Obesity, Weight Loss and Cardiovascular Risk

Background: The global prevalence of obesity is on the rise, contributing to increased incidence and prevalence of cardiovascular morbidity and mortality. Obesity has adverse effects on cardiac structure and function, directly through a hemodynamic overload, and indirectly through cardiovascular risk factors and low-grade inflammation. Still, epidemiologic studies have found that once cardiovascular disease has developed, people with obesity may experience better prognosis than those with normal weight; a phenomenon termed “the obesity paradox”. Aims: The objects of the present thesis were: 1) to investigate the effect of surgically induced long-term weight loss on the incidence of atrial fibrillation and heart failure; 2) to study possible mechanisms linking obesity to the development of heart failure; and 3) to examine the prognostic significance of different BMI categories on outcomes in a cohort of patients with ST-elevation myocardial infarction (STEMI) treated with percutaneous coronary intervention (PCI) Method: We analyzed data from the Swedish Obese Subjects (SOS) study, a prospective matched intervention study comparing bariatric surgery (n=2,010) and conventional obesity treatment (n=2,040). The SOS data was merged with the Swedish National Patient Register (NPR) and with the Cause of Death Register (COD). Data from the SOS obese control group was used to study the link between obesity and heart failure (n=2,040). Data from the Swedish Registry of Catheter-borne Coronary Vessel Surgery (SCAAR) (n=25,384) was merged with the COD Register to study the prognostic significance of different BMI classes. Results: Surgically induced weight loss resulted in a significantly lower incidence of atrial fibrillation and heart failure during long-term follow-up. Atrial fibrillation and myocardial infarction, as time-dependent variables, were strongly related to incident heart failure. In patients with STEMI treated with PCI, those with BMI > 30 kg/m2 had the best outcome in unadjusted analysis, but after adjustment for age and sex individuals with BMI 25-30 kg/m2 displayed the best prognosis. Underweight patients with BMI < 18.5 kg/m2 had the highest 30-day and 1-year mortality. Conclusion: In people with severe obesity, bariatric surgery induced a substantial and a sustained weight loss, which resulted in a lower incidence of atrial fibrillation and heart failure. Atrial fibrillation is probably reflected by diastolic dysfunction and myocardial infarction is likely to be related to systolic dysfunction, proposing two different mechanistic pathways for the development of heart failure. Overweight displays the lowest risk for 30-day and 1-year mortality after PCI treatment of STEMI

Prognostic comparison of atrial and ventricular functional mitral regurgitation

Objective Atrial functional mitral regurgitation (A-FMR) has been suggested as a new aetiology of functional MR (MR); however, its prognosis and prognostic predictors are not fully elucidated. Aim of this study was to investigate the prognosis and prognostic predictors of A-FMR in comparison with ventricular functional MR (V-FMR).Methods Three hundred and seventy-eight consecutive patients with moderate-to-severe or severe functional MR were studied. Functional MR was classified into V-FMR (N=288) and A-FMR (N=90) depending on the alterations of left ventricle (LV) or left atrium (LA) along with clinical context and diagnosis of ischaemic heart disease or cardiomyopathy.Results During a median follow-up of 4.1 (2.0–6.7) years, all-cause mortality, cardiovascular mortality and heart failure (HF) hospitalisation occurred in 98 (26%), 81 (21%) and 177 (47%) patients, respectively, and rates of these events and the composite end point of all-cause mortality and HF hospitalisation were consistently higher in V-FMR than A-FMR (unadjusted HR 1.762 (95% CI 1.250 to 2.438), p&lt;0.001; adjusted HR 1.654 (95% CI 1.027 to 2.664), p=0.038, for the composite end point). Further analysis showed different prognostic predictors between V-FMR and A-FMR; while age and LA volume index were independent prognostic predictors of both V-FMR and A-FMR, systolic blood pressure and B-type natriuretic peptide were also those of V-FMR, and estimated glomerular filtration rate, LV end-systolic dimension and tricuspid regurgitation were also those of A-FMR.Conclusions The prognosis of V-FMR was significantly worse than that of A-FMR, and prognostic predictors were different between V-FMR and A-FMR. Our study suggests the importance of discriminating A-FMR and V-FMR, and that different treatment strategies may be considered for each aetiology

Prognostic significance of BMI after PCI treatment in ST-elevation myocardial infarction: a cohort study from the Swedish Coronary Angiography and Angioplasty Registry

Background Obesity along with clustering of cardiovascular risk factors is a promoter for coronary artery disease. On the other hand, a high body mass index (BMI) appears to exert a protective effect with respect to outcomes after a coronary artery event, termed the obesity paradox.Methods The Swedish Coronary Angiography and Angioplasty Registry collects information on all patients who undergo percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) in Sweden along with demographic and procedure-related data. We studied the predictability of four categories of BMI for 1-year all-cause mortality in people with STEMI undergoing PCI.Results Among 25 384 patients, mean (SD) age 67.7 (12.1) years and 70.2% male, who underwent PCI for STEMI, a total of 5529 (21.8%) died within 1 year. Using normal weight (BMI 18.5–24.9 kg/m2) as a reference, subjects with obesity (BMI ≥30 kg/m2) had a low 1-year all-cause mortality risk in unadjusted analysis, HR 0.59 (95% CI 0.53 to 0.67). However, after adjustment for age, sex and other covariates, the difference became non-significant, HR 0.88 (95% CI 0.75 to 1.02). Patients with overweight (BMI 25.0–29.9 kg/m2) had the lowest 1-year mortality risk in analysis adjusted for age, sex and other covariates, HR 0.87 (95% CI 0.79 to 0.97), whereas those with underweight (BMI &lt;18.5 kg/m2) had the highest mortality in both unadjusted HR 2.22 (95% CI 1.69 to 2.92) and adjusted analysis, HR 1.62 (95% CI 1.18 to 2.23).Conclusion The protective effect of obesity with respect to 1-year mortality after coronary intervention became non-significant after adjusting for age, sex and relevant covariates. Instead, overweight people displayed the lowest risk and underweight individuals the highest risk for adjusted all-cause mortality.Trial registration number NCT02311231

Incidence of type 2 diabetes after gastric by-pass surgery in a Swedish controlled cohort study

AimsTo assess the long-term risk of developing type 2 diabetes in patients with obesity who have undergone gastric bypass surgery compared to non-operated patients with obesity and the general population.MethodsThis study included 71,495 patients aged 20–65 years with a principal diagnosis of obesity in the Swedish Patient Register in 2001–2013. Of these, 23,099 had undergone gastric bypass and 32,435 had not. Each patient was matched by age, sex and geographic region with two controls from the general population without obesity diagnosis, i.e., 44,735 controls for the gastric bypass cohort and 62,522 controls for the non-operated cohort with obesity. Operated and non-operated patients with obesity were also directly compared using Cox regression analysis, providing hazard ratios (HR) with 95% confidence intervals (CI) adjusted for age, education, and sex.ResultsDuring a median follow-up of 4.3 years (interquartile range [IQR] 2.4, 7.0 years), 3792 (11.7%) non-operated patients with obesity developed type 2 diabetes (incidence rate 22.8/1000 person-years, 95% CI 22.1–23.6) compared to 394 (1.7%) among gastric bypass patients (incidence rate 4.0/1000 person-years, 95% CI 3.6–4.5). The latter incidence was comparable to population controls (3.5/1000 person-years, 95% CI 3.2–3.8). Gastric bypass patients had 85% lower risk of diabetes compared to non-operated patients with obesity during the first six years of follow-up (HR 0.15; 95% CI 0.13–0.17).ConclusionGastric bypass surgery for obesity seems to reduce the risk of developing type 2 diabetes to levels similar to that of the general population during the first six years of follow-up but not thereafter

Surgical treatment of obesity and excess risk of developing heart failure in a controlled cohort study

AIM: We aim to assess the risk of heart failure in patients with obesity with and without gastric bypass surgery compared with population controls. METHODS AND RESULTS: This cohort study included all patients aged 20–65 years with a first ever registered principal diagnosis of obesity in the Swedish Patient Register in 2001–2013. These patients were matched by age, sex, and region with two population controls from the general Swedish population without obesity diagnosis. The obesity cohort was divided into two groups: 27 882 patients who had undergone gastric bypass surgery within 2 years of obesity diagnosis and 39 564 patients who had not undergone such surgery. These groups were compared with 55 149 and 78 004 matched population controls, respectively. Cox regression provided hazard ratios (HR) with 95% confidence intervals (CI), adjusted for age, education, and sex. During follow‐up (maximum 10 years, median 4.4 years, and interquartile range 2.5–7.2 years), 1884 participants were hospitalized for heart failure. Compared with population controls, gastric bypass patients had no excess risk of heart failure during the initial 0–≤4 years of follow‐up (HR = 1.35 [95% CI = 0.96–1.91]) but a marked increased risk during the final >4–10 years of follow‐up (HR = 3.28 [95% CI = 2.25–4.77]). Non‐operated patients with obesity had a marked excess risk of heart failure throughout the study period compared with population controls. CONCLUSIONS: Gastric bypass for obesity seems to reduce the risk of heart failure to levels similar to the general population during the initial 4 years after surgery, but not thereafter

Antibacterial Envelope to Prevent Cardiac Implantable Device Infection

Background Infections after placement of cardiac implantable electronic devices (CIEDs) are associated with substantial morbidity and mortality. There is limited evidence on prophylactic strategies, other than the use of preoperative antibiotics, to prevent such infections. Methods We conducted a randomized, controlled clinical trial to assess the safety and efficacy of an absorbable, antibiotic-eluting envelope in reducing the incidence of infection associated with CIED implantations. Patients who were undergoing a CIED pocket revision, generator replacement, or system upgrade or an initial implantation of a cardiac resynchronization therapy defibrillator were randomly assigned, in a 1:1 ratio, to receive the envelope or not. Standard-of-care strategies to prevent infection were used in all patients. The primary end point was infection resulting in system extraction or revision, long-term antibiotic therapy with infection recurrence, or death, within 12 months after the CIED implantation procedure. The secondary end point for safety was procedure-related or system-related complications within 12 months. Results A total of 6983 patients underwent randomization: 3495 to the envelope group and 3488 to the control group. The primary end point occurred in 25 patients in the envelope group and 42 patients in the control group (12-month Kaplan-Meier estimated event rate, 0.7% and 1.2%, respectively; hazard ratio, 0.60; 95% confidence interval [CI], 0.36 to 0.98; P=0.04). The safety end point occurred in 201 patients in the envelope group and 236 patients in the control group (12-month Kaplan-Meier estimated event rate, 6.0% and 6.9%, respectively; hazard ratio, 0.87; 95% CI, 0.72 to 1.06; P&lt;0.001 for noninferiority). The mean (+/- SD) duration of follow-up was 20.7 +/- 8.5 months. Major CIED-related infections through the entire follow-up period occurred in 32 patients in the envelope group and 51 patients in the control group (hazard ratio, 0.63; 95% CI, 0.40 to 0.98). Conclusions Adjunctive use of an antibacterial envelope resulted in a significantly lower incidence of major CIED infections than standard-of-care infection-prevention strategies alone, without a higher incidence of complications