BMI, Infarct Size, and Clinical Outcomes Following Primary PCI: Patient-Level Analysis From 6 Randomized Trials

Body Mass Index and All-Cause Mortality in Elderly Patients with Percutaneous Coronary Intervention: A Meta-Analysis

INTRODUCTION

The "obesity paradox" in elderly patients suffering from percutaneous coronary intervention (PCI) remains a source of controversy. The present meta-analysis focused on exploring the real existence of "obesity paradox" in these patients.

METHODS

As of November 2022, PubMed, Cochrane, and Embase databases were comprehensively searched to identify articles reporting all-cause mortality according to diverse body mass index (BMI) categories after PCI among the old cases developing coronary artery disease (CAD). Summary estimates of relative risks (RRs) were assigned to four BMI groups, including underweight, normal weight, overweight, and obesity groups.

RESULTS

There were altogether nine articles involving 25,798 cases selected for further analysis. Relative to normal weight group, overweight and obesity groups had decreased all-cause mortality (RR: 0.86, 95% CI: 0.77-0.95 for overweight group; RR: 0.57, 95% CI: 0.40-0.80 for obesity group), while underweight group had elevated all-cause mortality (RR: 1.52, 95% CI: 1.01-2.29).

CONCLUSION

Our study revealed an "obesity paradox" relation of BMI with all-cause mortality in elderly cases receiving PCI. In comparison with normal weight group, overweight and obesity groups had decreased all-cause mortality, while underweight group had increased all-cause mortality.

Associations between body mass index and all-cause mortality: A systematic review and meta-analysis

Fasting insulin and c-reactive protein confound the association between mortality and body mass index. An increase in fat mass may mediate the associations between hyperinsulinemia, hyperinflammation, and mortality. The objective of this study was to describe the "average" associations between body mass index and the risk of mortality and to explore how adjusting for fasting insulin and markers of inflammation might modify the association of BMI with mortality. MEDLINE and EMBASE were searched for studies published in 2020. Studies with adult participants where BMI and vital status was assessed were included. BMI was required to be categorized into groups or parametrized as non-first order polynomials or splines. All-cause mortality was regressed against mean BMI squared within seven broad clinical populations. Study was modeled as a random intercept. β coefficients and 95% confidence intervals are reported along with estimates of mortality risk by BMIs of 20, 30, and 40 kg/m2 . Bubble plots with regression lines are drawn, showing the associations between mortality and BMI. Splines results were summarized. There were 154 included studies with 6,685,979 participants. Only five (3.2%) studies adjusted for a marker of inflammation, and no studies adjusted for fasting insulin. There were significant associations between higher BMIs and lower mortality risk in cardiovascular (unadjusted β -0.829 [95% CI -1.313, -0.345] and adjusted β -0.746 [95% CI -1.471, -0.021]), Covid-19 (unadjusted β -0.333 [95% CI -0.650, -0.015]), critically ill (adjusted β -0.550 [95% CI -1.091, -0.010]), and surgical (unadjusted β -0.415 [95% CI -0.824, -0.006]) populations. The associations for general, cancer, and non-communicable disease populations were not significant. Heterogeneity was very large (I2  ≥ 97%). The role of obesity as a driver of excess mortality should be critically re-examined, in parallel with increased efforts to determine the harms of hyperinsulinemia and chronic inflammation.

Sex-specific impact of anthropometric parameters on outcomes after transcatheter edge-to-edge repair for secondary mitral regurgitation

BACKGROUND

Body surface area (BSA) has been reported to be the stronger predictor for prognosis than body mass index in heart failure (HF) patients. The sex-specific association of BSA with mortality has been unclear.

METHODS

EuroSMR, a European multicenter registry, included patients who underwent edge-to-edge repair (TEER) for secondary mitral regurgitation (SMR). The outcome was two-year all-cause mortality.

RESULTS

The present cohort included 1594 HF patients (age, 74 ± 10 years; male, 66%). Association of calculated BSA with two-year all-cause mortality was evaluated. Patients were classified into three BSA groups: the lowest 10% (S), the highest 10% (L), and intermediate between S and L (M). Mean BSA was 1.87 ± 0.21 m² (male, 1.94 ± 0.18 m²; female, 1.73 ± 0.18 m²). The association of BSA with the endpoint in females showed a U-shaped curve, indicating worse prognosis for both S and L. The association in males followed a linear regression, demonstrating better prognosis for L. Hazard ratio (HR) of L to S in males was 0.43 (95% confidence interval [CI], 0.25-0.74; p = 0.002), whereas HR of L to M in females was 1.76 (95% CI, 1.11-2.78; p = 0.016) (p for interaction = 0.003).

CONCLUSIONS

Sex-specific association patterns demonstrate the complex influence of anthropomorphic factors in HF patients scheduled for TEER. Further investigation beyond simple evaluation of weight and height is needed for better comprehension of the obesity paradox and better prediction of the results of transcatheter therapy in HF patients.

BMI Modifies Increased Mortality Risk of Post-PCI STEMI Patients with AKI

Mortality from acute ST elevation myocardial infarction (STEMI) was significantly reduced with the introduction of percutaneous catheterization intervention (PCI) but remains high in patients who develop acute kidney injury (AKI). Previous studies found overweight to be protective from mortality in patients suffering from STEMI and AKI separately but not as they occur concurrently. This study aimed to establish the relationship between AKI and mortality in STEMI patients after PCI and whether body mass index (BMI) has a protective impact. Between January 2008 and June 2016, two thousand one hundred and forty-one patients with STEMI underwent PCI and were admitted to the Tel Aviv Medical Center Cardiac Intensive Care Unit. Their demographic, laboratory, and clinical data were collected and analyzed. We compared all-cause mortality in patients who developed AKI after PCI for STEMI and those who did not. In total, 178 patients (10%) developed AKI and had higher mortality (p < 0.001). Logistic regression analysis was performed to determine the relationship between AKI, BMI, and mortality. AKI was significantly associated with both 30-day and overall mortality, while BMI had a significant protective effect. Survival analysis found a significant difference in 30-day and overall survival between patients with and without AKI with a significant protective effect of BMI on survival at 30 days. AKI presents a major risk for mortality and poor survival after PCI for STEMI, yet a beneficial effect of increased BMI modifies it.

Impact of BMI on Long-Term Outcomes in Patients with ST-Segment Elevation Myocardial Infarction after Primary Percutaneous Coronary Intervention

AIM

Obesity paradox remains a point of debate in ST-segment elevation myocardial infarction (STEMI) patients. The aim of this study was to examine the relationship between body mass index (BMI) and clinical outcomes in STEMI patients undergoing primary percutaneous coronary intervention (PPCI).

METHODS

Outcomes were assessed in 1429 STEMI patients undergoing PPCI between January 2009 and January 2010 in Beijing. Patients were classified into 6 groups according to age (the younger and elderly groups consisting of patients ≤65 and > 65 years old) and baseline BMI (normal weight, BMI < 24 kg/m²; overweight, 24 kg/m² ≤BMI < 28 kg/m²; obese, BMI ≥ 28 kg/m²). The primary outcome was death, acute myocardial infarction (AMI), or revascularization.

RESULTS

On long-term follow-up (mean follow-up of 59 months), 13.9% of patients experienced the adverse event. Multivariate logistic regression analyses showed that low BMI was a significant predictor of the primary outcome only in the younger group. The odds ratio for overweight in comparison with normal weight was 0.741 (95% CI: 0.413-0.979; p = 0.038), the odds radio for obesity in comparison with normal-weight patients was 0.508 (95% CI: 0.344-0.750; p = 0.016) in the younger group. In the elderly group, diabetes, hypertension, triple disease, regular exercise, angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor blockers (ARBs) use after discharge, and bleeding complication were associated with primary outcome.

CONCLUSION

The obesity paradox was recognized only in the younger age group in STEMI patients undergoing PPCI.

Impact of Obesity on Microvascular Obstruction and Area at Risk in Patients After ST-Segment-Elevation Myocardial Infarction: A Magnetic Resonance Imaging Study

BACKGROUND

Better survival for overweight and obese patients after ST-segment elevation myocardial infarction (STEMI) has been demonstrated. The association between body mass index (BMI), microvascular obstruction (MVO), and area at risk (AAR) after STEMI was evaluated.

METHODS

A prospective observational study was performed to enrolled patients undergoing primary percutaneous coronary intervention (pPCI) for STEMI and cardiac magnetic resonance was performed within 5-7 days. Patients were classified as normal weight (18.5 ≤BMI <24.0 kg/m²), overweight (24.0 ≤BMI <28.0 kg/m²), or obese (BMI ≥28 kg/m²).

RESULTS

Among 225 patients undergoing pPCI, 67 (30.00%) were normal weight, 113 (50.22%) were overweight, and 45 (20.00%) were obese. BMI ≥28 kg/m² was significantly associated with less risk of MVO when compared with a normal BMI after multivariable adjustment (overweight: HR 0.29, 95% CI 0.13-0.68, p = 0.004). Compared with normal weight patients, obese and overweight patients tend to have larger hearts (greater left ventricular end-diastolic volume [LVEDV] and left ventricular [LV] mass). In adjusted analysis, increased BMI was significantly associated with a smaller AAR. In addition, obese patients had a smaller AAR (β = -0.252, 95% CI -20.298- -3.244, p = 0.007) and AAR, % LV mass (β = -0.331, 95% CI -0.211- -0.062, p < 0.001) than normal weight patients.

CONCLUSION

Obesity (BMI ≥28 kg/m²) is independently associated with lower risks of MVO and a smaller AAR, % LV mass than normal weight patients among subjects undergoing pPCI for STEMI.

Body Mass Index and Long-Term Follow-Up Outcomes in Patients With Acute Myocardial Infarction by the Median of Non-HDL Cholesterol: Results From an Observational Cohort Study in China

Background: The association between obesity, non-HDL cholesterol, and clinical outcomes in subjects with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI) is incompletely understood. The aim of this investigation was to explore the association between body mass index (BMI), non-high density lipoprotein (non-HDL) cholesterol, and long-term follow-up prognosis.

Methods: This present study used data obtained by the Cardiovascular Center of Beijing Friendship Hospital Database Bank. We identified 3,780 consecutive AMI populations aged 25–93 years from 2013 to 2020. Participants were categorized as normal weight (18.5 ≤ BMI <22.9 kg/m²), overweight (23.0 ≤ BMI <24.9 kg/m²), obese class I (25.0 ≤ BMI <29.9 kg/m²), and obese class II (BMI ≥ 30.0 kg/m²). The endpoint of interest was cardiovascular (CV) death, all-cause death, myocardial infarction (MI), stroke, unplanned revascularization, and cardiac hospitalization.

Results:Participants with higher BMI were younger and more likely to be males compared with lower BMI groups. Elevated non-HDL cholesterol was present in 8.7, 11.0, 24.3, and 5.9% of the normal, overweight, obese class I, and obese class II groups, respectively. After multivariate adjustment, compared to normal-weight participants with decreased non-HDL cholesterol (reference group), obese participants with and without elevated non-HDL cholesterol had a lower risk of mortality (with obese class I and elevated non-HDL cholesterol: hazard ratio [HR] 0.44, 95% confidence interval [CI] 0.28–0.67; with obese class I and decreased non-HDL cholesterol: HR, 0.68, 95% CI, 0.47–0.98; with obese class II and elevated non-HDL cholesterol: HR, 0.42, 95% CI, 0.20–0.87; with obese class II and decreased non-HDL cholesterol: HR, 0.35, 95% CI, 0.16–0.72).

Conclusion: In AMI participants performing with PCI, obesity had a better long-term prognosis which probably unaffected by the level of non-HDL cholesterol.

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 <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.