included cine images for RWMA, first-pass images for RPD, and delayed images for DCE. Blinded readers independently assessed each technique. Subsequently, a final combined analysis (cine + rest + DCE) was performed. The universal definition for MI by the 2007 American Heart Association task force was used as the “gold standard.” Results Twenty-four of 48 patients (50%) had infarct by the universal definition. The combined CT analysis was most accurate (90%) with the highest per-patient sensitivity (88%) and specificity (92%) versus individual assessments (RWMA, 79% and 88%; RPD, 67% and 92%; DCE, 79% and 88%). Similar findings were observed on a per-vessel basis analysis. A combination of DCE and cine showed a good accuracy (85%) and high sensitivity (92%). Conclusions Infarct detection with CT is feasible with overall good diagnostic accuracy compared with the universal definition. A combined evaluation that included all techniques (cine, RPD, and DCE) had the highest diagnostic accuracy. These findings may have implications when designing future clinical and research CT protocols for optimal infarct detection.
Abstract Background We hypothesized that recombinant B-type natriuretic peptide (BNP) (nesiritide) could improve urine output and neurohormonal markers of heart failure without worsening renal ...function in pediatric patients. Methods and Results We analyzed our experience involving 140 nesiritide infusions in 63 consecutive children. Serum levels of BNP and electrolytes were measured before and after therapy. Dosing was begun at 0.01 mcg·kg·min without a bolus and titrated to a maximum of 0.03 mcg·kg·min, in 0.005-mcg·kg·min increments. Blood pressure, heart rate, and heart rhythm were monitored. In a substudy, 20 patients with decompensated cardiomyopathy-related heart failure received 72 hours of nesiritide with prospective assessment of aldosterone, norepinephrine, plasma renin, and endothelin-1 levels before and after therapy. The heart rate decreased significantly ( P = .001). Urine output increased significantly on Days 1 and 3 ( P ≤ .001 and .004, respectively). The mean serum creatinine level decreased from 1.135 to 1.007 mg/dL ( P ≤ .001). In the substudy, aldosterone levels decreased from 37.5 ± 57.1 to 20.5 ± 41.9 ng/dL ( P = .005). Plasma renin, norepinephrine, and endothelin-1 levels decreased nonsignificantly. Two infusions were discontinued because of hypotension. Conclusions Nesiritide safely treated decompensated heart failure in children. Increased urine output reflected improving renal function. Improved neurohormonal markers were seen after 72 hours of therapy, and complications were uncommon.
Background A number of studies have compared 64-slice multidetector row computed tomography (MDCT) and magnetic resonance imaging (MRI) for left ventricular (LV) function; however, none were ...performed in patients with reperfused acute myocardial infarction. Objectives We compared global and regional LV function assessment by 64-slice CT (MDCT) with cardiac magnetic resonance (CMR) after reperfused ST elevation myocardial infarction. Methods Twenty-one patients were scanned after reperfusion with contrast-enhanced CMR and MDCT. Reconstructed short axis images were used to assess global (quantitative assessment of LF end-diastolic volume LVEDV, end-systolic volume LVESV, stroke volume LVSV, ejection fraction LVEF, and mass, by Simpson's method) and regional cardiac function (qualitative assessment on a 4-point scale 4 = normal, 3 = hypokinesia, 2 = dyskinesia, 1 = akinesia) in a standard 17-segment myocardial model. Results We scanned 21 persons (age, 60 ± 10 years; 19 men) with CMR and MDCT. Good correlation was observed for all global parameters between MDCT and CMR (LVEF, r = 0.90; LVEDV, r = 0.91; LVESV, r = 0.94; LVSV, r = 0.84; LV mass, r = 0.91). Interobserver agreement for regional function was excellent (weighted κ, 0.81). The interobserver agreement for regional function on MDCT and CMR were comparable (weighted κ of 0.86 and 0.88, respectively). MDCT had a better sensitivity, specificity, positive predictive value, and negative predictive value for akinetic segments on CMR than did hypokinetic segments (71%, 91%, 68%, and 93% versus 84%, 97%, 81%, and 98%, respectively). Conclusion MDCT provides an accurate and reproducible measurement of regional and global LV function in patients with reperfused acute myocardial infarction.
PDF
