Estimation of right ventricular mass in normal subjects and in patients with primary pulmonary hypertension by nuclear magnetic resonance imaging

Katz, José; Whang, John; Boxt, Lawrence M.; Barst, Robyn J.

doi:10.1016/0735-1097(93)90327-w

Cited by 160 publications

(83 citation statements)

References 21 publications

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“…Mean error for intraobserver and interobserver variability was 10.3% and 5.8%, respectively, for indexed RV EDV, and 11.8% and 5.7%, respectively, for indexed LV EDV (2). Mean intraobserver and interobserver variability for RV mass was 11.7 6 10.4% (r ¼ 0.99, standard error of estimate (SEE) ¼ 6.53 g) and 11.02 6 3.92% (r ¼ 0.99, SEE ¼ 7.86 g), respectively (32).…”

Section: Discussionmentioning

confidence: 95%

Measuring the heart in pulmonary arterial hypertension (PAH): Implications for trial study size

Bradlow

Hughes

Keenan

et al. 2009

Magnetic Resonance Imaging

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Purpose: To calculate the sample size for a theoretical pulmonary arterial hypertension (PAH) randomized controlled trial (RCT) by using cardiovascular magnetic resonance (CMR) imaging to determine the repeatability of measures between two scans. Materials and Methods:Two same-day examinations from 10 PAH patients were analyzed manually and semiautomatically. Study size was calculated from the standard deviation (SD) of repeatability. Different approaches to right-ventricle (RV) mass were investigated, agreement between methods tested and interobserver reproducibility measured by Bland-Altman analysis to explore how the PAH heart might be best measured.Results: Repeatability was good for almost all manuallymeasured indices but poor for semiautomated measurement of RV mass and left-ventricle (LV) end-diastolic volume (EDV). Thus, for an RCT (power, 80%; significance level, 5%) analyzing ''outcome'' indices (RVEDV, LVEDV, RV ejection fraction, and RV mass; anticipated change: 10 mL, 10 mL, 3%, and 10 g, respectively) manually, 34 patients are required compared to 78 if analysis is semiautomated. RV mass was repeatable if the interventricular septum was divided between ventricles or if wholly apportioned to the LV. Limits of agreement between manual and semiautomated analyses were unsatisfactory for RV measures and interobserver reproducibility was worse for semiautomated than manual analysis. Conclusion:Manual is more robust than semiautomated analysis and at present should be favored in RCTs in PAH as it leads to lower sample size requirements.

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Section: Discussionmentioning

confidence: 95%

Measuring the heart in pulmonary arterial hypertension (PAH): Implications for trial study size

Bradlow

Hughes

Keenan

et al. 2009

Magnetic Resonance Imaging

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“…Radionuclide angiography measures the right ventricular ejection fraction (RVEF) [79], as does MRI, considered to be the "gold-standard" for assessing right atrial and ventricular dimensions, ventricular mass, and ventricular wall motion [80][81][82][83][84][85]. One study has shown an association between lower baseline RVEF and an increased risk of death, independent of other factors [45].…”

Section: Other Cardiac Imaging Modalitiesmentioning

confidence: 99%

Surrogate End Points in Pulmonary Arterial Hypertension: Assessing the Response to Therapy

Snow¹,

Kawut²

2007

Clinics in Chest Medicine

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Pulmonary arterial hypertension (PAH) is a rare disease which is characterized by increased pulmonary vascular resistance and right heart failure. Recent discoveries in disease pathophysiology have been translated into effective therapies tested in clinical trials. The studies which have led to the regulatory board approval of therapies for PAH have focused on surrogate and intermediate end points, thought to reflect quantity and quality of life, respectively. However, validation of many of these surrogates is incomplete. It is also unknown which indicators of function or long-term survival should be used to formulate decisions regarding addition, discontinuation, or combination of therapies. Identification of suitable end points would therefore not only help investigators design appropriate clinical trials, but also assist clinicians in caring for patients with PAH. Hemodynamic, cardiac imaging, plasma biomarkers, and exercise testing hold some promise as potential surrogate end points for PAH. Functional status and quality of life assessments may also have important roles. Future studies should validate the most promising surrogate markers, so that patients, clinicians, subjects, and investigators may benefit from the advantages they confer on clinical care and on clinical trials.The past several years have yielded an explosion of randomized clinical trials (RCTs) of several new medical therapies for pulmonary arterial hypertension (PAH). The hopes for these and all treatments for potentially fatal diseases are 1) to improve how a patient feels or functions and/ or 2) to prolong survival. While simply stated, the assessment of progress towards these goals may be quite complex [1][2][3][4][5][6].New PAH therapies have gained regulatory board approval based on studies with intermediate and surrogate end points as primary outcomes, believed to reflect the impact of these drugs on quality of life (QOL) and survival, respectively. While hemodynamic, plasma, cardiac imaging, exercise, functional, and QOL parameters are promising candidates, the reliability and validity of these measures are not clearly established. In addition, there are no RCTs addressing the use of such end points in guiding management decisions in PAH, such as changing, intensifying, escalating, or combining therapies. Despite this lack of evidence, clinicians who

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“…Impressive results for accuracy have been demonstrated by several investigators in various disease states [11][12][13][14][15]. The interstudy reproducibility of CMR-derived parameters of ventricular function and mass is good for both the left and right ventricles and is superior to two-dimensional and Mmode echocardiography [16][17][18].…”

Section: Cardiac Magnetic Resonance Imaging Introductionmentioning

confidence: 99%

“…2). Right ventricular hypertrophy is a consequence of the increased pulmonary afterload [13]. The left ventricular mass does not differ significantly from normal values in pulmonary hypertension patients [13].…”

Section: Ventricular Massmentioning

confidence: 99%

Cardiac magnetic resonance imaging for the assessment of the heart and pulmonary circulation in pulmonary hypertension

McLure

Peacock²

2009

European Respiratory Journal

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Pulmonary hypertension is a disease of the pulmonary arteries resulting in a progressive increase in pulmonary vascular resistance, ultimately leading to right ventricular failure and death. The functional capacity of the right ventricle is a major prognostic determinant. Our understanding of right ventricle performance in pulmonary hypertension has been hindered by the lack of techniques that give a reliable picture of right ventricle morphology and function. Cardiac magnetic resonance (CMR) imaging enables a unique combination of morphological and functional assessment of the right ventricle and pulmonary circulation. In this review article, we introduce the technique of CMR imaging, review its use in imaging of the heart and pulmonary circulation and discuss its current and future application to the management of patients with pulmonary hypertension.There have been recent major advances in our understanding of the mechanism of disease development, in the diagnostic process, and in the treatment of pulmonary hypertension. Therapeutic advances in the management have reinforced the requirement for noninvasive, accurate and reproducible methods of assessment to act as ''end-points'' to measure the effects of treatment. We anticipate CMR imaging will increasingly be utilised as the primary modality for combined anatomic and functional assessments that enable more complete and efficient evaluation of pulmonary hypertension patients.

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Estimation of right ventricular mass in normal subjects and in patients with primary pulmonary hypertension by nuclear magnetic resonance imaging

Cited by 160 publications

References 21 publications

Measuring the heart in pulmonary arterial hypertension (PAH): Implications for trial study size

Measuring the heart in pulmonary arterial hypertension (PAH): Implications for trial study size

Surrogate End Points in Pulmonary Arterial Hypertension: Assessing the Response to Therapy

Cardiac magnetic resonance imaging for the assessment of the heart and pulmonary circulation in pulmonary hypertension

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