19 research outputs found
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Cardiology consultation as a gatekeeper prior to cardiac multi-detector computed tomography scan
Multi-detector computed tomography has advanced enormously and now enables non-invasive evaluation of coronary arteries as well as cardiac anatomy, function and perfusion. However, the role of cardiac MDCT is not yet determined in the medical community and, consequently, many clinically unnecessary scans are performed solely on a self-referral basis.
To prospectively evaluate the role of a cardiologist consultation and recommendation prior to the scan, and the influence on the diagnostic yield of cardiac MDCT.
In our center a CT service was initiated, but with the prerequisite approval of a cardiologist before performance of the CT. Each individual who wanted and was willing to pay for a cardiac CT was interviewed by an experienced cardiologist who determined whether cardiac MDCT was the most appropriate next test in the cardiovascular evaluation. Subjects were classified into three groups: a) those with a normal or no prior stress test, no typical symptoms and no significant risk factors of coronary artery disease were recommended to perform a stress test or to remain under close clinical follow-up without MDCT; b) those with an equivocal stress test, atypical symptoms and/or significant risk factors were allowed to have cardiac MDCT; and c) those with positive stress test or clinically highly suspected CAD were advised to go directly to invasive coronary angiography. CT findings were categorized as normal CAD (normal calcium score and no narrowings), 50% CAD.
A total of 254 people were interviewed, and in only 39 cases did the cardiologist approve the CT. However, 61 of the 215, despite our recommendation not to undergo CT, decided to have the scan. Assessment of the 100 cases that underwent MDCT showed a statistically significant better discrimination of significant CAD, according to the cardiologist's recommendation: MDCT not recommended in 3/54 (6%) vs. MDCT recommended in 12/39 (31%) vs. recommended invasive coronary angiography in 4/7 (57%)(P<0.001).
Detection of coronary calcification, as well as MDCT angiography can provide clinically useful information if applied to suitable patient groups. It is foreseeable that MDCT angiography will become part of the routine workup in some subsets of patients with suspected CAD. Selection of patients undergoing MDCT scans by a cardiologist improves the ability of the test to stratify patients, preventing unnecessary scans in both high and low risk patients
Pulmonary arterial capacitance in patients with heart failure and reactive pulmonary hypertension
Abstract
AIMS:
Reactive pulmonary hypertension (PH) is a severe form of PH secondary to left-sided heart failure (HF). Given the structural and functional abnormalities in the pulmonary vasculature that occur in reactive PH, we hypothesized that pulmonary artery capacitance (PAC) may be profoundly affected, with implications for clinical outcome.
METHODS AND RESULTS:
We studied 393 HF patients of whom 124 (32%) were classified as having passive PH and 140 (36%) as having reactive PH, and 91 patients with pulmonary arterial hypertension (PAH). Mean PAC was highest in patients without PH (4.5\u2009\ub1\u20092.1\u2009mL/mmHg), followed by the passive PH group (2.8\u2009\ub1\u20091.4\u2009mL/mmHg) and was lowest in those with reactive PH (1.8\u2009\ub1\u20090.7\u2009mL/mmHg) (P\u2009=\u20090.0001). PAC and pulmonary vascular resistance (PVR) fitted well to a hyperbolic inverse relationship (PAC\u2009=\u20090.25/PVR, R(2) \u2009=\u20090.70), with reactive PH patients dispersed almost predominantly on the flat part of the curve where a reduction in PVR is associated with a small improvement in PAC. Elevated PCWP was associated with a significant lowering of PAC for any PVR (P\u2009=\u20090.036). During a median follow-up of 31 months, both reactive PH [hazard ratio (HR) 2.59, 95% confidence interval (CI) 1.14-4.46, P\u2009=\u20090.02] and reduced PAC (HR 0.72 per 1\u2009mL/mmHg increase, 95% CI 0.59-0.88, P\u2009=\u20090.001) were independent predictors of mortality.
CONCLUSIONS:
The development of reactive PH is associated with a marked reduction in PAC. PAC is a strong independent haemodynamic marker of mortality in HF and may contribute to the increased mortality associated with reactive PH
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Anomalous origin of right coronary artery: Diagnosis and dynamic evaluation with multidetector computed tomography
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Multidetector CT of the coronary arteries and aortic root in a pediatric patient with homozygous familial hypercholesterolemia – correlation with invasive coronary angiography
Sixteen slice multidetector cardiac CT findings of a homozygous familial hypercholesterolemia pediatric patient are presented. Multidetector cardiac CT followed by invasive coronary angiography depicted a variety of diagnostic findings involving the aortic root and coronary arteries. This case illustrates the full capabilities of multidetector cardiac CT in monitoring aortic root and coronary artery disease in pediatric patients with homozygous familial hypercholesterolemia
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Diagnostic accuracy of myocardial hypoenhancement on multidetector computed tomography in identifying myocardial infarction in patients admitted with acute chest pain syndrome
To evaluate prevalence and diagnostic accuracy of myocardial hypoenhancement (MH) using multidetector computed tomography (MDCT) in patients admitted for acute chest pain syndromes.
Sixty-nine patients underwent first-pass MDCT, coronary angiography, and echocardiography. Using a standardized analysis protocol, left ventricular short-axis reformations were evaluated for presence, size, and density of MH in 16 myocardial segments. These were correlated with the presence and location of myocardial infarction (MI), regional myocardial dysfunction, and coronary artery disease.
Myocardial hypoenhancement was found in acute MI (27/35), healed MI (6/14), unstable angina (3/9), and atypical chest pain (0/11). Sensitivity, specificity, and positive and negative predictive values of MH for diagnosing any MI were 67%, 85%, 92% and 52%, respectively.
The presence of MH on MDCT in acute chest pain patients has high positive predictive value and specificity but only moderate sensitivity for presence of acute or healed MI using the strict criteria proposed in this study
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Angiographically uncertain left main coronary artery narrowings: correlation with multidetector computed tomography and intravascular ultrasound
Background Angiographic assessment of left main coronary artery (LMCA) stenosis is often difficult and unreliable. To date, intravascular ultrasound (IVUS) is used to determine the significance of lesions in patients with LMCA stenosis of uncertain significance. We aimed to prospectively show the ability of multidetector computed tomography (MDCT) to assess LMCA luminal and plaque dimensions, and to characterize atherosclerotic plaque, as compared to IVUS and quantitative coronary angiography (QCA), in patients with angiographically uncertain LMCA stenosis. Methods Twenty patients, with angiographically uncertain LMCA stenosis, underwent coronary evaluation with IVUS, QCA and 16-slice MDCT. Minimal lumen diameter (MLD), minimal lumen area (MLA), lumen area stenosis (LAS) and plaque burden (PB) were assessed. Results The MLD (median [interquartile range]) was 3.2 mm (2.5–3.7) by IVUS, 2.8 mm (2.3–3.3) by QCA (r = 0.52, P < 0.05), and 2.8 mm (2.5–3.8) by MDCT (r = 0.77, P < 0.01). MDCT estimated MLA as 10.7 mm2 (7.1–12.6) Vs. 9.9 mm2 (6.5–13.5) by IVUS (r = 0.93, P < 0.01). Very high correlations were observed between MDCT and IVUS in assessing LAS (mean ± SD) (25.8 ± 19.1% and 29.0 ± 24.9% respectively, r = 0.83, P < 0.01), and PB (49.2 ± 15.8% and 49.2 ± 19.7% respectively, r = 0.94, P < 0.01). MDCT assigned plaque as being non-calcified with a sensitivity of 100%, while calcified plaques with a sensitivity of 75%. Conclusion A high degree of correlation was found between MDCT and IVUS regarding the assessment of minimal lumen diameter and area, lumen area stenosis and plaque burden as well as plaque characterization in patients with angiographically borderline LMCA stenosis. Therefore, in patients selected for non-invasive coronary tree evaluation, MDCT may provide a valuable tool for the assessment, decision-making and follow-up of patients with uncertain LMCA disease
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Comparison of Multidetector Computed Tomography Versus Echocardiography for Assessing Regional Left Ventricular Function
Multidetector computed tomography (MDCT) of the heart is a rapidly developing technique mainly used to evaluate the coronary arteries. However, it is also capable of evaluating ventricular function. It compares well with magnetic resonance imaging in calculating volumes and ejection fractions, but little has been reported on its ability to assess left ventricular (LV) segmental wall motion (LVSWM). This study compared semiquantitative LVSWM scoring by MDCT with echocardiography as the gold standard. Thirty-nine patients underwent MDCT angiography on a 16-slice scanner. Short- and long-axis LV slices were created at different phases of the cardiac cycle and visually evaluated using cine mode. Echocardiography was performed <48 hours after MDCT for 21 patients after acute myocardial infarctions and <1 month after MDCT for 18 patients without acute myocardial infarctions. Two blinded observers scored the MDCT and echocardiographic examinations according to the 16-segment model, scoring each segment from 1 (normal) to 3 (akinetic). Segmental dysfunction was found in 27 patients by echocardiography and in 24 by MDCT. An identical score was given by the 2 methods in 502 of 616 assessable segments (82%). Using a binary analysis (normal or abnormal), there was 89% agreement (546 of 616 segments). MDCT had a sensitivity of 66% (103 of 155 segments) and a specificity of 96% (443 of 461 segments) compared with echocardiography as the gold standard. Most disagreements occurred in the right coronary artery segments. In conclusion, MDCT can be used to evaluate LVSWM, showing good agreement with echocardiography, except for the right coronary artery segments
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16-MDCT coronary angiography versus invasive coronary angiography in acute chest pain syndrome: a blinded prospective study
The purpose of our study was to prospectively evaluate the usefulness of CT coronary angiography versus invasive coronary angiography for the detection of clinically significant coronary artery disease in patients hospitalized for acute chest pain syndrome.
Sixty-six consecutive patients (52 men and 14 women; average age, 57 +/- 11 [SD] years) who were hospitalized for acute chest pain syndrome underwent CT coronary angiography and invasive coronary angiography within an average time interval of 4 days. ECG-gated CT coronary angiography was performed with a 16-MDCT scanner (0.42-sec rotation time, 16 x 0.75 mm detector collimation). Beta-blockers were not administered routinely, and thus the average heart rate was 71 +/- 11 beats per minute. CT coronary angiographic images were evaluated concurrently by two radiologists, who were blinded to invasive coronary angiography results, for stenoses having a diameter of 50% or more, using a 15-segment classification, including all segments 2 mm or more in diameter. The consensus interpretation was compared with results of invasive coronary angiography.
CT coronary angiography was technically successful in 59 patients (89%). After exclusion of 20 (3.1%) of 649 coronary segments, which were classified as nonevaluable by CT coronary angiography, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CT coronary angiography for identifying significant coronary artery disease in the remaining 629 coronary segments were 80% (68/85), 89% (482/544), 52% (68/130), 97% (482/499), and 87% (550/629), respectively. The overall accuracy for the main vessels (left main, left anterior descending, left circumflex, and right coronary arteries) was 93%, 88%, 86%, and 86%, respectively.
CT coronary angiography using a 16-MDCT scanner enables accurate noninvasive detection of significant coronary artery disease in patients hospitalized for acute chest pain syndrome. Furthermore, relative high sensitivity and specificity of CT coronary angiography can be achieved without pharmacologic manipulation of patient heart rates