Muhammad A. Latif

Association of Subjective and Objective Sleep Duration as well as Sleep Quality with Non-Invasive Markers of Sub-Clinical Cardiovascular Disease (CVD): A Systematic Review

Aim: Abnormal daily sleep duration and quality have been linked to hypertension, diabetes, stroke, and overall cardiovascular disease (CVD) morbidity & mortality. However, the relationship between daily sleep duration and quality with subclinical measures of CVD remain less well studied. This systematic review evaluated how daily sleep duration and quality affect burden of subclinical CVD in subjects free of symptomatic CVD. Methods: Literature search was done via MEDLINE, EMBASE, Web of Science until June 2016 and 32 studies met the inclusion criteria. Sleep duration and quality were measured either via subjective methods, as self-reported questionnaires or Pittsburg Sleep Quality Index (PSQI) or via objective methods, as actigraphy or polysomnography or by both. Among subclinical CVD measures, coronary artery calcium (CAC) was measured by electron beam computed tomography, Carotid intima-media thickness (CIMT) measured by high-resolution B-mode ultrasound on carotid arteries, endothelial/microvascular function measured by flow mediated dilation (FMD) or peripheral arterial tone (PAT) or iontophoresis or nailfold capillaroscopy, and arterial stiffness measured by pulse wave velocity (PWV) or ankle brachial index (ABI). Results: Subjective short sleep duration was associated with CAC and CIMT, but variably associated with endothelial dysfunction (ED) and arterial stiffness; however, subjective long sleep duration was associated with CAC, CIMT and arterial stiffness, but variably associated with ED. Objective short sleep duration was positively associated with CIMT and variably with CAC but not associated with ED. Objective long sleep duration was variably associated with CAC and CIMT but not associated with ED. Poor subjective sleep quality was significantly associated with ED and arterial stiffness but variably associated with CAC and CIMT. Poor objective sleep quality was significantly associated with CIMT, and ED but variably associated with CAC. Conclusions: Overall, our review provided mixed results, which is generally in line with published literature, with most of the studies showing a significant relationship with subclinical CVD, but only some studies failed to demonstrate such an association. Although such mechanistic relationship needs further evaluation in order to determine appropriate screening strategies in vulnerable populations, this review strongly suggested the existence of a relationship between abnormal sleep duration and quality with increased subclinical CVD burden.

Subclinical Cardiovascular Disease in Patients with Chronic Obstructive Pulmonary Disease: A Systematic Review

Background Cardiovascular disease (CVD) accounts for a significant portion of deaths in patients with COPD; however, evidence for early detection strategies for CVD in this population remain limited. Our paper aims to summarize existing data regarding subclinical CVD in patients with COPD with a view to identifying screening strategies in these patients. Methods A systematic review of published literature was conducted for studies examining the relationship of COPD and markers of subclinical disease such as coronary artery calcification (CAC), carotid intima media thickness (cIMT), endothelial dysfunction, arterial stiffness as measured by pulse wave velocity (PWV) and augmentation indices (AIx). Both MEDLINE and EMBASE databases were searched till October 2015. Results A total of 22 studies were included in the review. Compared with control subjects, patients with COPD had significantly higher cIMT (SMD 0.53, 95% CI 0.16-0.90), PWV (SMD 0.91, 95% CI 0.67-1.16) and AIx (SMD 0.86, 95% CI 0.52-1.19). Additionally, an overall higher prevalence of subclinical CVD as assessed by CAC, ABI and FMD was noted in our review. Conclusion Although our findings need further evaluation in prospective studies, our review presents significant evidence in support of increased subclinical CVD burden in COPD patients independent of smoking status. Further large-scale case-control studies are required to highlight the significance of subclinical CVD screening in COPD patients.

Effect of Thyroxin Treatment on Carotid Intima–Media Thickness (CIMT) Reduction in Patients with Subclinical Hypothyroidism (SCH): a Meta-Analysis of Clinical Trials

Aim: Research shows that subclinical hypothyroidism (SCH) is related to an increased carotid intima –media thickness (CIMT), a surrogate marker of subclinical cardiovascular disease (CVD). It is controversial whether or not SCH should be treated to reduce CVD morbidity and mortality. This meta-analysis aimed to determine whether SCH is associated with an increase in CIMT as compared to Euthyroidism (EU) and whether thyroxin (T4) treatment in SCH can reverse the change in CIMT. Methods: Two independent reviewers conducted an extensive database research up to December 2016. A total of 12 clinical trials discussed the effect of Thyroxin on CIMT values at pre- and post-treatment in subjects with SCH. Results: CIMT was significantly higher among SCH (n = 280) as compared to EU controls (n = 263) at baseline; the pooled weighted mean difference (WMD) of CIMT was 0.44 mm [95% confidence interval (CI) 0.14, 0.74], p = 0.004; I2 = 65%. After treatment with thyroxin in subjects with SCH (n = 314), there was a statistically significant decrease in CIMT from pre- to post-treatment; the pooled WMD of CIMT decrease was [WMD −0.32; 95% CI (−0.47, −0.16), p = < 0.0001; I2 = 2%], and it was no longer different from EU controls [WMD 0.13 mm; 95% CI (−0.04, 0.30); p = 0.14; I2 = 27%]. The total cholesterol (TC), triglycerides (TG), and low-density lipoprotein (LDL) were higher in SCH as compared to EU controls and decreased significantly after treatment with thyroxin. Conclusion: This meta-analysis shows that thyroxin therapy in subjects with SCH significantly decreases CIMT and improves lipid profile, modifiable CVD risk factors. Thyroid hormone replacement in subjects with SCH may play a role in slowing down or preventing the progression of atherosclerosis.

EFFECT OF SHORT AND LONG SLEEP DURATION IN PREDICTING OBESITY AMONG VARIOUS RACIAL GROUPS OF A LARGE MULTI-ETHNIC ORGANIZATION

Literature shows strong association of abnormal sleep duration with obesity & increased CVD morbidity& mortality, but less is known how abnormal sleep duration is related to obesity among racial groups. The purpose of this study is to predict relationship of self-reported sleep duration with obesity

Cardiovascular CT for Assessment of Pericardial/Myocardial Disease Processes

Pericardial and myocardial diseases represent an important cause of morbidity and mortality. Although echocardiography remains the initial standard diagnostic tool for identifying these diseases it has limited detail for the morphological and functional analysis of the pericardium and myocardium. Cardiac CT (CCT) and MR (CMR) are the primary modalities of choice when comprehensive functional assessment of the heart is required. These imaging techniques provide advanced information on anatomy and cardiac function to optimize diagnosis and treatment. However, as CMR is relatively more costly and time consuming, it is often only used when diagnosis is not clear. Due to the volumetric nature of image acquisition, cardiac CT provides an accurate and reproducible method for assessing both myocardial and pericardial morphology and function. The excellent spatial resolution and contrast to noise ratio of CT allows for the detection of mural thrombi in patients with severely reduced left ventricular function. CCT can easily help identify pericardial diseases such as inflammation, effusion, pericardial cyst, benign or malignant masses, as well as pericardial calcification in the case of constrictive pericarditis. CCT is also proficient in diagnosing the functional assessment of the heart. As most of cardiomyopathies have functional compromise, CCT is best suited for cardiomyopathies in terms of functional analysis. With the advancement of CT technology, radiation exposure is minimal, and with continued improvement in post-processing software, it is able to produce a variety of high-quality images in multiple reformats with historically low radiation and contrast dose. The new General Electric (GE) Revolution CT scanner has made it possible to image the heart with abnormal rate and rhythm without compromising image quality. It is especially useful for patients who have contraindications to beta-blockers or who have atrial fibrillation.

A SYSTEMATIC REVIEW AND META-ANALYSIS: PREVALENCE OF CORONARY PLAQUE HIGH-RISK FEATURES (LOW ATTENUATION, ENLARGED DIAMETER OR POSITIVE REMODELING, NAPKIN RING, AND SPOTTY CALCIFICATION (LENS) IN ACUTE CORONARY SYNDROME AS ASSESSED BY CORONARY COMPUTED TOMOGRAPHIC ANGIOGRAPHY (CTA)

Coronary CT Angiography high-risk plaque features have been linked to acute coronary syndrome (ACS). In the current study, we aim to assess the association of low attenuation plaque, enlarged diameter or positive remodeling, napkin ring, and spotty calcification (LENS) with the presence of ACS.