The Relationship Between Body Mass Index and In-Hospital Mortality in the Contemporary Era of an Acute Myocardial Infarction Management

Obesity Paradox in the Intrahospital and Follow-Up Phases of the Acute Coronary Syndrome: A Meta-Analysis and Systematic Review

BACKGROUND

Obesity is an important risk factor for the development of dyslipidemia, diabetes mellitus, hypertension, coronary artery disease, ventricular dysfunction, congestive heart failure (HF), stroke, and cardiac arrhythmias.

OBJECTIVES

This meta-analysis brings comprehensive evaluation about still controversial association between the body mass index (BMI) and the outcomes of acute coronary syndrome.

METHOD

PubMed/ScienceDirect databases were systematically searched for studies with baseline parameters, primary (HF, cardiogenic shock, cardiac arrest, reinfarction, stroke, death, total in-hospital complications) and secondary outcomes (reinfarction, stroke, death, total major adverse cardiovascular events [MACE]) in relation to BMI strictly classified into four groups (underweight [<18.5 kg/m2], normal weight [18.5-24.9 kg/m2], overweight [25.0-29.9 kg/m2], and obese [≥30.0 kg/m2], grouped into mildly obese [30.0-34.9 kg/m2] and severely obese [≥35.0 kg/m2]).

RESULTS

We included 24 studies, with 585,919 participants (55.5% males), aged 66.8 years. Underweight was negatively associated with hypertension, hyperlipidemia and diabetes, and positively with primary outcomes {HF (odds ratio [OR] = 1.37, confidence interval [CI] [1.15-1.63]), cardiogenic shock (OR = 1.43, CI [1.04-1.98]), stroke (OR = 1.21, CI [1.05-1.40]), overall death (OR = 1.64, CI [1.20-2.26]), total in-hospital complications (OR = 1.39, CI [1.24-1.56])} and secondary outcomes during 34-month follow-up {cardiovascular/overall death (OR = 3.78, CI [1.69-8.49]/OR = 2.82, CI [2.29-3.49]), respectively, total MACE (OR = 2.77, CI [2.30-3.34])} (for all p < 0.05). Obesity had positive association with hypertension, hyperlipidemia, diabetes and smoking, and negative with primary outcomes {reinfarction (OR = 0.83, CI [0.76-0.91]), stroke (OR = 0.67, CI [0.54-0.85]), overall death (OR = 0.55, CI [0.49-0.63]), total in-hospital complications (OR = 0.81, CI [0.70-0.93])} and secondary outcomes {cardiovascular/overall death (OR = 0.77, CI [0.66-0.88]/OR = 0.62, CI [0.53-0.72]), respectively, total MACE (OR = 0.63, CI [0.60-0.77])} (for all p < 0.05). This negative association with several primary outcomes (cardiogenic shock, overall death, total in-hospital complications) and secondary outcomes (cardiovascular/overall death, total MACE) was more pronounced in mild obesity (p < 0.05). These results give an "obesity paradox" with a bimodal pattern (slightly U-shaped).

CONCLUSIONS

Obesity is positively associated with traditional cardiovascular risk factors and negatively with primary and secondary outcomes, which confirms the persistence of overall "obesity paradox."

The Relationship between Body Mass Index and In-Hospital Mortality in Bacteremic Sepsis

BACKGROUND

The association between Body Mass Index (BMI) and clinical outcomes following sepsis continues to be debated. We aimed to investigate the relationship between BMI and in-hospital clinical course and mortality in patients hospitalized with bacteremic sepsis using real-world data.

METHODS

A sampled cohort of patients hospitalized with bacteremic sepsis between October 2015 and December 2016 was identified in the National Inpatient Sample (NIS) database. In-hospital mortality and length of stay were defined as the relevant outcomes. Patients were divided into 6 BMI (kg/m²) subgroups; (1) underweight ≤ 19, (2) normal-weight 20-25, (3) over-weight 26-30, (4) obese I 31-35, (5) obese II 36-39, and (6) obese stage III ≥ 40. A multivariable logistic regression model was used to find predictors of mortality, and a linear regression model was used to find predictors of an extended length of stay (LOS).

RESULTS

An estimated total of 90,760 hospitalizations for bacteremic sepsis across the U.S. were analyzed. The data showed a reverse-J-shaped relationship between BMI and study population outcomes, with the underweight patients (BMI ≤ 19 kg/m²) suffering from higher mortality and longer LOS as did the normal-weight patients (BMI 20-25 kg/m²) when compared to the higher BMI groups. The seemingly protective effect of a higher BMI diminished in the highest BMI group (BMI ≥ 40 kg/m²). In the multivariable regression model, BMI subgroups of ≤19 kg/m² and ≥40 kg/m² were found to be independent predictors of mortality.

CONCLUSIONS

A reverse-J-shaped relationship between BMI and mortality was documented, confirming the "obesity paradox" in the real-world setting in patients hospitalized for sepsis and bacteremia.

Clinical features and predictors of non-cardiac death in patients hospitalised for acute myocardial infarction: Insights from the Tokyo CCU network multicentre registry

BACKGROUND

Patients with acute myocardial infarction (AMI) commonly have multiple comorbidities, and some die in hospitals due to causes other than cardiac complications. However, limited information is available on noncardiac death in patients hospitalised for AMI. Therefore, the present study was performed to determine the incidence, annual trend, clinical characteristics, and predictors of in-hospital non-cardiac death in patients with AMI using the Tokyo Cardiovascular Care Unit (CCU) network registry.

METHODS

The registry included 38,589 consecutive patients with AMI who were admitted to the CCU between 2010 and 2019. The primary endpoint was in-hospital noncardiac death. Further, predictors of cardiac and non-cardiac death were identified.

RESULTS

The incidence of all-cause in-hospital mortality was 7.0% (n = 2700), and the proportion of mortality was 15.6% (n = 420) and 84.4% (n = 2280) for noncardiac and cardiac causes, respectively. The proportion of noncardiac deaths did not change annually over the last decade (p = 0.66). After adjusting for all variables, age, Killip classification grade, peak creatine kinase, hemoglobin, serum creatinine, and C-reactive protein were common predictors of cardiac and non-cardiac deaths. Indicators of malnutrition, such as lower body mass index (kg/m²) [odds 0.94, 95%CI (0.90-0.97), p < 0.001] and serum low-density lipoprotein cholesterol level (per 10 mg/dl) [odds 0.92, 95%CI (0.89-0.96), p < 0.001] were the specific predictors for non-cardiac deaths.

CONCLUSIONS

The incidence of in-hospital noncardiac death was significant in patients with AMI, accounting for 15.6% of all in-hospital mortalities. Thus, prevention and management of non-cardiac complications are vital to improve acute-phase outcomes, especially those with predictors of non-cardiac death.

The Relation of Body Mass Index with In-Hospital Mortality in Patients with ST-Segment Elevation Myocardial Infarction

Objectives: In this study, we aimed to determine whether body mass index (BMI) is an independent predictor of in-hospital mortality in ST-segment elevation myocardial infarction (STEMI) patients and to assess the relationship between BMI and mortality. Methods: One thousand three hundred fifty-seven patients with STEMI were included to the study. Primary outcome was in-hospital mortality. The multivariable logistic regression was used to assess the relationship between BMI and in-hospital mortality using age, gender, diabetes mellitus, systolic blood pressure, heart rate, smoking status, serum creatinine and hemoglobin, type of STEMI, and Killip class as adjustment variables. Results: The frequency of in-hospital mortality was 14.7%. The mean BMI was found to be 28.2 ± 4.8 kg/m². Considering the in-hospital mortality frequencies between the groups, mortality was observed in 61.7% of the BMI <20 kg/m² group, 15.5% of the 20-25 kg/m² group, 8.5% of the 25-30 kg/m² group, and 9.5% of the >30 kg/m² group (chi-square P value <0.001). In the multivariable logistic regression analysis, a change in BMI from 20 to 30 kg/m² was associated with a reduced risk of in-hospital mortality (odds ratio: 0.39, 95% confidence interval: 0.23-0.67, P < 0.001). Conclusion: Our study results revealed that there was inverse significant association between BMI and in-hospital mortality in STEMI patients.

Comparison of Mortality Outcomes in Acute Myocardial Infarction Patients With or Without Standard Modifiable Cardiovascular Risk Factors

Background

Acute myocardial infarction (AMI) cases have decreased in part due to the advent of targeted therapies for standard modifiable cardiovascular disease risk factors (SMuRF). Recent studies have reported that ST-elevation myocardial infarction (STEMI) patients without SMuRF (termed “SMuRF-less”) may be increasing in prevalence and have worse outcomes than “SMuRF-positive” patients. As these studies have been limited to STEMI and comprised mainly Caucasian cohorts, we investigated the changes in the prevalence and mortality of both SMuRF-less STEMI and non-STEMI (NSTEMI) patients in a multiethnic Asian population.

Methods

We evaluated 23,922 STEMI and 62,631 NSTEMI patients from a national multiethnic registry. Short-term cardiovascular and all-cause mortalities in SMuRF-less patients were compared to SMuRF-positive patients.

Results

The proportions of SMuRF-less STEMI but not of NSTEMI have increased over the years. In hospitals, all-cause and cardiovascular mortality and 1-year cardiovascular mortality were significantly higher in SMuRF-less STEMI after adjustment for age, creatinine, and hemoglobin. However, this difference did not remain after adjusting for anterior infarction, cardiopulmonary resuscitation (CPR), and Killip class. There were no differences in mortality in SMuRF-less NSTEMI. In contrast to Chinese and Malay patients, SMuRF-less patients of South Asian descent had a two-fold higher risk of in-hospital all-cause mortality even after adjusting for features of increased disease severity.

Conclusion

SMuRF-less patients had an increased risk of mortality with STEMI, suggesting that there may be unidentified nonstandard risk factors predisposing SMuRF-less patients to a worse prognosis. This group of patients may benefit from more intensive secondary prevention strategies to improve clinical outcomes.

Association Between Obesity and Lower Short- and Long-Term Mortality in Coronary Care Unit Patients: A Cohort Study of the MIMIC-III Database

INTRODUCTION

Obesity has long been considered an independent risk factor for cardiovascular diseases (CVD), even in the COVID-19 pandemic. However, recent studies have found that a certain degree of obesity may be beneficial for patients who have already suffered from CVD, which is called the "obesity paradox". Our objective was to investigate whether the obesity paradox existed in coronary care unit (CCU) patients and the relationship between body mass index (BMI) and short- and long-term mortality.

METHODS

We performed a cohort analysis of 3,502 adult CCU patients from the Medical Information Mart for Intensive Care III (MIMIC-III) database. The patients were divided into four groups according to the WHO BMI categories. Both multivariable logistic regression and Cox regression were used to reveal the relation between BMI and mortality. Subgroup analyses were performed based on Simplified Acute Physiology Score (SAPS) and age.

RESULTS

After adjusting for confounders, obese patients had 33% and 30% lower mortality risk at 30-day and 1-year (OR 0.67, 95% CI 0.51 to 0.89; HR 0.70, 95% CI 0.59 to 0.83; respectively) compared with normal-weight patients, while the underweight group were opposite, with 141% and 81% higher in short- and long-term (OR 2.41, 95% CI 1.37 to 4.12; HR 1.81, 95% CI 1.34 to 2.46; respectively). Overweight patients did not have a significant survival advantage at 30-day (OR 0.91, 95% CI 0.70 to 1.17), but did have a 22% lower mortality risk at 1-year (HR 0.78; 95% CI 0.67 to 0.91). The results were consistent after being stratified by SAPS and age.

CONCLUSION

Our study supports that obesity improved survival at both 30-day and 1-year after CCU admission, and the obesity paradox existed in CCU patients.