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J H Reiber

Publications and source records attributed to J H Reiber.

At least 73 records · Page 4Linked to original sources
PubMed1996

LDL-Apheresis Atherosclerosis Regression Study (LAARS). Effect of aggressive versus conventional lipid lowering treatment on coronary atherosclerosis.

BACKGROUND: Intensive lipid lowering may retard the progression of coronary atherosclerosis. LDL-apheresis has the potential to decrease LDL cholesterol to very low levels. To assess the effect of more aggressive lipid lowering with LDL-apheresis, we set up a randomized study in men with hypercholesterolemia and severe coronary atherosclerosis. METHODS AND RESULTS: For 2 years, 42 men were treated with either biweekly LDL-apheresis plus medication or medication alone. In both groups a dose of simvistatin of 40 mg per day was administered. Baseline (mean+/-SD) LDL cholesterol was 7.8+/-1.9 mmol x L(-1) and 7.9+/-2.3 mmol x L(-1) in the apheresis and medication groups, respectively. The mean reduction in LDL cholesterol was 63% (to 3.0 mmol x L(-1)) and 47% (to 4.1 mmol x L(-1)), respectively. Primary quantitative coronary angiographic end points were changes in average mean segment diameter and minimal obstruction diameter. No differences between the apheresis and medication groups were found in mean segment diameter (-0.01+/-0.16 mm versus 0.03+/-0.16 mm, respectively) or in minimal obstruction diameter (0.01+/-0.13 mm versus 0.01+/-0.11 mm, respectively), expressed as means per patient. On the basis of coronary segment, mean percent stenosis of all lesions showed a tendency to decrease; only in the apheresis group more minor lesions disappeared in comparison to the medication group. On bicycle exercise tests, the time to 0.1 mV ST-segment depression increased significantly by 39% and the maximum level of ST depression decreased significantly by 0.07 mV in the apheresis group versus no changes in the medication group. CONCLUSIONS: Two years of lipid lowering both with medication alone or LDL-apheresis with medication showed angiographic arrest of the progression of coronary artery disease. However, more aggressive treatment induced functional improvement, which may precede anatomic changes.

Adult↗
PubMed1996

Comparisons of angiographic core laboratory analyses of phantom and clinical images: interlaboratory variability.

Centralized, quantitative coronary analysis (QCA) has become the standard for determining change in coronary anatomy in clinical investigations. QCA systems and laboratory methods, however, vary among core facilities, and analysis variability among angiographic core laboratories (ACL) has not be studied. We evaluated QCA accuracy and variability among active ACL, using differing QCA systems by comparing analyses of phantom and clinical cinefilm images. Automated, unedited analyses were performed on images of 11 plexiglass phantom lumens (0.67-5.05 mm) acquired under varying radiographic conditions. Analysis differences from actual luminal diameters ranged widely (+0.42 - (-)0.45 mm) among ACL. Measurement of diameters < 1.0 mm were overestimated and diameters > 3.0 mm were underestimated. Measurements of midrange diameters (> 1.0 mm and < 3.0 mm) were most comparable among ACL (93% within +/- 0.2 mm). Clinical image analysis was performed using differing QCA systems and laboratory methodology on 11 randomly selected study films. Comparative analyses revealed significant variability between laboratories in the assessment of minimal lumen diameter (0.22 +/- 0.38 mm P < 0.05). These data describe analysis variability among ACL and demonstrate a need for establishing ACL performance standards.

Clinical Laboratory Techniques↗
PubMed1996

Inaccuracy of quantitative coronary arteriography when analyzed from S-VHS videotape.

In the transition period between 35-mm cinefilm as the medium for coronary arteriographic data and digital media such as CD-R, S-VHS videotape has been used both as an exchange and store medium, and for quantitative coronary arteriographic (QCA) studies. To determine the extent to which S-VHS video tape affects QCA measurements, an X-ray phantom study was completed. A plexiglass phantom with 12 straight circular tubes (0.51-5.00 mm in diameter) filled with contrast medium was recorded under clinical conditions using both the 5" and 7" modes of the image intensifier with the phantom tubes positioned horizontally as well as vertically in the field of view. The digitally acquired images were recorded on S-VHS tape without any image enhancement (raw data) and with default image enhancement. Video frames were then selected on a professional VCR such that individual tubes were positioned in the center of the field of view and digitized (512(2) x 8 bits) with a high-quality frame grabber onto a QCA workstation. The contours along the individual tubes were defined using previously validated automated contour detection techniques. For each tube, an average diameter (mm) and a standard deviation (mm) were calculated. Calibration was based on a cm-grid acquired at the same geometry as the phantom. Due to the poor signal-to-noise ratio and the limited bandwidth of the S-VHS video tape, the following objective observations were made: 1) large overestimations (up to 0.87 mm) occur for tube sizes below 1 mm for vertically positioned tubes; 2) random errors in measurements are much larger for vertically positioned tubes (0.36 mm, 7" II) than for horizontally positioned tubes (0.17 mm, 7" II); and 3) little differences in results between enhanced and nonenhanced images were found due to these deteriorating factors. In conclusion, S-VHS video tape is unacceptable for QCA and should be excluded from quantitative angiographic clinical trials.

Coronary Angiography↗
PubMed1996

Micro stent, quantitative coronary angiography, and procedural results.

The Micro stent (MS) is a radiopaque stainless steel balloon expandable intracoronary stent. The stent is mounted on a rapid-exchange delivery system. From August 1994-March 1995, 127 MS were implanted in 85 patients (pts, 1.5 stents/pt, 85 in native vessels and 42 in bypass vein grafts, 61 males and 24 female, age 33-77 yr, mean age 61 +/- 10 yr). Pts studied were scheduled for either elective PTCA (n = 62, 73%) or PTCA for acute myocardial infarction (n = 23, 27%). Elective stent implantation was performed in 45 pts (53%). An MS was implanted because of a suboptimal balloon angioplasty result in 26 pts (31%). The stent was implanted because of threatened or acute vessel closure after balloon angioplasty in 14 pts (16%). During the procedure, 500 mg aspirin and 2 x 7,500 units of heparin were administered intravenously, followed by systemic heparinization for 48 hr. Pts were discharged with 100 mg aspirin daily (n = 50, 59%), or anticoagulant drugs and 100 mg aspirin daily (n = 19, 22%), or anticoagulant drugs only (n = 16, 19%). Angiographic results were analyzed with computer-assisted quantitative coronary arteriography. Angiographic success (defined as a residual stenosis of < 30%) was achieved in 124 of 127 attempts (98%). The mean minimal luminal diameter of the target lesions increased from 0.88 +/- 0.79 mm before stent implantation to 3.08 +/- 0.56 mm (P < 0.001). The percentage of diameter stenosis was reduced from 77.9 +/- 20.9% before to 13.3 +/- 10.5% (P < 0.001) after stent implantation. The average initial gain was 2.53 +/- 1.37 mm. The procedural success rate (defined as a residual stenosis of < 30% without occurrence of major clinical events within 3 wk after procedure) was 84%. Major clinical events included: death 1 pt (1%); cerebrovascular accident, 1 pt (1%); subacute stent closure, 5 pts (6%); coronary artery bypass grafting, 3 pts (4%); false femoral aneurysm, 2 pts (2%). The initial results of Micro stent implantation are promising. No anticoagulant therapy was given to most of the patients (59%). Few vascular and bleeding complications were observed. However, at this stage, no data about the restenosis rate after implantation of a Micro stent are available.

Adult↗
PubMed1996

Reproducibility of left ventricular size, shape and mass with echocardiography, magnetic resonance imaging and radionuclide angiography in patients with anterior wall infarction. A plea for core laboratories.

After myocardial infarction, left ventricular volume and ejection fraction can be assessed by echocardiography, magnetic resonance imaging and radionuclide angiography to guide therapy and determine prognosis. Whether a measured parameter gives the same results irrespective of the method used and the observer who performs the analysis is only partly known. Intra-observer and inter-observer variability were determined for echo and magnetic resonance imaging. Left ventricular ejection fraction measured by these techniques was related to radionuclide angiograms performed in the same period. Intra-observer variability for both echo and MRI was low and in most instances below 5%. Inter-observer variability for the echo and MRI measurements were substantially higher than intra-observer variability. Comparison of the three imaging modalities revealed systematic differences. Therefore, in clinical studies, left ventricular volume and function parameters have to be measured with the same technique and by the same observer in qualified core laboratories.

Adult↗
PubMed1996

Validation of coronary artery saphenous vein bypass graft diameter measurements using quantitative angiography.

The accepted value for reproducibility (true change) is two standard deviations (SD) of the differences between repeat measurements. It has been well established for coronary artery measurements using several different quantitative coronary angiography (QCA) systems, but it has not been well documented for saphenous vein grafts (SVG). The purpose of this study was to assess, using the Cardiovascular Measurement System (CMS), the measurement reproducibility of 24 vein grafts from 24 patients who had symptom-directed control angiography. Three equal graft segments were studied separately. Focal narrowings expressed in percent stenosis varied from 5 to 80% (mean 20.8 +/- 15.9%). The average minimum lumen diameter (MLD) was 3.07 +/- 0.81 mm and the average interpolated reference diameter (Ref. D) was 3.87 +/- 0.58 mm. We assessed the reproducibility of measurements obtained from two separate imagings of the graft in the same view but at least 20 minutes apart, near the beginning and at the end of the angiographic procedure (simulating baseline and end-trial examinations). The SD for differences in measurements (variability) was 0.183 mm for the MLD, 0.193 mm for the Ref.D, 0.184 mm for the mean diameter (Mean D) and 3.72% for the percent diameter stenosis (PDS). A reasonable true change cut-off for SVG measurements in our laboratory is > or = 0.4 mm for the minimum and mean lumen diameters, and > or = 10% for the PDS, when QCA is obtained with the QCA-CMS analytical software package.

Cineangiography↗
PubMed1996

Assessment of left ventricular volume and mass by cine magnetic resonance imaging in patients with anterior myocardial infarction intra-observer and inter-observer variability on contour detection.

Remodeling of the left ventricle after myocardial infarction can be documented by calculation of left ventricular volume and mass, using endocardial and epicardial tracings of multilevel multiphase short-axis cine magnetic resonance (MR) imaging series. We assessed left ventricular volume and mass from 8 slices and during 12 phases of the cardiac cycle in seven patients with an anterior wall myocardial infarction; one patient was studied twice, leaving eight MR examinations to be evaluated. Purpose of this study was to assess the intra-observer and inter-observer variability of epicardial volume, endocardial volume, and left ventricular mass from contours manually traced by two independent observers. For the eight MR examinations, epicardial volume was found to be 292 +/- 51 ml (mean +/- SD) at end-diastole, which decreased to 237 +/- 55 ml at end-systole. Endocardial volume was 141 +/- 31 ml at end-diastole, which decreased to 79 +/- 27 ml at end-systole. Left ventricular ejection fraction was 45 +/- 8%. Mean left ventricular mass, when averaged over all patient studies and all phases, was 159 +/- 30 g. Intra-observer and inter-observer variability were found to be 3.5% and 5.2% for endocardial volume, 2.0% and 2.5% for epicardial volume, and 3.6% and 3.6% for left ventricular mass, respectively. The contour analysis showed a statistically significant phase effect in the endocardial contour in the midventricular slices, which was resolved after establishing a more precise definition for the tracing of the endocardial border. In conclusion, left ventricular volume and mass in patients with an anterior wall myocardial infarction can be assessed with high reproducibility and reliability from manual contour tracings. A precise protocol for the definition of endocardial and epicardial contours is required to obtain reproducible and reliable results.

Humans↗
PubMed1996

Left ventricular regression equations from single plane cine and digital X-ray ventriculograms revisited.

For the assessment of left ventricular volume from X-ray ventriculograms, widely known regression equations are used to correct for the irregular shape of the left ventricular lumen and the presence of the papillary muscles and trabeculations. These regression equations were derived in the late nineteen sixties and seventies. With all the changes in X-ray technology that have taken place over the past 20-30 years, the question was raised whether these regression equations were still valid. Therefore, 23 left ventricular casts of known volume were imaged in RAO20, RAO30 and RAO40 angiographic views and recorded on 35 mm cinefilm as well as in digital format. All the frames were traced manually by two observers and the volumes calculated by the Area Length and Simpson Rule approaches. The following conclusions could be drawn: inter- and intra-observer variations were small (systematic differences < 1.5 ml; random differences < 2.9 ml) and statistically not significant; the regression equations are virtually the same for the RAO20, RAO30 and RAO40 views under the different circumstances; the Area Length method was associated with slightly smaller values for the standard-error-of-the-estimate (SEE) suggesting a slight preference for this approach versus the Simpson Rule; significant differences were found between the cinefilm and digital regression equations; and the following new regression equations are proposed, which indeed differ significantly from the earliest proposals and less from the monoplane formulas proposed by Kennedy & Lange in the 1970s: [table: see text]

Angiography, Digital Subtraction↗
PubMed1996

Regional myocardial shape alterations in patients with anterior myocardial infarction.

OBJECTIVE: To assess the impact of regional left ventricular curvature in patients with an acute anterior myocardial infarction on ventricular volume. METHODS: Left ventricular curvature was calculated at 100 points from apical four chamber echocardiograms of 68 patients with an acute anterior wall infarction. Curvature at any point of the contour was defined as the reciprocal of the radius of the circle that intersects that point tangentially and was independent of volume and geometric assumptions. Curvature, volume and shape of the patient group was compared with these measurements in 20 normal volunteers. RESULTS: Diastolic curvature differed at the borderzone of the infarct and the apical area. In the basal septal area (point 9-18) mean curvature was lower in the patient group (0.1 +/- 2.7 versus 2.1 +/- 0.7; p < 0.0001) as compared to the normal individuals. In the mid-septal area (point 22 to 27), mean curvature was more concave (-0.1 +/- 2.6) in the patient group corresponding to in the normal population (-0.4 +/- 1.3) p < 0.005. In the apex point 52 and 53 diverged with a curvature of 9.9 +/- 1.9 in patients versus 9.4 +/- 2.9 p < 0.005 in normal individuals. Systolic curvature diverged at the basal septum (point 1-4) with a mean curvature of 1.4 +/- 1.1 in patients compared to 3.5 +/- 2.5 in normal individuals p < 0.01. Curvature differed also in the mid-septal region (point 9-29) with a curvature of -1.7 +/- 1.2 in patients versus 0.4 +/- 0.9 (p < 0.01) in normal individuals and in the apical septum (point 48-52) with a curvature of 16.6 +/- 5.2 in patients and 13.9 +/- 2.6 (p < 0.0001) in healthy individuals Separation of patients with the greatest curvature alteration to those with minor curvature change revealed, that baseline curvature analysis can discriminate patients at risk for left ventricular remodelling. CONCLUSION: Regional curvature analysis correctly identifies the geometric changes induced by myocardial infarction. Apical systolic curvature can distinguish those patients that are at risk for left ventricular remodelling from those who are not at risk.

Adult↗
PubMed1996

Magnetic resonance angiography of dialysis access shunts: initial results.

The objective of this study was the feasibility of imaging hemodialysis fistulae with magnetic resonance angiography (MRA). MRA was performed in eight Brescia-Cimino fistulae and seven goretex loop grafts, five of which were stenosed and 10 normal. We compared two MRA methods: a 2D magnetization prepared turbo field echo (MPTFE) and a 3D phase contrast (PC) sequence. Digital subtraction angiography served as the gold standard. MPTFE MRA provided satisfactory quality images of the entire fistula in 14 out of 15 cases, and PC MRA in 9 of 15 cases (p < .05). MPTFE MRA identified all eight stenoses with one false-positive result. PC MRA identified seven of eight stenoses with two false positives. It is feasible to obtain diagnostic images of dialysis fistulae with MRA.

Angiography, Digital Subtraction↗
PubMed1996

A model for the modulation transfer function of cardiovascular x-ray systems.

RATIONALE AND OBJECTIVES: To derive a theoretical model for the modulation transfer function (MTF) of the complete imaging chain of a cardiovascular x-ray system. A sufficiently accurate MTF model may be used in quantitative coronary arteriographic applications to decrease the systematic overestimation of small coronary vessels. The model could be used to restore blurred images in image restoration applications and also may be used for image quality assurance measurements. METHODS: Digital images of a step wedge phantom were acquired at different modes (5-, 7-, and 9-inch) of the image intensifier and at different kilovolt levels of the x-ray generator. From these images the MTFs that were used to estimate the parameters of the model were assessed. RESULTS: The total MTF of the cardiovascular x-ray imaging chain consisting of image intensifier, video camera, optical elements, and analog/digital converter can be modeled by the simple formula MTF = e-(w/f)R, where w is the frequency in linepairs per millimeter. The constants frequency f and the device index n are parameters that can be derived for an individual x-ray system using the phantom. In this formula, the contribution from the focus of the x-ray source has been excluded. The mean square error (MSE) between the measured values and those assessed from the theoretical model of the MTF for the horizontal direction was found to be equal to 0.00003 for the 5-inch mode of image intensifier, and for the vertical resolution at the 9-inch mode this MSE was equal to 0.00038. In addition, we have demonstrated that the contributions of the video camera and the image intensifier to the total MTF can be replaced by an imaginary electron-optical device. CONCLUSION: An accurate representation for the MTF of a cardiovascular x-ray system has been derived. This MTF model can be used in x-ray image quality assurance measurements and in quantitative image processing applications.

Cardiovascular System↗
PubMed1996

Assessment of the progression of emphysema by quantitative analysis of spirometrically gated computed tomography images.

RATIONALE AND OBJECTIVES: The authors assessed the progression of pulmonary emphysema by means of quantitative analysis of computed tomography images. METHODS: Twenty-three patients suffering from emphysema due to an alpha 1-antitrypsin deficiency, aged 45 +/- 7 years and exsmokers, were scanned twice with a 1-year time interval. At 90% of the vital lung capacity, slices with a thickness of 1.5 mm were acquired at the level of the carina and 5 cm above the carina; slices with a thickness of 1 cm were acquired 5 cm below the carina. The entire lung was scanned spirally at a respiratory status, corresponding with 75% of the total lung capacity at baseline. The mean lung densities (MLD) were calculated in an objective manner with new analytic software featuring automated detection of the lung contours. RESULTS: Mean lung densities decreased by 14.2 +/- 12.0 Hounsfield units (HU; P < 0.001) above the carina, by 18.1 +/- 14.4 HU (P < 0.001) at the carina level, by 23.6 +/- 15.0 HU (P < 0.001) below the carina, and by 12.8 +/- 22.2 HU (P < 0.01) for the entire lung. The decrease in MLD was most obvious in the lower lung lobes. For the same patient group, the annual decrease in the forced expiratory volume (FEV1) and the carbon monoxide-diffusion were 120 +/- 190 mL (P < 0.01) and 10 +/- 70 mmol/kg/minute ( P < 0.2), respectively. No significant correlation was found between the decrease in MLD and the decrease in FEV1. CONCLUSIONS: Progression of emphysema can be assessed in an objective manner based on the mean lung density (MLD), measured from computed tomography volume scans as well as from single-slice scans. Mean lung density has proved to be more sensitive than FEV1 and carbon monoxide-diffusion.

Adult↗
PubMed1996

Evidence for a synergistic effect of calcium channel blockers with lipid-lowering therapy in retarding progression of coronary atherosclerosis in symptomatic patients with normal to moderately raised cholesterol levels. The REGRESS Study Group.

To date, lipid-lowering therapy appears to be the most effective medical intervention to retard progression of coronary atherosclerosis. In spite of promising experimental results, clinical trials completed so far have failed to demonstrate that calcium channel blockers (CCBs) alone influence the evolution of established coronary atherosclerosis. To assess whether the two therapies may have an additive or synergistic beneficial effect on human atherosclerosis, we reviewed in this regard the data of the angiographic Regression Growth Evaluation Statin Study (REGRESS) trial. REGRESS was designed to determine the effect of lipid-lowering therapy with pravastatin in symptomatic patients with normal to moderately raised cholesterol levels. Angiographically, with respect to the minimum obstruction diameter, in the pravastatin group, patients had on average 0.05 mm (95% confidence interval [CI]: 0.01-0.09) less progression if cotreated with CCBs compared with no CCB treatment, whereas in the placebo (no pravastatin) group, no effect of CCB treatment was observed (interaction test for differential effect of CCB treatment in patients with pravastatin compared with patients receiving placebo: P=.0016). With respect to the mean segment diameter, similar although not significant (P=.33) results were found. With respect to new lesion formation, in the pravastatin group, there were 50% (CI: 25-83) fewer patients with new angiographic lesions if cotreated with CCBs compared with no CCB cotreatment, whereas in the placebo (no pravastatin) group, no significant effect of CCB treatment was observed (interaction test: P=.0026). No beneficial effects of CCB treatment on clinical events were observed. Although the REGRESS trial was not designed to evaluate combination therapy, the results suggest strongly that addition of CCBs to 3-hydroxy-3-methyl-glutaryl-coenzyme reductase inhibitor therapy (pravastatin) acts synergistically in retarding the progression of established coronary atherosclerosis.

Aged↗
PubMed1996

The influence of angiographic endpoints on the outcome of lipid intervention studies. A proposal for standardization. REGRESS study group.

The aims of this study were to evaluate the influence of different coronary angiographic endpoints on the outcome of lipid intervention studies and to formulate a proposal for angiographic endpoint standardization. In recent angiographic intervention studies a confusing diversity in angiographic endpoints has been used to determine the outcome. In addition, differences in study populations (eg, bypass patients included or not) could influence results. This makes comparisons between studies cumbersome and raises the question to what extent the results of various studies may be subject to the selection of angiographic endpoints. The investigators compared three frequently used endpoints (mean segment diameter, minimum obstruction diameter, and % stenosis) in a group of 505 patients who had just finished a trial designed to assess the effect of cholesterol lowering by pravastatin. To exclude a potential bias this analysis was carried out at the time that the study was still blinded. They found poor intercorrelation coefficients for mean segment diameter calculated in different ways, ranging from 0.55 to 0.95, dependent on inclusion or exclusion of segments influenced by coronary angioplasty or bypass grafting and on whether or not a value of 0 was assumed for occluded segments and segments distal to occlusions. The correlation between mean segment diameter and minimum obstruction diameter was 0.79; between minimum obstruction diamete and % stenosis, 0.85; and between mean segment diameter and % stenosis, only 0.64. Different endpoints sometimes correlate poorly. This may lead to differences in results of angiographic intervention trials. The authors propose standardization by (1) using both mean sement diameter and minimum obstruction diameter as endpoints and (2) excluding from the primary analysis segments influenced by mechanical interventions.

Angioplasty, Balloon, Coronary↗
PubMed1995

Effect of pravastatin on progression and regression of coronary atherosclerosis and vessel wall changes in carotid and femoral arteries: a report from the Regression Growth Evaluation Statin Study.

Few data are available about the potential benefit of serum cholesterol reduction in the broad range of patients with coronary atherosclerosis and normal to moderately elevated serum cholesterol levels. REGRESS is a double-blind, placebo-controlled, multicenter study to assess the effect of a 2-year treatment with the 3-hydroxy-3-methylglutaryl co-enzyme A reductase inhibitor pravastatin on progression and regression of coronary atherosclerosis using quantitative coronary arteriography in 885 male patients with a total serum cholesterol value of 155-310 mg/dl (4-8 mmol/liter). Among symptomatic men with significant coronary atherosclerosis and normal to moderately raised levels of serum cholesterol, patients treated with pravastatin had less progression of coronary atherosclerosis and fewer new cardiovascular events than patients in the placebo group. Ultrasound examinations of carotid and femoral arteries were performed in 255 patients. Changes in intimal-medial thickness also showed a treatment effect from pravastatin; however, on a per patient basis, there was no correlation with the treatment effect in the coronary arteries.

Analysis of Variance↗
PubMed1995

Comparison of echocardiographic methods with magnetic resonance imaging for assessment of right ventricular function in children.

Assessment of right ventricular (RV) function is clinically relevant in the follow-up of various forms of congenital heart disease. Agreement on the value of different echocardiographic approaches for this purpose is lacking. Magnetic resonance imaging (MRI) provides dimensionally accurate RV volumes and ejection fraction. Transthoracic 2-dimensional echocardiography from 3 different views and gradient-echo tomographic MRI were performed in 16 children with congenital heart disease and 17 age-matched healthy children. RV volumes and ejection fraction were calculated with 5 mono- and biplane area-length and multiple-slice echocardiographic methods. Adequate MRI and echocardiographic apical 4-chamber images could be obtained in all 33 children. The best correlation between MRI and echocardiographic volumes was with the biplane pyramidal approximation method. End-diastolic volume by MRI was 92 +/- 27 ml: systematic difference with echocardiography was +14 +/- 16 ml (r = 0.86). End-systolic volume by MRI was 33 +/- 13 ml: systematic difference with echocardiography was -4 +/- 7 ml (r = 0.82). Ejection fraction by MRI was 65 +/- 8%: systematic difference with echocardiography was +5 +/- 7% (r = 0.72), using monoplane ellipsoid approximation. For all echocardiographic methods, significant effects of RV geometry were noted. Echocardiographic mono- and biplane area-length and multiple-slice calculations demonstrated moderate correlation and significant systematic errors compared with MRI-derived RV volumes. Echocardiographic results were influenced by RV geometry. The relatively simple monoplane area-length method provides ejection fraction results acceptable for clinical practice; results are not improved by more complex biplane and/or multislice methods.

Adolescent↗
PubMed1995

Effects of lipid lowering by pravastatin on progression and regression of coronary artery disease in symptomatic men with normal to moderately elevated serum cholesterol levels. The Regression Growth Evaluation Statin Study (REGRESS).

BACKGROUND: Intensive lowering of serum cholesterol may retard progression of coronary atherosclerosis in selected groups of patients. However, few data are available on the potential benefit of serum cholesterol reduction in the broad range of patients with coronary atherosclerosis and normal to moderately elevated serum cholesterol levels who undergo various forms of treatment. The Regression Growth Evaluation Statin Study (REGRESS) addresses this group of patients. METHODS AND RESULTS: REGRESS is a double-blind, placebo-controlled multicenter study to assess the effects of 2 years of treatment with the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor pravastatin on progression and regression of coronary atherosclerosis in 885 male patients with a serum cholesterol level between 4 and 8 mmol/L (155 and 310 mg/dL) by quantitative coronary arteriography. Primary end points were (1) change in average mean segment diameter per patient and (2) change in average minimum obstruction diameter per patient. Clinical events were also analyzed. Of the 885 patients, 778 (88%) had an evaluable final angiogram. Mean segment diameter decreased 0.10 mm in the placebo group versus 0.06 mm in the pravastatin group (P = .019): The mean difference between treatment groups was 0.04 mm, with a 95% CI of 0.01 to 0.07 mm. The median minimum obstruction diameter decreased 0.09 mm in the placebo group versus 0.03 mm in the pravastatin group (P = .001): The difference of the medians between the treatment groups was 0.06 mm, with a CI of 0.02 to 0.08 mm. At the end of the follow-up period, 89% (CI, 86% to 92%) of the pravastatin patients and 81% (CI, 77% to 85%) of the placebo patients were without new cardiovascular events (P = .002). CONCLUSIONS: In symptomatic men with significant coronary atherosclerosis and normal to moderately elevated serum cholesterol, less progression of coronary atherosclerosis and fewer new cardiovascular events were observed in the group of patients treated with pravastatin than in the placebo group.

Angioplasty, Balloon, Coronary↗