Jad Omran

Impact of Obesity and Weight Loss on Cardiac Performance and Morphology in Adults

Obesity, particularly severe obesity is capable of producing hemodynamic alterations that predispose to changes in cardiac morphology and ventricular function. These include increased cardiac output, left ventricular hypertrophy and diastolic and systolic dysfunction of both ventricles. Facilitated by co-morbidities such as hypertension, the sleep apnea/obesity hypoventilation syndrome, and possibly certain neurohormonal and metabolic alterations, these abnormalities may predispose to left and right heart failure, a disorder known as obesity cardiomyopathy.

Effects of Obesity on Cardiovascular Hemodynamics, Cardiac Morphology, and Ventricular Function

Obesity produces a variety of hemodynamic alterations that may cause changes in cardiac morphology which predispose to left and right ventricular dysfunction. Various neurohormonal and metabolic alterations commonly associated with obesity may contribute to these abnormalities of cardiac structure and function. These changes in cardiovascular hemodynamics, cardiac morphology, and ventricular function may, in severely obese patients, predispose to heart failure, even in the absence of other forms of heart disease (obesity cardiomyopathy). In normotensive obese patients, cardiac involvement is commonly characterized by elevated cardiac output, low peripheral vascular resistance, and increased left ventricular (LV) end-diastolic pressure. Sleep-disordered breathing may lead to pulmonary arterial hypertension and, in association with left heart failure, may contribute to elevation of right heart pressures. These alterations, in association with various neurohormonal and metabolic abnormalities, may produce LV hypertrophy; impaired LV diastolic function; and less commonly, LV systolic dysfunction. Many of these alterations are reversible with substantial voluntary weight loss.

Effect of obesity and weight loss on ventricular repolarization: a systematic review and meta‐analysis

We performed a systematic review and meta‐analysis of the effects of obesity ± overweight and weight loss on the corrected QT interval (QTc) and QT or QTc dispersion (indices of ventricular repolarization). Mean difference for both QTc and QT or QTc dispersion with 95% confidence intervals (CIs) was calculated comparing obese ± overweight subjects and normal weight controls and QTc and QT or QTc dispersion before and after weight loss from diet ± exercise or bariatric surgery. A total of 22 studies fulfilled the selection criteria. Compared with normal weight controls, there was a significantly longer QTc in obese ± overweight subjects (mean difference of 21.74 msec, 95% CI: 18.76 to 22.32) and significantly longer QT or QTc dispersion (mean difference of 15.17 msec, 95% CI: 13.59 to 16.74). Weight loss was associated with a significant decrease in QTc (mean difference −25.77 msec, 95% CI: −28.33–23.21) and QT or QTc dispersion (mean difference of −13.46 msec, 95% CI: −15.60 to −11.32 in obese ± overweight subjects. Thus, obesity ± overweight is associated with significant prolongation of QTc and QT or QTC dispersion. Weight loss in obese ± overweight subjects produces significant decreases in these variables.

Effect of Weight Loss on Ventricular Repolarization in Normotensive Severely Obese Patients With and Without Heart Failure

Background:Obesity has been reported to be associated with delayed ventricular repolarization. The purpose of this study was to assess ventricular repolarization in normotensive severely obese subjects with and without heart failure (HF) and to assess the effect of weight loss on ventricular repolarization in such patients. Methods:Twenty-eight patients with and 39 patients without HF (body mass index ≥ 40 kg/m2) were studied before and after weight loss from bariatric surgery. Corrected QT interval (QTc) was measured on 12-lead electrocardiograms using Bazetts formula. QTc dispersion was calculated by subtracting the minimum from the maximum QTc on each 12-lead electrocardiogram. Electrocardiograms and transthoracic echocardiograms were performed preoperatively and at the nadir of postoperative weight loss. Results:Mean QTc and QTc dispersion were significantly longer/greater in subjects with HF than in those without HF (P < 0.0001). Weight loss produced significant reductions in mean QTc and QTc dispersion in both subgroups (P < 0.0001). Pre-weight loss left ventricular (LV) mass/height2.7 and presence or absence of HF independently predicted pre-weight loss QTc and QTc dispersion (P < 0.0001). Weight loss-induced decrease in LV mass/height2.7 independently predicted weight loss-induced decreases in QTc and QTc dispersion (P < 0.0001). Conclusions:HF independently predicts QTc and QTc dispersion in normotensive severely obese patients. Decrease in the LV mass resulting from weight loss independently predicts reduction in QTc and QTc dispersion in such patients.

Dyslipidemia in Patients with Chronic and End-Stage Kidney Disease

In this review, we discuss the physiology, diagnosis and treatment of dyslipidemia in patients with chronic and end-stage renal disease. The recent important clinical trials in patients with chronic kidney disease and dyslipidemia are reviewed. Because of the lack of evidence in treating lipid abnormalities in this specific patient population, we propose that future studies should focus on the pathophysiological mechanisms and treatment of dyslipidemia in this special patient population.

Proximal balloon occlusion versus distal filter protection in carotid artery stenting: A meta-analysis and review of the literature

Carotid artery stenting (CAS) is typically performed using embolic protection devices (EPDs) as a means to reduce the risk of procedure‐related stroke. In this study, we compared procedural morbidity and mortality associated with distal (D‐EPD) vs. proximal (P‐EPD) protection.

Endovascular versus surgical treatment for acute limb ischemia: a systematic review and meta-analysis of clinical trials

BACKGROUND A number of small studies have suggested that outcomes following endovascular (ENDO) therapy are comparable to those following surgical (SURG) revascularization for patients presenting with acute limb ischemia (ALI). We sought to compare mortality, limb amputation and recurrent ischemia across both revascularization strategies. METHODS A comprehensive database search of MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL) electronic databases from January 1990 through January 2016 was performed to identify studies of ENDO versus SURG for ALI. Two independent reviewers selected studies and extracted the data. Random-effects meta-analysis was used to pool results across studies. Heterogeneity of treatment effect among trials was assessed using the I2 statistics. The primary endpoints were mortality and limb amputation at 1 month, 6 and 12 months. Secondary endpoint was recurrent ischemia at one year. RESULTS A total of 1,773 patients were included from six studies (five randomized prospective and one observational retrospective) comparing ENDO and SURG in the setting of ALI. The mean age was 67 years and 65% of patients were male. There were no differences in mortality between the two groups at 1 month [risk ratio (RR) for ENDO vs. SURG is 0.70; 95% confidence interval (CI), 0.33 to 1.50], 6 months (RR 1.12; CI, 0.78 to 1.61) or 12 months (RR 0.74; CI, 0.29 to 1.85). Similarly, there was no significant difference in amputation rates between ENDO and SURG at 1 month (RR 0.75; CI, 0.40 to 1.42), 6 months (RR 0.87; CI, 0.52 to 1.48) or 12 months (RR 0.81; CI, 0.55 to 1.18). When looking into secondary outcomes, recurrent ischemia was not different between the two groups (RR 1.12; CI, 0.75 to 1.67). CONCLUSIONS In patients presenting with ALI (<2 weeks of duration), ENDO and SURG approaches have similar rates of short-term and 12 month mortality, limb amputation and recurrent ischemia.

Comparison of Outcomes of ST-Elevation Myocardial Infarction Treated by Percutaneous Coronary Intervention During Off-Hours Versus On-Hours

Previous studies have reported worse outcomes and longer door-to-balloon times (DBTs) in patients presenting with ST-elevation myocardial infarction (STEMI) after normal working hours, during weekends, and on holidays (off-hours) compared with normal business hours (on-hours). Recent studies, however, have reported similar outcomes regardless of presentation time. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were queried from January 1990 through December 2016. Only studies comparing STEMI outcomes during off-hours versus on-hours with percutaneous coronary intervention were included. A random-effects meta-analysis model was used to pool outcomes across the studies. Clinical end points included short- (<30 days of presentation), intermediate- (at 1 to 2 years), and long-term (at 3 to 4 years) stent thrombosis, mortality, recurrent myocardial infarction (MI), and major adverse cardiovascular events (MACEs). A total of 86,776 patients (62 years and 74.5% male) were identified from 39 studies. There was no significant difference between both groups with regard to mean DBT (odds ratio [OR] 0.74, 95% confidence interval [CI] -2.73 to 4.22, p = 0.67) or median DBT (p = 0.19). There was no significant difference between the 2 groups for short-term end points including mortality (OR 1.11, 95% CI 0.99 to 1.25, p = 0.08), MI (OR 1.25, 95% CI 0.90 to 1.74, p = 0.18), MACE (OR 1.06, 95% CI 0.93 to 1.20, p = 0.40), or stent thrombosis (OR 1.23, 95% CI 0.83 to 1.82, p = 0.31). Similarly, intermediate-term end points were not statistically different for mortality (OR 0.97, 95% CI 0.89 to 1.05, p = 0.46), MI (OR 0.86, 95% CI 0.73 to 1.02, p = 0.08), or MACE (OR 1.00, 95% CI 0.92 to 1.08, p = 0.98). Long-term end points did not differ statistically between groups for mortality (OR 0.95, 95% CI 0.83 to 1.09, p = 0.46), MI (OR 1.19, 95% CI 0.77 to 1.84, p = 0.44), or MACE (OR 0.98, 95% CI 0.89 to 1.08, p = 0.67). In conclusion, patients presenting with STEMI during off-hours and treated with percutaneous coronary intervention had similar short-, intermediate-, and long-term outcomes compared with patients presenting during on-hours. DBT was not affected by the time of presentation.

Fractional flow reserve versus angiography guided percutaneous coronary intervention: An updated systematic review

To compare outcomes of fractional flow reserve (FFR) to angiography (ANGIO) guided percutaneous coronary intervention (PCI).

Clinical outcomes of PCSK9Is: a meta-analysis of randomized clinical trials

Background Previous studies of proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9Is) were not designed to detect clinical benefit and were underpowered for this outcome. However, recently published trials reported improvement in clinical outcomes. The aim of this meta-analysis to assess the impact of PCSK9Is on clinical outcomes. Methods Medline, Embase and the Cochrane Central Register of Controlled Trials (CENTRAL) were queried from January 2000 through March 2017. Only randomized controlled trials (RCTs) comparing clinical outcomes in patients treated with PCSK9I versus control group were included. Two independent reviewers selected the studies and extracted data in duplicate. Random-effects meta-analysis was used to pool outcomes across studies. Study endpoints included: major adverse cardiovascular events (MACE), myocardial infarction (MI), stroke, coronary revascularization, cardiovascular (CV) mortality and all-cause mortality. Results A total of 62,776 patients (mean age 61 years, 73% were males) were included from six randomized clinical trials. In comparison to control group, PCSK9I use was associated with lower MACE (RR =0.81, 95% CI, 0.70-0.93, P=0.003), MI (RR =0.78, 95% CI, 0.63-0.97, P=0.03), stroke (RR =0.74, 95% CI, 0.64-0.87, P=0.0002) and coronary revascularization (RR =0.79, 95% CI, 0.73-0.86, P<0.00001). There was no statistically significant difference between both groups in terms of all-cause mortality (RR =1.01, 95% CI, 0.86-1.20, P=0.86) or CV mortality (RR =0.98, 95% CI, 0.78-1.22, P=0.83). Conclusions PCSK9Is should be strongly considered to improve clinical outcomes in patients at high risk for atherosclerotic CVD.