The obesity paradox: association of obesity with improved survival in medically managed severe aortic stenosis

Clinical, echocardiographic and prognostic outcomes of patients with concordant and discordant high-gradient aortic stenosis in an Asian cohort

Literature of patients with severe high-gradient aortic stenosis (HG AS) (mean pressure gradient [MPG] ≥ 40 mmHg and aortic valve area [AVA] ≥ 1.0 cm2) remains limited. This study seeks to compare the prognostic outcomes of patients with high-gradient concordant (HGCON-AS) and discordant AS (HGDIS-AS) in an Asian cohort. From 2010 to 2015, patients with moderate-to-severe AS with preserved left ventricular ejection fraction (LVEF ≥ 50%) were recruited and stratified into 3 groups based on index echocardiogram-(1) HGDIS-AS, (2) HGCON-AS and (3) moderate AS (MOD-AS). The primary study endpoints was all-cause mortality, with secondary endpoints of congestive heart failure (CHF) admissions and aortic valve replacement (AVR). Multivariable Cox regression was used and Kaplan-Meier curves were constructed to evaluate associations between HGDIS-AS, HGCON-AS and MOD-AS, and the study outcomes. A total of 467 patients were studied, comprising of 6.2% HGDIS-AS, 13.9% HGCON-AS and 79.9% MOD-AS patients. There was significantly higher AVR rates in the HGCON-AS group (58.5%), followed by HGDIS-AS (31.0%) and MOD-AS (4.6%), p < 0.001) groups. After adjusting for confounders, HGCON-AS was significantly associated with all-cause mortality (HR 3.082, 95% CI 1.479-6.420, p = 0.003) and CHF admissions (HR 12.728, 95% CI 2.922-55.440 p = 0.001) but not HGDIS-AS, with MOD-AS as the reference group. Both HGDIS-AS (HR 7.715, 95% CI 2.927-20.338; p < 0.001) and HGCON-AS (HR 21.960, 95% CI 10.833-44.515, p < 0.001) were independent predictors of AVR. After exclusion of reversible high-flow states, HGDIS-AS patients appear to have a more favourable prognostic profile compared to HGCON-AS patients. Large prospective interventional studies examining the prognostic differences between the two groups will be the next important step.

Long-term Prognosis of Acute Myocardial Infarction Associated with Metabolic Health and Obesity Status

BACKGROUND

Emerging evidence supports the favourable cardiovascular health in non-obese subjects with healthy metabolism. However, little is known regarding the prognosis across the range of metabolic phenotypes once cardiovascular disease is established. We examined the prognosis of patients with acute myocardial infarction (AMI) stratified according to metabolic health and obesity status.

METHODS

This is a retrospective study on consecutive patients with AMI admitted to a tertiary hospital between 2014-2021. Patients were allocated into 4 groups based on metabolic and obesity profile: metabolically healthy obese (MHO), metabolically healthy non-obese (MHNO), metabolically unhealthy obese (MUO) and metabolically unhealthy non-obese (MUNO). Metabolic health was defined in accordance to the BioSHARE-EU Healthy Obese Project. The primary outcome was all-cause mortality. Cox regression analysis examined the independent association between mortality and metabolic phenotypes, adjusting for age, sex, AMI type, chronic kidney disease, smoking status and left ventricular ejection fraction.

RESULTS

Of 9958 patients, the majority (68.5%) were MUNO, followed by MUO (25.1%), MHNO (5.6%), and MHO (0.8%). MHO had the lowest mortality (7.4%), followed by MHNO (9.7%), MUO (19.2%) and MUNO (22.6%) (p<0.001). Compared to MHNO, MUO (HR 1.737, 95%CI 1.282-2.355, p<0.001) and MUNO (HR 1.482, 95%CI 1.108-1.981, p=0.008) had significantly higher mortality risk, but not MHO (HR 1.390, 95%CI 0.594-3.251, p=0.447), after adjusting for confounders. Kaplan-Meier curves showed favourable survival in the metabolically healthy and obesity groups, with the highest overall survival in the MHO followed by MHNO, MUO and MUNO (p<0.001).

CONCLUSION

Metabolically healthy and obese AMI patients have favourable prognosis compared to metabolically unhealthy and non-obese patients. It is equally important to prioritize intensive metabolic risk factor management to weight reduction in the early phase after AMI.

Heart valve surgery and the obesity paradox: A systematic review

Obesity has been associated with increased incidence of comorbidities and shorter life expectancy, and it has generally been assumed that patients with obesity should have inferior outcomes after surgery. Previous literature has often demonstrated equivalent or even improved rates of mortality after cardiac surgery when compared to their lower-weight counterparts, coined the obesity paradox. Herein, we aim to review the literature investigating the impact of obesity on surgical valve interventions. PubMed and Embase were systematically searched for articles published from 1 January 2000 to 15 October 2021. A total of 1315 articles comparing differences in outcomes between patients of varying body mass index (BMI) undergoing valve interventions were reviewed and 25 were included in this study. Patients with higher BMI demonstrated equivalent or reduced rates of postoperative myocardial infarction, stroke, reoperation rates, acute kidney injury, dialysis and bleeding. Two studies identified increased rates of deep sternal wound infection in patients with higher BMI, although the majority of studies found no significant difference in deep sternal wound infection rates. The obesity paradox has described counterintuitive outcomes predominantly in coronary artery bypass grafting and transcatheter aortic valve replacement. Recent literature has identified similar trends in other heart valve interventions. While the obesity paradox has been well characterized, its causes are yet to be identified. Further study is essential in order to identify the causes of the obesity paradox so patients of all body sizes can receive optimal care.