Haroon Chughtai

Renal sinus fat and poor blood pressure control in middle-aged and elderly individuals at risk for cardiovascular events.

Fat in the renal sinus (RS), a region of the kidney in which low pressure venous and lymphatic vessels are present, may indirectly influence blood pressure. The purpose of this study was to assess the association between RS fat and control of blood pressure on receipt of antihypertensive medications. A total of 205 participants aged 55 to 85 years at risk for cardiovascular events underwent MRI assessments of abdominal and RS fat, measurement of blood pressure, and determination of the number of prescribed antihypertensive medications. Multivariable linear regression was used to determine associations among RS fat, blood pressure, and the number of prescribed antihypertensive medications. Abdominal fat averaged 416±160 cm3 (median and interquartile range of 396 cm3 and 308 to 518 cm3); intraperitoneal fat averaged 141±73 cm3 (median and interquartile range of 129 cm3 and 86 to 194 cm3); and RS fat averaged 4.6±3.2 cm3 (median and interquartile range of 4.2 cm3 and 2.2 to 6.6 cm3). After accounting for age, sex, height, body mass index, and intraperitoneal fat, RS fat correlated with the number of prescribed antihypertensive medications (P=0.010), stage II hypertension (P=0.02), and renal size (P≤0.001). In conclusion, after accounting for other body fat depots and risk factors for hypertension, RS fat volume is associated with the number of prescribed antihypertensive medications and stage II hypertension. These results indicate that further studies are warranted to determine whether fat accumulation in the RS promotes hypertension.

Adverse effect of increased left ventricular wall thickness on five year outcomes of patients with negative dobutamine stress

BackgroundTo determine if patients without dobutamine induced left ventricular wall motion abnormalities (WMA) but an increased LV end-diastolic wall thickness (EDWT) exhibit a favorable cardiac prognosis.ResultsBetween 1999 and 2001, 175 patients underwent a dobutamine stress cardiovascular magnetic resonance (DCMR) procedure utilizing gradient-echo cines. Participants had a LV ejection fraction >55% without evidence of an inducible WMA during peak dobutamine/atropine stress. After an average of 5.5 years, all participants were contacted and medical records were reviewed to determine the post-DCMR occurrence of cardiac death, myocardial infarction (MI), and unstable angina (USA) or congestive heart failure (CHF) warranting hospitalization.In a multivariate analysis, that took into account Framingham and other risk factors associated with cardiac events, a cine gradient-echo derived LV EDWT ≥12 mm was associated independently with an increase in cardiac death and MI (HR 6.0, p = 0.0016), and the combined end point of MI, cardiac death, and USA or CHF warranting hospitalization (HR 3.0, p = 0.0005).ConclusionSimilar to echocardiography, CMR measures of increased LV wall thickness should be considered a risk factor for cardiac events in individuals receiving negative reports of inducible ischemia after dobutamine stress. Additional prognostic studies of the importance of LV wall thickness and mass measured with steady-state free precession techniques are warranted.

Periaortic fat and cardiovascular risk: a comparison of high-risk older adults and age-matched healthy controls.

Objective:Fat accumulation around the heart and aorta may impact cardiovascular (CV) health. The purpose of this study was to conduct a systematic investigation to examine potential associations of these fat depots with risk factors for CV events, which has not been done before.Methods:Pericardial fat, periaortic fat around the ascending aorta (AA), descending aorta (DA) and aortic arch, and abdominal subcutaneous and visceral fat were measured by MRI in older adults with (n=385, 69±8 years, 52% female) and without (n=50, 69±8 years, 58% female) risk factors for a CV event.Results:Individuals with CV risk factors exhibited greater fat volumes across all fat depots compared with those without risk factors. In analysis of covariance accounting for age, gender, race/ethnicity, diabetes, hypertension, coronary artery disease, smoking and body mass index (BMI), individuals with risk factors possessed higher epicardial, pericardial, AA, DA and abdominal visceral fat (P<0.05). When matched one-to-one on age, gender, race/ethnicity and BMI, AA and DA fat were higher in those with versus without CV risk factors (P<0.01).Conclusions:Older adults with a high risk for CV events have greater periaortic fat than low-risk adults, even after accounting for BMI. More studies are needed to determine whether greater periaortic fat predicts future CV events.

Intraperitoneal fat is associated with thickening of the thoracic aorta in individuals at high risk for cardiovascular events.

Increased intraperitoneal (IP) fat is associated with increased cardiovascular (CV) risk, but mechanisms for this increase in risk are not completely established. We performed this study to assess whether IP fat is associated with ascending aortic wall thickness (AOWT), a risk factor for CV events. Four hundred and forty‐one consecutive participants, aged 55–85 years, with risk factors for CV events underwent magnetic resonance measures of AOWT and abdominal fat (subcutaneous (SC) fat + IP fat). For the ascending aorta, mean wall thickness of the 4th quartile of the IP fat was higher relative to the 1st quartile (P ≤ 0.001). This difference persisted after accounting for SC fat (P ≤ 0.001), as well as age, gender, height, weight, smoking, diabetes, hypertension, low‐density lipoprotein‐cholesterol (LDL‐C), high‐density lipoprotein‐cholesterol (HDL‐C), and C‐reactive protein (CRP) (P < 0.03). Elevated IP fat volume is associated with an increase in ascending AOWT, a condition that promotes CV events in middle aged and elderly adults.

Iatrogenic intrapericardial diaphragmatic hernia diagnosed by cardiovascular magnetic resonance

Intrapericardial diaphragmatic hernias are very uncommon and are most typically caused by high-force blunt trauma. Other iatrogenic causes such as prior surgical formation of a pericardial window have been described, but are exceedingly rare. We present a case of an intrapericardial diaphragmatic hernia in a patient with a prior pericardial window in which the diagnosis was unclear using conventional imaging modalities, but was established using cardiovascular magnetic resonance.

Adiposity Is Associated with Gender-Specific Reductions in Left Ventricular Myocardial Perfusion during Dobutamine Stress

Background Obesity and visceral adiposity are increasingly recognized risk factors for cardiovascular disease. Visceral fat may reduce myocardial perfusion by impairing vascular endothelial function. Women experience more anginal symptoms compared to men despite less severe coronary artery stenosis, as assessed by angiography. Women and men have different fat storage patterns which may account for the observed differences in cardiovascular disease. Therefore, our objective was to evaluate the relationship between visceral adipose tissue distributions and myocardial perfusion in men and women. Methods Visceral and subcutaneous fat distributions and myocardial perfusion were measured in 69 men and women without coronary artery disease using magnetic resonance imaging techniques. Myocardial perfusion index was quantified after first-pass perfusion with gadolinium contrast at peak dose dobutamine stress. Results We observed inverse relationships between female gender (r = -0.35, p = 0.003), pericardial fat (r = -0.36, p = 0.03), intraperitoneal fat (r = -0.37, p = 0.001), and retroperitoneal fat (r = -0.36, p = 0.002) and myocardial perfusion index. Visceral fat depots were not associated with reduced myocardial perfusion at peak dose dobutamine in men. However, in women, BMI (r = -0.33, p = 0.04), pericardial fat (r = -0.53, p = 0.02), subcutaneous fat (r = -0.39, p = 0.01) and intraperitoneal fat (r = -0.30, p = 0.05) were associated with reduced myocardial perfusion during dobutamine stress. Conclusions Higher visceral fat volumes are associated with reduced left ventricular myocardial perfusion at peak dose dobutamine stress in women but not in men. These findings suggest that visceral fat may contribute to abnormal microcirculatory coronary artery perfusion syndromes, explaining why some women exhibit more anginal symptoms despite typically lower grade epicardial coronary artery stenoses than men.

Aging reduces left atrial performance during adrenergic stress in middle aged and older patients.

BACKGROUND During adrenergic stress, the influence of age on left atrial (LA) function is unknown. We hypothesized that aging decreases LA total emptying fraction (LAEF) during maximal adrenergic stress. The aim of the study was to determine the influence of aging on LA function during adrenergic stress in middle aged and older patients. METHODS We enrolled 167 middle aged and elderly participants, and measured LA and left ventricular (LV) volumes using a multi-slice three-dimensional cine white blood cardiovascular magnetic resonance (CMR) technique before and during intravenous dobutamine infused to achieve 80% of the maximum heart rate response for age. Paired sample t-test was used to detect differences in LA and LV volumes between baseline and peak dose stage of dobutamine stress CMR, and multivariable linear regression was used to identify predictors of LA function. RESULTS Participants averaged 68 ± 8 years in age, 53% were men, 25% exhibited coronary artery disease, 35% had diabetes, 9% had a remote history of atrial fibrillation, 90% had hypertension, and 11% had inducible LV wall motion abnormalities indicative of ischemia during dobutamine CMR. Increasing age correlated with LA volumes (maximal and minimal) and inversely correlated with LAEF at rest and after peak adrenergic stress. Age was an independent predictor of LAEF during adrenergic stress, even after accounting for gender, LV volumes, and other co-morbidities including inducible ischemia. CONCLUSIONS Age is associated with a decrease in LA function during adrenergic stress even after adjusting for co-morbidities associated with cardiovascular disease and LV function.

Visceral fat is associated with an adverse increase in the thickness of the wall of the ascending thoracic aorta

Findings When comparing the 1st and 4th quartiles of IP fat (1st quartile mean = 59 + 2.5 cm3, 4th quartile mean = 245 + 5.5 cm3), the minimum, maximum, and mean AOWT was 15% (p = 0.002), 18% (p = 0.001), and 18% (p < 0.001) larger, respectively, in the 4th quartile relative to the 1st quartile. Higher IP fat was associated with higher AOWT in participants < or ≥ 65 years of age (Figure 1). There were similar associations with RP fat, but no relationship was found between AOWT and SC fat. In the multivariate model, IP fat remained associated with minimum, maximum, and mean AOWT after accounting for age, gender, height, diabetes, hypertension, and coronary artery disease (p = 0.01, 0.01 and 0.01, respectively).