Sameer Shaharyar

Systematic review on noninvasive assessment of subclinical cardiovascular disease in obstructive sleep apnea: new kid on the block!

Patients with obstructive sleep apnea (OSA) have a high burden of cardiovascular disease (CVD) but a causal relationship between OSA and atherosclerotic CVD remains unclear. We systematically reviewed the literature analyzing the relationship. A review of the Medline database for studies noninvasively evaluating subclinical CVD in OSA was conducted. A total of fifty-two studies were included in this review. Across the studies the prevalence of atherosclerosis, as assessed by coronary artery calcification, carotid intima-media thickness, brachial artery flow-mediated dilation and pulse wave velocity was higher in patients with OSA and correlated with increasing severity and duration of OSA. This study shows OSA is an independent predictor of subclinical CVD as CVD is more likely to occur in patients with long standing and severe OSA. Further research is however necessary to identify specific OSA populations that would benefit from aggressive screening.

Subclinical cardiovascular disease in plaque psoriasis: Association or causal link?

BACKGROUND Psoriasis patients have a high prevalence of cardiovascular events and are thought to have a relative risk increase of 25% as compared to the general population. However, a causal relationship between psoriasis and cardiovascular disease has not been established. We sought to perform a systematic review of existing data regarding the presence of endothelial dysfunction and subclinical atherosclerosis in patients with plaque psoriasis. METHODS A systematic literature search was performed, using Medline database and Ovid SP for relevant literature up to November 2012. Twelve studies met inclusion criteria from an initial search result of 529 articles. RESULTS Among the twelve studies meeting inclusion criteria, two (17%) reported increased mean coronary artery calcification (CAC) in psoriatic patients. Six studies (50%) showed carotid intima-media thickness [CIMT] increase in psoriasis. Five studies (42%) examined flow mediated dilation [FMD], of which three showed decreased FMD in psoriasis patients. One study (8%) each demonstrated a decreased coronary flow reserve and increased arterial stiffness as assessed by pulse wave velocity. CONCLUSIONS Patients with psoriasis have an increased burden of subclinical atherosclerosis and endothelial dysfunction. Patients with greater severity and/or disease duration should be targeted for primary screening for cardiovascular disease risk reduction.

Obesity and metabolic phenotypes (metabolically healthy and unhealthy variants) are significantly associated with prevalence of elevated C-reactive protein and hepatic steatosis in a large healthy Brazilian population

Background. Among the obese, the so-called metabolically healthy obese (MHO) phenotype is thought to confer a lower CVD risk as compared to obesity with typical associated metabolic changes. The present study aims to determine the relationship of different subtypes of obesity with inflammatory-cardiometabolic abnormalities. Methods. We evaluated 5,519 healthy, Brazilian subjects (43 ± 10 years, 78% males), free of known cardiovascular disease. Those with <2 metabolic risk factors (MRF) were considered metabolically healthy, and those with BMI ≥ 25 kg/m2 and/or waist circumference meeting NCEP criteria for metabolic syndrome as overweight/obese (OW). High sensitivity C reactive protein (hsCRP) was measured to assess underlying inflammation and hepatic steatosis (HS) was determined via abdominal ultrasound. Results. Overall, 40% of OW individuals were metabolically healthy, and 12% normal-weight had ≥2 MRF. The prevalence of elevated CRP (≥3 mg/dL) and HS in MHO versus normal weight metabolically healthy group was 22% versus 12%, and 40% versus 8% respectively (P < 0.001). Both MHO individuals and metabolically unhealthy normal weight (MUNW) phenotypes were associated with elevated hsCRP and HS. Conclusion. Our study suggests that MHO and MUNW phenotypes may not be benign and physicians should strive to treat individuals in these subgroups to reverse these conditions.

Objective measures of the frailty syndrome (hand grip strength and gait speed) and cardiovascular mortality: A systematic review.

BACKGROUND Handgrip strength (HGS) and gait speed (GS) are objective components of the frailty syndrome in the elderly, and are associated with increased all-cause mortality. However, their association with cardiovascular (CVD) mortality is less lucid. The present systematic review aims to summarize the available literature assessing HGS, GS and their association with CVD Mortality. METHODS Medline and Embase databases were searched systematically using controlled vocabulary and free text terms. A total of 344 results were obtained and scanned for inclusion. Articles were included if they presented results of original research and provided information on HGS or GS and CVD mortality. RESULTS A total of 19 studies (N=63,396) were included for review. Twelve studies examined hand grip strength with CVD mortality and 7 studies assessed gait speed. Almost all included studies demonstrated an association of HGS/GS with CVD mortality on univariate analyses. Decreased HGS or GS were associated with increased mortality in most studies (8/12 for HGS and 6/7 for GS). In most positive studies, the association of HGS/GS was usually found to be independent of traditional CVD risk factors. CONCLUSION The present review demonstrates that decreased HGS and GS are associated with CVD mortality, with the association found to be more consistent for GS as compared to HGS. Both of these measures provide valuable prognostic information above and beyond traditional scoring methods and should be considered for implementation in clinical practice.

Delayed Heart Rate Recovery is Strongly Associated With Early and Late-Stage Prehypertension During Exercise Stress Testing

BACKGROUND Heart rate recovery (HRR) has been shown to predict cardiovascular disease mortality. HRR is delayed in hypertension, but its association with prehypertension (PHT) has not been well studied. METHODS The study population consisted of 683 asymptomatic individuals (90% men, aged 47±7.9 years). HRR was defined as peak heart rate minus heart rate after a 2-minute rest. PHT was categorized into stage I (systolic blood pressure (SBP) 120-129mm Hg or diastolic BP (DBP) 80-84mm Hg) or stage II (SBP 130-139mm Hg or DBP 85-89mm Hg). Logistic regression was used to generate odds ratios (ORs) for the relationship between HRR and PHT. RESULTS The mean HRR was lower in the PHT groups than in those who were normotensive (60 bpm and 58 bpm in stages I and II PHT vs. 65 bpm in normal BP; P <0.01). Persons with PHT were more likely to be in the lowest quartile of HRR compared with those with normal BP (adjusted OR, 3.80 and 95% confidence interval [CI], 1.06, 13.56 for stage II PHT and adjusted OR, 3.01 and 95% CI 1.05, 8.66 for stage I PHT). In a fully adjusted model, HRR was still significantly associated with both stages of PHT. CONCLUSION Among asymptomatic patients undergoing stress testing, delayed HRR was independently associated with early and late stages of PHT. Further studies are needed to determine the usefulness of measuring HRR in the prevention and management of hypertension.

Measuring coronary artery calcification: is serum vitamin D relevant?

OBJECTIVES To synthesize evidence of the association between low vitamin D levels and subclinical coronary atherosclerosis measured by coronary artery calcium (CAC). METHODS A systematic MEDLINE search was conducted for relevant published literature. Ten studies (7 cross-sectional, 3 longitudinal) met the inclusion criteria. RESULTS Three of 6 studies showed association with CAC prevalence (CAC >0 or >10). Four of 8 studies found an association with CAC severity. One of two studies reported an association with CAC progression, while the only study that assessed CAC incidence did not find a significant relationship. Several of the studies had small sample sizes, many did not adjust for confounders and the cut-off for low vitamin D was inconsistent. CONCLUSION There is insufficient evidence to support a consistent association between low vitamin D levels and CAC. Further high-quality studies are needed to examine serum 25-OH vitamin D in relation to subclinical coronary atherosclerosis.

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.

High flow nasal cannula versus conventional oxygen therapy and non-invasive ventilation in adults with acute hypoxemic respiratory failure: A systematic review

INTRODUCTION Humidified oxygen via a high flow nasal cannula (HFNC) is a form of supplemental oxygen therapy that has significant theoretical advantages over conventional oxygen therapy (COT). However, the clinical role of HFNC in acute hypoxemic respiratory failure (AHRF) has not been well established. This review compares the efficacy of HFNC with COT and non-invasive ventilation (NIV) in patients with AHRF. METHODS Studies reviewed were selected based on relevance from a systematic literature search conducted in Medline and EMBASE to include all published original research through May 2016. Twelve studies matched the inclusion criteria. RESULTS In the majority of the studies, HFNC was associated with superior comfort and patient tolerance as compared to NIV or COT. HFNC was associated with reduced work of breathing in comparison with COT in some, but not all, studies in the review. COT and NIV were associated with a higher 90-day mortality rate compared to HFNC in only one multicenter randomized trial versus no mortality difference reported by others. Three out of four studies demonstrated a decreased need for escalation of oxygen therapy with HFNC. Six out of eight studies demonstrated improved oxygenation with HFNC as compared to COT. Two of three studies revealed worse oxygenation with HFNC as compared to NIV. CONCLUSION This review suggests that HFNC may be superior to COT in AHRF patients in terms of oxygenation, patient comfort, and work of breathing. It may be reasonable to consider HFNC as an intermediate level of oxygen therapy between COT and NIV.

Use of high-flow nasal cannula in obese patients receiving colonoscopy under intravenous propofol sedation: A case series

Intravenous sedation during colonoscopy has become the standard practice in the United States given its higher patient satisfaction and procedural quality. This practice is not free of side effects as a significant proportion of patients undergoing this procedure tend to have respiratory depression and desaturation events. Obesity, as it relates to higher levels of body mass index (BMI) has a positive correlation with the incidence of hypoxemia. During colonoscopy High flow nasal cannula (HFNC) may potentially improve oxygen performance in patients receiving colonoscopy under intravenous sedation. Here we present 3 cases of patients undergoing adjunctive oxygen therapy with HFNC during colonoscopy with intravenous sedation. We found patients to have lower number of desaturation events and were satisfied with their experience.

Feasibility and Safety of Flexible Bronchoscopy Performed Via Tracheal Tubes in Patients With Tracheostomies: A Retrospective, Single-Center Experience

Background: Flexible bronchoscopy (FB) is commonly performed to assess, diagnose, and treat patients with respiratory disease, and is typically performed via transnasal or transoral approaches. FB can be performed via tracheal tubes in patients with tracheostomies; however, the safety and technical feasibility has not been established. The present study evaluates the safety and feasibility of performing FB via tracheal tubes. Materials and Methods: A total of 45 patients underwent 56 procedures involving FB via tracheal tubes at a single institution from November 2013 to November 2014 and were included in this retrospective case series. Results: Patients had a median age of 68 years (interquartile range, 56 to 82.5), and 51% were female. Most patients had 2 comorbidities (interquartile range, 1 to 3), with the most common being hypertension, diabetes mellitus, and chronic kidney disease. Upper airway obstruction was the primary indication for bronchoscopy in 40% of patients. Fifty-three percent of patients had a Shiley tube #6, [internal cannula diameter (ICD) of 6.5 mm]; tracheal tubes in the remaining patients ranged from Shiley #4 (ICD, 5.5 mm) to Shiley #8 (ICD, 8.5 mm). One patient did not complete the procedure due to severe hypertension (intraprocedural systolic blood pressure >180 mm Hg). During FB, no patients experienced cardiorespiratory arrest, arrhythmia, bleeding, or desaturation that required resuscitation. Eleven patients had a mucus plug leading to atelectasis during bronchoscopy, and 8 of these had a postprocedural chest x-ray finding of lung reexpansion. Conclusion: FB via tracheal tubes is a technically feasible and safe procedure that does not compromise patient oxygenation.