The risk of adverse cardiovascular outcomes after bariatric surgery in patients with morbid obesity with and without obstructive sleep apnea

Background: Weight loss after bariatric surgery in obese patients reduces adverse cardiovascular (CV) outcomes; however, it is not known if similar benefits are maintained in patients with and without obstructive sleep apnea (OSA). We investigated whether weight loss after laparoscopic adjustable gastric banding (LAGB) results in similar CV event rates in patients with and without OSA. Methods: Differences in LAGB-induced weight loss on CV outcomes (myocardial infarction, heart failure, stroke, atrial fibrillation [AF] and pulmonary embolism) in those with OSA and matched non-OSA patients were determined by Kaplan-Meier and Cox regression analysis and predictors of CV events identified. Results:Out of 828 obese patients [body mass index (BMI) ≥35 kg/m2] who underwent LAGB and were followed for 11 years, OSA was present in 217 (26%).The mean age was 44±11 years, mean BMI 49±8 kg/m2 and median follow-up 63.6 months; the mean reduction in BMI was 10 kg/m2 at 3 years. Patients with no history of OSA had minimal CV events compared to those with OSA (Fig A and B, at 5 years 1% vs 22%, p Conclusions: Patients with OSA, despite weight loss after LABG, continued to have higher CV events, particularly heart failure and AF. Further investigation is warranted into whether compliance with OSA treatment helps reduce CV events

Impact of obstructive sleep apnea severity on cardiac events in patients with normal or prolonged ventricular repolarization

BACKGROUND: Prolonged cardiac repolarization is associated with increased risk of ventricular arrhythmias which are aggravated by several triggering factors including excess catecholamine state and electrolyte abnormalities. We studied the impact of severity of obstructive sleep apnea (OSA) on ventricular tachyarrhythmias and mortality in patients with normal or prolonged ventricular repolarization as this is not well defined. METHODS: 338 patients [59% male, mean age: 61 ± 13] undergoing polysomnography between January 2012 to June 2015 who also had a 12-lead ECG were divided into 4 groups: Group 1-no evidence of OSA, Group 2-mild, Group 3-moderate, Group 4-severe, based on apnea-hypopnea index (AHI) none\u3c5, mild 5-14, moderate 15-29, severe \u3e29 respectively. The differences in prevalence of non-sustained ventricular tachycardia between the 4 groups and incidence of ventricular fibrillation (VF) and overall mortality were determined using Cochran-Armitage Trend and Chi-Square. In addition, differences in VT and VF and overall mortality were determined between the 4 groups and compared to those with normal or prolonged repolarization (defined as JTc interval [JTc=QTc -QRS] \u3e380ms for female and \u3e360ms for male). RESULTS: Out of 338 patients, [51% with preexisting heart failure] the prevalence of VT increased with OSA severity from 44% in Group 1 to 46%, 50%, 67% in Group 2 to 4 [p=0.004] respectively. In patients with normal repolarization, prevalence of VT increased with OSA severity from 33% in Group 1 to 50%, 60% and 84% in Group 2 to 4 [p=0.001]. However, in patients with prolonged repolarization, there was no additional impact of OSA severity on VT in Group 1 to 4: 50%, 45%, 45%, 60% [p=0.094]. The risk of VF or death increased with worsening OSA severity from Groups 1 -4: 2.7%, 5.4%, 5.8%, 9.8%, however this was not significantly significant [p=0.53]. CONCLUSIONS: In patients with underlying cardiac disease, the prevalence of VT increases with OSA severity mainly in patients with normal repolarization but have minimum effect on patients with prolonged repolarization. There is a trend toward higher risk of VF or death with worsening sleep apnea that needs to be confirmed in a larger population

Gender differences in risk of stroke in patients with restless legs syndrome

Background Patients with Restless Legs Syndrome (RLS) have been recently reported to have a higher risk of stroke when compared to non-RLS patients, but the difference appears to be related to the duration of RLS. We hypothesize that diabetes mellitus, a condition that accelerates cardiovascular diseases, may enhance the risk of stroke more in RLS than in non-RLS patients. Methods and Results Patients diagnosed with RLS based on the International Restless Legs Syndrome Study Group criteria from a community-based sleep study center were compared to a 1:2 propensity matched non-RLS group. The association of diabetes and stroke in RLS and non-RLS patients in men and women were performed using Chi-Square and Cochran-Mantel-Haenszel Tests. Results Stroke was diagnosed in 29 out of 385 (7.5%) patients with RLS (mean age 55.1±0.7 years, 45% female) which was significantly higher than 32 out of 770 (4.2%; p=0.02) patients without RLS (mean age 54±0.5 years, 46% females). The presence of diabetes in the RLS group was associated with a 3 fold increased risk of stroke (OR 2.96, 95% Confidence Interval 1.05-8.37, p=0.03) compared to a 1.1 fold increased risk in non-RLS patients (OR: 1.08, 95% CI 0.44-2.65; p=0.87). This was significantly higher in female diabetics with RLS (18.2%) than in male diabetics (7.0%, p=0.03) or nondiabetics (5.7% in females vs 3.9% in males, p=0.52). Predictors of stroke in patients with RLS were the presence of hypertension, diabetes and female sex. Hypertension, diabetes and atrial fibrillation were predictors of stroke in non-RLS patients. Conclusions Gender differences exist in the risk of stroke in RLS patients with a 3.0 fold higher risk of stroke in diabetic women compared to diabetic men. In non-RLS patients, no significant difference in risk of stroke was found between women and men. Mechanisms underlying increased risk of stroke in RLS patients need to be defined and whether better diabetes control help reduce the stroke risk in RLS patients needs to be further investigated