[Show abstract][Hide abstract] ABSTRACT: Background
Abnormal resting arterial stiffness is present in middle‐aged and elderly persons with abnormalities of fasting glucose (diabetes or impaired fasting glucose) and is associated with exercise intolerance. We sought to determine whether these same persons exhibited stress‐related abnormalities of arterial stiffness.
Methods and Results
We analyzed dobutamine magnetic resonance stress imaging results from 373 consecutively recruited persons aged 55 to 85 years with normal fasting glucose, impaired fasting glucose, or diabetes who were at risk for but without symptomatic heart failure. Personnel blinded to participant identifiers measured arterial stiffness (brachial pulse pressure/left ventricular stroke volume indexed to body surface area, the aortic elastance index [brachial end‐systolic pressure/left ventricular stroke volume indexed to body surface area], and thoracic aortic distensibility) at 80% of the maximum predicted heart rate response for age. Participants averaged 69±8 years of age; 79% were white, 92% were hypertensive, and 66% were women. After accounting for hypertension, sex, coronary artery disease, smoking, medications, hypercholesterolemia, and visceral fat, we observed an effect of glycemic status for stress measures of arterial stiffness in those with diabetes and impaired fasting glucose relative to those with normal fasting glucose (P=0.002, P=0.02, and P=0.003, respectively).
Middle‐ and older‐aged individuals with diabetes or impaired fasting glucose have higher stress measures of arterial stiffness than those with normal fasting glucose. These data emphasize the need for future studies with larger sample sizes to determine whether stress‐related elevations in arterial stiffness are related to exercise intolerance and future episodes of heart failure experienced by those with abnormalities of fasting glucose.
Clinical Trial Registration
URL: http://clinicaltrials.gov/. Unique identifier: NCT00542503.
Journal of the American Heart Association 12/2015; 4(1). DOI:10.1161/JAHA.114.000991 · 4.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Dobutamine associated left ventricular (LV) wall motion analyses exhibit reduced sensitivity for detecting inducible ischemia in individuals with increased LV wall thickness. This study was performed to better understand the mechanism of this reduced sensitivity in the elderly who often manifest increased LV wall thickness and risk factors for coronary artery disease.
During dobutamine cardiovascular magnetic resonance (DCMR) stress testing, we assessed rate pressure product (RPP), aortic pulse wave velocity (PWV), LV myocardial oxygen demand (pressure volume area, PVA, mass, volumes, concentricity, and the presence of wall motion abnormalities (WMA) and first pass gadolinium enhanced perfusion defects (PDs) indicative of ischemia in 278 consecutively recruited individuals aged 69 ± 8 years with pre-existing or known risk factors for coronary artery disease. Each variable was assessed independently by personnel blinded to participant identifiers and analyses of other DCMR or hemodynamic variables.
Participants were 80% white, 90% hypertensive, 43% diabetic and 55% men. With dobutamine, 60% of the participants who exhibited PDs had no inducible WMA. Among these participants, myocardial oxygen demand was lower than that observed in those who had both wall motion and perfusion abnormalities suggestive of ischemia (p = 0.03). Relative to those with PDs and inducible WMAs, myocardial oxygen demand remained different in these individuals with PDs without an inducible WMA after accounting for LV afterload and contractility (p = 0.02 and 0.03 respectively), but not after accounting for either LV stress related end diastolic volume index (LV preload) or resting concentricity (p = 0.31-0.71).
During dobutamine stress testing, elderly patients experience increased LV concentricity and declines in LV preload and myocardial oxygen demand, all of which are associated with an absence of inducible LV WMAs indicative of myocardial ischemia. These findings provide insight as to why dobutamine associated wall motion analyses exhibit reduced sensitivity for identifying inducible ischemia in elderly.
This study was registered with Clinicaltrials.gov (NCT00542503).
Journal of Cardiovascular Magnetic Resonance 12/2015; 17(1). DOI:10.1186/s12968-015-0131-3 · 4.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background:
Left ventricular wall motion abnormalities (LVWMA) observed during cardiovascular magnetic resonance (CMR) pharmacologic stress testing can be used to determine cardiac prognosis, but currently, information regarding the prognostic utility of upright maximal treadmill induced LVWMA is unknown. Our objective was to determine the prognostic utility of upright maximal treadmill exercise stress CMR.
One hundred and fifteen (115) men and women with known or suspected coronary arteriosclerosis and an appropriate indication for cardiovascular (CV) imaging to supplement ST segment stress testing underwent an upright treadmill exercise CMR stress test in which LVWMA were identified before and immediately after exercise. Personnel blinded to results determined the post-test incidence of cardiac events (cardiac death, myocardial infarctions [MI], and unstable angina warranting hospital admission or coronary arterial revascularization).
All participants completed the testing protocol, with 90 % completing image acquisition within 60 s of exercise cessation. MI or cardiac death occurred in 3 % of individuals without and 17 % of individuals with inducible LVWMA (p = 0.024). The combination of MI, cardiac death, and unstable angina warranting hospitalization occurred in 14 % of individuals without and 47 % of individuals with inducible LVWMA (p = 0.002). The addition of CMR imaging identified those at risk for future events (p = 0.002), as opposed to the electrocardiogram stress test alone (p = 0.63).
In patients with or suspected of coronary arteriosclerosis and appropriate indication for imaging to supplement ST segment analysis during upright treadmill exercise, the presence of inducible LVWMA during treadmill exercise stress CMR supplements ST segment monitoring and helps identify those at risk of the future combined endpoints of myocardial infarction, cardiac death, and unstable angina warranting hospitalization.
Journal of Cardiovascular Magnetic Resonance 12/2015; 17(1). DOI:10.1186/s12968-015-0208-z · 4.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective Although the clinical importance of left ventricular noncompaction cardiomyopathy (LVNC) is known, few data exist that describe the prognosis associated with intermediate levels of LV trabeculations that do not meet criteria for LVNC. Methods Trabeculation/possible LVNC by CMR was retrospectively observed among 122 consecutive cases. We assessed the end-systolic noncompacted-to-compacted ratios (ESNCCR) along with deaths, embolic events, congestive heart failure (CHF) readmissions, ventricular arrhythmias, myocardial thickening (MT), and ejection fraction (EF). ESNCCRs were categorized as follows: < 1, 1< 1.5, 1.5< 2, ≥ 2. General linear models were used to compare combined events (death, CHF readmission, embolism, ventricular arrhythmia) between categories of ESNCCR. There were 3 models used: model 1: unadjusted; model 2: adjusted for age, race, gender, body surface area, LV ejection fraction, and trabeculated segments; model 3: model 2 + adjustment for myocardial thickening. Results In model 1, those with an ESNCCR < 1 had a lower association with composite clinical events than those with a ratio between 1.5 < 2 and those ≥ 2 (P < 0.002 and P < 0.001, respectively). In model 2, the lower association continued, (P = 0.009 and P < 0.001, respectively), but in model 3, those with a ratio from 1.5-2 only had a trend towards a higher association with composite clinical events than those with a ratio < 1 (P =-0.09). Those with a ratio ≥ 2 continued to have a higher association (P =-0.001). Conclusion Patients with intermediate trabeculations not meeting criteria for LVNC had a higher association with composite clinical events, but it was mediated by decreased myocardial thickening in the associated compacted layer.
[Show abstract][Hide abstract] ABSTRACT: Background
Although adverse left ventricular shape changes (remodeling) after myocardial infarction (MI) are predictive of morbidity and mortality, current clinical assessment is limited to simple mass and volume measures, or dimension ratios such as length to width ratio. We hypothesized that information maximizing component analysis (IMCA), a supervised feature extraction method, can provide more efficient and sensitive indices of overall remodeling.
IMCA was compared to linear discriminant analysis (LDA), both supervised methods, to extract the most discriminatory global shape changes associated with remodeling after MI. Finite element shape models from 300 patients with myocardial infarction from the DETERMINE study (age 31–86, mean age 63, 20 % women) were compared with 1991 asymptomatic cases from the MESA study (age 44–84, mean age 62, 52 % women) available from the Cardiac Atlas Project. IMCA and LDA were each used to identify a single mode of global remodeling best discriminating the two groups. Logistic regression was employed to determine the association between the remodeling index and MI. Goodness-of-fit results were compared against a baseline logistic model comprising standard clinical indices.
A single IMCA mode simultaneously describing end-diastolic and end-systolic shapes achieved best results (lowest Deviance, Akaike information criterion and Bayesian information criterion, and the largest area under the receiver-operating-characteristic curve). This mode provided a continuous scale where remodeling can be quantified and visualized, showing that MI patients tend to present larger size and more spherical shape, more bulging of the apex, and thinner wall thickness.
IMCA enables better characterization of global remodeling than LDA, and can be used to quantify progression of disease and the effect of treatment. These data and results are available from the Cardiac Atlas Project (http://www.cardiacatlas.org).
Journal of Translational Medicine 11/2015; 13(1-1):343. DOI:10.1186/s12967-015-0709-4 · 3.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Myocardial injury because of oxidative stress manifesting through reductions in left ventricular ejection fraction (LVEF) may occur after the administration of anthracycline-based chemotherapy (A-bC). We hypothesized that bilirubin, an effective endogenous antioxidant, may attenuate the reduction in LVEF that sometimes occurs after receipt of A-bC. We identified 751 consecutively treated patients with cancer who underwent a pre-A-bC LVEF measurement, exhibited a serum total bilirubin level <2 mg/dl, and then received a post-A-bC LVEF assessment because of symptomatology associated with heart failure. Analysis of variance, Tukey's Studentized range test, and chi-square tests were used to evaluate an association between bilirubin and LVEF changes. The LVEF decreased by 10.7 ± 13.7%, 8.9 ± 11.8%, and 7.7 ± 11.5% in group 1 (bilirubin at baseline ≤0.5 mg/dl), group 2 (bilirubin 0.6 to 0.8 mg/dl), and group 3 (bilirubin 0.9 to 1.9 mg/dl), respectively. More group 1 patients experienced >15% decrease in LVEF compared with those in group 3 (p = 0.039). After adjusting for age, coronary artery disease/myocardial infarction, diabetes mellitus, hematocrit, and the use of cardioactive medications, higher precancer treatment bilirubin levels and lesser total anthracycline doses were associated with LVEF preservation (p = 0.047 and 0.011, respectively). In patients treated with anthracyclines who subsequently develop symptoms associated with heart failure, pre-anthracycline treatment serum bilirubin levels inversely correlate with subsequent deterioration in post-cancer treatment LVEF. In conclusion, these results suggest that increased levels of circulating serum total bilirubin, an intrinsic antioxidant, may facilitate preservation of LVEF in patients receiving A-bC for cancer.
The American journal of cardiology 10/2015; 116(11). DOI:10.1016/j.amjcard.2015.08.042 · 3.28 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: With advancements in technology and a better understanding of human cardiovascular physiology, research as well as clinical care can go beyond dimensional anatomy offered by traditional imaging and investigate aortic functional properties and the impact disease has on this function. Linking the knowledge of the histopathological changes with the alterations in aortic function observed on noninvasive imaging results in a better understanding of disease pathophysiology. Translating this to clinical medicine, these noninvasive imaging assessments of aortic function are proving to be able to diagnose disease, better predict risk, and assess response to therapies. This review is designed to summarize the various hemodynamic measures that can characterize the aorta, the various noninvasive techniques, and applications for various disease states.
[Show abstract][Hide abstract] ABSTRACT: The Multi-Ethnic Study of Atherosclerosis (MESA), initiated in July 2000, is a six-center longitudinal population-based study that included 6,814 men and women at baseline study. Cardiac MRI was part of the study procedures, representing the first large-scale application of cardiac MRI in a multi-center and multi-ethnic population study in the USA. To date, this is the largest ever MRI study. Such effort would come with a great potential for variability due to the number of professionals involved; therefore, an intensive quality control process was implemented since the very beginning. A workflow for process control was used to match image protocols in different types of MRI scanners, transfer images to the reading center, train technicians, and implement image quality scorecards. This article reviews the influence of research management for quality control and work standardization processes in cardiac magnetic MRI results at the 10th year of follow-up in MESA.
Current Cardiovascular Imaging Reports 05/2015; 8(5). DOI:10.1007/s12410-015-9329-x
[Show abstract][Hide abstract] ABSTRACT: Recent studies show an association between statin therapy and a reduced risk of heart failure among breast cancer survivors. Our goal was to evaluate whether statin therapy for prevention of cardiovascular disease (CVD) would ameliorate declines in left ventricular ejection fraction (LVEF) often observed during anthracycline-based chemotherapy (Anth-bC).Methods
In 51 participants (33 women and 18 men; aged 48±2 years), we performed CV magnetic resonance (CMR) measurements of LVEF before and 6 months after initiation of Anth-bC for patients with breast cancer, leukemia, or lymphoma. Fourteen individuals received statin therapy, and 37 received no statin. MR image analysts were blinded to participant identifiers.ResultsThose receiving statins were older and often had diabetes (DM), hypertension (HTN), and hyperlipidemia (HLD). For those receiving statins, LVEF was 56.6±1.4% at baseline and 54.1±1.3% 6 months after initiating anthracycline (p=0.15). For those not receiving a statin, LVEF was 57.5±1.4% at baseline and decreased to 52.4±1.2% over a similar 6 month interval (p=0.0003). In a multivariable model accounting for age, sex, DM, HTN, HLD, and cumulative amount of anthracycline received, LVEF remained unchanged in participants receiving a statin (+ 1.1±2.6%) versus a -6.5±1.5% decline among those not receiving a statin (p=0.03).Conclusion
In conclusion, these data highlight that individuals receiving statin therapy for prevention of CVD may experience less deterioration in LVEF upon early receipt of Anth-bC than individuals not receiving a statin. Further studies with large numbers of participants are warranted to determine if statins protect against LVEF decline in patients receiving Anth-bC.
The Canadian journal of cardiology 11/2014; 31(3). DOI:10.1016/j.cjca.2014.11.020 · 3.94 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The assessment of right ventricular (RV) perfusion defects has remained challenging during vasodilator stress perfusion with cardiovascular magnetic resonance (CMR). The significance of RV signal abnormalities during vasodilator stress perfusion and late gadolinium-enhanced CMR is yet uncertain.
Among 61 individuals who underwent adenosine CMR stress testing before cardiac catheterization, we assessed the severity of coronary artery stenoses, mortality, the presence of stress and rest perfusion defects, as well as the presence of late gadolinium enhancement (LGE).
Right ventricular stress-induced perfusion defects were positively associated with left anterior descending artery and proximal right coronary artery stenoses but were negatively associated with left circumflex artery stenoses. The presence of RVLGE was associated with mortality, but 77% of those with RVLGE also had left ventricular LGE.
Proximal right coronary artery and left anterior descending artery stenoses are positively associated, whereas left circumflex artery stenoses are negatively associated with RV stress-induced perfusion defects. Right ventricular LGE was associated with mortality, but further study is needed to determine whether this is independent of left ventricular LGE.
Journal of Cardiovascular Magnetic Resonance 11/2014; 16(Suppl 1). DOI:10.1097/RCT.0000000000000175 · 4.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Left ventricular (LV) noncompaction cardiomyopathy (LVNC) is a form of cardiomyopathy in which trabeculations fail to "compact" with the left ventricular endocardium during fetal cardiac development and is classically associated with subsequent impairment of LV function, significant mortality, ventricular dysrhythmias, and embolic phenomena. As awareness and medical imaging quality have improved, it is becoming easier to identify trabeculations that traverse the LV cavity and serve as a distinguishing feature of this disorder. Differentiating true noncompaction from mild increases in trabeculations requires prudent imaging and clinical correlation. This review seeks to discuss the potential methods of evaluating left ventricular trabeculations, the role of increased trabeculations in cardiovascular disease, and how their presence may affect clinical management.
Current Heart Failure Reports 11/2014; 12(1). DOI:10.1007/s11897-014-0237-1