Objective

To prospectively evaluate the cardiac magnetic resonance (MR) imaging-derived measurement of right ventricular (RV) septomarginal trabeculation (SMT) mass as a noninvasive marker for pulmonary hypertension (PH), compared to the ventricular mass index (VMI= RV mass/left ventricular mass) and RV mass.

Materials and Methods

Forty-nine patients (60 years ±12; 35 female) with suspected PH underwent cardiac MR and right heart catheterization (RHC) on the same day. Eighteen normal volunteers were also included. The performance of SMT mass, VMI and RV mass measurement, with regard to PH detection, was analyzed using receiver operating characteristic (ROC) curves. Logistic regression analysis was used to assess the association between SMT mass, RV mass, VMI, and PH.

Results

The area under the ROC curve for SMT mass/BSA, VMI and RV mass/BSA in diagnosing the presence or absence of PH was 0.88, 0.87 and 0.73 respectively. In multivariable models, both SMT mass/body surface area (BSA) (p=0.005, odds ratio 8.6) and VMI (p=0. 012, odds ratio 1.1) were found to be significant, independent predictors of PH.

Conclusion

Compared to RHC measurement, SMT mass and VMI are reproducible and non-invasive MR imaging markers for the diagnosis of PH.

Objectives

To quantify resting myocardial blood flow (MBF) in the left ventricular (LV) wall of HCM patients and to determine the relationship to important parameters of disease: LV wall thickness, late gadolinium enhancement (LGE), T2-signal abnormalities (dark and bright signal), LV outflow tract obstruction and age.

Materials and Methods

Seventy patients with proven HCM underwent cardiac MRI. Absolute and relative resting MBF were calculated from cardiac perfusion MRI by using the Fermi function model. The relationship between relative MBF and LV wall thickness, T2-signal abnormalities (T2 dark and T2 bright signal), LGE, age and LV outflow gradient as determined by echocardiography was determined using simple and multiple linear regression analysis. Categories of reduced and elevated perfusion in relation to non- or mildly affected reference segments were defined, and T2-signal characteristics and extent as well as pattern of LGE were examined. Statistical testing included linear and logistic regression analysis, unpaired t-test, odds ratios, and Fisher’s exact test.

Results

804 segments in 70 patients were included in the analysis. In a simple linear regression model LV wall thickness (p<0.001), extent of LGE (p<0.001), presence of edema, defined as focal T2 bright signal (p<0.001), T2 dark signal (p<0.001) and age (p = 0.032) correlated inversely with relative resting MBF. The LV outflow gradient did not show any effect on resting perfusion (p = 0.901). Multiple linear regression analysis revealed that LGE (p<0.001), edema (p = 0.026) and T2 dark signal (p = 0.019) were independent predictors of relative resting MBF. Segments with reduced resting perfusion demonstrated different LGE patterns compared to segments with elevated resting perfusion.

Conclusion

In HCM resting MBF is significantly reduced depending on LV wall thickness, extent of LGE, focal T2 signal abnormalities and age. Furthermore, different patterns of perfusion in HCM patients have been defined, which may represent different stages of disease.

OBJECTIVE

The purpose of this study was to assess predictors of MRI-identified septal delayed enhancement mass at the right ventricular (RV) insertion sites in relation to RV remodeling, altered regional mechanics, and pulmonary hemodynamics in patients with suspected pulmonary hypertension (PH).

SUBJECTS AND METHODS

Thirty-eight patients with suspected PH were evaluated with right heart catheterization and cardiac MRI. Ten age- and sex-matched healthy volunteers acted as controls for MRI comparison. Septal delayed enhancement mass was quantified at the RV insertions. Systolic septal eccentricity index, global RV function, and remodeling indexes were quantified with cine images. Peak systolic circumferential and longitudinal strain at the sites corresponding to delayed enhancement were measured with conventional tagging and fast strain-encoded MRI acquisition, respectively.

RESULTS

PH was diagnosed in 32 patients. Delayed enhancement was found in 31 of 32 patients with PH and in one of six patients in whom PH was suspected but proved absent (p = 0.001). No delayed enhancement was found in controls. Delayed enhancement mass correlated with pulmonary hemodynamics, reduced RV function, increased RV remodeling indexes, and reduced eccentricity index. Multiple linear regression analysis showed RV mass index was an independent predictor of total delayed enhancement mass (p = 0.017). Regional analysis showed delayed enhancement mass was associated with reduced longitudinal strain at the basal anterior septal insertion (r = 0.6, p < 0.01). Regression analysis showed that basal longitudinal strain remained an independent predictor of delayed enhancement mass at the basal anterior septal insertion (p = 0.02).

CONCLUSION

In PH, total delayed enhancement burden at the RV septal insertions is predicted by RV remodeling in response to increased afterload. Local fibrosis mass at the anterior septal insertion is associated with reduced regional longitudinal contractility at the base.

Objectives

To determine whether nitrogen-containing bisphosphonate (NCBP) therapy is associated with the prevalence of cardiovascular calcification.

Background

Cardiovascular calcification correlates with atherosclerotic disease burden. Experimental data suggest that NCBP may limit cardiovascular calcification, which has implications for disease prevention.

Methods

The relationship of NCBP use to the prevalence of aortic valve, aortic valve ring, mitral annulus, thoracic aorta, and coronary artery calcification (AVC, AVRC, MAC, TAC, and CAC, respectively) detected by computed tomography was assessed in 3,636 women within the Multi-Ethnic Study of Atherosclerosis (MESA) using regression modeling.

Results

Analyses were age-stratified because of a significant interaction between age and NCBP use (interaction p-values: AVC p<0.0001; AVRC p<0.0001; MAC p=0.002; TAC p<0.0001; CAC p=0.046). After adjusting for age, body mass index, demographics, diabetes, smoking, blood pressure, cholesterol levels, and statin, hormone replacement, and renin-angiotensin inhibitor therapy, NCBP use was associated with a lower prevalence of cardiovascular calcification in women ≥65 years old (prevalence ratio [95% confidence interval]: AVC 0.68 [0.41, 1.13]; AVRC 0.65 [0.51, 0.84]; MAC 0.54 [0.33, 0.93]; TAC 0.69 [0.54, 0.88]; CAC 0.89 [0.78, 1.02]), whereas calcification was more prevalent in NCBP users among the 2,181 women <65 years old (AVC 4.00 [2.33, 6.89]; AVRC 1.92 [1.42, 2.61]; MAC 2.35 [1.12, 4.84]; TAC 2.17 [1.49, 3.15]; CAC 1.23 [0.97, 1.57]).

Conclusions

Among women in the diverse MESA cohort, NCBPs were associated with decreased prevalence of cardiovascular calcification in older subjects, but more prevalent cardiovascular calcification in younger ones. Further study is warranted to clarify these age-dependent NCBP effects.

Background

Increasing evidence suggests that elevated plasma fibrinogen is associated with incident heart failure. However, the underlying pathophysiological mechanisms have not been well elucidated.

Methods

We examined the relationship between plasma fibrinogen level and peak systolic mid-wall circumferential strain(Ecc) at the base, mid-cavity and apex of the left ventricle measured by magnetic resonance imaging myocardial tagging in 1,096 participants without clinical cardiovascular disease enrolled in the Multi-Ethnic Study of Atherosclerosis(MESA).

Results

After adjustment for demographics, established risk factors and body-mass-index, elevated fibrinogen was independently associated with reductions in absolute Ecc indicative of impaired systolic function in all regions(all P=0.015). The relationships were consistently significant upon further adjustment for measures of atherosclerosis(all P≤0.024), and were modestly attenuated with regional heterogeneity after additional adjustment for other inflammatory biomarker and N-terminal pro-brain-natriuretic peptide. In this fully-adjusted model, every one-standard deviation(74mg/dL) increment in plasma fibrinogen was independently associated with a reduction in left ventricular absolute Ecc of 0.29%(95%CI=0.03%–0.59%, P=0.048) at the base, 0.22%(95%CI=0.006%–0.43%, P=0.044) at mid-cavity, 0.20%(95%CI=−0.035%–0.43%, P=0.097) at the apex, and 0.24%(95%CI=0.05–0.43, P=0.015) overall.

Conclusions

Among asymptomatic individuals without clinical cardiovascular disease, elevated fibrinogen is independently associated with impaired myocardial systolic function. These findings support roles of inflammation, procoagulation and hyperviscosity underlying hyperfibrinogenemia in the pathogenesis of incipient myocardial dysfunction.

Background

Heart failure is a major contributor to cardiovascular morbidity and mortality in rheumatoid arthritis. However, little is known about myocardial structure and function in this population.

Methods

Using cardiac magnetic resonance imaging, measures of myocardial structure and function were assessed in men and women with rheumatoid arthritis enrolled in ESCAPE RA, a cohort study of subclinical cardiovascular disease in rheumatoid arthritis, and compared with controls without rheumatoid arthritis enrolled in the Baltimore cohort of the Multi-Ethnic Study of Atherosclerosis.

Results

Myocardial measures were compared between 75 rheumatoid arthritis patients and 225 matched controls. After adjustment, mean left-ventricular mass was 26 grams lower for the RA group compared to controls (p<0.001), an 18% difference. After similar adjustment, mean left-ventricular ejection fraction, cardiac output, and stroke volume were modestly lower in the rheumatoid arthritis group vs. controls. Mean left-ventricular end-systolic and end-diastolic volumes did not differ by rheumatoid arthritis status. Within the rheumatoid arthritis group, higher levels of anti-CCP antibodies and current use of biologics, but not other disease activity or severity measures, were associated with significantly lower adjusted mean left-ventricular mass, end-diastolic volume, and stroke volume, but not ejection fraction. The combined associations of anti-CCP antibody level and biologic use on myocardial measures were additive, without evidence of interaction.

Conclusions

These findings suggest that the progression to heart failure in RA may occur through reduced myocardial mass rather than hypertrophy. Both modifiable and non-modifiable factors may contribute to lower levels of left-ventricular mass and volume.

Purpose

To compare standard of care nuclear SPECT imaging with cardiac magnetic resonance imaging (MRI) for emergency room (ER) patients with chest pain and intermediate probability for coronary artery disease.

Materials and Methods

Thirty-one patients with chest pain, negative electrocardiogram (ECG), and negative cardiac enzymes who underwent cardiac single photon emission tomography (SPECT) within 24 h of ER admission were enrolled. Patients underwent a comprehensive cardiac MRI exam including gated cine imaging, adenosine stress and rest perfusion imaging and delayed enhancement imaging. Patients were followed for 14 ± 4.7 months.

Results

Of 27 patients, 8 (30%) showed subendocardial hypoperfusion on MRI that was not detected on SPECT. These patients had a higher rate of diabetes (P = 0.01) and hypertension (P = 0.01) and a lower global myocardial perfusion reserve (P = 0.01) compared with patients with a normal cardiac MRI (n = 10). Patients with subendocardial hypoperfusion had more risk factors for cardiovascular disease (mean 4.4) compared with patients with a normal MRI (mean 2.5; P = 0.005). During the follow-up period, patients with subendocardial hypoperfusion on stress MRI were more likely to return to the ER with chest pain compared with patients who had a normal cardiac MRI (P = 0.02). Four patients did not finish the MR exam due to claustrophobia.

Conclusion

In patients with chest pain, diabetes and hypertension, cardiac stress perfusion MRI identified diffuse subendocardial hypoperfusion defects in the ER setting not seen on cardiac SPECT, which is suspected to reflect microvascular disease.

Objective

We examined the frequency and significance of extracoronary findings in a sample of asymptomatic of Multiethnic Study of Atherosclerosis participants who had coronary magnetic resonance angiography (MRA).

Subjects and Methods

The Multiethnic Study of Atherosclerosis is a cohort study that, at baseline, included 6814 participants 45 to 84 years old, and free of clinical cardiovascular disease. A random subset of 254 participants underwent coronary MRA. Two experienced readers evaluated all images, and a consensus reading was performed. The findings were classified based on their clinical significance.

Results

Extracoronary findings were detected in 101 (39.8%) of the 254 participants. Additional imaging or clinical referral was need for 15 (5.9%) of the 254 participants. None of the participants required emergency referral. Signal loss in a pulmonary artery branch due to navigator beam saturation occurred in 59 (23%) of the 254 participants simulating a pulmonary embolus.

Conclusions

The prevalence of reportable extracoronary findings on coronary MRA is high. Familiarity with noncardiac magnetic resonance imaging interpretation may help in avoiding unnecessary testing resulting from inconclusive identification of extracoronary abnormalities detected incidentally on coronary MRA.

Purpose

To determine the spatial localization errors of magnetic resonance imaging (MRI) guided core biopsy for breast lesions using the hand-held vacuum assisted core biopsy device in phantoms and patients.

Materials and Methods

Biopsies were done using a 10-gauge hand-held vacuum-assisted core biopsy system (Vacora, Bard, Arizona) on a 1.5 T MRI scanner (Philips Achieva, Best, The Netherlands). A standardized biopsy localization protocol was followed by trained operators for multi-planar planning of the biopsy on a separate workstation. Biopsy localization errors were determined as the distance from needle tip to center of the target in 3 dimensions.

Results

Twenty MRI-guided biopsies of phantoms were performed by 3 different operators. The biopsy target mean size was 6.8 ± 0.6 mm. The overall mean three dimensional (3D) biopsy targeting error was 4.4 ± 2.9 mm. Thirty two MRI breast biopsies performed in 22 patients were reviewed. The lesion mean size was 10.5 ± 9.4 mm. The overall mean 3D localization error was 5.7 ± 3.0 mm. No significant differences between phantom and patients biopsy errors were found (p-value >0.5).

Conclusion

MRI guided hand-held vacuum assisted core biopsy device shows good targeting accuracy and should allow localization of lesions to within approximately 5–6 mm.

BACKGROUND:

Cardiac magnetic resonance imaging (MRI) is a non-invasive technique used to accurately and reproducibly measure biological parameters such as left ventricular mass. However, some subjects either refuse or are unable to complete testing, and the impact of excluding these missing data from predictive models is unknown.

METHODS:

Multiple imputation was applied to cardiac MRI data that were previously analyzed using a complete case approach. The model variables – 10 traditional cardiovascular risk factors and five sociodemographic variables – were used as a basis for imputation. Men and women were imputed separately. The primary focus was assessing the change in the cardiovascular predictors of left ventricular geometry and systolic function.

RESULTS:

Although 27% of participants were missing cardiac MRI data, multiple imputation returned results similar to those of a complete case analysis. These results were robust to the point of including additional variables in the imputation analysis above and beyond the model variables. The degree of variance explained by the models increased marginally but the statistical inference was altered for only two predictors out of 53 cardiovascular risk factors using multiple imputation.

DISCUSSION:

The results suggest that the cardiac MRI data in the Multi-Ethnic Study of Atherosclerosis (MESA) do not substantively change when missing data are handled using multiple imputation. Future analyses of cardiac MRI data may consider the complete case approach to be adequate despite the high rate of missing data in this population.

We report the case of a 67 year-old patient who presented with worsening chest pain and shortness of breath, four days post acute myocardial infarction. Contrast enhanced computed tomography of the chest ruled out a pulmonary embolus but revealed an unexpected small subepicardial aneurysm (SEA) in the lateral left ventricular wall which was confirmed on cardiac magnetic resonance imaging. Intraoperative palpation of the left lateral wall was guided by the cardiac MRI and CT findings and confirmed the presence of focally thinned and weakened myocardium, covered by epicardial fat. An aneurysmorrhaphy was subsequently performed in addition to coronary bypass surgery and a mitral valve repair. The patient was discharged home on post operative day eight in good condition and is feeling well 2 years after surgery.