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Milind Y Desai

Publications and source records attributed to Milind Y Desai.

At least 19 recordsLinked to original sources
PubMed2007

Reproducibility of free-breathing cardiovascular magnetic resonance coronary angiography.

OBJECTIVE: Contemporary free-breathing non contrast enhanced cardiovascular magnetic resonance angiography (CMRA) was qualitatively and quantitatively evaluated to ascertain the reproducibility of the method for coronary artery luminal dimension measurements. SUBJECTS AND METHODS: Twenty-two healthy volunteers (mean age 32 +/- 7 years, 12 males) without coronary artery disease were imaged at 2 centers (1 each in Europe and North America) using navigator-gated and corrected SSFP CMRA on a commercial whole body 1.5T System. Repeat images of right (RCA, n = 21), left anterior descending (LAD, n = 14) and left circumflex (LCX, n = 14) coronary arteries were obtained in separate sessions using identical scan protocol and imaging parameters. True visible vessel length, signal-to-noise (SNR), contrast-to-noise ratios (CNR) and the average luminal diameter over the first 4 cm of the vessel were measured. Intra-observer, inter-observer and inter-scan reproducibility of coronary artery luminal diameter were determined using Pearson's correlation, Bland-Altman analysis and intraclass correlation coefficients (ICC). RESULTS: CNR, SNR and the mean length of the RCA, LAD and LCX imaged for original and repeat scans were not significantly different (all p > 0.30). There was a high degree of intra-observer, inter-observer and inter-scan agreements for RCA, LAD and LCX luminal diameter respectively on Bland-Altman and ICC analysis (ICC's for RCA: 0.98. 0.98 and 0.86; LAD: 0.89, 0.89 and 0.63; LCX: 0.95, 0.94 and 0.79). CONCLUSION: In a 2-center study, we demonstrate that free-breathing 3D SSFP CMRA can visualize long continuous segments of coronary vessels with highly reproducible measurements of luminal diameter.

Adult↗
PubMed2006

Detection of transplant coronary artery disease using multidetector computed tomography with adaptative multisegment reconstruction.

OBJECTIVES: This study sought to determine whether multidetector computed tomography (MDCT) may be able to detect occlusive coronary disease in transplanted hearts. BACKGROUND: In heart transplant recipients, asymptomatic coronary disease requiring frequent surveillance commonly develops. Recent advancements in MDCT allow for noninvasive assessment of the coronary vessels. METHODS: Electrocardiogram-gated contrast-enhanced MDCT scans (16 x 0.75-mm detectors, 420 ms rotation, 100 ml contrast) with multisegment reconstruction were performed on 54 transplant recipients within 6 +/- 11 days of quantitative coronary angiography (QCA). Heart rate at the time of the scan was 90 +/- 11 beats/min. Coronary arterial segments >1.5 mm in diameter were analyzed by independent investigators. RESULTS: There was a good correlation between MDCT and QCA percent stenosis (r = 0.75, p < 0.01, SEE = 15%). Of the 791 segments identified by QCA, 754 (95%) were analyzable by MDCT. The sensitivity, specificity, and positive and negative predictive values of MDCT compared with QCA for the detection of segments with significant (>50%) stenosis were 86%, 99%, 81%, and 99%, respectively. The MDCT correctly identified 15 of the 16 (94%) transplant patients classified by QCA as having occlusive coronary artery disease and 29 of the 37 patients without significant stenosis (78%). In 1 patient who received intravenous beta-blockers, transient bradycardia requiring temporary pacing developed, but there were no other complications. CONCLUSIONS: Detection of occlusive coronary disease in heart transplant recipients with elevated resting heart rate by MDCT is feasible using multicycle reconstruction. The need for surveillance invasive coronary angiography in transplant recipients might be mitigated by use of MDCT.

Adult↗
PubMed2006

Use of tissue Doppler imaging to guide tube current modulation in cardiac multidetector computed tomographic angiography.

In multidetector computed tomographic coronary angiography, strategies to minimize effective radiation dose (ERD) are urgently needed. Prospective tube current modulation (TCM) allows a decrease in ERD, although it may limit reconstruction options. We sought to determine if tissue Doppler imaging (TDI) by echocardiography could predict an optimal phase for multidetector computed tomography and be used to guide TCM. Echocardiographic studies were performed in 94 patients immediately before multidetector computed tomography (83% men; mean 60 +/- 11 years of age, mean body mass index 27.7+/-4.1 kg/m2) and identified the most quiescent phase of the cardiac cycle within the atrioventricular groove. In 40 patients, prospective TCM was programmed according to TDI (TCM(TDI) group); 54 patients underwent multidetector computed tomography without TCM (no-TCM). In 25 patients assigned to the TCM(TDI) group, multidetector computed tomograms were correlated with invasive quantitative coronary angiograms to ensure maintenance of diagnostic accuracy. Optimal phase determined by TDI was 71 +/- 11%, with a distinct bi-modal distribution. Compared with no-TCM, effective radiation dose was decreased by 42% in the TCM(TDI) group (6.6 +/- 1.2 vs 11.4 +/- 2.2 mSv, p < 0.0001). Only 8 segments (3%) were unevaluable due to motion artifact. In 296 segments, sensitivity, specificity, and positive and negative predictive values to detect lesions > 50% by multidetector computed tomography were 92%, 94%, 65%, and 99%, respectively. There was good correlation between quantitative coronary angiography and multidetector computed tomography for absolute degree of stenosis (r = 0.70, p < 0.0001). In conclusion, TDI is a useful tool to guide prospective TCM in multidetector computed tomography. ERD in multidetector computed tomography may be significantly decreased using this technique while maintaining excellent image quality.

Cardiac Catheterization↗
PubMed2006

Association of body mass index, metabolic syndrome, and leukocyte count.

Obesity and metabolic syndrome (MS), which often co-exist, are associated with an increased cardiovascular risk. An increased leukocyte count is also associated with an increased cardiovascular risk. However, the role of obesity, independent of MS, has been debated. We sought to assess the influence of MS on the association of obesity and leukocyte count in asymptomatic patients. The data from 431 asymptomatic Brazilian men (mean age 46 +/- 7 years), who presented for cardiovascular risk assessment, were analyzed. MS was defined as the presence of > or =3 of the following risk factors: hypertension (> or =130/85 mm Hg), truncal obesity (> or =102 cm or 40 in), hypertriglyceridemia (> or =150 mg/dl), high-density lipoprotein cholesterol (< or =40 mg/dl), and hyperglycemia (glucose > or =110 mg/dl). Obesity was defined as a body mass index of > or =30 kg/m(2). Confounding variables (age, smoking, lipid-lowering therapy, and physical activity) and leukocyte count (10(9)/L) were recorded. The patients were divided into 4 groups: group1, no obesity and no MS; group 2, obesity but no MS; group 3, no obesity but MS; and group 4, obesity and MS. The mean leukocyte count increased from groups 1 to 4 (6.10 +/- 0.09, 6.42 +/- 0.28, 6.71 +/- 0.21, and 6.96 +/- 0.22 x 10(9)/L, p < 0.001 for trend). Multivariate regression analysis demonstrated that the leukocyte count was significantly higher in groups 3 (coefficient 0.61, p = 0.007) and 4 (coefficient 0.86, p < 0.001) compared with group 1. However, no significant difference was found in the leukocyte count between groups 1 and 2 (coefficient 0.29, p = 0.42) and groups 3 and 4 (coefficient 0.25, p = 0.41). The association between obesity and leukocyte count was highly dependent on the presence of MS.

Body Mass Index↗
PubMed2006

B1-insensitive T2 preparation for improved coronary magnetic resonance angiography at 3 T.

At 3 T, the effective wavelength of the RF field is comparable to the dimension of the human body, resulting in B1 standing wave effects and extra variations in phase. This effect is accompanied by an increase in B0 field inhomogeneity compared to 1.5 T. This combination results in nonuniform magnetization preparation by the composite MLEV weighted T2 preparation (T2 Prep) sequence used for coronary magnetic resonance angiography (MRA). A new adiabatic refocusing T2 Prep sequence is presented in which the magnetization is tipped into the transverse plane with a hard RF pulse and refocused using a pair of adiabatic fast-passage RF pulses. The isochromats are subsequently returned to the longitudinal axis using a hard RF pulse. Numerical simulations predict an excellent suppression of artifacts originating from B1 inhomogeneity while achieving good contrast enhancement between coronary arteries and surrounding tissue. This was confirmed by an in vivo study, in which coronary MR angiograms were obtained without a T2 Prep, with an MLEV weighted T2 Prep and the proposed adiabatic T2 Prep. Improved quantitative and qualitative coronary MRA image measurement was achieved using the adiabatic T2 Prep at 3 T.

Adult↗
PubMed2006

Imaging of atherosclerosis using magnetic resonance: state of the art and future directions.

Atherosclerosis is the leading cause of morbidity and mortality in industrialized societies, and its incidence is projected to increase in the future. Because the atherosclerotic process begins in the vessel wall, the focus of cardiovascular imaging is shifting from the arterial lumen to imaging of the vessel wall, with the goal of detecting preclinical atherosclerosis. MRI, because of its high resolution, three-dimensional capabilities, noninvasive nature, and capacity for soft tissue characterization, is emerging as an important modality to assess the atherosclerotic plaque burden in the arterial wall and can monitor atherosclerosis in different arterial beds, including the carotid arteries, aorta, and more recently, the coronary arteries. Furthermore, it has also been successfully utilized to monitor plaque regression following therapeutic interventions. Finally, the emergence of high-resolution MRI and development of sophisticated contrast agents offers tremendous promise for in vivo molecular imaging of the atherosclerotic plaque.

Atherosclerosis↗
PubMed2005

Reproducibility of 3D free-breathing magnetic resonance coronary vessel wall imaging.

AIMS: Although the coronary artery vessel wall can be imaged non-invasively using magnetic resonance imaging (MRI), the in vivo reproducibility of wall thickness measures has not been previously investigated. Using a refined magnetization preparation scheme, we sought to assess the reproducibility of three-dimensional (3D) free-breathing black-blood coronary MRI in vivo. METHODS AND RESULTS: MRI vessel wall scans parallel to the right coronary artery (RCA) were obtained in 18 healthy individuals (age range 25-43, six women), with no known history of coronary artery disease, using a 3D dual-inversion navigator-gated black-blood spiral imaging sequence. Vessel wall scans were repeated 1 month later in eight subjects. The visible vessel wall segment and the wall thickness were quantitatively assessed using a semi-automatic tool and the intra-observer, inter-observer, and inter-scan reproducibilities were determined. The average imaged length of the RCA vessel wall was 44.5+/-7 mm. The average wall thickness was 1.6+/-0.2 mm. There was a highly significant intra-observer (r=0.97), inter-observer (r=0.94), and inter-scan (r=0.90) correlation for wall thickness (all P<0.001). There was also a significant agreement for intra-observer, inter-observer, and inter-scan measurements on Bland-Altman analysis. The intra-class correlation coefficients for intra-observer (r=0.97), inter-observer (r=0.92), and inter-scan (r=0.86) analyses were also excellent. CONCLUSION: The use of black-blood free-breathing 3D MRI in conjunction with semi-automated analysis software allows for reproducible measurements of right coronary arterial vessel-wall thickness. This technique may be well-suited for non-invasive longitudinal studies of coronary atherosclerosis.

Adult↗
PubMed2005

Relation of serum uric acid with metabolic risk factors in asymptomatic middle-aged Brazilian men.

This study in 352 asymptomatic middle-aged Brazilian men demonstrated that serum uric acid increases linearly with an increasing number (0 to >/=3) of metabolic risk factors (5.78 +/- 1.1, 6.14 +/- 1.0, 6.27 +/- 1.1, and 6.79 +/- 1.3, p <0.001). In patients who had >/=3 metabolic risk factors, there was a higher prevalence of serum uric acid in the highest quartile (7.2 to 10.3 mg/dl) than in the lowest quartile (2.6 to 5.4 mg/dl, 35% vs 12%, p <0.001). Mean serum levels of uric acid were higher in those who had an abnormal ratio of >/=3 for triglyceride to high-density lipoprotein (suggesting insulin resistance) than in those who had a normal ratio (6.6 +/- 1.2 vs 5.87 +/- 1 mg/dl, p <0.001).

Adult↗
PubMed2005

The apparent inversion time for optimal delayed enhancement magnetic resonance imaging differs between the right and left ventricles.

BACKGROUND: Delayed post-contrast magnetic resonance (MR) imaging involves suppression of signal from myocardium using inversion times (TI) between 150-225 ms, when the myocardium appears dark and fibrotic scar appears bright. We noticed that at a TI optimized for signal suppression of the left ventricle (LV), the right ventricle (RV) appeared brighter. PURPOSE: The purpose of this study was to evaluate the TI for signal suppression in RV compared to LV, and to try and identify the cause of this observation. Methods. We studied 31 patients (ages ranged from 17-79 years, 11 females) who had an MR scan on a 1.5 T GE scanner. Delayed post-contrast short-axis images were obtained 20 minutes after injection of 0.2 mmol/kg of intravenous gadolinium chelate. TI optimization was performed by acquiring a range of TI times within a single breath hold, in increments of 25 msec. The TI time that resulted in lowest signal for the RV arid LV was recorded. RESULTS: With the imaging sequence employed, the TI leading to LV signal suppression ranged from 150-225 ms. At the TI that resulted in LV signal suppression, the corrected signal from the RV was significantly higher as compared to the LV (29 +/- 13 au vs. 15 +/- 8 au, p < 0.001). The findings were similar using only the body coil. The TI required to suppress the RV was usually < or =150 msec. The observation persisted before and after gadolinium infusion. CONCLUSION: The TI for myocardial signal suppression appears to be different between LV and RV. Potential mechanisms include partial volume averaging with fat or blood pool (related to increased trabeculation) in the RV. Alternatively, increased blood pool signal (within Thebesian veins or arterioluminal communications) in RV compared to LV leads to altered TI times due to similar partial volume effects.

Adolescent↗
PubMed2005

Delayed contrast-enhanced MRI of the aortic wall in Takayasu's arteritis: initial experience.

OBJECTIVE: Delayed contrast-enhanced MRI is increasingly being used for cardiac viability imaging. Takayasu's arteritis is a rare inflammatory disorder of unknown cause that affects the aorta, its major branches, and the pulmonary artery; it is characterized by inflammation and fibrosis in the arterial wall. We report our initial experience with seven patients (six women, one man; age range, 25-62 years) with delayed (20 min) gadolinium-enhanced MRI (inversion recovery prepared gated fast gradient-echo pulse sequence) in patients with known Takayasu's arteritis. CONCLUSION: Patients with Takayasu's arteritis (particularly those with abnormal laboratory values) have evidence of delayed hyper-enhancement on delayed contrast-enhanced MRI. Thus, delayed contrast-enhanced MRI might be a useful technique to identify inflammation in arterial wall.

Adult↗
PubMed2004

Acute changes in circulating natriuretic peptide levels in relation to myocardial ischemia.

OBJECTIVES: The aim of this study was to determine the effect of transient myocardial ischemia on circulating natriuretic peptide levels. BACKGROUND: Natriuretic peptides are released by the heart in response to wall stress. We hypothesized that transient myocardial ischemia would cause acute changes in circulating natriuretic peptide levels. METHODS: B-type natriuretic peptide (BNP), N-terminal fragment of BNP pro-hormone (NT-pro-BNP), and N-terminal fragment of atrial natriuretic peptide pro-hormone (NT-pro-ANP) levels were measured in 112 patients before, immediately after, and 4 h after exercise testing with nuclear perfusion imaging. RESULTS: Baseline levels of BNP were associated with the subsequent severity of provoked ischemia, with median levels of 43, 62, and 101 pg/ml in patients with none, mild-to-moderate, and severe inducible ischemia, respectively (p = 0.03). Immediately after exercise, the median increase in BNP was 14.2 pg/ml in patients with mild-to-moderate ischemia (p = 0.0005) and 23.7 pg/ml in those with severe ischemia (p = 0.017). In contrast, BNP levels only rose by 2.3 pg/ml in those who did not develop ischemia (p = 0.31). A similar relationship was seen between baseline NT-pro-BNP levels and inducible ischemia, but the changes in response to ischemia were less pronounced. NT-pro-ANP levels rose with exercise in both ischemic and non-ischemic patients. When added to traditional clinical predictors of ischemia, a post-stress test BNP >or=80 pg/ml remained a strong and independent predictor of inducible myocardial ischemia (odds ratio 3.0, p = 0.025). CONCLUSIONS: Transient myocardial ischemia was associated with an immediate rise in circulating BNP levels, and the magnitude of rise was proportional to the severity of ischemia. These findings demonstrate an important link between the severity of an acute ischemic insult and the circulating levels of BNP.

Atrial Natriuretic Factor↗
PubMed2004

Statin-induced cholesterol lowering and plaque regression after 6 months of magnetic resonance imaging-monitored therapy.

BACKGROUND: Statin therapy reduces adverse outcomes, with a minimal decrease in vessel stenosis. Magnetic resonance imaging (MRI) noninvasively detects atherosclerotic plaque (AP) reduction. We hypothesized that statin-induced AP regression can be monitored by MRI and detected earlier than previously reported and is significantly associated with its lipid-lowering effect. METHODS AND RESULTS: APs in thoracic aorta were measured by combined surface/transesophageal MRI in 27 patients (treated with simvastatin 20 to 80 mg daily) before and after 6 months of therapy. AP volume and luminal dimensions were measured from 6 cross sections used to construct a 2.4-cm 3D volume of the aorta that included plaque and lumen. Method reproducibility was studied in 10 patients imaged twice, 1 week apart. AP volume was reduced from 3.3+/-0.1.4 to 2.9+/-1.4 cm3 at 6 months (P<0.02), whereas luminal volume increase was less accentuated (from 12.0+/-3.9 to 12.2+/-3.7 cm3, P<0.06). LDL cholesterol decreased by 23% (from 125+/-32 to 97+/-27 mg/dL, P<0.05) in 6 months. AP regression (plaque volume/area reduction) was significantly related to LDL cholesterol reduction (P<0.02 and P<0.005, respectively), and luminal volume increase was inversely related to LDL cholesterol reduction (P<0.04). Plaque volume measurement was highly reproducible (intraclass correlation R=0.98 and variability=4.8%). Intraobserver (0.91) and interobserver (0.81) concordances were documented for plaque volume assessment. CONCLUSIONS: AP regression and reverse remodeling can be detected accurately by MRI 6 months after statin therapy initiation, and it is strongly associated with LDL cholesterol reduction.

Aged↗
PubMed2004

Relation of degree of physical activity to coronary artery calcium score in asymptomatic individuals with multiple metabolic risk factors.

Lack of physical activity (PA) increases risk of coronary heart disease. Metabolic risk factors increase the risk of coronary heart disease and development of advanced coronary artery calcium (CAC). We hypothesized that, in a population with multiple metabolic risk factors (> or =2), the degree of PA would be inversely associated with the degree and prevalence of CAC. After excluding subjects who had known diabetes and coronary heart disease, we studied 779 asymptomatic patients referred for electron beam tomography. All patients had > or =2 of the following metabolic risk factors: blood pressure > 130/85 mm Hg, serum triglycerides >150 mg/dl, serum high-density lipoprotein < 40 and < 50 mg/dl in men and women, respectively, and body mass index >30 kg/m(2). Advanced CAC was defined as a calcium score >75th percentile based on gender and age. In the study, 37% patients were sedentary, 26% engaged in moderate-duration (< 30 minutes 1 to 2 times/week) PA, and 37% engaged in long-duration (> or =30 minutes > or =3 times/week) PA. The median CAC scores were 24 (sedentary), 18 (moderate PA), and 11 (long-duration PA; p <0.002). Advanced CAC was prevalent in 26% of sedentary patients, 24% of patients who performed moderate PA, and 16% of patients who engaged in long-duration PA (p <0.05). On logistic regression analysis, long-duration PA had an independent inverse association with advanced CAC. Thus, asymptomatic patients who have > or =2 metabolic risk factors and who regularly engage in long-duration PA have a lower prevalence of CAC than do those who are sedentary or participate in moderate-duration PA.

Calcinosis↗
PubMed2004

Cardiovascular magnetic resonance imaging: current and emerging applications.

Magnetic resonance (MR) imaging is gaining importance in cardiology as the newest, most complex, and rapidly emerging noninvasive test of choice for patients with a multitude of cardiovascular problems. It has long been recognized to provide an accurate and reliable means of assessing the function and anatomy of the heart and great vessels, but its emerging role as one of the dominant imaging modalities in other aspects of cardiology such as perfusion imaging, atherosclerosis imaging, and coronary artery imaging cannot be understated. As MR technology evolves, newer therapeutic applications are also being developed, including specific MR-compatible catheters for electrophysiology studies/ablation as well as interventional cardiology related procedures, which may alter the way we practice cardiology in the future. Also, MR is entering an important phase in its evolution, with an anticipated exponential growth in its current applications and through the development of newer molecular imaging applications. It is anticipated that such developments will be coupled to the utilization of molecular markers to index biologic processes to allow for their in vivo visualization. This combination of biochemical markers and imaging methodology will also usher in an era of molecular imaging during which much progress in the diagnosis and treatment of cardiovascular disease is anticipated.

Cardiovascular Diseases↗
PubMed2004

Underlying risk factors incrementally add to the standard risk estimate in detecting subclinical atherosclerosis in low- and intermediate-risk middle-aged asymptomatic individuals.

BACKGROUND: Traditional risk factors predict the 10-year risk of developing coronary heart disease (CHD). Underlying risk factors like physical inactivity, obesity (BMI >30 kg/m2), and family history of premature CHD are independently associated with CHD. High burden of coronary artery calcification (CAC) on electron beam tomography (EBT) is a CHD risk equivalent. GOALS: To determine the association between CAC and traditional risk assessment and whether the presence of added underlying risk factors is associated with advanced CAC in low- and intermediate-risk individuals. METHODS: After excluding patients with CHD, we studied 8549 asymptomatic individuals referred for EBT for cardiac risk assessment. Traditional myocardial infarction risk score was estimated according to Framingham criteria, and individuals were divided into 3 groups: low-risk (< or =9% MI risk over the next 10 years), intermediate-risk (10%-20% risk), and high-risk (>20 % risk). Advanced CAC was defined as a calcium score > or =75th percentile based on sex and age. RESULTS: The prevalence of advanced CAC was 20% in low-risk, 27% in intermediate-risk, and 31% in high-risk individuals (P < .001). Underlying risk factors were incrementally associated with advanced CAC in low- and intermediate-risk individuals (P < .001). A receiver operating characteristic curve analysis revealed that addition of underlying risk factors to traditional risk assessment increased the area under the curve significantly from 0.56 to 0.62 (P < .001). CONCLUSION: A substantial proportion of low- and intermediate-risk individuals have advanced CAC. Adding family history, obesity, and physical inactivity to traditional risk assessment improves prediction of advanced CAC, which may lead these individuals to be treated more aggressively at an earlier age.

Calcinosis↗